QL | ' 628 C6E47 1914 | FISHES VotumE XI NuMBER I | THE ~ UNIVERSITY OF COLORADO STUDIES "FRANCIS RAMALEY PUBLISHED BY THE UNIVERSITY OF COLORADO BOULDER, COLO. MarcH, 1914 Price, 50 Cents DIVISION OF FISHE: Ue. Se NATIONSL MU + Re WwW i “All i CGE! 14/4 E\ oh P VoLtumME XI NuMBER I THE ~UNIVERSITY OF COLORADO STUDIES ‘FRANCIS RAMALEY EDITOR PUBLISHED BY THE UNIVERSITY OF COLORADO BOULDER, COLO. Marcu, 1914 Price, 50 Cents a ee ike | Fi aS wee ree Oar Oar er aac) Pac CONTENTS PAGE IISHESHORSCOLORADO. (2G So niin 8) US) 8 we ee 5 Max M. E tis, Pu.D. of the Department of Biology FISHES OF COLORADO: By Max M. ELtis PAGE I. INTRODUCTION AND ACKNOWLEDGMENTS ....... . 5 ie ELYDROGRAPHY, OF, /(COLORADO., 9s) 70). 2 7 Kt v i | TS) ~ “a er =~ WV 7, meee Hes, A ny 1 a_ — —fol, wee t hile ts, We Re, “7) 4 . 7 y\ ah, %, ¢ ‘4 WY eae 142 5 t) atts p= )Colo. Spe 4 VV, aa Sa f Ry yy Hay Ss 3 ) Tee Zw sot! ’ va ‘) ya ant! {s""'gCtrode ee “> Se od ol Zh, 0 L d ‘ 7 Wie, ap W aisdabure EE Ls Map of Colorado showing principal places from which collections were examined. portion of the year, join the South Platte from the north and south, west of 103° 30’. East of this meridian the Platte is without tribu- taries from the south since it flows quite close to the Platte-Republican divide. The Republican River is confined to the plains; it rises at an elevation of less than 6,000 feet. Five streams, the tributaries of which are for the most part wet-weather creeks, flow into the Repub- lican River from Colorado. The North Fork of the Republican, FISHES OF COLORADO 9 which is the shortest of the five, leaves the state near the goth parallel and unites with the Arikaree River a few miles beyond the Colorado line; the South Fork of the Republican parallels the Arikaree some twenty miles south of it. North of the North Fork of the Republi- can are two small streams, Red Willow Creek and Frenchman’s Creek. The Smoky Hill River leaves the state near the Platte- Arkansas divide and comprises the extreme southeastern portion mp, i | ATi Lt 2 a iJ O x et REPUBLICAN DRAINAGER 0,0 2 aie : eae 0,0, @ @, wo rT an EK SKE a as - 55 BK OSS / 635 << : ER DRAINAGE Xoo 28 J i he OS 5 lf a (Sa BQ EER

GEL ae Bet eee The food of this species, as shown by the contents of the alimentary canals examined, consists of the brown and green diatomaceous and algal slime and such other material as may be taken with this. So much green algal material was contained by the specimens from West Plum Creek that the alcohol in which they were preserved became bright green within a few days. Two specimens in this same collection were badly infected with larval trematodes. Chrosomus erythrogaster and its varieties range throughout the northern portion of the Mississippi Valley, east into Maine and west into Colorado. Colorado specimens.— University Museum: St. Vrain Creek, Longmont, October 17, 1903 (65 mm.), C. Juday and D. W. Spangler, No. 18; Boulder Creek, Boulder, October, 1903 (5 speci- mens, 60-65 mm.), C. Juday and J. Henderson, No. 27; West Plum Creek near Castle Rock, June 8, 1912 (6 specimens, 50-65 mm.), A. G. Vestal and M. M. Ellis, No. 334; Boulder Creek 6 miles east of Boulder, July 25, ror2 (5 specimens, 40-60 mm.), M. M. Ellis, No. 335; State Teachers’ College Museum: Greeley, A. E. Beardsley. Subfamily PIMEPHALINAE Genus PIMEPHALES Rafinesque The Fat-headed Minnows Pimephales Rafinesque, Ichthyologia Ohiensis, p. 52, 1820. Small herbivorous Cyprinids; alimentary canal more than twice the length of the body; peritoneum black; premaxillaries protractile; mouth terminal; head « “The Spawning Habits of Chrosomus erythrogaster Rafinesque,” Biol. Bull., Vol XIV, pp. 9-18, 1908 . FISHES OF COLORADO 4I short and broad, its top usually somewhat flattened; no maxillary barbel; first (rudimentary) ray of the dorsal fin separated from the second, short, thick and blunt, especially so in the males; lateral line more or less incomplete. Species of the Mississippi Valley, represented in Colorado by the Black-headed Minnow. Pimephales promelas Rafinesque BLACK-HEADED MINNow, Fat-HEAD (Figs. 15, 17, 18 and 19) Pimephales promelas Rafinesque, Ichthyologia Ohiensis, p. 53, 1820 (pond near Lexington, Kentucky); Jupay, Univ. Colo. Studies, Vol. Il, p. 113, 1903 (Longmont); Jupay, Bull. U.S. Fish Com. for 1904, p. 226, 1905 (Longmont). Pimephales promelas confertus(Girard)—Jorpan, Bull. U.S. Fish Com., Vol. IX, p. 16, 1889 (Arkansas at Canyon City; Pueblo; pond near Canyon City; Fountain Creek near Pueblo). Pimephales maculosus Girard, Proc. Acad. Nat. Sci. Phila., p. 180, 1856 (sluices of the Arkan- sas River, Ft. Makee, Arkansas). Hyborhynchus nigellus Cope, Wheeler Survey, Vol. V, p. 671, 1875 (Arkansas River, Pueblo). Body short, deep and stout, slightly compressed; head short and rather globose, its length about equal to the depth of the body; depth 3.25 to 4 in the length to the base of the caudal; eye 4 to 4.5 in the head, equal to or a little less than the snout, 2 to 3 in the interorbital distance; mouth terminal and small; angle of the mouth not reaching the level of the anterior margin of the eye by about the diameter of the eye; nostril large, prominent, septum high; dorsal fin short, length of its base equal to or less than the length of the longest ray; first ray of the dorsal, especially in breeding males, short, thick and blunt, separated from the second; base of the first dorsal ray on a level with or slightly in front of the ventrals; dorsal rays, not counting the first short thick one, 7 or 8; pectorals short, not reaching the ventrals by the diameter of the eye; ventrals reaching to the anal opening or beyond; anal fin short; anal rays, not counting the first short thick one, 7; caudal peduncle broad, its least depth less than 2 in the head; caudal fin deeply forked; scales 8 or 9, 45-55, 5 Or 6; lateral line more or less incomplete, rather straight; length 4 inches or less, average specimens about 3 inches in length. Color of young and females olivaceous above, shading to yellowish below, with a rather distinct mid-dorsal dusky stripe; young with a dusky lateral stripe 2 to 4 rows of scales wide, extending from behind the gill opening to the base of the caudal fin; this stripe usually wanting or incompletely developed in adult males and often very much reduced in adult females; sides of the body with a brassy luster; scales more or less outlined with dusky; fin rays often dusky. Breeding males with the entire head excepting the posterior margin of the operculum dusky to jet black; outer third of the dorsal fin dusky, its first 2 or 3 rays, including the first blunt ray and the basal two-thirds of each of the remaining rays, dusky to jet black; membranous portion of the fins hyaline; the pre-dorsal region more or less swollen; anterior portion of the head with conical, white or yellow tubercles 42 UNIVERSITY OF COLORADO STUDIES arranged in three rows between the nostrils and the margin of the upper lip, and in two rows below the lower lip; three or more smaller tubercles just in front of the eye; males at other than the breeding season much like adult females, but more brassy in color and with a more or less dusky head. This species spawns in late spring, laying its eggs in sheltered places under stones and débris in shallow excavations. Males in breeding colors and with tubercles, and females with the abdomen much distended with eggs were taken from West Plum Creek at an altitude of 6,500 feet June 8, 1912, and from Glacier Lake, Boulder County, at an altitude of 9,500 feet on July 30, 1912. The smallest breeding male found was 55 mm. in length and the smallest female distended with eggs was 30mm. long. Many of the Plum Creek specimens were badly infected with larval trematodes. Like the other small herbivorous Cyprinids with long intestines, the Black-headed Minnow feeds upon slime and ooze and the contained substances. The alimentary canals of the many specimens opened were packed with dark masses of this material. The Pimephales maculosus Girard described from the Arkansas River and based on specimens with a rather complete lateral line is here considered synony- mous with P. promelas since individuals in a single collection from the Republican River at Wray were found with quite complete and very incomplete lateral lines. Pimephales promelas ranges throughout the western and upper portions of the Mississippi Valley and Great Lakes region. It is a species of the quieter, more weedy parts of small streams. Colorado specimens.—University Museum: St. Vrain Creek, Longmont, October 17, 1903 (7omm.), C. Juday and D. W. Spangler, No. 26; West Plum Creek near Castle Rock, June 8, 1912 (15 specimens, 45-80 mm.), A. G. Vestal and M. M. Ellis, No. 336; Lodgepole Creek near Ovid, July 20, 1912 (75 mm.), J. Henderson and M. M. Ellis, No. 337; Glacier Lake, Boulder County, July 30, 1912 (240 specimens, 45-55 mm.), Howell Ellis, No. 338; Boulder Creek 6 miles east of Boulder, July 25, 1912 (60 mm.), M. M. Ellis, No. 339; Republican River, Wray, October 26, 1912 (504 specimens, 30-80 mm.), A. G. Vestal and M. M. Ellis, No. 340; Sells Lake, Canyon City, September, 1912 (2 specimens, 40-45 mm.), F. A. Reidel, No. 341; State Teachers’ College Museum: Cache la Poudre near Greeley, A. E. Beardsley. Genus HYBOGNATHUS Agassiz The Silvery Minnows Hybognathus Agassiz, Amer. Journ. Sci. Arts, p. 223, 1855. Small herbivorous Cyprinids; alimentary canal 3 to 8 times the length of the body; peritoneum black; inner surface of the lower jaw with a small, hard pro- tuberance near the tip; premaxillaries usually protractile; no maxillary barbel; first (rudimentary) ray of the dorsal fin adnate to the second; base of the first dorsal ray in front of the level of the ventrals. Species of central and southern United States and northern Mexico. FISHES OF COLORADO 43 Hybognathus nuchalis Agassiz SILVERY MINNOW Hybognathus nuchalis Agassiz, Amer. Journ. Sci. Arts, p. 224, 1855 (Quincy, Illinois); Jupay, Bull. U.S. Fish Com. for 1904, p. 226, 1905 (Boulder; Longmont); Jupay, Univ. Colo. Studies, Vol. II, p. 113, 1903 (Boulder; Longmont). Hybognathus nuchalis placita (Girard)—Jorpan, Bull. U.S. Fish Com., Vol. IX, pp. 8 and 17, 1889 (Denver; Pueblo). Body elongate and compressed; head subconic, rather long, its length equal- ling or exceeding the greatest depth of the body; depth 4 to 4.5, or 5 (young), head 3.8 to 4.75 in the length to the base of the caudal; eye medium, 3.8 to almost 5 in the head (Table III); snout rather prominent, tip of the snout rounded, pro- jecting slightly beyond the upper jaw; mouth small, terminal, slightly ventral, lips thin, angle of the mouth not reaching the level of the anterior margin of the eye by half the diameter of the eye or more; inside of the median portion of the lower jaw enlarged at the tip, into a hard, more or less conical protuberance, so that the jaw when seen from in front is A-shaped; lower jaw shorter than the upper and obtuse at the tip; dorsal fin short and high, the length of its base almost 2 in the length of its longest ray; base of the first ray of the dorsal distinctly in front of the level of the ventrals; dorsal of 8, sometimes 7 rays; pectorals short, about 1.25 in the head, not reaching the ventrals by almost the length of the latter; ventrals just reaching the anal opening; anal fin short, of 8, rarely 7 rays; caudal peduncle tapering, its least depth about 2 in the head, caudal fin moder- ately broad and distinctly forked; scales moderately large and well imbricated, 5 or 6, 36-40, 4; lateral line complete and prominent, straight, little if at all decurved in the pectoral region, pores large; size rather small, length up to 6 inches, average adults 3 or 4 inches in length. Color above the lateral line pale olivaceous to brownish green, with a distinct dusky mid-dorsal stripe, sides and body below the lateral line silvery with a steel- blue iridescence; ventral parts cream color to silvery; scales in the region just above the lateral line with numerous fine blue-black chromatophores overlying an indistinct dusky stripe (this stripe is quite distinct or even prominent in pre- served specimens, but usually obscured in living specimens by the silvery color of the sides); fins hyaline, rays outlined with dusky. A western subspecies of this Minnow, known as Hybognathus nuchalis placita (Girard), has been recognized by some writers on the basis of the smaller eye, its diameter in this variety being 5 in the head. Such specimens were found in the collections examined but, associated as they were with specimens having larger eyes and not being confined to a particular drainage area, the subspecies is not separated from the species proper in this report. Table III gives the number of times the eye was contained in the head for several series of specimens. Since the specimens with the small eyes occur in the collections from the Arkansas River drainage with one exception and the specimens from the Platte 44 UNIVERSITY OF COLORADO STUDIES and Republican drainages are quite similar in having larger eyes it may be shown by the examination of large series from the upper Arkansas that this subspecies is valid for that drainage. Hybognathus nuchalis placita (Girard) was described from the Arkansas River at Ft. Makee, in 1856, under the name of Hybognathus placitus Girard.* TABLE III DIAMETER OF THE EYE IN THE LENGTH OF THE HEAD Locality SeSi i 3tOn 4 tONl Ann Ana) Als aA TAN RAS aiea Ou, 4:7) OIA. Sania. Of 51.0 Lodgepole Creek. . I 2 6 2 4 I I 2 I I Be SeiVirain Creek2i43 Wc Sey ny exe ie are eee eas ers I puts Kae Republican River.. I I 3 ee I I Se I EEN CRY UR A a nls I pi Canyon City...... SNe hte sence hates of Palas PSUs a ayia I St Hg Satan cts A Mra I Gripple Greek en Paes Maer ney mis daa begs Ceci AML Avia R/S otMl (ests ceaneeC syeomaic ete DM IME dosed A cyee Maye I Totalerr erecta. 2 3 9 2 5 2 I 5 I I ° I 2 The Silvery Minnow is quite abundant in the plains streams of eastern Colo- rado where it is taken in company with Pimephales promelas, Notropis scylla and Catostomus commersonii sucklii. Like that of the other herbivorous Cyprinids, its food consists of the slime and water-logged material at the bottom of the stream. This species is occasionally used as live bait but is not so valuable for that pur- pose as some of the other more hardy Cyprinids. Large individuals are often eaten. Hybognathus nuchalis ranges from the east coast through southern United States west to the Rocky Mountains and north through the Mississippi Valley to the Red River of the North. Colorado specimens.—University Museum: Boulder Creek, Boulder, September and October, 1903 (3 specimens, 45-55 mm.), C. Juday and J. Henderson, No. 24; St. Vrain Creek, Longmont, October 17, 1903 (85 mm.), C. Juday and D. W. Spangler, No. 17; South Platte River, Julesburg, July 19, 1912 (12 specimens, 70-100 mm.), J. Henderson and M. M. Ellis, No. 342; Lodgepole Creek near Ovid, July 20, 1912 (57 specimens, 65-95 mm.), J. Henderson and M. M. Ellis, No. 343; Boulder Creek 6 miles east of Boulder, July 25, 1912 (38 specimens, 50-75 mm.), M. M. Ellis, No. 344; Republican River, Wray, October 26, 1912 (161 specimens, 35-80 mm.), A. G. Vestal and M. M. Ellis, No. 345; 4 miles west of Cripple Creek, July, 1913 (80 mm.), F. A. Hassenpflug, No. 346; Sells Lake, Canyon City, September, 1913 (2 specimens, 50-60 mm.), F. A. Reidel, No. 347; Colorado State Historical and Natural History Museum: Clear Creek near Denver, August 7, 1900 (150 mm.), W. C. Ferril; State Teachers’ College Museum: Greeley, A. E. Beardsley. Subfamily LEUCISCINAE To this subfamily belong all of the species of carnivorous Cyprinids found in Colorado. Most of them are small forms represented by large numbers of indi- viduals in the small plains streams of eastern Colorado. One species is found in the Rio Grande drainage and three west of the Continental Divide in Colorado. One of these western slope species is the enormous “White Salmon.” t Proc. Acad. Nat. Sci. Phila., p. 182, 1856. FISHES OF COLORADO 45 Genus PHENACOBIUS Cope The Sucker-mouthed Minnows Phenacobius Cope, Proc. Acad. Nat. Sci. Phila., p. 96, 1867. Rather small, elongate, carnivorous Cyprinids; alimentary canal short; peritoneum white; mouth ventral and sucker-like; premaxillaries protractile; no maxillary barbel; scales rather large, lateral line complete; first ray of the dor- sal adnate to the second; base of the first ray of the dorsal in front of the level of the ventral fins. Species of the western and southern portions of the Mississippi Valley. A single species is found in eastern Colorado. Phenacobius mirabilis (Girard) SUCKER-MOUTHED MInNow (Figs. 20, 21, 22, 23 and 24) Exoglossum mirabile Girard, Proc. Acad. Nat. Sci. Phila., p. 191, 1856 (Arkansas River, Ft. Smith). Sarcidium scopiferum Cope, Hayden Geol. Survey of Wyoming for 1870, p. 440, 1871 (Missouri River near St. Joseph, Missouri). Phenacobius scopifer (Cope)—Jupay, Univ. Colo. Studies, Vol. II, p. 113, 1903 (Longmont); COCKERELL, Science, N.S., Vol. XXXIV, p. 615, 1911 (Julesburg). Body rather elongate, fusiform, and somewhat compressed behind the dorsal, depth 4.25 to 5 in the length to the base of the caudal; head broad and flattened above, rather short and blunt, in some males covered with fine tubercles, its length 3.9 to 4.5 in the length of the body to the base of the caudal; dorsal and ventral profiles both sloping toward the tip of the snout; snout broad and blunt, overhang- ing the mouth; eye prominent, medium, situated about midway between the tip of the snout and the posterior margin of the opercle, in the upper half of the side of the head, its upper margin almost on a level with the flat portion of the top of the head, its diameter about 1.5 in the interorbital space, 1.75 to 2 in the snout, and 3.75 to 4.75 in the head; nostrils large and prominent, directed dorsally; mouth ventral and sucker-like; lips large and fleshy, the upper recurved around the angles of the mouth; premaxillaries protractile; dorsal fin rather short, inserted in front of the ventrals and in the anterior half of the body, the base of the first ray of the dorsal being nearer the tip of the snout than the base of the caudal by the length of the snout or more; dorsal rays usually 8, rarely 7 or 9; pectorals not reaching the ventrals; ventrals barely if at all reaching the anal opening; anal shorter than the dorsal; anal rays 7, rarely 8; caudal large, its width equal to or greater than the greatest depth of the body; scales 6 or 7, 44-52, 5 or 6, rather circular, with 12 to 29 apical radii and rarely one or two basal radii. Body above the lateral line dusky olive to brownish, mid-dorsal region with a very narrow but distinct dark stripe which is more prominent in front of the dorsal than behind it; a rather broad stripe of bluish, greenish or dark-blue color, along the lateral line, ending in a distinct black caudal spot; a double series of small 46 UNIVERSITY OF COLORADO STUDIES black hyphen-shaped marks, one on each side of the pore in each scale of the lateral line, forming the middle of the lateral stripe; below the lateral stripe immaculate, white to cream color, often tinged with pink; sides as a whole silvery; top and sides of the head to the level of the lower margin of the eyes dark; rays of the dorsal, of the caudal excepting the most ventral ones, and those of the other fins to some extent, outlined with black; scales above the lateral line outlined with dusky; length 4 inches or less. The Sucker-mouthed Minnow is a species of the shallow rapid streams of the western portion of the Mississippi Valley, ranging east of the Rocky Mountains to Illinois and from South Dakota south into southern Texas. Each of the Colo- rado collections of this species was made in clear shallow water with a sand or gravel bottom. This minnow feeds on the small insect larvae and snails found on the stream bed. Colorado specimens.—University Museum: St. Vrain Creek, Longmont, October 17, 1903 (3 specimens, 95-100 mm.), C. Juday and D. W. Spangler; Lodgepole creek near Ovid, July 20, Igi2 (16 specimens, 75-95 mm.), J. Henderson and M. M. Ellis, No. 348; Boulder Creek 6 miles east of Boulder, July 25, 1912 (8 specimens, 60-70 mm.), M. M. Ellis, No. 340. Genus RICHARDSONIUS Girard The Dace Richardsonius Girard, Proc. Acad. Nat. Sci. Phila., p. 201, 1856. Moderately large to small carnivorous Cyprinids; alimentary canal short; mouth rather large, terminal and slightly oblique; no maxillary barbel; lateral line decurved, usually complete; pharyngeal teetht in two rows, 2-5—5-2, I-5-4-1 or rarely 1-4-4-1, usually hooked and without grinding surfaces. Most species of this genus are found west of the Rocky Mountains, although the genus is represented in the Mississippi Valley and eastern United States. The species are variable and concerning many little is known. In general the species of Richard- sonius have finer scales and are larger and more elongate than the species of Notropis which, in many respects, they resemble. Two species? of Richardsonius are known from Colorado. «The formulae refer to the number of teeth in the two rows on each side of the head. By 2-5—4-1 is understood 5 large teeth in one row with 2 smaller ones in front of them on one side of the head, and 4 large teeth with 1 small one in front of them on the opposite side of the head, i.e., the fish need not be bilaterally symmetrical as regards pharyngeal teeth. To examine these teeth, raise the operculum, insert a small pair of forceps or a hook behind the last gill, seize the pharyngeal bone which lies just behind and below the last gill, and remove the bone. Wash the adhering material from the bone and the teeth may be readily counted with a low-power lens. Care must be used not to break off the teeth while removing the bone from the fish 2 Professor A. E. Beardsley reports to the writer the species Richardsonius intermedius (Girard) from Durango, Colorado. Since no specimens of this species have been examined in the present study, it is not listed. If found it may be separated by the smaller scales (the formula being 15, 73-78, 9) from R. pulchellus, which it closely resembles. R. intermedius is a species of the Gila River. FISHES OF COLORADO 47 a. Scales quite small, 60 to 70 in the lateral line; size rather large, length up to 12 inches; color bluish silvery, no lateral stripe; species of the Rio Grande. R. pulchellus (Baird and Girard) aa. Scales larger, 45 to 47 in the lateral line; size small, length 3.5 inches; with a dusky lateral stripe; species of the South Platte . : : s : : : . R. evermanni (Juday) Richardsonius puichellus (Baird and Girard) “PESCADITO,”” R10 GRANDE CHUB Gila pulchella Baird and Girard, Proc. Acad. Nat. Sci. Phila., p. 29, 1854 (Rio Mimbres, Lake Guzman, Chihuahua). Tigoma nigrescens Girard, Proc. Acad. Nat. Sci. Phila., p. 207, 1856 (Boca Grande and Janos River, Chihuahua). Leuciscus pulcher (Girard)—Jorpan, Bull. U.S. Fish Com., Vol. TX, p. 20, 1889 (Rio Conejos 15 miles south of Alamosa; Del Norte). Leuciscus nigrescens (Girard)—JORDAN AND EvERMANN, Bull. 47, U.S. Nat. Mus., p. 235, 1896 (Rio Grande, Alamosa); CocKERELL AND ALLISON, Proc. Biol. Soc. Wash., Vol. XXII, p. 159, 1909 (Alamosa). Clinostomus pandora Cope, Hayden Survey of Montana for 1871, p. 475, 1872 (tributaries of the Rio Grande, Sangre de Cristo Pass). Body elongate, subterete, not strongly compressed; head conical; depth 4 to 4.5, head 3.8 to 4.2 in the length to the base of the caudal; eye large, 4 (young) to 5.5 in the head, about 1.25 in the snout and 1.25 to almost 2 in the interorbital distance; mouth large, slightly if at all oblique; angle of the mouth barely if at all reaching the anterior margin of the eye; dorsal fin short and rather high, of 8 rays, length of its base less than that of its longest ray, base of the first dorsal ray just behind the level of the ventrals; pectorals long, almost reaching the ventrals; ventrals just reaching the anal opening; anal fin short, of 7 or usually 8 rays; caudal peduncle rather narrow, its least depth a little more than 2 in the head; caudal fin rather narrow and deeply forked; scales small, closely imbricated, 15 to 17, 60-70, 10 or 11; lateral line complete and strongly decurved in the pectoral region; size moderately large, length 12 inches or less. Color above the lateral line dark, iridescent steel blue, mid-dorsal region with a faint dusky stripe; sides of the body and head densely sprinkled with purplish- blue chromatophores; below the lateral line lighter, shading to silvery white ventrally; dorsal, caudal, and to some extent the anal, fins, sprinkled with dusky; top of the head dark; axil of the pectorals and ventrals, and body at the base of the anal yellowish to orange-red. This species is known only from the Rio Grande drainage, ranging from Colo- rado south into Mexico. It is very abundant and very variable and as a result several species now considered as synonyms of this one have been proposed. Colorado specimens.— University Museum: Rio Grande, Alamosa, August, 1889 (110 mm.), D. S. Jordan, No. 350; San Luis Lake, Costilla County, June 5, 1909 (3 specimens, 170-190 mm.), E. R. Warren, No. 351; Rio Grande, Alamosa, July 27, 1912 (251 specimens, 50-200 mm.), M. M. Ellis, No. 352. State Teachers’ College Museum: Antonito, Conejos County, A. E. Beardsley; Colorado College Museum: San Luis Lake, Costilla County, June 5, 1909, E. R. Warren. 48 UNIVERSITY OF COLORADO STUDIES Richardsonius evermanni (Juday) EVERMANN’S DACE Leuciscus evermanni Juday, Univ. Colo. Studies, Vol. II, p. 113, 1903 (Boulder Creek, Boulder); Idem, Bull. U.S. Fish Com. for 1904, p. 226, 1905 (Boulder Creek, Boulder). Body elongate, somewhat compressed; head about 3.75, depth about 4.5 in the length to the base of the caudal; eye about 4.5 in the head, a little more than 1 in the snout, and 1.5 in the interorbital distance; mouth large, angle of the mouth almost reaching the level of the anterior margin of the eye; base of the first ray of the dorsal fin on a level with the base of the ventrals, dorsal rays 8; pecto- rals short, not reaching the ventrals by the diameter of the eye; ventrals passing the anal opening but scarcely reaching the anal fin; anal fin of 8 rays; caudal peduncle rather broad, about 2.5 in the head; scales 8 or 9, 45-47, 5, 25 in the pre- dorsal series; lateral line interrupted, decurved in the pectoral region. Dusky above, lighter below; a dark mid-dorsal stripe and a dusky lateral band; scales outlined with dusky, giving the body above the lateral line somewhat reticulated pattern. This species is known at present from three specimens collected by Juday in 1903 in Boulder Creek near Boulder. The above description was made from Cotype No. 1, University of Colorado Museum, No. 14. Genus NOTROPIS Rafinesque The Shiners Notropis Rafinesque, Amer. Monthly Magazine, Vol. II, p. 204, 1818. Small compressed or elongate, carnivorous Cyprinids, the larger species rather deep; alimentary canal short; mouth terminal, usually not very large; no maxil- lary barbel; pharyngeal teeth (see Richardsonius) in one or two rows, 0-4-4-0, I-4-4-I OF 2-4-4-2; species very numerous and variable, distributed throughout the United States and lower Canada east of the Rocky Mountains. The follow- ing key will serve to separate the Colorado species of this genus. Key TO COLORADO SPECIES OF NOTROPIS a. With dusky latera! band or stripe, or at least dusky lateral clouds; sides more or less silvery- b. Lateral stripe prominent, extending across the side of the head through the eye to the tip of the snout . i 4 i N. cayuga Meek bb. Lateral stripe not euendine) across fhe hevd i the tip ie the head, often rather indistinct and much interrupted. c. Anal rays 7 or 8; body elongate and not deep. d. Entire predorsal region usually scaleless, or scales if present in this region small, crowded and wanting near the head. , f ‘ 1 N. piptolepis (Cope) dd. Predorsal region regularly and evenly scaled; 14 to 16 scales of rather uniform size, in front of the dorsal fin . d : : ; bccn wean, Verscyiiaa(Cope) cc. Anal rays 9 or 10. 7 e. 5 to 7 scales between the base of the first ray of the dorsal fin and the lateral line. FISHES OF COLORADO 49 f. Body elongate; depth 5.2 in the length. ; 4 , . N. horatit Cockerell ff. Body compressed, quite deep in adults; depth 4.4 (young) to 3.25 (adults) in the length; scales on the sides much deeper than long. WN. cornutus (Mitchill) ee. g scales between the base of the first ray of the dorsal fin and the lateral line. N. universitatis Evermann and Cockerell aa. Without dusky lateral bands or clouds; body much compressed and deep; color bluish, sides dull silvery, a dusky violet humeral bar; fins of the males often bright red. N. lutrensis (Baird and Girard) Notropis cayuga Meek Sao CayuGA SHINER Notropis cayuga Meek, Ann. Acad. Nat. Hist. N.Y., p. 305, 1888 (Cayuga Lake, New York); Jupay, Univ. Colo. Studies, Vol. I, p. 113, 1903 (Longmont); Jupay, Bull. U.S. Fish Com. for I904, Pp. 227, 1905 (Longmont). Body elongate, not strongly compressed, head rather long; depth 4.5 to 5.25, head 3.75 to 4 in the length to the base of the caudal; eye large, 3 to 3.5 in the head and about 1 in the snout; mouth small terminal and somewhat oblique, angle of the mouth not reaching the level of the anterior margin of the eye; dorsal short and high, base of its first ray posterior to the level of the ventrals; dorsal rays 8; pectorals short, not reaching the ventrals; ventrals reaching the anal opening; anal fin of 8 or sometimes 7 rays; scales 5, 34-38, 3 or 4, lateral line rather straight, somewhat interrupted; 12 to 16 rows of scales in front of the dorsal fin; size small, length 2.5 inches or less. Color olivaceous dorsally, shading to lighter below; sides more or less silvery; a very faint dusky mid-dorsal stripe; a distinct black lateral stripe extending from a faint spot at the base of the caudal fin along the lateral line, across the side of the head, through the eye to the tip of the snout; scales above the lateral line outlined with dusky. This little shiner ranges through northern United States and lower Canada east of the Rocky Mountains and south into Arkansas. It spawns in late spring and early summer. Colorado specimens.—University Museum: Boulder Creek, Boulder, October, 1903 (6 speci- mens, 45-60 mm.), C. Juday and J. Henderson, No. 25. Notropis piptolepis (Cope) PLATTE RIVER SHINER Photogenis piptolepis Cope, Hayden Geol. Survey of Wyoming for 1870, p. 438, 1871 (Red . Cloud Creek, tributary of the North Platte River). Notropis piptolepis (Cope)—Jupay, Univ. Colo. Studies, Vol. Il, p. 113, 1903 (Boulder); Jupay, Bull. U.S. Fish Com. for 1904, p. 227, 1905 (Boulder). Notropis gilberti Jordan and Meek—Jorpan, Bull. U.S. Fish Com., Vol. IX, p. 8, 1889 Denver. (Listed as possibly Photogenis piptolepis Cope.) Body elongate, subterete, but slightly compressed; head rather long; depth 4 to 4.5, head 3.75 to 4 in the length to the base of the caudal; eye rather large, 50 UNIVERSITY OF COLORADO STUDIES 3 to 3.5 in the head, about 1 in the snout; mouth small and rather ventrally placed, angle of the mouth not reaching the level of the anterior margin of the eye; pharyn- geal teeth usually 1-4-4-1; dorsal fin short and high, length of its base about 1. 5 in the length of the longest ray, base of the first dorsal ray on a level with or very slightly behind the base of the ventrals; dorsal rays 7 or 8; pectorals short, not reaching the ventrals; ventrals barely reaching the anal opening; anal fin short, of 7 or 8 rays; scales 5 or 6, 38-42, 4; lateral line complete and somewhat decurved in the pectoral region; predorsal region without scales, or scales if present small and much crowded just in front of the dorsal and wanting near the head; size small, length 3 inches or less. Color above the lateral line yellowish or light olivaceous, overlaid with dusky or greenish; sides silvery, lighter ventrally; a distinct dusky mid-dorsal stripe; a dusky bluish lateral stripe along the lateral line, this stripe often much inter- rupted and obscured by the silvery color of the sides; a series of small, black hyphen-shaped marks on each side of the pores of the lateral line; fins hyaline, rays more or less outlined with dusky. This shiner is much like the following species, Notropis scylla, from which it may be recognized most easily by the absence of scales in the predorsal region. Notropis piptolepis is known only from the western portion of the Platte River drainage, being a species of the small shallow streams of the plains and foothills. Most of the females of this species collected at Boulder, July 25, 1912, were dis- tended with well-developed eggs, so it is probable that the spawning season is July and early August. Colorado specimens.— University Museum: Boulder Creek, Boulder, October, 1903 (127 specimens, 55-70 mm.), C. Juday and J. Henderson, No. 9; West Plum Creek near Castle Rock, June 8, 1912 (59 specimens, 35-75 mm.), A. G. Vestal amd M. M. Ellis, No. 353; South Platte, Julesburg, July 19, 1912 (5 specimens, 60-70 mm.), J. Henderson and M. M. Ellis, No. 354; Lodge- pole Creek near Ovid, July 20, 1912 (15 specimens, 50-70 mm.), J. Henderson and M. M. Ellis, No. 355; Boulder Creek 6 miles east of Boulder, July 25, 1912 (11 specimens, 40-65 mm.), M: M. Ellis, No. 356. Notropis scylla (Cope) rt we $< WESTERN SHINER (Fig. 28) Hybopsis scylla Cope, Hayden Geol. Survey of Wyoming for 1870, p. 438, 1871 (Red Cloud Creek, tributary of Platte River); Cope anp Yarrow, Wheeler Survey, Vol. V, p. 566, 1875 (Foun- tain Creek). Notropis scylla (Cope)—JorDAN, Bull. U.S. Fish Com., Vol. IX, p. 8, 1889 (Denver; Pueblo); Jupay, Univ. Colo. Studies, Vol. II, p. 113, 1903 (Boulder; Longmont); Jupay, Bull. U.S. Fish Com. for 1904, p. 227, 1905 (Boulder; Longmont). Body elongate, slightly compressed, head rather long; depth 3.9 to 4.5, (3.6 in gravid females), head 3.75 to 4 in the length to the base of the caudal; eye rather large, 3 to 3.5 in the head, about 1 in the snout and 1 to 1.5 usually about 1.25 in the interorbital distance; snout short, abrupt and rounded anteri- FISHES OF COLORADO 51 orly, slightly overhanging the closed mouth; mouth rather small, oblique to ventral; angle of the mouth not reaching the anterior margin of the eye, but on a level with the nostril; pharyngeal teeth usually o-4-4-0, distinctly hooked; dorsal fin short and rather high, length of its base about 1.5 in the length of its longest ray; base of the first ray of the dorsal on a level with the base of the ventrals, dorsal rays 7, sometimes 8; pectorals short, not reaching the ventrals by almost the length of the latter (females) or by about one-half the length of the ventrals (males); ventrals barely if at all reaching the anal opening; anal fin short, of usually 7 rays; scales large, 5 or 6, 33-30, 4; lateral line complete, slightly decurved in the pectoral region; predorsal region regularly scaled, 14 to 16 scales in front of the dorsal; size small, length 3 inches or less. Color above the lateral line yellowish overlaid with dusky and greenish; sides silvery, ventral parts cream color to white; mid-dorsal region with a narrow but distinct dusky stripe (indistinct in but 3 out of 147 specimens examined for this character); sides just above the lateral line with a dusky bluish stripe, usually rather distinct in the caudal half of the body, where in the young it ends in a small caudal spot, this spot often indistinct in adults; a row of hyphen-shaped black marks on each side of the lateral line pores; scales above the lateral line outlined with dusky giving the upper half of the body, especially in the predorsal region, a distinctly reticulated pattern; fins hyaline, rays often outlined with dusky; head dark above. Notropis scylla is a species of the plains streams of the western part of the Mis- sissippi Valley near the Rocky Mountains. Females taken at Julesburg and Ovid, July 19 and 20, 1912, were distended with well-developed eggs. Colorado specimens.—University Museum: Boulder Creek, Boulder, October, 1903 (3 specimens, 60-75 mm.), C. Juday and J. Henderson, No. 28; St. Vrain Creek, Longmont, Octo- ber 17, 1903 (3 specimens, 60-70 mm.), C. Juday and D. W. Spangler, No. 20; South Platte, Julesburg, July 19, 1912 (174 specimens, 40-70 mm.), J. Henderson and M. M. Ellis, No. 357; Lodgepole Creek near Ovid July 20, 1912 (18 specimens, 50-75 mm.), J. Henderson and M. M. Ellis, No. 358; Republican River, Wray, October 26, 1912 (51 specimens, 30-70 mm.), A. G. Vestaland M. M. Ellis, No. 359; State Teachers’ College Museum: Cache la Poudre near Greeley, A. E. Beardsley. Notropis horatii Cockerell Notro pis horatit Cockerell, Science, N.S., Vol. XXXIV, p. 614, to11 (South Platte, Julesburg). A very doubtful species, based at present on a single specimen. Although extensive collections have since been made at the exact station from which this unique specimen was taken, no other individuals referable to this species have been found. The following data are compiled from the original description: Head 5.2 in the length to the base of the caudal; dorsal rays 8; anal rays 9; scales 5 or 6, 38-40, 4; eye a little more than 1 in the snout; mid-dorsal stripe present; length 47 mm. 52 UNIVERSITY OF COLORADO STUDIES Notropis cornutus (Mitchill) Common SHINER (Figs. 27 and 60) Cyprinus cornutus Mitchill, Amer. Monthly Magazine, Vol. I, p. 280, 1817 (Wallkill River, New York). Notropis cornutus (Mitchill)—Jupay, Univ. Colo. Studies, Vol. II, p. 113, 1003 (Boulder; Longmont); Jupay, Bull. U.S. Fish Com. for 1904, p. 227, 1905 (Boulder; Longmont). Notropis megalops (Rafinesque)—JorpDan, Bull. U.S. Fish Com., Vol. UX, p. 8, 1889 (Denver). Body moderately elongate (young) and quite compressed (adults), and in adults moderately deep; depth 4.25 (young) to 3.2 (adult), head 4.25 to 3.7 in the length to the base of the caudal; head short and rather chubby; eye large, 4 to 5 in the head, about 1.5 in the snout and 2 in the interorbital distance; mouth large, slightly oblique, angle of the mouth not reaching the anterior margin of the eye; nostril large and prominent, situated on the dorsal surface of the head about one-half of the diameter of the eye in front of the eye; dorsal fin short, of 8 rays, base of the first ray nearer to the tip of the snout than to the base of the caudal, about on a level with the ventrals; pectorals short, not reaching the ventrals; ventrals barely if at all reaching the anal opening; anal fin of about the same length as the dorsal, of 9, sometimes 10 rays; caudal peduncle mioderately deep, its least depth about 2.5 (young) to 2 (adult) in the head; caudal fin broad and deeply forked; scales large, those on the sides with the exposed portion much deeper than long, 6 or 7, 37-45, 3 Or 4, 16 or more in front of the dorsal; lateral line complete, strongly decurved in the pectoral region; length g inches or less, average adults about 4 inches in length. Color olivaceous dorsally, shading to almost white below, sides silvery, with a bluish iridescence; mid-dorsal region especially in the young with a narrow . rather well-defined, dusky stripe; lateral line region with a broad dusky lateral stripe, sometimes quite prominent, but in adults usually much interrupted and poorly defined; top of the head dark bluish green; dorsal and caudal fins dusky. Sides of breeding males much blotched with salmon pink and dusky emerald green; dorsal, caudal and anal fins broadly margined with rose pink; pectorals and ven- trals cream color with suffuse pink along the rays; anterior margin of the pec- torals dusky blue; top of the head with numerous horny tubercles; throat and under parts of the head pearly white; sides with a steel-blue iridescence. The common shiner ranges over the whole of the United States east of the Rocky Mountains excepting the southern portion of the Mississippi Valley, and through lower Canada. It is often the most abundant fish in the small clear streams of the central states. From an economic standpoint the shiner is of little importance except as its young are eaten by other more valuable fishes. Large specimens are, however, often eaten, as this species readily takes any sort of still bait. By some it is recommended as live bait for bass. Notropis cornutus spawns in late spring. Like that of most of the other FISHES OF COLORADO 53 species of this genus, its food consists of surface insects, aquatic insects and some plant material, other types of food being utilized occasionally. Colorado specimens.—University Museum: Boulder Creek, Boulder, October, 1903 (5 speci- mens, 90-140 mm.), C. Juday and J. Henderson, No. 2; St. Vrain Creek, Longmont, October 17, 1903 (120mm.), C. Juday and D. W. Spangler, No. 41; Boulder Creek, Boulder, April 23, 1904 (2 specimens, 150 mm.), J. Henderson, No. 23; West Plum Creek near Castle Rock, June 8, 1912 (148 specimens, 35-135 mm.), A. G. Vestal and M. M. Ellis, No. 360; Boulder Creek 6 miles east of Boulder, July 25, 1912 (92 specimens, 50-130 mm.), M. M. Ellis, No. 361; South Platte, Julesburg, July 19, 1912 (66 specimens, 70-100 mm.), J. Henderson and M. M. Ellis, No. 362; Lodgepole Creek near Ovid, July 20, 1912 (59 specimens, 75-125 mm.), J. Henderson and M. M. Ellis, No. 363; State Teachers’ College Museum: Cache la Poudre near Greeley, A. E. Beardsley; Colorado College Museum: Cache la Poudre River near Greeley, I. C. Hall. Notropis universitatis Evermann and Cockerell Notropis universitatis Evermann and Cockerell, Proc. Biol. Soc. Washington, Vol. XXII, p. 187, 1909 (Boulder Creek, Boulder). This species is based at present on one specimen collected in Boulder Creek at a time when all of the fishes were killed by the introduction of mine waste in the canyon above Boulder. No other specimens have been found in the several subsequent collections made at Boulder. The original description is quoted below: Close to NV. zonatus, but with smaller scales and different coloration. There are 45 scales in the lateral line and 9 between the origin of the dorsal and the lateral line, as against 42 and 6 in N. zonatus. A pale-orange dorsal band on a bright straw-yellow ground, the scales minutely black-dotted, but not appearing dusky margined; sides strongly silvery; lateral line complete; a grayish lateral stripe; dorsal and caudal fins yellowish; dorsal and chin black-speckled. Notropis lutrensis (Baird and Girard) REDFIN (Fig. 29) Leuciscus lutrensis Baird and Girard, Proc. Acad. Nat. Sci. Phila., p. 391, 1853 (Otter Creek, tributary of the north fork of Red River, Arkansas). Notropis lutrensis (Baird and Girard)—JorpDAN, Bull. U.S. Fish Com., Vol. IX, pp. 8 and 16, 1889 (Denver; Pueblo; Fountain Creek, Pueblo); Jupay, Univ. Colo. Studies, Vol. II, p. 113, 1903 (Longmont); Jupay, Bull. U.S. Fish Com. for 1904, p. 227, 1905 (Longmont). Hypsilepis jugalis (Cope)—CoPE AND YARROW, Wheeler Survey, Vol. V, p. 654, 1875 (Pueblo). Body strongly compressed, rather deep in adults; head short and conic; depth 3.25 to almost 4, head 3.75 to 4.25 in the length to the base of the caudal; young and females more slender than adult males, their depth often as low as 5 in the length; eye 3 (very small specimens) to 4 (adult males) in the head, about 2.25 in the interorbital distance and 1 to 1.5 in the snout; mouth small, terminal and oblique, angle of the mouth not reaching the anterior margin of the eye; nostril prominent, on the dorsal surface of the head, septum large; dorsal fin short and high, of usually 8 rays, length of its base less than that of its longest ray 54 UNIVERSITY OF COLORADO STUDIES base of the first ray of the dorsal slightly behind the level of the ventrals; pec- torals short, 1 or a little more in the head, not reaching the ventrals; ventrals reaching the anal opening or the base of the anal fin; anal fin short, of 8 or 9 rays, length of its base less than that of its longest ray; caudal peduncle rather narrow, its least depth 2 or a little more in the head; caudal fin rather broad and deeply forked; scales large, closely imbricate, those on the sides broader than long, 6, 35-40, 3; lateral line complete, strongly decurved in the pectoral region; size small, length under 4 inches, average adults 2.5 to 3 inches. Young and females pale olivaceous dorsally, with a bluish or lead-gray cast, shading through dull silvery to almost white below; adult males dusky dorsally, the region above the lateral line a bright steel blue, with a purplish or pinkish iridescence; dull silvery below the lateral line; top of the head bluish; scales in both sexes, especially above the lateral line, rather regularly outlined with dusky or bluish, giving the sides a somewhat reticulated pattern; adults with a long narrow triangular dusky violet humeral spot, margined behind with paler; fins in all excepting breeding males rather hyaline, the dorsal and caudal some- what dusky, and the anal and ventrals whitish; in breeding males, dorsal reddish, pectorals, ventrals and anal yellowish to cherry-red; the head and predorsal region with small tubercles; operculum and sides of the body posterior to the violet humeral spot with more or less red. The Redfin is one of the more abundant fishes of the western portion of the Mississippi Valley, ranging from the Rio Grande River north through western United States east of the Rocky Mountains into South Dakota, and east into Illinois. Colorado specimens.—University Museum: St. Vrain Creek, Longmont, October 17, 1903 (6 specimens, 50-70 mm.), C. Juday and D. W. Spangler, No. 12; Lodgepole Creek near Ovid, July 20, 1912 (32 specimens, 40-75 mm.), J. Henderson and M. M. Ellis, No. 364; Republican River, Wray, October 26, 1912 (13 specimens, 30-85 mm.), A. G. Vestal and M. M. Ellis, No. 365; 4 miles west of Cripple Creek, July, 1913 (2 specimens, 165-170 mm.), F. A. Hassenpflug, No. 366; Colorado State Historical and Natural History Museum: South Platte River near Denver, August 3, 1900 (65 mm.), W. C. Ferril; State Teachers’ College Museum: Cache la Poudre near Greeley, A. E. Beardsley. Genus PTYCHOCHEILUS Agassiz The Squawfish and “White Salmon” Ptychocheilus Agassiz, Amer. Journ. Sci. Arts, p. 229, 1855. Very large carnivorous Cyprinids, the largest known North American Cypri- nid being a member of this genus; body rather elongate; head long and pike- like; alimentary canal short; caudal peduncle not abruptly narrowed just in front of the caudal fin; basal fulcra of the caudal fin not strongly developed. All of the species of this genus are found west of the Continental Divide. Ptycho- cheilus is represented in Colorado by the “ White Salmon.” FISHES OF COLORADO 55 Ptychocheilus lucius Girard ““WHITE SALMON”’ OF THE COLORADO Ptychocheilus lucius Girard, Proc. Acad. Nat. Sci. Phila., p. 209, 1856 (Rio Colorado); JoRDAN, Bull. U.S. Fish Com., Vol. TX, p. 28, 1889 (Gunnison and Uncompahgre rivers at Delta). Body elongate, subterete and but slightly compressed, head long; depth 5 to 5.5, head 3.25 to almost 4, usually about 3.5, in the length to the base of the caudal; eye small, 6 to 8 in the head, about 2.25 in the snout; mouth terminal and large, angle of the mouth reaching the level of the anterior margin of the eye or beyond; dorsal fin high, length of its base less than that of its longest ray, base of the first ray of the dorsal posterior to the level of the ventrals, dorsal rays 9; pectorals short, not reaching the ventrals; ventrals barely if at all reaching the anal opening; anal fin short, of 9 rays; caudal peduncle rather deep, not abruptly narrowed just in front of the base of the caudal, least depth of the caudal peduncle about 3 in the head; basal fulcra of the caudal fin not strongly developed; caudal fin broad and deeply forked; scales small and loosely imbricate, lateral line decurved, of 80 to go scales; size very large, reaching a length of 5 feet and a weight of almost 100 pounds. Color dusky greenish dorsally, sides somewhat silvery, ventral parts dirty yellow; fins hyaline, reddish or yellowish in the spring; young, with a distinct caudal spot and a dusky lateral stripe often margined below with lighter. This remarkable fish, the largest of the North American Cyprinids, occurs in Colorado only in the Grand, White and Yampa rivers and their tributaries. Because of the large size of this species, even though it be but a minnow, it is a valuable food fish. Ptychocheilus lucius is a species of the Colorado River drainage. Colorado specimens.—University Museum: Uncompahgre River, August, 1889 (115 mm.), No. 367; State Teachers’ College Museum: Delta, A. E. Beardsley. Genus GILA Baird and Girard The Bony Tails Gila Baird and Girard, Proc. Acad. Nat. Sci. Phila., p. 368, 1853. Moderately large carnivorous Cyprinids; alimentary canal short; peritoneum dusky; no maxillary barbel; mouth oblique and large; base of the first ray of the dorsal posterior to the level of the ventrals; basal fulcra of the caudal fin large and prominent; caudal peduncle narrowed just before the caudal fin; scales small, loosely imbricated, mid-dorsal and mid-ventral regions often incompletely scaled or naked. The species of this genus are known only from the Colorado River drainage and are quite different from the ordinary Cyprinids. A single species is found in Colorado. 56 UNIVERSITY OF COLORADO STUDIES Gila robusta Baird and Girard Rounp Tait, Bony Tart, “Gita Trout’ (Figs. 34, 35 and 36) Gila robusta Baird and Girard, Proc. Acad. Nat. Sci. Phila., p. 368, 1853 (Zuni River); JorDAN AND EveRMANN, Bull. 47, U.S. Nat. Mus., p. 227, 1806 (Uncompahgre River at Delta). Gila elegans Baird and Girard—Jorpan, Bull. U.S. Fish Com., Vol. TX, p. 27, 1889 (Gunnison at Delta). Gila pandora Cope—Corre anp Yarrow, Wheeler Survey, Vol. V, p. 661, 1875 (Pagosa). = Gila egregia Cope—Corr AND Yarrow, Wheeler Survey, Vol. V, p. 662, 1875 (Loma, Grand River, wrongly ascribed to the Rio Grande). Body elongate, somewhat compressed, depth 4.6 (young) to almost 6, usually about 5 in the length to the base of the caudal fin; dorsal and ventral profiles sloping regularly in small specimens, dorsal profile just back of the head rising abruptly, so that the body in this region bears a more or less distinct hump; head rather large, somewhat flattened dorsally, especially in old individuals, 3. 5 (young) to 4.7 in the length; eye large, situated nearer to the tip of the snout than to the posterior margin of the operculum, its diameter 5 or 6 in the head, about 2 in the interorbital distance, 2 or a little less in the snout; nostril large, septum very prominent and much elevated, its length about 2 in the eye; mouth terminal, broad, and slightly oblique, angle of the mouth reaching the level of the anterior margin of the eye; premaxillaries protractile; dorsal fin short, length of its base less than that of the first ray, base of the first ray almost equidistant from the tip of the snout and the base of the caudal, rays usually 10, sometimes 9; tip of pectorals not reaching the ventrals; ventrals reaching or passing the anal opening; anal fin with 9 or 10 rays; caudal peduncle elongate and quite narrow, its least depth 1.25 to 1.5 in the maxillary, equalling or slightly exceeding the diameter of the eye; basal fulcra of the caudal fin much developed; caudal fin long and broad, deeply forked, its width equalling or exceeding the greatest depth of the body; scales small, irregularly placed, ventral parts and mid-dorsal region often incompletely scaled or naked; lateral line very prominent, strongly decurved and rather irregular, pores beginning at the base of the occipital region and extend- ing well out onto the base of the caudal fin; scales about 30 in vertical series between the base of the first ray of the dorsal and the base of the ventrals, 85 to 95 in the lateral line. General color silvery, dusky dorsally; axils of the pectorals and ventrals and the base of the anal fin yellowish to orange; males with more or less red on the sides of the head. Size small to moderately large, average specimens about 9 inches in length, very large individuals 12 to 15 inches. The Round Tail has very little economic importance since its body is so bony as to make its value as a food fish slight. The flesh of large specimens is occa- sionally eaten and is said to have a very good flavor. While collecting at Grand Junction the writer found this species confused with the young and small speci- mens of Ptychocheilus lucius Girard by the local fishermen, both species being known as ‘‘Squawfish.” FISHES OF COLORADO 57 Gila robusta is found only in the Colorado River and its tributaries. Gila elegans Baird and Girard is here considered as synonymous with this species, since intermediate forms and those agreeing with the descriptions of both species were taken from the same station in the Grand River at Grand Junction. In addition, specimens were collected with both the ventral and dorsal portions of the body free from scales, the character given as diagnostic for Gila seminuda Cope and Yarrow. ‘This character seemed fairly constant, although individuals with the ventral region partly scaled were found. Since those individuals naked ventrally and dorsally agreed in other points with Gila robusta, Gila seminuda has been retained as a subspecies of Gila robusta. The specimens examined are listed here under the species proper since intermediate forms were present and this subspecies may not be separable. Colorado specimens.—University Museum: Bear River, Lily, Moffatt County, June 30, 1907 (230 mm.), E. R. Warren and J. W. Frey, No. 368; Grand River, Grand Junction, August 8, 1912 (33 specimens, 40-180 mm.), J. Henderson and M. M. Ellis, No. 369; State Teachers’ Col- lege Museum: Delta, A. E. Beardsley; Colorado College Museum: Bear River, Lily, Moffatt County, E. R. Warren (labeled G. seminuda). Gila robusta seminuda (Cope and Yarrow) Gila seminuda Cope and Yarrow, Wheeler Survey, Vol. V, p. 666, 1875 (Rio Virgen, Utah). Specimens of this subspecies differ from the typical G. robusta in having no scales on the mid-ventral portion of the body as far posterior as the base of the ventrals and no scales on the mid-dorsal region as far back as the middle or last ray of the dorsal fin. Genus SEMOTILUS Rafinesque The Fall-fishes Semotilus Rafinesque, Ichthyologia Ohiensis, p. 49, 1820.4 Moderately large carnivorous Cyprinids; alimentary canal short; mouth large and terminal, very slightly oblique; maxillary barbel present, attached to the upper outer surface of the upper jaw just above the junction of the two jaws, the free portion of the barbel dropping downward and backward into the groove at the junction of the two jaws; lateral line complete and strongly decurved in the pectoral region; length under 20 inches. Species of upper United States and Lower Canada east of the Rocky Mountains; represented in Colorado by the Horned Dace. Semotilus atromaculatus (Mitchill) HorNED DAcE, CREEK CHUB, THE “CHUB” (Figs. 25, 26 and 61) Cyprinus atromaculatus Mitchill, Amer. Monthly Magazine, Vol. I, p. 324, 1818 (Wallkill River). Semotilus atromaculatus (Mitchill)—Jorpan, Bull. U.S. Fish Com., Vol. IX, p. 8, 1889 (Den- ver); Jupay, Univ. Colo. Studies, Vol. II, p. 113, 1903 (Boulder; Longmont). Semotilus atromaculatus macrocephalus (Girard)—CocKERELL, Science, N.S., Vol. XXXIV, p. 615, 1911 (Julesburg). 58 UNIVERSITY OF COLORADO STUDIES Body elongate, subterete, not strongly compressed; head large, rather conical, its length exceeding the greatest depth of the body; depth 4.7 (young) to 4, head 3.2 to 3.9 in the length to the base of the caudal; eye rather large, 2 in the snout, 5 to 7 in the head and 2.5 to 3 in the interorbital distance; mouth large, terminal and somewhat oblique; angle of the mouth barely reaching the level of the anterior margin of the eye; maxillary barbel present, quite small, often very obscure in the young, placed on the upper, outer surface of the upper jaw just above the junction of the two jaws, the free portion of the barbel dropping back- ward and downward into the groove at the junction of the two jaws; nostril large and prominent, septum much elevated; dorsal fin short and high, of 8, rarely g rays, base of the first ray distinctly posterior to the level of the ventrals; pectorals short, not reaching the ventrals by about half the length of the latter; ventrals not reaching the anal opening; anal fin short, of 8 rays; least depth of the caudal peduncle 3 or a little less in the head, caudal broad and moderately forked; scales 10 or 11, 55-70, 5 to 7; lateral line complete, strongly decurved in the pectoral region; size moderately large, average adults about 8 inches, large specimens reaching the length of 12 inches. Color above dusky to quite dark with a bluish or greenish cast dorsally; below the lateral line almost white with a yellowish or pinkish cast shading to pearly white on the ventral surface between the pectorals; a rather indistinct dusky stripe from the tip of the snout crossing the side of the head and the oper- culum at the level of the eye and continuing along the side of the body as a dusky or blackish lateral stripe, extending to the base of the caudal where it terminates in a distinct caudal spot; this stripe and spot quite prominent in the young, but often rather indistinct in the adults, the stripe breaking up into a suffuse lateral band or entirely wanting; a rather distinct dusky or black spot covers the bases of the first three or four rays of the dorsal fin, fins otherwise hyaline, the rays some- what outlined with dusky; sides of the body and axils of the pectoral and ventral fins in breeding males with more or less rose-red. The larger individuals of Semotilus atromaculatus are used for food, although the Chub is not greatly esteemed as a food fish. Because of the hardiness of this species it is generally considered one of the best live baits for bass and wall-eyed pike. The common Chub ranges over most of the United States east of the Rocky Mountains, in Colorado being quite abundant in the plains streams of the eastern part of the state. The chub is an active, vigorous fish and will often provide considerable sport when hooked, fighting much like some of the game fishes. The larger individuals congregate in the deeper pools of the small streams while the small specimens are found in the more shallow and weedy portions with the small species of minnows. The adult chub is a voracious fish feeding upon surface insects, aquatic insects, small fishes and even the spawn of other fishes. Not infrequently this species feeds upon vegetable matter. The Chub spawns in late FISHES OF COLORADO 59 spring, the eggs being deposited in a shallow excavation made in the sand or gravel by the male. Colorado specimens.—University Museum: St. Vrain Creek, Longmont, October 17, 1903 (2 specimens, 90 and 180 mm.), C. Juday and D. W. Spangler, No. 7; Boulder Creek, Boulder, October, 1903 (59 specimens, 35-190 mm.), C. Juday and J. Henderson, No. 8; Boulder Creek east of Boulder, May, 1909 (3 specimens, 95-120 mm.), David Rusk and Donald Kloke, No. 303 Sterling, June ro, 1910 (115 mm.), H. G. Smith, No. 370; West Plum Creek near Castle Rock, June 8, 1912 (90 specimens, 50-135 mm.), A. G. Vestal and M. M. Ellis, No. 371; South Platte, Julesburg, July 19, 1912 (395 specimens, 30-140 mm.), J. Henderson and M. M. Ellis, No. 3723 Lodgepole Creek near Ovid, July 20, 1912 (37 specimens, 35-140 mm.), J. Henderson and M. M. Ellis, No. 373; Boulder Creek 6 miles east of Boulder, July 25, 1912 (84 specimens, 30-110 mm.), M. M. Ellis, No. 374; Republican River, Wray, October 25, 1912 (125 specimens, 45-190 mm.), A. G. Vestal and M. M. Ellis, No. 375; State Teachers’ College Museum: Cache la Poudre near Greeley, A. E. Beardsley. Genus COUESIUS Jordan The Mountain Dace Couesius Jordan, Bull. Hayden Geol. Survey Terr., Vol. IV, p. 785, 1878. General characters the same as Semotilus to which this genus is very closely related and from which it differs in the number of pharyngeal teeth. These are 2-4-4-2 in Couesius and 2-5-4-2 in Semotilus. The species of the genus Couesius have not been studied in detail so that at present this genus is rather uncertain. A single species, Couesius dissimilis, is known from Colorado. Couesius dissimilis (Girard) Mountain DAcE Leucosomus dissimilis Girard, Proc. Acad. Nat. Sci. Phila., p. 189, 1856 (Milk River and Little Muddy River, Montana). Couesius dissimilis (Girard)—Jupay, Univ. Colo. Studies, Vol. II, p. 113, 1903 (Boulder); Jupay, Bull. U.S. Fish Com. for 1904, p. 227, 1905 (Boulder). Body elongate, somewhat fusiform; head conical, moderately short, its length a little more or a little less than the greatest depth of the body; in adult specimens depth 4 to 4.75, head 4.25 to 4.5 rarely 4, in the length to the base of the caudal; eye rather large, 4 to 5 in the head, about 1.5 in the snout, 2 ora little less in the interorbital distance; mouth large, terminal and oblique, angle of the mouth not reaching the level of the anterior margin of the eye, barbe] prominent, attached on the upper, outer surface of the upper jaw, just above the junction of the upper and lower jaws, but its free portion dropping downward and back into the groove at the junction of the two jaws; dorsal fin short and rather high, of 8 rays, length of its base less than the length of its longest ray; pectorals short, about 1.25 to 1.5 in the head, not reaching the ventrals by almost the length of the latter; ventrals barely reaching the anal opening; anal fin short, of 8 rays; least depth of the caudal peduncle about 2 or 2.5 in the head; caudal 60 UNIVERSITY OF COLORADO STUDIES fin moderately forked; scales rather small, 12 or 13, 65-75, 7 or 8; lateral line complete, and rather straight, but slightly decurved in the pectoral region; length under 6 inches. Color above the lateral line lead gray to rather dark, with a distinct bluish cast; somewhat darker along the mid-dorsal line; abruptly lighter below the lateral line, yellowish shading to almost white ventrally; sides somewhat silvery with a more or less bluish iridescence; fins hyaline, the rays more or less outlined with dusky; scales above the lateral line, and below the lateral line in the pectoral region more or less distinctly outlined with dusky. This species, although quite distinct from Semotilus atromaculatus in detail, resembles it in general appearance. The Mountain Dace is a species of the upper Missouri and Platte drainages. Colorado specimens.—University Museum: St. Vrain Creek, Longmont, October 17, 1903 (rt10 mm.), C. Juday and D. W. Spangler, No. 44; Boulder Creek, Boulder, September and Octo- ber, 1903 (34 specimens, 55-115 mm.), C. Juday and J. Henderson, No. 1. Genus HYBOPSIS Agassiz The Horny-heads Hybopsis Agassiz, Amer. Journ. Sci. Arts, p. 358, 1854. Moderately large to small carnivorous Cyprinids; body somewhat elongate and compressed; alimentary canal short; peritoneum pale, dusky or black; mouth large and terminal; a conspicuous maxillary barbel present on each side at the junction of the upper and lower jaws (one species has two barbels on each side); premaxillaries protractile; lateral line complete; species small to medium, length up to 12 inches. A genus of about 20 species distributed over the United States east of the Rocky Mountains; two species have been taken in Colorado. a. Maxillary barbels 4; dorsal fin inserted directly above the ventrals . 4H. tetranemus Gilbert aa. Maxillary barbels 2; dorsal fin inserted behind the ventrals . H. kentuckiensis (Rafinesque) Hybopsis tetranemus Gilbert FOUR-BARBELED CHUB Hybopsis tetranemus Gilbert, Bull. Washburn College Lab., p. 208, 1886 (Elm and Spring Creeks, Medicine Lodge, Kansas); JorpaNn, Bull. U.S. Fish Com., Vol. TX, p. 17, 1889 (Pueblo). A single specimen of this remarkable fish was collected at Pueblo by Jordan in 1889. It has not been recorded from Colorado in any subsequent collection. As it does not occur in any of the collections examined its description is copied below: Head 4; depth 5.3; snout 2.5 in the head, one-third of it projecting beyond the mouth; eye small, 5inthe head. D.8; A.8; lateral line 36 to 38; teeth 4-4. Closely resembling H. aestivalis but with two long barbels at each angle of the mouth, the one pair taking the place of the fleshy prominence seen in gelidus and aestivalis; longest barbel as long as the eye. Head very slender, slenderer than in aestivalis. Dorsal over ventrals, a little nearer tip of snout than caudal. Fins large. Color as in aestivalis, translucent silvery, with irregular, scattered black dots above; median FISHES OF COLORADO 61 trays of each caudal lobe dusky at base. Length 2inches. Tributaries of Arkansas River in Kansas and Arkansas; not rare; a most remarkable little fish, the only American Minnow with more than two barbels—JORDAN AND EVERMANN, Bull. 47, U.S. Nat. Mus., pp. 315-16, 1896. Hybopsis kentuckiensis (Rafinesque) HorNY-HEAD, INDIAN CHUB, JERKER Luxilus kentuckiensis Rafinesque, Ichthyologia Ohiensis, p. 48, 1820 (Ohio River). Hybopsis kentuckiensis (Rafinesque)—Jupay, Univ. Colo. Studies, Vol. II, p. 113, 1903 (Boul- der; Longmont); Jupay, Bull. U.S. Fish Com. for 1904, p. 227, 1905 (Boulder; Longmont). Body elongate, somewhat compressed; head rather long, equalling or usually exceeding the depth of the body; depth 4 to 4.75, head 3.75 to 4.1 in the length to the base of the caudal; eye medium, 4 to 4.25, or even 5.6 in large specimens, in the head, 1.5 to 2 in the snout, and 2 ora little more in the interorbital distance; mouth rather large, terminal, slightly oblique; angle of the mouth not reaching the anterior margin of the eye but reaching the level of the posterior margin of the nostril; maxillary barbel prominent, its length a little more than 2 in the diameter of the eye, situated in the depression at the junction of the upper and lower jaws, dorsal fin short, base of the first dorsal ray on a level with or usually distinctly posterior to the ventral; dorsal rays 8; pectorals short, 1.5 to 1.75 in the head, not reaching the ventrals by half or more of the length of the latter; ventrals short, barely reaching the anal opening; anal fin with 7 or 8 rays; caudal peduncle rather broad, least depth about 2 in the head; caudal fin moderately forked; scales 6 or 7, 40-45, 5; lateral line almost straight, scarcely decurved in the pectoral region; size rather large, reaching the length of 10 inches, average adults 6 or 7 inches in length. Color above dark green shading to yellowish gray below; sides dull gray with greenish or brassy iridescence, but not silvery; a more or less indistinct lateral dusky band ending in faint caudal spot (this stripe and spot quite prominent in young specimens); sides of the head yellowish green with a pale red spot just back of the eye; a dusky bar just back of the operculum; dorsal and caudal fins yellowish to orange yellow, margined with bluish gray; pectoral and ventral fins light; anal fin yellow or orange; breeding males with the colors much brighter; top of the head elevated and with numerous tubercles. The Horny-head ranges through the northern portion of the United States east of the Rocky Mountains and south through the Mississippi Valley into Alabama. It is a species of small streams and lakes, preferring rather rapid water. This species is an omnivorous feeder, taking both animal and vegetable matter. The larger individuals have many of the qualities of true game fish and would doubtless be prized as such were it not for the fact that the bass and other more interesting game fishes are usually found in the same locality with the Horny- head. It will take any kind of bait and on light tackle will give an interesting fight. The flesh of this species is of fair flavor and is often eaten. The young 62 UNIVERSITY OF COLORADO STUDIES Horny-heads are very hardy and make excellent bait for the large game fishes, being recommended by many as the best live bait. This Chub spawns in the late spring. Colorado specimens.— University Museum: St. Vrain Creek, Longmont, October 17, 1903 (2 specimens, 85 and 115 mm.), C. Juday and D. W. Spangler, No. 16; Boulder Creek, Boulder, April 23, 1904 (90 mm.), J. Henderson, No. 36; Colorado State Historical and Natural History Museum: Clear Creek, August 15, 1900 (2 specimens, 105 mm.), W. C. Ferril; State Teachers’ College Museum: Cache la Poudre near Greeley, A. E. Beardsley. Genus PLATYGOBIO Gill The Flat-headed Chubs Platygobio Gill, Trans. Amer. Phil. Soc. Phila., Vol. V, p. 178, 1863. Moderately large carnivorous Cyprinids; body rather elongate and com- pressed; head short; alimentary canal short; mouth large, terminal or slightly oblique; maxillary barbel present and prominent, inserted at the junction of the upper and lower jaws; dorsal fin inserted on a level with or usually in front of the ventrals; scales large; lateral line complete and quite straight; size small to medium, length up to 12 inches. The two species of this genus are found in the western portion of the Mississippi Valley, one species ranging as far north as Saskatchewan. A single species is here listed from Colorado, this in the Arkansas River. The record of Cope,! under the name Pogonichthys communis Girard from Pueblo, is placed under Platygobio physignathus (Cope), as subsequent collections from the Arkansas, at Pueblo and above, have yielded only that species of Platygobio. Pogonichthys communis Girard was described from the upper Missouri and is considered a synonym of Platygobio gracilis (Richardson). If it should be shown by more extended collections that two species of Platygobio are found in the Arkansas at Pueblo, Cope’s record would have to be transferred to P. gracilis (Richardson). Since there is a possibility that these two species do occur together in the Arkansas, or that P. gracilis occurs in the Platte drainage, as it is a species of the upper Missouri, the following key for their separation is given: a. Dorsal, pectoral and ventral fins deeply falcate; length of the free portion at the tip of the dorsal 2 or 3 times the diameter of the eye in length . ! : P. gracilis (Richardson) aa. Dorsal, pectoral and ventral fins slightly falcate; length of the free portion at the tip of the dorsal about equal to the diameter of the eye in length. . : . P. physignathus (Cope) Platygobio physignathus (Cope) THICK-JAWED CHUB (Fig. 30) Ceratichthys physignathus Cope—CorE AND YARROW, Wheeler Survey, Vol. V, p. 651, 1875 (Arkansas River, Pueblo). Platygobio physignathus (Cope)—JorDan, Bull. U.S. Fish Com., Vol. 1X, p. 17, 1889 (Fountain Creek, Pueblo; Arkansas River, Canyon City); JORDAN AND EVERMANN, Bull. 47, U.S. Nat. Mus., p. 326, 1896 (Arkansas River, Pueblo). t Wheeler Survey, Vol. V, p. 653, 1875. FISHES OF COLORADO 63 Pogonichthys communis Girard—Core anp Yarrow, Wheeler Survey, Vol. V, p. 653, 1875 (Pueblo). Body rather elongate, compressed to somewhat fusiform; depth 4 to 4.6 in the length to the base of the caudal; head rather broad, slightly flattened dorsally, in males with fine tubercles; length of the head 4.3 to 4.6 in the length; dorsal and ventral profiles sloping evenly to the tip of the snout; snout broad and blunt, but slightly overhanging the mouth, length of the snout 3 in the head; eye moderately large and prominent, its center nearer to the tip of the snout than to the posterior margin of the operculum, its diameter 4.8 to 5.5 in the head, 1.5 or a little more in the snout, about 2 in the interorbital distance; nostrils prominent, double, situated less than half the diameter of the eye directly in front of the eye, each divided by a broad vertical septum, the anterior chamber circular in outline and larger than the posterior; mouth ventral, slightly oblique, angle of the mouth reaching almost or distinctly to the level of the eye; barbel in the axil just posterior to the angle of the mouth, prominent, its length 2 in the diameter of the eye; lips fleshy but not sucker-like; premaxillaries protractile; dorsal fin short and rather high, length of its base about 1.5 in the length of its longest ray, posterior margin distinctly but not deeply emarginate, base of the first ray on a level with or slightly in front of the ventrals; pectorals large, length equal to or slightly exceeding that of the head, posterior margin more or less emarginate at the tip, tip of the pectorals not reaching the ventrals; length of the ventrals 1.5 in the pectorals, ventrals barely if at all reaching the anal opening; anal small, of 7, usually 8 rays, slightly emarginate; caudal peduncle broad, its least depth about 2 in the head; caudal rather deeply forked; scales large, 5 to 7, 50-65, 4. Color above the lateral line olivaceous, below cream color to silvery white; an indistinct lead gray lateral stripe extending from the posterior margin of the operculum along the lateral line to the base of the caudal; no caudal spot; sides somewhat silvery, upper half of the sides sprinkled with minute blue-black dots; fins hyaline, rays, especially those of the caudal, outlined with dusky; top of the head dark. Size small; length to 6 inches. Colorado specimens.—University Museum: Arkansas River, Salida, May 8, (165 mm.), No. 376; Sells Lake, Canyon City, September, 1913 (2 specimens, 75-125 mm.), F. A. Reidel, No. 377; Grape Creek near Canyon City, November 8, 1913 (120mm.), A. G. Vestal and M. M. Ellis, No. 378; reported very abundant at Salida by Cockerell. Genus RHINICHTHYS Agassiz The Black-nosed Dace Rhinichthys Agassiz, Lake Superior, p. 353, 1850. Body elongate, fusiform, very slightly compressed; head rather long and conical; mouth small, ventral and sucker-like; premaxillaries not protractile, the upper lip being continuous with the skin of the top of the head, forming a 64 UNIVERSITY OF COLORADO STUDIES broad frenum; a very small maxillary barbel on each side at the junction of the upper and lower jaws; alimentary canal short; scales quite small; lateral line complete; size rather small, length under 5 inches. The species of this genus inhabit the cool, rapidly moving streams of northern United States and southern Canada, ranging from coast to coast. This genus is represented in Colorado by the Dulcis Minnow, a species abundant in the mountain streams east of the Continental Divide. Rhinichthys cataractae (Cuvier and Valenciennes) LONG-NOSED DACE Gobio cataractae Cuvier and Valenciennes, Hist. Poiss., Vol. XVI, p. 315, 1842 (Niagara Falls). This species is represented in Colorado by the western subspecies Rhinichthys cataractae dulcis (Girard), which may be separated from the true Rhinichthys cataractae by the sharper snout and the position of the dorsal fin, the first ray of the dorsal being nearer the base of the caudal fin than to the tip of the snout, equidistant from the nostril and the base of the caudal. The location of the base of the first ray of the dorsal is subject to some variation (see Table IV). Rhinichthys cataractae dulcis (Girard) Dutcts MINNow, WESTERN LONG-NOSED DACE (Fig. 31) Argyreus dulcis Girard, Proc. Acad. Nat. Sci. Phila., p. 185, 1856 (Sweetwater River, Nebraska). Rhinichthys maxillosus Cope—Core AND YARROW, Wheeler Survey, Vol. V, p. 44, 1875 (Twin Lakes; Colorado Springs). Rhinichthys transmontaus Cope, Amer. Nat., p. 441, 1879 (Rio Grande in Colorado). Rhinichthys dulcis (Girard) —JorpDan, Bull. U.S. Fish Com., Vol. IX, pp. 8, 11, 16, 22, 1889 (Denver; South Platte at Hartsels Springs; Bear Creek above Morrison; Pueblo; Lake Creek at Granite; Arkansas at Leadville; Twin Lakes; Alamosa; Del Norte; Rio Conejos fifteen miles south of Alamosa). Rhinichthys cataractae dulcis (Girard)—Jupay, Univ. Colo. Studies, Vol. Il, p. 113, 1903 (Boulder); Jupay, Bull. U.S. Fish Com., Vol. XXVI, p. 162, 1906 (Twin Lakes). Body elongate, slightly compressed; depth 4.5 to 5.5 in the length to the base of the caudal fin; head depressed, long and pointed, its length 3.5 to 4 in the length; dorsal profile of the head sloping anteriorly, ventral profile almost straight; snout produced, overhanging the mouth, length of the snout 2.6 to 3 in the length of the head; eye prominent, situated near the center of the side of the head, its diameter about 2 in the snout, 1.8 to 2 in the interorbital distance, and 5 in the head; nostril large, just in front of and somewhat dorsal to the eye; mouth ventral, sucker-like; lips large and fleshy, the upper recurved around the angle of the mouth; a small but distinct barbel in a slight depression at the angle of the mouth, which is about level with the posterior margin of the nostril; pre- :SnypDER, Bull. U.S. Fish Com., Vol. XXVII, p. 178, 1907, reports R. dulcis (Girard) from Corvallis, Oregon. FISHES OF COLORADO 65 maxillaries not protractile; frenum equal to the diameter of the eye; dorsal fin rather short, the length of its longest ray greater than that of the base of the fin, inserted in the posterior half of the body behind the origin of the ventrals, the distance from the base of the first ray of the dorsal to the base of the caudal equalling the distance from the base of the first ray to the nostril (Table IV); dorsal rays 8, rarely 7; pectorals moderately large, larger in the males than in the females, inserted low on each side, not reaching the ventrals; ventrals smaller than the pectorals, not reaching the anal by the diameter of the eye or more; anal of much the same size and shape as the dorsal, anal rays 7, rarely 8; caudal moderately forked, its width when spread greater than the depth of the body; scales small and closely imbricated, with both dorsal and apical radii, 11 to 14, 58-72, 9 to 12; lateral line complete, little if at all decurved. TABLE IV . No. of Specimens . Locality mh cies wk Dorsal A Grey ete Doe Tip of Snout c Miri Caudal nou Base of Caudal South Platte Drainage— IBOUIGETE eet Cae eMac I 130 @herny;Creekos 20). oe t (D7; A-7) 4 1 (D.8; A.8) WesteblumiGreekeu\. scsse),) hehasideieecnas I 17 Arkansas Drainage— aiwantlalkesape ark senaencaente ne | 6, dt i a de | Del Oh Ear Ae Ne 3 CanvonvGity siete eee Pel pemnoee al cb erteus ae seh I Rio Grande Drainage— Alamosa cae Leer oy auf eH ee eel, Oe GUAR pe tefl a 2 DY ETBING rte eee eee eee esa Ln glee oan UTD Ven, ta Pia T eb I Greece eons ete ayaa Nha dite eaeeh anche clone I 12 Motalleia septs eee et I 7 167 General color above greenish brown to dusky, mid-dorsal region with at least the indication of a dusky stripe; sides lighter, especially in large specimens which are often somewhat silvery, profusely spotted with dark brown, spots fewer below the lateral line; body below the pectorals without markings, white, cream-colored, yellowish, often with a pinkish cast; head dark, almost black above, lighter and spotted on the sides, yellowish or pinkish below, a narrow black stripe usually present extending from the tip of the snout to the anterior margin of the eye; in small specimens continuing through the eye to the posterior margin of the oper- culum, in very small specimens often continuing along the lateral line as a lateral stripe; specimens of all sizes with a rather conspicuous caudal spot; rays of the fins, especially of the dorsal and anal, usually outlined with black; males in the spring with the lips and under parts of the head orange-red to crimson, bases of the pectorals, ventrals and anal, and the small tubercles just above the origins of the pectorals and ventrals, orange-red to vermilion, fins and entire ventral portion of the body with more or less pink. Length of average specimens two to four inches, maximum size about five and a quarter inches. 66 UNIVERSITY OF COLORADO STUDIES The variation of this species has been given considerable attention since several species now placed in its synonymy have been described. Three of these nominal species have been reported from Colorado, Rhinichthys dulcis (Girard), Rhinich- thys maxillosus Cope and Rhinichthys transmontanus Cope, the first two from the region east of the mountains and the third from the Rio Grande Valley. Table IV gives the results of an examination of the Colorado specimens as to position of the dorsal fin. In Girard’s original description of R. dulcis he says of the dorsal fin: “Its anterior margin is nearer the extremity of the snout than to the insertion of the caudal fin.”” Cope in describing R. mavillosus states that “from the base of the caudal to the base of the front ray of the dorsal equal from latter point to opposite the middle of the orbit.’ Later in writing of this same species from the Rio Grande in Colorado under the name of Rhinichthys transmontanus he says:3 “Tt differs from the more eastern species in having the dorsal fin equidistant between the base of caudal and the end of the muzzle, and in having the longitudinal series of scales below the lateral line more numerous (12 to 13), and equal to the number of scales above.”” Disregarding the other points of these descriptions which have seemed similar enough to warrant the placing of all of these species in the same synonymy by several authors, these three species differ in the position of the dorsal fin. As may be seen from Table IV, but one of the specimens examined can be referred to R. dulcis as defined by Girard and seven to Cope’s R. transmontanus. The remaining one hundred and sixty-seven specimens are all clearly referable to R. maxillosus Cope. There seems to be no relation between the variation of the position of the fin and the locality from which the fish were collected, for but one of the specimens from the Rio Grande is of the R. transmontanus type. The fol- lowing table (V) shows that there is not the correlation between the number of scale rows and the position of the dorsal fin that has been suggested by Cope. In general the scales of the specimens from the Rio Grande are slightly smaller although the two series of counts overlap. The other variations looked for were those of the fin rays. Two specimens only were found irregular in number of fin rays and these have been mentioned in Table IV discussing the position of the dorsal fin. From the material at hand it seems that the three species R. dulcis (Girard), R. maxillosus Cope and R. transmontanus Cope are synonymous since all three types have been found in the Platte drainage and two in the Arkansas and Rio Grande drainages, in which case the oldest name applies. It is quite possible that the examination of a large series of specimens of this fish from the Sweetwater in Nebraska, the type locality of R. dulcis, would show a preponderance of indi- viduals with the base of the first ray of the dorsal nearer to the tip of the snout than to the base of the caudal, in which case the name R. dulcis should be restricted t Proc. Acad. Nat. Sci. Phila., p. 185, 1856. 2 Tbid., p. 278, 1864. 3 Amer. Nal., p. 441, 1870. FISHES OF COLORADO 67 to the fishes of that type and our single specimen of this kind regarded as a varia- tion. In this case the name of the subspecies found in Colorado should stand R. cataractae maxillosus (Cope). TABLE V SCALE FORMULAE OF 10 RANDOM SPECIMENS ScALE FORMULAE OF 10 RANDOM SPECIMENS Creede, Rio Grande Boulder Creek, Boulder 12-67-12 11-62-11 12-68-11 II-5Q-I1 12-69-11 12-58- 9 12-70-11 12-64-10 12-70-12 12-66-10 13-66-11 12-67-12 14-61-10 13-05-11 14-68-11 13-63-11 14-69-12 13-59-12 14-71-12 14-60-12 scalesiaboverlateralline isi tty sepa aves ele Mule II 12 13 14 INOW ofispecimensniGreedewiats eit tui CIM ee aA salt a bit 5 INovorspecimens, Boulders sai. eee le urpcia sates slslegleterclolele 2 4 3 I Scalesibelowilateralline yaiee tea Aan Salem atone ad eel etal, 9 10 II 12 INovofspecimens Creede Wiait or 2) \ are POR ett Sy Pa Na vs I 5 4 INoxof specimens Bouldenae sic a) Weiss reysieetstnris chavs iat ile ree abe I 2 4 3 Scales in the lateral line......... 58 590 60 61 62 63 64 65 66 67 68 69 7o 71 No. of specimens, Creede........ : iy I : Ta a) ay War sun aN No. of specimens, Boulder....... Ep ee Rh (ete ew Ene Oth on kD Al ur we a The Dulcis Minnow, although of the carnivorous group of Cyprinids, feeds to a considerable extent on plant material. The stomach contents of 20 speci- mens from Boulder Creek near Boulder showed that the algae and brown diato- maceous slime so generally eaten by herbivorous Cyprinids are important elements in the food of this minnow, forming about two-thirds of the material. Small crustaceans, insect larvae, small snails and water-logged material comprised the remaining third. It is known that the Dulcis Minnow also eats the spawn of the trout. On the other hand, the Dulcis Minnows are eaten by the trout, making the presence of these minnows in the mountain streams of value. This species is also used as live bait. Rhinichthys cataractae dulcis spawns in the early spring. Colorado specimens.—University Museum: Boulder Creek, Boulder, October, 1903 (56 specimens, 65-80 mm.), C. Juday and J. Henderson, No. 11; Twin Lakes, August, 1903 (3 speci- mens, 100-105 mm.), C. Juday, No. 34; West Plum Creek near Castle Rock, June 8, ro12 (18 specimens, 35-70 mm.), A. G. Vestal and M. M. Ellis, No. 379; Cherry Creek near Frankton, June 9, 1912 (5 specimens, 65-85 mm.), A. G. Vestal and M. M. Ellis, No. 380; Boulder Creek six miles east of Boulder, July 25, 1912 (138 specimens, 35-85 mm.), M. M. Ellis, No. 381; Rio Grande, Alamosa, July 27, 1912 (2 specimens, 50-55 mm.), M. M. Ellis, No. 382; Rio Grande, Creede, 68 UNIVERSITY OF COLORADO STUDIES July 28, 1912 (13 specimens, 65-95 mm.), M. M. Ellis, No. 383; four miles west of Cripple Creek, July, 1913 (2 specimens, roo and 115 mm.), F. A. Hassenpflug, No. 384; Grape Creek, near Canyon City, November 8, 1913 (5 specimens, 70-90 mm.), A. G. Vestal and M. M. Ellis, No. 386; Sells Lake, Canyon City, September, 1913 (90 mm.), F. A. Reidel, No. 385; State Teachers’ College Museum: Cache la Poudre, Greeley, and twenty miles above Antonito, A. E. Beardsley; Colorado State Historical and Natural History Museum: South Platte River near Denver, August 3, 1900 (2 specimens, 65-75 mm.), W. C. Ferril. Genus AGOSIA Girard The Western Dace Agosia Girard, Proc. Acad. Nat. Sci. Phila., p. 186, 1856. General characters the same as Rhinichthys from which this genus differs in the protractile premaxillaries. Premaxillaries protractile, upper lip not continu- ous with the skin of the top of the head, no frenum. Species of the Rocky Moun- tain region on the west slope, ranging northward through the Great Basin into the Pacific region and south through the Colorado River drainage. Size small, length 5 inches or less. Agosia yarrowi Jordan and Evermann = R*-> chthes Yarrow’s Dace (Figs. 32 and 33) Agosia yarrowi Jordan and Evermann, Bull. U.S. Fish Com., Vol. IX, p. 28, 1889 (Tomichi Creek and Gunnison River, Gunnison; Uncompahgre, Delta; Eagle River, Gypsum; Rio d. 1. Animas; Rio Florida; Lightner’s Creek). A pocope oscula (Girard)—Core AND YARROW, Wheeler Survey, Vol. V, p. 647, 1875 (Pagosa), wrongly identified. Body elongate, subterete, slightly compressed; depth 4.25 to 5.5 in the length to the base of the caudal; head slightly depressed, long and pointed, its length 3.5 to 4.5 in the length; dorsal profile of the head sloping anteriorly, ventral profile rather straight; snout produced, overhanging the mouth; eye prominent, situated near or slightly above the center of the head, its diameter 2 to almost 3 in the snout, r. 5 to 2 in the interorbital distance, 4.5 to 6. 5 in head; nostril large and prominent, just in front of and somewhat dorsal to the eye; mouth ventral, sucker-like, lips large and fleshy, the upper recurved around the angle of the mouth; a small but distinct barbel in the depression at the junction of the upper and lower jaws; premaxillaries protractile, no frenum connecting the upper lip with the skin of the top of the head (a narrow frenum sometimes present); dorsal fin rather short, length of its base less than the length of its longest ray, base of the first ray of the dorsal nearer to the base of the caudal than to the tip of the snout, inserted just above or slightly behind the level of the origin of the ventrals, dorsal rays 7-9; pectorals medium to small, not quite or just reaching the ventrals; ventrals smaller than the pectorals, reaching the anal; anal fin of much the same size and shape as the dorsal, of 7 or 8 rays; scales usually about 14 to 16, 77-89, 13 to 15; lateral line complete or interrupted, little if at all decurved; size rather small, length 5 inches or less. FISHES OF COLORADO 69 Three distinct color patterns and the combination of these were found: 1. General color above olive-brown to dark gray, darker along the mid-dorsal region, giving at least indications of a dark mid-dorsal stripe; a distinct, dark, TABLE VI TABLE OF VARIATIONS IN Agosia yarrowi DISTANCE FROM THE BASE OF DWAR Ge a THE First Ray OF THE Dor- a P| SAL TO a BASE OF THE want ie ae Dorsat Rays a 5 5 e u Bop Re esanee |" or Heap aq |Pom! 9 | Se |oge “CSc cg Se (RE Be i J 5 <4 aie OWN Beyond Nostril} Nostril| Eye 4-5 | 5-6.5 7 8 9 re a es iA ok asin | ey are reece doce venn'lle‘tehenstey=i[\P a pM omuilinxescvorstall U ONG ed feet skal stall Dusrcecls's > GaN lonioiseio acme ea socnec fe] (( ogee allele Sal MAD Sell (easel |Excte crs (eRe >. Gis eaten arecevarcd [Raa x me << 0 RGM Fe eN eet ere ret seid heel] Mere ahey evelllecaveceneresttet aerem |lcieew tar at lave varewaiall iserstalcus xX x x $.2 UPA atovexe te) |oreh sistas y DMT") flayeteteMeael rarity is fi DRO wb [aed dueyacal| omen rate Payer cnoners x x x as ets XS Wlscbanall eS Napcoedkecoceall: OS Wlodacrallsdaclos|lodonec x x < n SN heated [SA Rape Ls Gal (OU A | Se (ert TO GA ND eo be x x x << Ulssasicc|bouneel |lbSe leboo.dcl vlcs- Ullecals.crel joao Grodan OG ec) ameorse x x< x< =) “eee ee DS ea 6.6 «elle oe sve 2) x a) 8) ,a) a! a) haa we) ote) Be 0.e16 re @: 2) 0 //sekabe oS hi lSoio se 0) |S aces | dessin ld o'otval |) iu 2.4abl bag ceo) Haeraersl ceria. x Xx x ROM Morey ell crore ere |b eee ONG Mac vere teeyehell ly Ghd een) ics Milena Gee a x Notaeealisidsctolleccacall PS: dboosculiScuoooll (P< bab conlldsnocc x x x 2) IH PRIS foment Incanto lee 4em Micro eo] ln Gat Reeiaio Price es Imi x x x Shh Poppers SVG ooAaRUI OS | ilippeaacdliccouce|| Be Misnrocsd aaeman bnmoee x Pea |sterstsrede A cits O's PS [SSeS os| ES SUEl| ES bonosell PG albesiaesl Kaci PEt) iletobecai ede teyoeparn ell ett ens SIMMER OS A ou Se ESR: FUSION) [GSK ys Res tite al else aa] stare ya ees (en ese BAe evel seekers sie eal eheto- Vers] | WONG erate tetesanene!| ) UO OMOMnIIS © cc arerelliay oi enaps Ihe PS ig G5 e Berea sterel (clots tele, < PA Nedageall oS ails oogod| [ao obs oll PA! asob collapse 4d sl loo siasal eos alec tome Sood ees ala cacicg piace Gato oe) vap-6 tal nereee| taco hhne.8 x x ie espsy ai > Sai loln titan) fyb tal |aoorso] icdotal cnc at. Ubi mernstsl (emer (he x x speeches PE Mosc nal | (eS Nlese ooclibmoeseledseiGall! Se lobeeaalh OS Woodie sollgoogeelioupeas ahiaalats XV lloeee Sl Westie edocs poco oG|lnobis. ae] |: iesg il Moores) oaaton lar lene calla cate Nao bot Gia leesrscasl |W ON Vil lilekervallestvsiyelline sieterell Mur oma fettelaiancy|loarereuvalh OS x x Beric bae aria es PR Ce Bice heteaSsh/| ciel owG) |icPsGs al Goic.rao 6] ueeencra ol (ojo Grok al [lei S x x eboec PM araeeev TMOG lcdlocanc\rsia fie teaver avell i OGL MISMO) ol en rovel] os acat cts)[ fa steht of TEIN x x Snead ea ecient ae MON ifouchetevea lls og vereyelllE Wea | taeia/ar's-xi|iene azure ON [ ALeuets: are lopeveten cceilPeMoueteyens CAT (| romeo Dil ignite DRAPE opciene 5 | characters >) Al lane Gaaear DS ae ner eid oped [oe Gee 20 aia ee ate SAN boo ea ecto > rl loeradias DORE ey stoite aveWatcaens erate at Tp | Seavercrra steerer ors bah Aen aee Wehr etal evaseysans Gils > een cee vee eteteuc tery see fei x S| Koe adie ON as ey: YS) Winteee cal ore ee Pei erste aie PO gn Gost cl eecleca| nig oe a8 x x x Soler el) Dee ASD ie eee eee SG inti ac pial rs: a esas a ses ee Daca PG bl oera eee ( Sexciceel hime Gat ectaeneea| fail IS halatalal nies MPPs | astiea ol ec oer loercerens srererat ate ea Nevers eae leone staza[C ON DS Wis ob Sool menos sia cial fianeaS) 4 Ie Biaobicl loa retical kelveies Aa Oaths Dy) SSS bisrally ue Sl eeeee bree On|, ue. Sai lemeta ocr Bol lem Widide.crn cl logo Hol comer Bet seth [tava eet ke x Xiu Uist trates ccs tect 9 Gur nate kas clllcys le stare | ea MONE tetetaneyal | euonetetatellleessbseee Setar ee) Fee x GW iicreitumecsd gad Oil! PaPooes eee anal Me aes mS |leoe solos Sb Golo ondee TB crake A apepyere need alors wceln g vhetetet || Mu POG flys ois. oe | sor sienatol| MMM acct Sieveu® | ote i titan’ ley si fever Sislevera >< Jullocdd a6| les Us| Ioeneate ke >. Saal ncbocslactagd pote naCo hia os6.o5l Spinco! asco ee. POP errata sietalsr=i|fl ON? [letevacsyerell MeN wl lorotore sve] ON ld oetogalllen eoeliodaee restate eines Bema | Sue. eb Geainen| LUO SMlR amosia Bisaeio ol beideciaall! ve x x yes wiles eed ll Gin leaeoon poacna |! weSt Ol apaocd cobras ocd) ox x x 7° UNIVERSITY OF COLORADO STUDIES lateral stripe along the lateral line; region from the origin of the pectorals to the base of the anal, below the lateral stripe, with a dusky shading which is usually distinct enough to form a second, incomplete, lateral stripe; all of the markings made up of fine, longitudinal lines which give the whole an engraved appearance. 2. The same as first type with the addition of numerous strong black spots in and above the lateral stripe, especially posterior to the origin of the dorsal. 3. All markings wanting or represented by blurred clouds; body rather uniform adobe-color, darker dorsally. These three color types may represent either extremes of a continuous series of variations in color pattern, i.e., this species may have three modes as regards color and markings; or there may be three or more distinct races of this species the interbreeding of which gives the various recombinations of these color patterns found. This matter is deserving of more attention when larger collections are available. Because of the variations found in the specimens examined and the close relation of Agosia yarrowi to Agosia couesii (Yarrow) and Agosia oscula (Girard) a table of variations seen is presented (Table VI). From Table VI it may be seen that the variation in the specimens of A gosia yarrowi examined is such that the three species A. oscula, A. yarrowi and A. couesii as defined by Jordan! are distinguishable only on the basis of scales. Material was not at hand to study the scales of the other two species. Colorado specimens.—University Museum: Uncompahgre, Montrose, August 8, 1912 (79 specimens, 25-110 mm.), J. Henderson and M. M. Ellis, No. 387; Durango, August 11, 1912 (12 specimens, 90-120 mm.), J. Henderson and M. M. Ellis, No. 388; State Teachers’ College Museum: Gunnison River, Delta, A. E. Beardsley. Subfamily PLAGOPTERINAE Genus PLAGOPTERUS Cope Plagopterus Cope, Proc. Amer. Phil. Soc. Phila., p. 301, 1874. Body scaleless; dorsal fin with a double dorsal spine, the anterior spine with a groove in which the posterior spine is received; inner margin of the ventral fins adherent to the sides of the body; maxillary barbel present; a single species known only from the Colorado River drainage. Plagopterus argentissimus Cope Plagopterus argentissimus Cope, Proc. Amer. Phil. Soc. Phila., p. 301, 1874 (San Luis Valley, Colorado) (wrongly ascribed to the Rio Grande). In his discussion of this remarkable species Cope, /.c., states that this fish is found in the Colorado Basin in western Colorado. It has subsequently been taken only in the lower Colorado drainage at Ft. Yuma, and is probably not a member of the Colorado fauna. t Bull. 47, U.S. Nat. Mus., pp. 309-310, 1896. FISHES OF COLORADO 7i Superorder PH YSOSTOMI Air bladder connected with the alimentary canal by a ductus pneumaticus; no Weberian apparatus. Order ISsOSPONDYLI’ Herring, Salmon, the Smelts and Related Deep-Sea Forms Maxillaries and premaxillaries distinct; barbels wanting; shoulder girdle connected with the skull by the postemporal bone. This order is represented in Colorado by the Grayling, Trout and Whitefish, all of which are game fishes. Family THY MALLIDAE The Graylings Dorsal fin high and long, of 19 to 24 rays; adipose fin present; general form trout-like; parietal bones meeting mesially; frontal bones not reaching the supra- occipital bone. This family includes five species all referable to the genus Thymallus, found in the cold clear waters of northern America and the Arctic regions. As food fishes and from the standpoint of the fisherman the Graylings are among the best of the fresh-water fishes. In both general appearance and habits the Graylings are much like the Trout, but the high dorsal fin and the striking colors of the former are quite distinctive. The name Thymailus is derived from a Greek word referring to the odor of thyme which is supposed to be quite evident when the Grayling is first taken from the water, a belief which Izaak Walton credited, for he wrote of the Grayling, ‘‘and some think he feeds on water thyme for he smells of it when first taken from the water.” It seems, however, that sportsmen do not agree in this matter, for Henshall? says of the Grayling that “however it may have been in days of old, it is not so now, though an odor of cucumbers is some- times perceptible when it is first out of the water.” Genus THYMALLUS Cuvier The Graylings Thymallus Cuvier, Regne Animal, ed. II, Vol. II, p. 306, 1820. Body somewhat compressed; head short; teeth on the premaxillaries, maxil- laries and lower jaw; air bladder very large; scales small, about 90 in the lateral line; species brightly colored, dorsal fin with orange, red or purplish spots; caudal fin distinctly forked; represented in Colorado by a single introduced species. Since the Isospondylous fishes found in Colorado, both native and introduced forms, have been planted in as many streams of the state as possible, the Colorado specimens examined are not listed, unless for particu- lar reasons, as they do not contribute to the understanding of the natural distribution of these species. 2 Bass, Pike, Perch and Others, p. 175, 1903, New York, 72 UNIVERSITY OF COLORADO STUDIES Thymallus montanus Milner MONTANA GRAYLING Thymallus montanus Milner, Rept. U.S. Fish Com., Vol. Il for 1872-73, p. 741, 1874 (tributaries of the Missouri at Camp Baker). Body somewhat elongate and compressed, not much elevated; depth 4.5 to 5 or a little more in the length; head rather short, its length about equal to the greatest depth of the body; diameter of the eye equalling the length of the snout, 3.5 to 4 in the head; dorsal fin long and rather high, length of its base equalling or slightly exceeding the length of the head, length of the longest dorsal ray barely equal to or usually a little less than the length of the base of the dorsal, dorsal rays 19 to 22; pectorals small, tip of the pectorals not reaching the base of the ventrals by the length of the pectorals; ventrals about the same size as the pectorals, base of the first rays of the ventrals on or slightly in front of the level of the last dorsal ray; anal rays 10 or 11; scales small and loose, 8 or 9, 80-90, 9 or 10; reaching the weight of 2 pounds or more. General color grayish to silvery, shading dorsally into rather dark grayish blue or purple, below the lateral line pinkish shading into silvery white ventrally; sides with a lilac or purplish reflection; sides of the body above the pectoral fins with several small irregular black spots, each covering portions of from one to four scales; dorsal fin rather dark greenish gray, margined with rose-pink, crossed by five or more rows of orange-red or pinkish spots some of which are distinctly ocellated with white, upper posterior portion of the dorsal with a few reddish blotches; ventral fins with three rose-red stripes; pectoral and anal fins white with a pinkish or brownish cast. The Montana Grayling is a native to the Missouri and its tributaries above the Great Falls, inhabiting the clear streams with rock or gravel bottoms. As this region was traversed by the Lewis and Clark expedition, the earliest record of this species occurs in their journal,' although the fish was not named at that time. It has been introduced in various parts of the country with but fair success. Thymallus montanus spawns in April and May, the eggs being much like those of the trout except that they are smaller. In Colorado the Grayling has been introduced on both sides of the Continental Divide by the United States Fish Commission, the State Fish Commission and by local fishing clubs.2, In rg01,3 100,000 fry and fingerlings were liberated in Colorado by the United States Fish Commission alone, yet the Grayling is not well established in the state at present. Many of the reports of Grayling in Colorado which have been received by t Bass, Pike, Perch and Others, p. 182, 1903, New York. 2 See Reports of the United States Fish Commission; of the Colorado Commissioner of Game and Fish; and reports of American Fisheries Society. 3 Rept. U.S. Fish Com. for 1901-1902, p. tot. FISHES OF COLORADO 73 the writer were shown to be reports of Williamson’s Whitefish, Coregonus william- soni Girard, which is often confused, locally, with the Grayling. Family SALMONIDAE The Trout, Charrs, Whitefish, and Salmon Dorsal fin moderate, of 15 or fewer rays; adipose fin present; parietal bones not meeting mesially but separated by the anterior portion of the supraoccipital which joins the frontals. The numerous species of Salmonidae are confined to the northern two-thirds of the northern hemisphere, ranging into the Arctic regions. Most of the Sal- monids are fresh-water forms and even the larger species of Salmon which spend a considerable portion of their lives in salt water ascend rivers to spawn. In this family are included some of the best-known game fishes, the Trout and Charrs, as well as other species of large commercial value. Several million pounds of the Lake Whitefish, Coregonus clupeiformis (Mitchill), are taken annually from the Great Lakes, and the large species of Salmon, Oncorhynchus tschawytscha (Wal- baum) and related forms, which are so abundant in the Columbia River region, have become the center of a large industry. Viewed from a purely commercial standpoint the Salmonid fishes of Colorado, particularly the Trout, are the most important fishes in the state, forming a valu- able natural asset. The presence of Trout in the mountain streams of Colorado adds annually several thousands of dollars to the general wealth of the state. The additional value of these fishes to the residents of the state cannot be reckoned so easily but it is certainly large, so that the care of the Trout and their artificial propagation well repay the funds so invested. Four genera of Salmonidae are represented in Colorado by either native or introduced species, or both. Three of these genera are so closely related that technical characters must be used for their separation, although the markings and colors of the Colorado species are added to facilitate rapid determination. The young of most species of Salmonids are marked with several vertical, dusky bars, known as “parr marks.”* These parr marks gradually disappear as the fish grows older, although they may persist in almost full-grown individuals, and are not to be confused with the black spots mentioned in the key. a. Jaws usually without teeth; teeth if present extremely minute; scales rather prominent; lower jaw shorter than the upper by which it is partly included; Colorado species silvery, bluish above, without spots, fins margined with black, parr marks only in the young. Coregonus (Artedi) Linnaeus, p. 74 aa. Jaws strongly toothed; scales small, often more or less obscure; species spotted with black; parr marks persisting in rather large individuals. t See Fig. 37. 74 UNIVERSITY OF COLORADO STUDIES b. Vomer flat; American species spotted with black but not with red, pink or gray; introduced European species spotted with black and scarlet, the scarlet spots being more or less ocellated with white, adipose fin tipped with bright orange-yellow, general color above brownish. Salmo (Artedi) Linnaeus, p. 75 bb. Vomer boat-shaped; species spotted with red, pink or gray, but without ocellated scarlet spots. c. Vomer without a raised crest; species much spotted with bright red; anterior margins of lower fins white . : , : 4 . Salvelinus Richardson, p. 84 cc. Vomer with a raised crest extending posteriorly from the head of the bone; species spotted or mottled with gray or rarely pale grayish pink, but without bright red spots. Cristivomer Jordan and Gill, p. 85 Subfamily COREGONINAE Genus COREGONUS (Artedi) Linnaeus The Whitefish Coregonus Artedi, Genera Piscium, p. 9, 1738. Coregoni Linnaeus, Systema Naturae, ed. X, p. 310, 1758. Body compressed; head rather short and somewhat conical; mouth small, angle of the mouth barely if at all reaching the level of the anterior portion of the eye; scales not extremely small, but rather prominent. Species of this genus are found in both the old and new worlds and most of them are food fishes of value. A single species is fairly abundant in northwestern Colorado. Coregonus williamsoni Girard WILLIAMSON’S WHITEFISH, Rocky MOUNTAIN WHITEFISH Coregonus williamsoni Girard, Proc. Acad. Nat. Sci. Phila., p. 136, 1856 (Deschutes River, Oregon); EvERMANN AND Situ, Rept. U.S. Com. Fisheries for 1893-094, Pp. 293, 1896 (Meeker, Colorado). Body compressed and somewhat elongate, its depth 4 to 5 in the length; head rather short and conical, its dorsal profile sloping rather abruptly, ventral profile almost straight, length of the head about equal to or a little less than the greatest depth of the body; eye large, nearer to the tip of the snout than to the gill opening, situated in the upper half of the head, diameter of the eye less than the length of the snout, 4 or more in the head; snout rather short and blunt in females and young, in breeding males somewhat produced and upturned at the tip; mouth small, slightly ventral, angle of the mouth barely reaching the level of the anterior margin of the orbit; lower jaw shorter than the upper, by which it is partly included; dorsal fin rather short and high, length of its longest ray almost or just equalling the length of the base of the dorsal, which is about 1.5 in the head; dorsal rays 12 to 14, base of the first ray of the dorsal about midway between the tip of the extended pectoral and the origin of the ventrals; pectorals short, separated from the ventrals by about their own length; ventrals much the same size as the pectorals, origin of the ventrals on a level with about the tenth FISHES OF COLORADO TS ray of the dorsal; anal fin almost as large as the dorsal, of 11 to 13 rays; adipose fin large and prominent, its tip reaching beyond the level of the last anal ray; caudal peduncle narrow, its least depth about 3 in the head; caudal fin deeply forked; scales not very small, 8 to 10, 80-90, 8 to ro, those on the sides of the body of breeding males with tubercles. Color above dark grayish or greenish blue shading into silvery on the sides and grayish white below; dorsal fin dark, adipose and caudal grayish blue to steel-blue, pectoral, ventral and anal fins dusky, outer portion of all fins margined with black; young with dusky parr marks. Size moderate, reaching a Jength of 12 inches or more and a weight of 5 pounds, average specimens about a pound. Williamson’s Whitefish is a species of the western slope of the Rocky Moun- tains, ranging from Colorado northwestward through Utah and Idaho to the Pacific Coast and British Columbia. A variety, C. williamsoni cismontanus Jordan, is known from the tributaries of the Upper Missouri east of the Continental Divide. In cold deep lakes the Whitefish finds its favorite habitat, running into small streams during the spawning season, the late fall and early winter... As a game fish this species is much like the trout, taking both the fly and still bait. Its flesh is excellent. In Colorado this fish is found in the Yampa and White River drainages and has been reported to the writer as quite abundant in several local- ities. It is known locally as the “‘Grayling,’ which it resembles superficially, but from which it may be easily separated by the small dorsal fin and the absence of several rows of bright orange spots on the dorsal fin and the three pink stripes on the ventrals, these markings being characteristic of the true Grayling, Thymallus montanus. ‘The Whitefish is also known as the “Rocky Mountain Herring.” Subfamily SALMONINAE Genus SALMO (Artedi) Linnaeus The Salmon and Trout Salmo Artedi, Genera Piscium, 1738. Salmo Linnaeus, Systema Naturae, ed. X, p. 308, 1758. Body moderately elongate and compressed; mouth large, its angle reaching to or beyond the level of the center of the eye; lower jaw equal to or barely exceeding the upper, lower jaw of breeding males often upturned at the tip; teeth on the tongue, palatine bones, vomer and both jaws; vomer flat; pyloric coeca numerous; scales small. Since the species of this genus, particularly the trout, are so closely related, the variation in the measurements usually given is less in some cases between different species of Salmonids than that between individuals of species of some other groups. Accordingly the technical descriptions of the Salmonids found in Colorado are omitted and the general description given under this head. 1 EVERMANN AND SMITH, Rept. U.S. Com. Fisheries, p. 293, 1896. 76 UNIVERSITY OF COLORADO STUDIES Depth 3.7 to 4.5, head 4 to 5 in the length; dorsal rays 10 to 12; anal rays 10 to 12; scales small, 20 or more between the base of the dorsal fin and the lateral line; 120 or more cross-rows of scales. This genus includes both marine and fresh-water species. The Atlantic Salmon, S. salar Linnaeus, the Sebago or Landlocked Salmon, S. sebago Girard, and the Trout of the Rocky Mountain and Pacific regions are the North American representatives. All of the species, particularly the fresh-water forms, are closely related, yet many rather definite types are found native in independent rivers or drainages. Some of these trout, as the Loch Leven Trout, S. fario levenensis (Walker), have been shown to be merely well-defined races resulting from peculiar local conditions, forms which when placed under slightly different conditions return to the original type from which they were derived.t_ Other types. appar- ently maintain their identity although closely resembling other trout with which they may be associated. As a result some ichthyologists believe the species of trout to be few and the varieties numerous, while others hold each form to be a distinct species. The fact of large importance is that differences do exist between the trout of separate streams and drainages, and this should be recognized. The trinomial nomenclature is used in this report since it points out both the rela- tionships and the differences for the forms considered. Eleven types of trout are to be found in Colorado and excepting two species, the Eastern Brook Trout, Salvelinus fontinalis (Mitchill), and the Mackinaw Trout, Cristivomer namaycush (Walbaum), all are members of the genus Salmo. Four of the forms belonging to this genus are native in Colorado, the Green- backed Trout, S. clarkii stomias (Cope), the Rio Grande Trout, S. clarkii spilurus (Cope), the Colorado River Trout, S. clarkii pleuriticus (Cope), and the Yellow Finned Trout, S. clarkii macdonaldi (Jordan and Evermann), the last-mentioned species occurring only in Twin Lakes. These four trout are known collectively in Colorado as ‘‘Native Trout” or “Natives.” In addition to the indigenous trout, five other forms may be taken, the Landlocked Salmon, S. sebago Girard, the Rainbow Trout, S. irideus shasta (Jordan) and S. rivularis Ayres, the Steel- head Trout, introduced from various parts of North America; and the Brown Trout, S. fario Linnaeus, and the Loch Leven Trout, S. fario levenensis (Walker), introduced from Great Britain. Both native and introduced trout have been carried from one drainage to another so that often several forms occur in the same stream. It is at once seen that this condition makes possible both competition and hybridization between species which would not be associated under natural conditions. In general the introduced Eastern Brook Trout is the most successful form, although the demand for this species and the resultant interest in its artificial propagation must be considered in this connection. As regards the hybridization of the trout there t JorDAN, Science, N.S., Vol. XXII, p. 714, 1905. FISHES OF COLORADO FL are almost no data from either Colorado fishermen or Colorado collections. The belief is current that the various native trout cross with the introduced Rainbow Trout and several reports of such hybrids have reached the University. The writer was also assured that Steelheads and Eastern Brook Trout crossed when kept in a lake near Durango. As opposed to such reports Jordan states that he “has examined many thousands of American Salmonidae, both of Oncorhynchus and Salmo,” and “‘while many variations have come to his attention, and he has been compelled more than once to modify his views as to specific distinctions, he has never yet seen an individual which he had the slightest reason to regard as a ‘hybrid.’” On the next page he quotes Giinther as writing that “hybrids between the salmon and other species are very scarce everywhere.”” That hybrids between some species of the genus Salmo are possible when the eggs are artificially fertilized is established by experiment, and Mr. S. E. Land of the Colorado State Fish Commission told the writer that such an artificial cross had been successfully made between the “Native” and the Rainbow at the Denver Hatchery. No specimens of authentic hybrids either from nature or from artificial fertilization have been examined in the present study. Trout are primarily fishes of the mountain streams and lakes since they are physiologically adjusted to live in cold clear water with a high oxygen content. All are carnivorous, feeding as adults for the most part on other fishes and to some extent on insects and other stream animals. Aside from man the chief enemies of the trout are the Sculpin,! Cottus punctulatus, the Dulcis Minnow, Rhinichthys dulcis, Yarrow’s Dace, Agosia yarrowi, and the suckers, all of which destroy trout eggs. Of these fishes the Sculpin is the most harmful since it is rarely eaten by the trout yet feeds upon both the young trout and trout eggs. Between the suckers, Dulcis Minnow and Yarrow’s Dace, and the trout there exists a com- pensating relation which makes each group of value to the other. The former eat trout eggs but the young suckers and both young and adults of the Dulcis Minnow and Yarrow’s Dace collectively form one of the most important items in the food of the adult trout. It has been shown that trout do not thrive in streams in which young or small fish are not available for food. In lakes where the supply of insects is greater the presence of small fishes is not so essential but they nevertheless form a considerable portion of the food of the adult trout when- ever present. Other factors limiting the number of trout in Colorado streams are overfishing, the introduction of mine and mill waste into the trout streams and the deflection of water for power or irrigation purposes. The species of trout found in Colorado may be separated by the following key. Since the various colors and markings of the trout vary with the individual and to some extent with the immediate environment as well as the season, it is difficult to give characters which will cover all specimens. Typical specimens t See pp. 64, 68, and 114. 78 UNIVERSITY OF COLORADO STUDIES in full color are quite distinct. Occasionally long slim individuals known as “Racers” are caught, the coloration of which is strikingly peculiar in some respects. A large racer with a bright red stripe along each side of the body below the lateral line was recently reported to the writer from Grand Lake. In using the key the red blotches due to the breaking-up of the lateral red band are not to be confused with the bright-red, well-defined spots of the Eastern Brook Trout and. the Brown Trout. Parr marks are to be disregarded unless mentioned. The scale cross- rows mentioned below refer to the oblique bands of scales which cross the body dorso-ventrally. These bands should be counted from the gill opening posteriorly to the base of the caudal fin, and may best be followed just above the lateral line. The scales in the lateral line are not to be counted unless mentioned specifically. Both color and anatomical characters are given, the more important of each being italicized. The species groups followed are those of Jordan.' a. Pyloric coeca 65 or more; scales large, about 120 in the lateral line and 23 between the base of the dorsal and the lateral line; vomer feebly toothed; color above brownish, sides silvery with numer- ous black spots some of which are almost as large as the pupil of the eye, but without red spots; five or more large, black spots on the operculum; sides of the body in breeding males with several suffuse reddish patches; 70 red on the throat near the inner edge of the lower jaw; dorsal, ventral and anal fins not tipped with white or yellowish; young with 11 or more parr marks; breeding males with the lower jaw hooked; flesh salmon red; tail without black spots. S. sebago Girard, “‘ Landlocked or Sebago Salmon” aa. Pyloric coeca go to 60, usually about 45; vomer strongly toothed; 120 or more cross-rows of scales; parr marks of the young usually less than 11; tail with black spots. b. Sides without red spots, although red clouds or a lateral red band may be present. c. About 125 cross-rows of scales; general color dusky or greenish; sides of the body in the lateral line region with a broad orange or red band, which is sometimes reduced to a series of reddish clouds; body, head and fins with numerous, small, rather uniform, black spots, which are especially close together dorsally and on the caudal and dorsal fins; usually no red on the throat near the inner edge of the lower jaw; ventral, anal and dorsal jins tipped with white or yellow; dorsal fin dusky, pectoral, ventral and anal fins more or less yellowish or even orange; sides of the body below the lateral line often with a bluish or lilac iridescence; scales of adults somewhat brassy. S. irideus shasta (Jordan), “Rainbow Trout”’ cc. 150 to 200 cross-rows of scales; dorsal, ventral and anal fins not tipped with white or yellowish. d. No red on throat near the inner margin of the lower jaw; about 150 cross-rows of scales; general color silvery, bluish dorsally and quite blue on the top of the head and in the mid-dorsal region; body above the lateral line, top of the head, dorsal and caudal fins rather closely spotted with black; ventral and anal fins dusky. S. rivularis Ayres, ‘Steelhead Trout’’ dd. A bright red mark on each side of the throat along the inner edge of the lower jaw, this mark often somewhat concealed by the edge of the dentary bone but usually rather prominent; scales small, usually 160 or more cross-series. e. Pectoral, ventral and anal fins red, reddish or pale, but not bright yellow; region along the lateral line more or less reddish, often bright red. 1 Fishes (‘‘Amer. Nature Series’’), p. 319, 1907, New York. FISHES OF COLORADO 79 f. Spots numerous, many below the lateral line; a pink or red lateral band usually present; in some specimens the head and region in front of the dorsal fin may be quite free from spots. . g. Scales rather prominent, about 160 cross-rows; general color light, often silvery, darker dorsally; sides iridescent, with a light pink band which may be quite red and prominent or almost wanting; spots more abundant back of the dorsal fin than in front of it . . S.clarkii spilurus (Cope), ‘‘Rio Grande Trout” gg. Scales smaller than the preceding form, about 185 cross-rows; general color greenish to dusky; a distinct, red, lateral band; black spots usually rather large and quite numerous over the entire body, both in front of and posterior to the dorsal fin; lower fins bright red; some individuals with the fins and lateral band orange-red; many specimens with a brassy luster. S. clarkit pleuriticus (Cope), ‘‘Colorado River Trout” ff. Spots large and not numerous except on the caudal peduncle, few if any below the lateral line and in the region in front of the dorsal fin; general color green, quite dark to almost black dorsally; lateral red band wanting or represented by but a few red clouds; pectoral, ventral and anal fins reddish, in breeding males bright red; red on the throat quite prominent; flesh usually red or pink; about 180 cross- rows of scales. . F . SS. clarkii stomias (Cope), “‘Green-backed Trout”’ ee. Pectoral, ventral and anal fins bright yellow; a broad, yellowish area along the lateral line; no red on the head, fins or body excepting the red mark on each side of the throat near the inner margin of the lower jaw; black spots small, almost confined to the posterior half of the body above the lateral line. S. clarkii macdonaldi (Jordan and Evermann), “‘ Yellow-finned Trout of Twin Lakes” bb." Sides of the body with red spots, which are more or less ocellated with white; tail without black spots. h. Adipose fin edged with orange-yellow; general color brownish; red spots numerous; black spots large and margined with light gray or white; sides of the body somewhat silvery. S. fario Linnaeus, “‘ Brown or Von Behr Trout” hh. Adipose fin very slightly if at all edged with orange yellow; red spots few or rarely entirely wanting; black spots few; general color brownish, sides quite silvery. S. fario levenensis (Walker), ‘‘Loch Leven Trout”’ Salmo sebago Girard LANDLOCKED SALMON, SEBAGO SALMON Salmo sebago Girard, Proc. Acad. Nat. Sci. Phila., p. 380, 1853 (Sebago Lake, Maine); Jupay, Bull. U.S. Fish Com., Vol. XXVI, p. 162, 1906 (Twin Lakes). Salmo salar sebago (Girard)—Jorpan, Bull. U.S. Fish Com., Vol. IX, p. 16, 1889 (Twin Lakes). The Landlocked Salmon is a native of the lakes of northern Maine, Lake Sebago, and other lakes, although it is derived, by becoming permanently land- locked, from the Atlantic Salmon, Salmo salar Linnaeus, of the eastern coast. The differences between the Sebago Salmon and the Atlantic Salmon are so slight that the former is often regarded as but a variety of the latter. The Landlocked or Sebago Salmon was introduced into Twin Lakes about 1885 and other ship- ments of this fish have been planted there subsequently, one of the largest being made in 1902. It has become established in the two lakes but is not very abun- dant. Juday* states that “one was caught weighing 6 and another 43 pounds” in t Bull. U.S. Fish Com., Vol. XXVI, p. 162, 1906. 80 UNIVERSITY OF COLORADO STUDIES Twin Lakes, and during his investigations at these lakes during the summers of 1902 and 1903 he took 24 specimens of the Landlocked Salmon, the largest of which was 23.5 inches in length. In Maine this fish reaches a weight of over 20 pounds. It is valued as a game fish, although less interesting to the sports- man than some of the other Salmonids. The flesh of the Landlocked Salmon is red, of a firm consistency and a very acceptable flavor. Salmo sebago lives in deep water which it leaves in the fall when it runs in small streams to spawn. Its food consists of small fishes, insect larvae and other aquatic invertebrates. Salmo irideus Gibbons Ratnsow Trout, Coast RANGE TROUT Salmo irideus Gibbons, Proc. Cal. Acad. Nat. Sci., p. 36, 1855 (San Leandro Creek, Alameda County, California). The Rainbow Trout and its varieties are natives of the Pacific Coast region, ranging from southern California north into Alaska. The Rainbow Trout which has been so generally introduced into the streams of the Rocky Mountains is a variety of the true Rainbow Trout. This variety, S. irideus shasta (Jordan), is a native of the streams of the Sierra Nevada Mountains in the vicinity of Mount Shasta. Since this trout is quite abundant in the McCloud River and has been distributed from that stream by the United States Fish Commission it has come to be known as the McCloud River Rainbow Trout as distinguished from the true Rainbow Trout. Salmo irideus shasta (Jordan) McC toup RIveER Ratnsow Trovt, Locatty “ RAInBow Trout” (Figs. 37 and 38) Salmo gairdneri shasta Jordan, Thirteenth Bien. Rept. Fish Com. of California, p. 142, 1894 (McCloud River at Baird, California). Salmo irideus shasta (Jordan)—Jupay, Bull. U.S. Fish Com., Vol. XXVI, p. 162, 1906 (Twin Lakes). Salmo irideus Gibbons—Jorpan, Bull. U.S. Fish Com., Vol. TX, pp. 6 and 16, 1889 (Twin Lakes). The McCloud River Rainbow Trout differs from the true Rainbow Trout in having slightly smaller scales, in the more frequent presence of a red coloration on the throat and in not running into salt water. It also reaches a larger size. The excellent game qualities and general hardiness of the Rainbow Trout have given them widespread popularity and have led to their successful introduction in many parts of the country. From the standpoint of the sportsman the true Rainbow is perhaps the most interesting of the trout, and the McCloud River variety is but little less of a fighter. It has been stated by several writerst that Rainbow Trout take fewer small fishes and correspondingly more insect larvae, t JORDAN AND EVERMANN, Amer. Food and Game Fishes, p. 198, 1902, New York; Chambers Journ. Nat. Fish Cult. Assoc. England, Vol. I, 1889. FISHES OF COLORADO 81 small worms and crustaceans than other trout. Juday,! however, in the examina- tion of the stomach contents of 106 specimens of this species taken at Twin Lakes found young suckers to form a very considerable item in the food taken. The Rainbow Trout in Colorado spawns in the late spring and early summer, from May to July, depending upon the altitude; the higher the station the later the spawning time. The young fish are quite active and grow very rapidly. Jordan and Evermann? give the following data regarding the relation of size to age under favorable conditions, for this fish: EUVCAT a trast a cies Soeche ei oraycethete e Grd AA snr fe RSI 34 to I ounce DEV CALS ter Artois eather ere ele eee 8 to 10 ounces BEY CALSIIN: wa Nee sire ATE Loretoe Siok erst aha 1 to 2 pounds MARVCAT SS fie Ais icns lores ciavoreyouatoys oraueucteaereiciet, s 2to 3 pounds They add that this species continues to grow until it is eight to ten years old, the rate of growth decreasing with the age of the fish. Many large individuals have been taken in Colorado since the introduction of this species. In the Museum of the University of Colorado there is a specimen of the McCloud River Rainbow 223 inches in length which was caught in Stapp’s Lake, Boulder County, August 22, 1912, by President James H. Baker. Several records of “‘Rainbows” caught recently, weighing over 5 pounds, have been received. In favorable conditions, particularly in warmer water than that of the mountain streams of Colorado, this species reaches the weight of ro pounds or more. Salmo rivularis Ayres STEELHEAD TROUT, ‘SALMON TROUT” Salmo rivularis Ayres, Proc. Cal. Acad. Nat. Sci., p. 43, 1855 (Martinez, California). This is the Salmo gairdneri of many writers. The Steelhead Trout is a large migratory species native in the Pacific Coast region, ranging north into Alaska. Along the coast it spends a considerable part of its life in the ocean and runs upstream to the headwaters of the Columbia, Snake and other coastwise rivers to spawn. The sea-going individuals become quite large, reaching a weight of 20 pounds or more, but those permanently landlocked do not grow so large. Wherever found this trout is a voracious species. Several plantings of Steelheads have been made in Colorado, by both federal and state fish commissions, 14,000 being placed in St. Vrain Creek near Lyons in 1902. No reports of recent catches of this species have been received. Salmo clarkii Richardson CoLuMBIA RIvER TROUT Salmo clarkit Richardson, Fauna Boreal. Amer., Vol. III, p. 225, 1836 (Cathlapootl River). This species and its subspecies are known collectively as the Cutthroat Trout because of the red mark on each side of the throat near the inner margin of the t Jupay, Bull. U.S. Fish Com., Vol. XXVI, p. 166, 1906. 2 Amer. Food and Game Fishes, p. 199, 1992, New York. 82 UNIVERSITY OF COLORADO STUDIES lower jaw. Four of these forms are found in Colorado as Native Trout. They were originally restricted to particular drainages until transported by man, but are now scattered over the state regardless of drainage boundaries. These Native Trout spawn in the early spring. Salmo clarkii spilurus (Cope) Rio GRANDE TROUT Salmo spilurus Cope, Hayden Geological Survey of Montana for 1871, p. 470, 1872 (Sangre de Cristo Pass). Salmo mykiss spilurus (Cope)—Jorpan, Bull. U.S. Fish Com., Vol. TX, p. 14, 1889 (Rio Grande). This species is native only in the Rio Grande drainage. In general coloration it is the lightest of the native species, although individuals vary greatly. Some specimens of this form taken from the Rio Grande at Creede in 1912 were quite silvery and had very small black spots; the lateral band was of a pale rose-red color. An individual caught in Boulder Creek where it has been introduced was, on the other hand, quite dusky. The Rio Grande Trout reaches a length of over 26 inches. Salmo clarkii pleuriticus (Cope) CoLorADO RIVER TROUT Salmo pleuriticus Cope, Hayden Geological Survey of Montana for 1871, p. 471, 1872 (head- waters of Green River in Wyoming); Cope AND YARROW, Wheeler Survey, Vol. V, p. 693, 1875 (Ft. Garland, Rio Grande; Pagosa). Salmo mykiss pleuriticus (Cope)—JorpDAN, Bull. U.S. Fish Com., Vol. TX, pp. 14, 28, 1889 (Trappers Lake; Eagle River; Canyon Creek; Sweetwater Lakes; Gunnison River; Rio Florida); JORDAN AND EveRMANN, Bull. 47, U.S. Nat. Mus., p. 496, 1896 (Eagle and Gunnison rivers). The Colorado River Trout is a native of the headwaters of the Colorado River, being quite abundant in Grand Lake, Trappers Lake, and the upper Grand River. Average specimens are quite dark with numerous rather large black spots which are rather uniformly distributed over the body. The red lateral band is usually very prominent in this form. Size moderately large, reaching a weight of 3 pounds or more. This trout and the Rio Grande trout have been considered almost if not quite identical by some writers. Salmo clarkii stomias (Cope) GREEN-BACKED TROUT Salmo stomias Cope, Hayden Geological Survey of Wyoming for 1870, p. 433, 1871 (South Platte River); Jupay, Bull. U.S. Fish Com., Vol. XXVI, p. 162, 1906 (Twin Lakes); CocKERELL, Univ. Colo. Studies, Vol. X, p. 174, 1908 (Boulder Creek, Boulder). Salmo mykiss stomias (Cope)—Jorpan, Bull. U.S. Fish Com., Vol. IX, p. 8, 1889 (Bear Creek above Morrison). The Green-backed Trout is the native trout of the Arkansas and Platte drainages. It is a small species, average individuals rarely exceeding a pound in FISHES OF COLORADO 83 weight. Specimens caught in Boulder Creek which weighed almost a pound have been examined. This species spawns in early spring and according to Jordan‘ prefers the water from melting snow to that of springs when running to spawn. Salmo clarkii macdonaldi (Jordan and Evermann) YELLOW-FINNED TROUT OF TWIN LAKES Salmo mykiss macdonaldi Jordan and Evermann, Proc. U.S. Nat. Mus. for 1889, p. 453, 1890 (Twin Lakes); Jorpan, Bull. U.S. Fish Com., Vol. IX, p. 11, 1889 (Twin Lakes). Salmo macdonaldi (Jordan and Evermann)—Jupay, Bull. U.S. Fish Com., Vol. XXVI, Pp. 162, 1906 (no specimens). This trout is a large form known only from Twin Lakes, where it inhabits the deep water, running into the adjoining streams to spawn in the early spring when the water begins to rise from the melting snows. The largest specimen of this form recorded weighed 8 pounds 113 ounces. Although it was reported abundant in 1889 it is apparently very rare in these lakes at present. No specimens were obtained by Juday during the summers of 1902 and 1903 and Mr. Irwin Simonson, who made inquiry of several persons who fish regularly in Twin Lakes, reports that no Yellow-finned Trout have been caught for several years. Salmo fario Linnaeus Brown Trout, VON BEHR TROUT The Brown Trout or Von Behr Trout is the trout of England concerning which much has been written both by anglers and by others. It has been intro- duced into many parts of the United States. Plantings of this species and its variety, the Loch Leven Trout, were made in Colorado in 1894 and 1go1 by the United States Fish Commission.? This trout is easily distinguished from the other species of the genus Sa/mo found in Colorado by the bright red spots which are more or less ocellated with white or pale pink, together with the bright orange tip of the adipose fin and the general brown color. The red spots might cause this species to be mistaken for the Eastern Brook Trout, Salvelinus fontinalis, which may be recognized by the broad white edging of the anterior margins of the pectoral, ventral and anal fins. No specimens of this trout collected in Colorado have been examined in the present study, although it has been reported to the writer from the Gunnison River. Salmo fario levenensis (Walker) LocH LEVEN TROUT This variety of the preceding species is a native of Loch Leven, Scotland. It was introduced into Colorado in 1894. This fish differs from the Brown Trout in having fewer spots, the red spots being entirely absent in some specimens, and tBull. U.S. Fish Com., Vol. TX, p. 13, 1889. 2See Repts. U.S. Fish Com. for 1894-95 and 1go1-02. 84 UNIVERSITY OF COLORADO STUDIES in the loss of the orange tip to the adipose fin. It has been noted? that the Loch Leven Trout when introduced into the streams of Yosemite Park reverted to the typical Brown Trout with bright-red spots and orange-tipped adipose. It is entirely possible that such a change may have taken place in the Loch Leven Trout planted in this state so that any caught will probably be the true Brown Trout as regards,markings. No specimens of this trout taken in Colorado have been examined by the writer. Genus SALVELINUS Richardson The Charrs Salvelinus Richardson, Fauna Boreal. Amer., Vol. III, p. 160, 1836. Species of this genus in general appearance are much like those of the genus Salmo, from which they may be separated by the boat-shaped vomer, the smaller scales, of which there are 200 or more cross-rows, by the round, bright-red or crimson spots on the sides of the body, and the white or orange edgings to the anterior margins of the pectoral, ventral and anal fins. Pyloric coeca 35 to 50. Species of this genus are known from both the Old and the New World, inhabit- ing cold and rapid waters of small streams. Salvelinus is represented in Colorado by the Eastern Brook Trout, an introduced species. Salvelinus fontinalis (Mitchill) EASTERN Brook Trout, SPECKLED Trout (Figs. 39, 40, 41, 42 and 43) Salmo fontinalis Mitchill, Trans. Litt. Phil. Soc. N.Y., Vol. I, p. 435, 1815 (near New York City). ain: fontinalis (Mitchill)—Jorpan, Bull. U.S. Fish Com., Vol. IX, p. 16, 1889 (reported as introduced into Twin Lakes); Jupay, Bull. U.S. Fish Com., Vol. X XVI, p. 162, 1906 (Twin Lakes); CocKERELL, Univ. Colo. Studies, Vol. V, p. 175, 1908 (Allen’s Park, Boulder County). Head 4 to 4.5, depth about 4.4 in the length; dorsal rays 10 or 11, anal rays 9. General color dusky to dark green, sides lighter, shading to pale yellow or reddish below; top of the head quite dark; body above the lateral line dark, mottled and marbled with dark olive-green but without spots except near the lateral line; two or more irregular rows of black and crimson spots, the latter being smaller than the pupil of the eye, in the lateral line region; ventral parts lighter, varying from pale yellow, to bright orange-red in breeding males; pectoral, ventral and anal fins with a rather broad, yellowish or orange area along their anterior margins, this area edged posteriorly with black or dusky; lower margin of the caudal fin marked in much the same manner; dorsal fin dusky, quite dark at the base, crossed by several irregular and broken bars of black or dusky; parr marks in the young quite distinct, often persisting as faint dusky, vertical bands on fair- sized individuals; size small to moderately large, average specimens usually 12 inches or less; in Maine specimens have been taken weighing 6 pounds or more. t JORDAN, Science, N.S., Vol. XXII, p. 714, 1905. FISHES OF COLORADO 85 This trout is one of the most handsome of the fresh-water fishes, and its brilliant coloration, the rugged situations from which it is usually taken and the splendid sport it offers have combined to make it one of the most prized game fishes. It is quite hardy, an additional factor contributing to its wide introduc- tion throughout the Rocky Mountain region. The Eastern Brook Trout is a native of northeast United States and southern Canada east of the Mississippi River, ranging south along the Appalachian Mountains into northern Georgia, yet so completely is it established in the streams of the Rocky Mountains, it seems part of the native fauna of Colorado. Salvelinus fontinalis in Colorado spawns from late October to early December, the eggs for the fish hatcheries being collected in November. The eggs are deposited on the gravel bottom of small, shallow streams and do not hatch until the water begins to get warm in the spring. Genus CRISTIVOMER Gill and Jordan The Great Lakes Trout Cristivomer Gill and Jordan, in JorDAN, Manual of Vertebrates Eastern U.S., ed. I, p. 356, 1878. The species of this genus differ from those of the genus Salvelinus in the type of vomer; this bone in Cristivomer has a raised crest. The species of Cristivomer are also more elongate and are without red spots, the sides of the body being much mottled and blotched with gray or rarely pinkish gray. This genus is represented in Colorado by the single introduced species, the Mackinaw Trout. Cristivomer namaycush (Walbaum) GREAT LAKES Trout, MACKINAW TROUT ““Namaycush Salmon’’—PENNANT, Arctic Zoology, Introd., p. 191, 1792 (Hudson Bay). Salmo namaycush Walbaum, Artedi Piscium, p. 68, 1792 (Hudson Bay). Cristivomer namaycush (Walbaum)—Jupay, Bull. U.S. Fish Com., Vol. XXVI, p. 162, 1906 (Twin Lakes). Body distinctly elongate; head long, 4 to 4.5, depth 4 or a little less in the length; caudal peduncle rather narrow, its least depth about 3 in the head; dorsal rays 11, anal rays 11. General color dusky or dark gray, lighter ventrally; head and mid-dorsal region quite dark; sides, dorsal and caudal fins much mottled with irregularly rounded, pale-gray or rarely pinkish-gray spots; the largest of the trout reaching a weight of over 100 pounds. The Mackinaw Trout is a native of the Great Lakes and of the larger lakes in northeastern United States and Canada, ranging from Maine into Alaska. Its odd specific name “‘ Namaycush”’ is that by which it is known among the Canadian Indians, who prize it as a food fish. In the Great Lakes this trout lives in the deep water, spawning in the late fall on the shoals and reefs. The food of this 86 UNIVERSITY OF COLORADO STUDIES fish, as given by the several writers who have studied it, consists of almost any- thing which comes the way of the fish. It has a voracious appetite and feeds to a considerable extent on small fishes. Cristivomer namaycush was introduced into Twin Lakes about twenty years ago with success, some very large specimens having been taken from those lakes in the past few years. Juday*' states that a number of individuals weighing from 15 to 20 pounds were caught during the summer of 1903, the fishermen using large hooks baited with pieces of suckers. Mr. Irwin Simonson secured for the writer the weight and measurements of a large specimen of this species caught in Twin Lakes on June 1, 1907, by Mr. W. W. Fay of Buena Vista. This fish weighed 201 pounds and was 393 inches in length; the head measured 83 inches in length, greatest circumference 213 inches, tail when spread 103 inches. A live minnow was used for bait. The Mackinaw Trout has been reported by several fishermen as the most abundant large fish now in Twin Lakes and it has been suggested that the increase of this fish is correlated with the decrease of the Yellow-finned Trout. Order HAPLOMI The Pike-like Fishes, including the Mud Minnows, the Pickerel, the Killifishes and the Cave Blindfishes Family POECILIIDAE The Killifishes and Top-minnows Body somewhat elongate, more or less terete in the anterior half, distinctly compressed posteriorly; top of the head usually flattened; mouth terminal and broad, lower jaw projecting in many species; scales large, cycloid; lateral line wanting or represented by but a few pores; sexual dimorphism pronounced in most species, many being ovoviviparous; size small; colors of tropical species brilliant and varied. The Poeciliidae are small fishes of the fresh waters of Europe, Asia, Africa and the Americas. A few species are marine and many are quite abundant in the brackish water of salt-marshes. Because of their small size and ability to live in warm and rather impure water they are often very numerous in small streams and ditches. One species, Acanthophacelus reticulatus (Peters) and several closely related forms, known collectively as ‘‘Barbadoes Millions,”’ have become of con- siderable economic importance recently as destroyers of mosquitos in the West Indies and South America. These little fishes are able to live in the shallow trenches of the sugar plantations and even the ditches in the streets of the small towns, feeding upon the mosquito larvae. The “Millions” have proven very effective enemies of the young mosquitos, contributing in this way to the control .U . Fish Com., Vol. XXVI p. 162, 1906. FISHES OF COLORADO 87 of malarial fever.t Several North American Poeciliids feed upon the young of mosquitos as well as other insects and are of value in reducing the numbers of these pests. A single genus, Fundulus, is represented in Colorado. Subfamily FUNDULINAE Genus FUNDULUS Lacépéde The Killifishes and Top-minnows Fundulus Lacépéde, Hist. Nat. Poiss., Vol. V, p. 37, 1803. Anal fin of the male not modified to function as an intromittent organ; species Oviparous; jaws with two or more rows of fine teeth; lower jaw projecting beyond the upper; caudal fin rounded. This genus includes a great variety of species, some of which are marine. It has been broken up by various ichthyologists into numerous genera and sub- genera, but the characters of the several groups of species intergrade to such an extent that these separations are possible only with the extreme species. Two species of this genus, referable to different subgenera, are known from Colorado, these being very abundant in the plains streams of the eastern part of the state. a. Dorsal fin of 14 or 15 rays; base of the first ray of the dorsal on or in front of the level of the first ray of the anal fin; body crossed by 11 to 21 vertical dusky bars. F. (Fontinus) zebrinus Jordan and Gilbert aa. Dorsal fin of 10 or 11 rays; base of the first ray of the dorsal behind the level of the first ray of the anal; color plain, olivaceous, fins edged with red . F. (Zygonectes) floripinnis (Cope) Fundulus zebrinus Jordan and Gilbert ZEBRA FIsH, ZEBRA TOP-MINNOW (Figs. 44, 45 and 46) Fundulus zebrinus Jordan and Gilbert, “Synopsis,” Bull. U.S. Nat. Mus. No. 16, p. 891, 1883: (after Girard, Hydrargyra zebra Girard, Proc. Acad. Nat. Sci. Phila., p. 60, 1859, name preoccupied in Fundulus); JorDAN, Bull. U.S. Fish Com., Vol. 1X, p. 17, 1889 (pond at Canyon City; Fountain Creek at Pueblo); Jupay, Univ. Colo. Studies, Vol. I, p. 113, 1903 (Boulder; Longmont); Jupay, Bull. U.S. Fish Com. for 1904, p. 227, 1905 (Boulder; Longmont). Fundulus multifasciatus (Cuvier)—Core aND Yarrow, Wheeler Survey, Vol. V, p. 695, 1875 (Pueblo), name preoccupied in Fundulus. Body rather short and deep, much compressed back of the pectorals, depth 4.4 to almost 5 in the length to the base of the caudal; head long and depressed, 3.3 to 3.8 in the length of the body; top of the head with the skin thickened into plate-like structures; snout blunt; eye prominent, its dorsal margin even with the top of the head, its diameter 2 or a little more in the interorbital distance, about 2.5 in the length of the snout and 5.5 to 6 or a little more in the head; interorbital distance 2.5 to 3 in the head; nostrils small, dorsal, placed in front of the dorsal margin of the eye; mouth terminal and somewhat dorsal, large and broad; upper t Battou, Pamphlet Ser. 55, Imperial Dept. Agric. West Indies, 1908. 88 UNIVERSITY OF COLORADO STUDIES jaw short and included by the projecting lower jaw; angle of the mouth about equidistant from the tip of the lower jaw and the anterior margin of the eye; pre- maxillaries protractile; dorsal fin longer than high, inserted in the posterior half of the body, slightly in front of the origin of the anal fin, the distance from the base of the first ray of the dorsal to the base of the caudal reaching forward to the posterior margin of the eye; dorsal rays 14 or 15, occasionally 16; pectorals not reaching (females) or barely reaching (males) the ventrals; ventrals barely reaching the anal fin; scales small, circular, circuli large and few, basal radii 8 to 12, apical radii none; lateral line wanting or represented by an occasional pore only; scales 58 to 64 along the middle of the side, in 18-21 rows between the dorsal and ventral fins; length under 6 inches. General color above greenish, shading from dark olive green to silvery white below; sides yellowish to bright orange-yellow; a dark mid-dorsal spot just in front of the dorsal fin; sides crossed by 11 to 21, usually 14 or 15, dusky vertical bars which are generally narrower than the light interspaces, and in many indi- viduals, particularly females, each alternate bar is lighter and narrower than two adjacent to it; under parts of the head yellowish white; dorsal and caudal fins more or less dusky; pectoral and ventral fins yellowish white; anal fin yellowish to orange-yellow. The variation in the number of lateral bars is shown by the following table, which includes the data from 111 specimens collected at one station on the South Platte River at Julesburg, July 19, 1912: Barsiecn SUI Eon rename aiareere OSB Shook AP QE ey, ANE Aue etetere sensi: Site aga pa Leiner ar tec x Gain Recs o.syetacs Are rains le’ | cles hcl chensyavexerereteae x DK ae Mae, acebee esto gs ert iete GOA: eh oats. 4.0 Sr icy sta oeoeceas heel aveneakoran yore Meyers x IB Onaicaeesvepherstce A OvgAe awa licts conecar ste tees eyehe x DRG Wy SPN ONG ic oetoreeye IBIS We Wyeie aay eseers ACM nil [hetessietars; sie saeesvehshs x > Ge Reh A eRe ao Oia 4 4 5 3 BouLpDER CREEK, BOULDER, OCTOBER, 1903 OOM tates APC eme git Ue cr tow sic remem sts Da. i Mere atet. eetetetene xe IS Sienahoronts iskere oi Bo Ge oo he Wicdwais ecaiaserslte Biets x Me Lt Hibs ooisense Ss tare. GE Ay poe evere aliece a 4.25 DDT Ha Ra ssaet ar anchereteud opens DE) os Taal ieesncecn a ecorangl Sees Oe orereicarse 4.2 FF aihey ote ats Sree euat shots Me Wikeke ee lemating AO isesieis teks favs AE ail Uple er ye lene ction eke x CEE TIED, FN. meta Ueneg ete in ce Bo arin pee yas 355 Kid eB ea crsneyen tava cuete DR ge Wl ae ns caaiee tetel s 3 3 5 I BouLpDER CREEK, BOULDER, JULY 25, 1912 IS OEE NOES 4.2 SE eer Ae a Re DR oP OMAN POE cae stens chsgere SSP Pisrctoxnreitiete 4.25 DC a IPS ct Brarcaeiecevatate cans Te HS a steierens be oka SS es sied conetet aes 4.25 DOE Tey By id eee acres tyenckar call esta she Stee tobeten cas x Ge eke crntctoete 4.25 SAE RS I eantcseetr ac ac ocReR AS tes RS it Mh, I iacetckelacerefencte enetars Cy arrears 4.5 SE, rua Us muestra water | eiaem uses ota lecotep ce x 5 ° 3 2 West PLum CEEEK NEAR CASTLE ROCK, JUNE 8, 1912 POR se his as ROW Gr ig lero earch hon Stoke x Dr OS Ao | Meare a Ne Ee GOR e ec eras 4-75 Dee RIE abet reload ele tas Da tok a [eon eae eee ie ee (Yoyo aoria Saeeeo 5.0 eer ad ail evento ynt ote lets S68 Pa broertcee aoe ei Greet veksteyersians 4.5 DOVE) Bl tkpertatercsersty eco, ee De TAL lactate arcesenrtctes BS ee Reece aiske TEATS eh iad Was Sa cP A Se x ieee ota (CRTC Fe SUS rae BO se tose eyo 4.0 > GAT nt | sic Cantey Ue RSE) prion ober cd Crean x 4 2 5 I Total, 25 specimens 16 fe) 18 7 II2 UNIVERSITY OF COLORADO STUDIES Considering the data, it seems proper to refer the Colorado specimens to the subspecies Boleosoma nigrum mesaeum (Cope). Boleosoma nigrum mesaeum (Cope) (Fig. 51) Poecilichthys mesaeus Cope, Proc. Acad. Nat. Sci. Phila., p. 232, 1864 (Platte River near Fort Kearney, Nebraska). Boleosoma nigrum mesaeum (Cope)—JORDAN AND EVERMANN, Bull. 47, U.S. Nat: Mus., p. 1059) 1896. Body elongate, not much compressed; depth 4.6 to 6 in the length to the base of the caudal; head rather large and broad; top of the head somewhat flattened, width of the head 1.5 to almost 2 in the length of the head, which is 3.8 to 4.25 in the length of the body; eye large, situated above the middle of the side of the head, center of the eye nearer to the tip of the snout than to the posterior margin of the operculum by almost the length of the snout; dorsal margin of the eye higher than the flattened top of the head; diameter of the eye greater than the interorbital distance, barely equal to or usually less than the length of the snout, 3.5 to 5, usually 4.25 to 4.5 (see Table VII), in the length of the head; snout short and blunt; mouth terminal, slightly oblique, lips rather fleshy, lower included by the upper; angle of the mouth barely if at all reaching the level of the anterior margin of the eye; premaxillaries protractile; operculum with a heavy spine, directed caudally on a level with the lateral line;t base of the spinous dorsal shorter than that of the soft dorsal, soft dorsal scarcely separated from the spinous dorsal, base of the first ray of the soft dorsal inserted slightly behind the level of the ventrals, spines VIII or IX, rays 12 or 13; pectorals large; ventrals small, of I spine and 5 rays; anal small, of I spine and 8 or 9g rays, base of the spine behind the level of the first ray of the soft dorsal; caudal large, fan-shaped, not forked; scales rather small, closely imbricated, strongly ctenoid, with about 16 basal radii, 4 Or 5, 42-54, 7 tog; cheeks scaled or naked. Color above greenish brown to dusky; mid-dorsal region with 4 or 5 saddle- shaped bands of dark brown which extend down each side for two or three rows of scales; lateral line crossed by 10 or more irregular black marks which often resemble the letters W, M or N; below this row of marks another of smaller blotches usually present, these alternating with those crossing the lateral line; most of the scales above the lateral line and many below it outlined with dusky, giving the entire fish more or less of a reticulate pattern; ventral parts yellowish or pinkish white, somewhat sprinkled with dusky; top of the head dark; a rather conspicuous dusky bar extending from the tip of the snout to the anterior margin of the eye and a less prominent bar below the middle of the ventral margin of the eye; opercular region dusky, usually with a dusky spot; rays of the soft dorsal, caudal, and to some extent the ventrals, crossed by rows of dusky spots which give * One indvidual, 65 mm., Boulder Creek 6 miles east of Boulder, July 25, 1912, had a normal spine on the left operculum, while that on the right operculum was directed ventrally at an angle of about sixty degrees from the normal position. FISHES OF COLORADO 113 the fins a barred appearance, 5 to 7 rows on the soft dorsal and 7 to 9 rows on the caudal; ventrals and anal but faintly marked. Males in breeding season with the fins and head dark to almost black. This interesting little fish is one of the best known of the darters. Like the other species of this subfamily, it feeds and is generally found on the bottom of the stream. Here it moves rapidly about among the small stones, often using the pectoral and ventral fins as supports by resting them on the bottom. When disturbed it darts away or it may almost bury itself in fine sand which it stirs up with the caudal fin. Although generally occurring in shallow, rapid streams or in lakes, it was found to be rather abundant in a deep broad pool with a silt bottom, back of a beaver dam on West Plum Creek. Colorado specimens.—University Museum: St. Vrain Creek, Longmont, October 17, 1903 (9 specimens, 40-70 mm.), C. Juday and D. W. Spangler, No. 39; Boulder Creek, Boulder, October, 1903 (59 specimens, 20-60 mm.), C. Juday and J. Henderson, No. 35; Boulder Creek 6 miles east of Boulder, July 25, 1912 (7 specimens, 55-60 mm.), M. M. Ellis, No. 408; West Plum Creek near Castle Rock, June 8, 1912 (13 specimens, 40-60 mm.), A. G. Vestal and M. M. Ellis, No. 400; State Teachers’ College Museum: Greeley, A. E. Beardsley. Reported very common at Greeley before the advent of the sugar factories, by A. E. Beardsley. Order LoricaTI The Rockfishes, Sea Robins and Sculpins Scales present or wanting; body often with bony scales or plates; a bony process extending across the cheek from below the eye to the preoperculum. Family COTTIDAE The Sculpins Body rather elongate, more or less fusiform; head large, broad and depressed; scales wanting in most species (some species are irregularly scaled above the lateral line), skin often rough and covered with minute prickles; lateral line present and prominent; third suborbital bone connected with the preoperculum by a bony stay; air bladder usually wanting. The Sculpins are rather small fishes found in both fresh and salt waters, many species living along the rocky coasts. Other forms inhabit rather deep water, as the species of Triglopsis, the Deep-water Sculpins of the Great Lakes. The more common fresh-water sculpins are species of the cold, rapidly moving brooks and mountain streams with rock or gravel bottoms. The food of such sculpins as have been studied shows the Cottidae to be voracious carnivorous forms often quite destructive to the eggs and young of other fishes. Both individuals and species are quite variable, and as Jordan and Evermann! state, “‘almost every species has an individuality of its own, and among the marine forms it is necessary to recognize « Bull. 47, U.S. Nat. Mus., p. 1880, 1898. II4 UNIVERSITY OF COLORADO STUDIES almost as many genera as species.”’ This variability has resulted in the publica- tion of descriptions of several probably synonymous species. A single species of Sculpin occurs in Colorado. Subfamily Corrinar Genus COTTUS (Artedi) Linnaeus The Fresh-Water Sculpins Cottus Artedi, Genera Piscium, p. 40, 1738. Cottus Linnaeus, Systema Naturae, ed. X, p. 264, 1758. Scales wanting; skin rather smooth; prickles when present most abundant near the axils of the pectoral fins; each ventral fin with I short, concealed spine and 4 soft rays. The species of this genus occur in the fresh waters of North America, Asia and Europe. Cottus punctulatus (Gill) Rocky MountTAIN BULLHEAD, SCULPIN (Figs. 53 and 54) Potamocottus punctulatus Gill, Proc. Boston Soc. Nat. Hist., p. 40, 1861 (Bridger’s Pass, Wyoming). Cottopsis semiscaber Cope, Hayden’s Survey of Montana for 1871, p. 476, 1872 (Fort Hall, Idaho). ranidea vheelert Cope, Proc. Amer. Philos. Soc., p. 138, 1847 (Bear River, Utah); Corr anp Yarrow, Wheeler Survey, Vol. V, p. 696, 1875 (Pagosa, Colorado). Cottus bairdi punctulatus (Gill)—Jorpan, Bull. U.S, Fish Com., Vol. IX, p. 20, 1889 (Eagle River; Roaring Fork; Gunnison, Delta; Rio Florida; Leitner’s Creek; Rio de las Animas Perdidas). Cottus semiscaber (Cope)—JORDAN AND EVERMANN, Bull. 47, U.S. Nat. Mus., p. 1949, 1808 (Eagle River, Gypsum). Body elongate, somewhat compressed posterior to the origin of the pectorals; depth about 5 in the length to the base of the caudal; head large, broad and distinctly depressed, its width almost equal to its length, which is 3 to 3.25 in the length to the base of the caudal, depth of the head 2 or a little more in, its breadth; eye large, 5.5 to 6.5 in the head, directed latero-dorsally; nostrils small, widely separated, each borne by a short, elevated tube, the posterior being about half the diameter of the eye in front of the eye and the anterior about the same distance below the posterior, the tube of the posterior longer and more elevated, its posterior margin produced and pointed; snout broad and flat; mouth broad and very large, angle of the mouth reaching the level of the anterior margin of the eye; pre- maxillaries protractile; opercular structure firm and bony, a well-developed, somewhat elevated preopercular bony process; spinous and soft dorsals separate, base of the spinous dorsal 1.75 in the base of the soft dorsal; dorsal spines VIII or IX, 17 or 18; pectorals very large, reaching to or beyond the level of the last dorsal spine, equal to the length of the head, tips of the first nine rays curved upward and exceeding the web of the fin, thus producing a serrate margin; ventrals FISHES OF COLORADO II5 small, the spine bearing a thick pad on its ventral surface; anal long, length of its base exceeding that of the spinous dorsal, of 11 or 13 rays the tips of which exceed the webbing of the fin; caudal peduncle slender, its least depth varying from the diameter of the eye to the length of the snout (the length of the snout equals the diameter of the eye in young specimens); caudal fin broad and fan-shaped, outer margin rounded and not forked; scales wanting, lateral line prominent; skin tough and leathery, varying from quite smooth to rather rough, as the prickles are developed or not. General color bluish or brownish gray, mottled with irregular blotches of dark brown or black; ventral parts white with a bluish or yellowish cast, under parts of the head, the sides, the pectoral fins and the ventral surface posterior to the anal * opening dusky with numerous minute black dots; fins dusky, rays and spines dark, crossed by several series of white bars. Small specimens much lighter than adults, rather uniformly covered dorsally with minute black dots. Because of the variation in the markings, the depth of the caudal peduncle and the development of the prickles in the skin, several nominal species of sculpins have been described from the Rocky Mountain region. These characters inter- grade and extreme types may often be taken in the same collection. Considering the extremes to represent subspecific types, three may be recognized, although intergradations are found. a. Skin smooth. b. Caudal peduncle slender, its depth slightly exceeding the diameter of the eye. Cottus punctulatus punctulatus bb. Caudal peduncle deeper, its depth almost equalling that of the snout. Cottus punctulatus vheelert aa. Skin with prickles, especially in the axils of the pectorals. . Cottus punctulatus semiscaber The Rocky Mountain Bullhead or ‘“‘Blob”’ as it is locally known reaches the length of six inches, although average specimens are usually about three and one- half inches long. In Colorado it is very abundant in the headwaters of the Colorado River drainage, particularly in the Rio Florida and the Rio Las Animas near Durango. It is found, however, on both sides of the range in the small mountain streams. As its name implies, it is a species of the Rocky Mountain region ranging from northern Montana south into New Mexico on both sides of the Continental Divide, and west into the Great Basin in Idaho and Utah. This species is of considerable economic importance because of its feeding habits. It moves about from stone to stone on the bottom of the stream, feeding upon the small fish which take refuge under the stones, caddis-fly larvae and snails. During the spawning season of the trout the Bullhead also consumes quantities of trout eggs. This destruction of young trout and trout eggs is a positive loss to the trout, for the young Bullheads are rarely if at all eaten by the trout, there being no compensating relation between these two fishes like that 116 UNIVERSITY OF COLORADO STUDIES between the trout and the suckers; the suckers eat trout eggs but in turn large numbers of young suckers are eaten by the trout. Colorado specimens.—University Museum: Big Beaver Creek, Rio Blanca County, July 9, 1907 (90 mm.), E. R. Warren and J. W. Frye, No. 410; Lightner’s Creek, Durango, August 10, 1912 (11 specimens, 20-30 mm.), M. M. Ellis, No. 411; Rio Florida, near Durango, August 11, 1912 (8 specimens, 55-140 mm.), J. Henderson and M. M. Ellis, No. 412; Colorado College Museum: Grand River near McCoy, Eagle County, Grand River 12 miles above Glenwood Springs, San Juan River, Pagosa Springs, E. R. Warren; State Teachers’ College Museum: Pueblo and Durango, A. E. Beardsley. TABLE VIII SUMMARY OF SPECIES KNOWN AT PRESENT FROM COLORADO PLATTE-ARKANSAS Rio GRANDE COLORADO TOTAL Family (| Native | Introd. Native | Introd. | Native | Introd. | Native | Introd. Siluridae neces: 2 I Tota ALI ad epee a eae Fees ee I 2 I Catostomidae...... Be eee cates i Gaede VAs Gib ae 3H alll ea, elo PAN ee es Gyprinidaeyac aa. 19 2 2 I 3 2 23 2 Mhymallidae ere -l|tereterrern- Li Ol iatayncsavsan| (heetey syatscey tate tke eer Te WH Avan 2 ye rt I Salmonidae........ 2 9 I 2 2 4 5 7 Poeciliidae........ Beek) Mianc oct tent ie Se das to teed: reg (Pee at OR Ars! a. ea ae 2 os) Re Se Aa a /MaMiliGhyes 4 5 goo0d||Coodoccullascoscas Dine He Neth cesSeatena| wlan Me avel| eis s oieael | eustocenoete Aeon Centrarchidae..... I 6 I Bese alee I I 7 Rercidaeaereeret ier: 3 De Rete taeda Soe lkedalorakeyswusll Greco svousrel letetevete.c foes 3 2 Cottidae?.). cece VAL 3d eet rner ear | RS apace ey Decne wna oH 1 at | | ee ee T, Gotaetco aces Total. sects )< 33 21 5 5 9 9 44 20 DISTRIBUTION OF FISHES IN COLORADO RELATIONS TO RIVER SYSTEMS Within the state the distribution of the fishes of Colorado is best shown by a comparison of the fauna of the four drainages and of the altitudinal zones. Barring the introduction of species by man, natural barriers as mountain ranges and arid areas are quite effective against the migration of fishes, so that in general the more isolated two river systems are the more diverse their fish fauna. Two of the four drainages of Colorado are entirely independent, the Rio Grande and the Colorado River. The Platte and the Arkansas form a third unit independent of the first two. Thus there are three different fish faunas represented, correlated with these three drainage units. As the mountains are approached there are abrupt changes in the nature of the streams and the temperature of their waters, rendering them unsuitable for certain fishes and making possible the presence of others. In this way there is an intra-drainage distribution correlated FISHES OF COLORADO Ey TABLE IX ALTITUDINAL DISTRIBUTION OF COLORADO FISHES Below 5,000 to 7,000 to Above 5,000 Ft. 7,000 Ft. 9,000 Ft. 9,000 Ft. Metaluntishpunccatus mere ret ae oc i) OS rt UU cocectlavsiccsih abel OLA Ae ab esteem oral iatar Lie EULER CHEWS 2 eect eke terete ty eer el cet tar cre tehcie ovarellerckaticietste nisi De AS i eset xterra a Carpiodes velifer...... Pee Boos eb aoe Catostomus commersonii SUCKINE Gnas IPANCOSCEUSYDICDLUSt ier ei eicles oes Giese hake aye heierereve iets A erate delphinusiy.j. serves dee. oes x DNYTAUCHEN | TEXANUS scat sss vy siels ss © SOT a epsnate ec aeoceiks [lseaperse ats eaten eo on eae Cy prnusicarnpiows ce eee ee ee ee ee x Warassiussaliratusene she ates ieilee een x Campostoma anomalum.............. x< x x x x Chrosomus erythrogaster dakotensis. . . . iPimephales)promelase $14 eck) es 2 Hybognathus nuchalis.-[s tes ec cele Phenacobiusimirabilisee ss > ace fester iRichardsoniusspiuicnellusteey erties as lice ce neal icine era x EVeErmMannissiys ceiscn ecole mee ccisicion x INOELOPIS Cay US ain i sete sch ciara scl | [eg wea eat ge Th x x x Diptolepisnweas ces cake ce sets BCy ae ee etre sac sane estes COFNULUSSPeiee rie © rete ie eke x CUNLVEVSICALISHE, yo Alea e note tees roscoe tera x LULTENISIS payee aac occ x x Rtychocheilusiluciise sist eee eee x x x x x x x Gilairobustae mes ces tio tee Saino Semotilus atromaculatus.............. Couesiusidissimilish “petits ose cress eral eieinsrato teeters Hy bopsisitetranemus.,;.55.2.....00:0- x entuckiensisis. fice scj.cs es ac x Platygobio physignathus.............. x x x Rhinichthys cataractae dulcis.......... Agosia yarrowi..... Egevor sipour eck ou Plavopterus areentissimuUses paces osc cccle cecil cee ats ~~ wXXKX xX shymallussmontanuseer eatececi cia irl M Ne LOT cI Nir cE il ince elt cate GCoregontusiwilliamsonitoemecoac cries cele cere coe ae SalmOise bacon sty Vereen ete eee amine oe eee aridensishasta sot . heen corres x< x ELV AULATIS eva SAE Le ay hate ker iareee otal x Clarktispiluruspecei een serncneralone ein: x x x x DICUTILICUSE cH <2 dercain aroilltes caine ats SEOMIAS HE ese nia sire ces thieve x x< NEVENENSIS EA tay tye as lente eee eee x Salvelinusitontinalise 4. eee asics occa x x 118 UNIVERSITY OF COLORADO STUDIES TABLE [X—Continued Below 5,000 to 7,000 to Above Name 5,000 Ft 7,000 Ft. 9,000 Ft. 9,000 Ft. Pomoxis/sparoides sneer secs x > GRIN Lees pa Nae) Me A edi Pa nN gE Ambloplites'supestris.():)4). 020.0. 0.-0 4). DEAN] WSR eR POL SUPSPuETIN TRAILER OI SU a Ae @haenobryttus!gulosus\) 04). 24.524. DL NN) PAR UN eA Buc ants | RUA UIE ee eae WG Ay ty eI abe (epomis)cyanellus: fe. se scise sists eee x x DRM obi ave Grane at labanen Pallas yA cies weyeteers ensure cused ie emaisuchniesarseessellieielatareieres hates Dei SER Sen ectith ale Micropterus salmoides................ x x DET Natit lard ated Golomiew ised dere ase seers een raeee ore DT SEI? cicda ei Stone tens bevy Ieee mStar Stizostedion vitreume 220) \) sceis cee: SCLIN AVA ESIGN Lae dete angen Pan peat east un aR Ue PeRca Havescensi sian as-6 elo eteeelekeuee x SUS MI ek re AAR SMD oe se FEHEOSEOMA, Crag Mei see cei eiacieiebecerieal |icre ore cuaecetohets/s SCE Vil EERSTE NS Pesaro | RMA Calon ley! JOW ACH ee irate Sone en x > UR OTL lee eee AA Ma esata A ots Boleosoma nigrum mesaeum........... x Devi chaise sigha Se eat ee eae Da Cottusipunctulatusi ee s.ceirme gee x x x x VE OtatOOnen ewes ui ae Bulenie rite r 44 47 24 13 > =Printed or specimen record for a Colorado locality. ? =Probable distribution in Colorado. See discussion of species so marked. with the altitude of the stream. In considering the distribution within the state, native species are of much more importance than introduced forms. The presence of an introduced fish at a given station speaks only of the ability of that fish to survive in a new environment, since the obstacles which have prevented its reaching the particular locality have been removed by man. ‘The native fish, on the other hand, have reached the particular station presumably as a result of their ability both to overcome the obstacles and to endure the present environment. The Rio Grande has fewer native fishes than any of the drainages in Colorado. Five native species are known from the Colorado por- tion of this system at present. One of these, Rhinichthys cataractae dulcis, the Dulcis Minnow, is found on both sides of the Continental Divide and is a fish of wide distribution west of the Mississippi River. No specimens of this Dace have been taken from the Colorado River drainage in Colorado, although it is known from as far west as Cor- vallis, Oregon. Three of the five native species are peculiar to the Rio Grande, occurring only in that system; they are the Rio Grande Trout, Salmo clarkit spilurus, the Rio Grande Sucker, Pantosteus plebius, and the ‘“‘Pescadito,” Richardsonius pulchellus. These fishes are western types and their nearest relatives occur in the Colorado FISHES OF COLORADO I1g TABLE X DISTRIBUTION OF COLORADO FISHES BY DRAINAGES Name Platte Arkansas Rio Grande Colorado Ameiurusmelaswee wiies Smelacriekiae n THE GL A Wilieeaie hacen eae ei i MEDULOSUS rah creer eke cues Doe oe Lek eee a vk HVE SRN Cd LSA EM Ere ae ke Retalurusipunctulatus: 4:gs. occ te ook n TNA yaabva ll pacsistatal cer Vcr eros earreveds ULE CAL LIS Myo e eter edad Hepa cutee ye he tedden caravan ettet [iat shetenevetevevevene re ag PA Cishe Ses cen Garpiodes/velifer sss isjsriee ase cicies cise £ AT ATU N d RSER aie Ree Pe a Een AN et UU 8 tae Catostomus commersonii sucklii........ n THYSAS IRN Ricy eee ee | ROS Nera ae ETISCUS HR tenia tars oa careless c n ER ITINIIS HPN Syn ee ieas seal | cect aean cnet ramets IE ec tnpe suotad WIP op CMA RIC n PantOSteusyple Disa sisiavac so) crovcde ai sseie oy oa] acne te ch exch nie ces: [lcleteas ever ete) alees MO Hs eee chosen Ge] DDITUS Rest seer g ene tar | eed reece a Me ns | cy eco vciereeatva IPL es ALVIS SE hae n PRU PAU CHEM PERAMUS Hiri cre sicpsteue clcutiesavereal forse searauteas states shal ropcicy apenas apcusine tata rera snertlatonsis n Cy Prinvishcarplore wee ie aay ce etc ae i Garassilstauratusinise cycler shojaelenaeieele i Campostoma anomalum).. 2. 5. 4..2).'... n Chrosomus erythrogaster dakotensis. ... THY HW | Rearepepesy ee ce aD ees altos seen ail Ae rn i fae Pimephales promelas................. n TNS} Re aS ee eee a Neenah eater es Hy bornathusmuchaliss/)sria.a.2 ccs n Phenacobius mirabilis ye dees n RIchArdson1us pulchellusis ieee se cielo ie tae ieee a eeceiee ele eitele 1 Paes (ER ust ea ne oe EVELMANN aes ase ae ost n INOETOpISICAVNP AR ccic see sender ties n DIDCOLEPISH As) lan elans aes/e nyse s TU ec ete 2 JOON Mma aer aceen edt RAAB ats Sy Mlaie tts eretany ee eee ey wickets n 1 eo SPT era ct tneee| bien CEs ered on n n n n Orative cern asia coen cu ete MULTENSIS ARMac wen setoiseie a auiehors Buby CHOCHEN USHAGLUS as eec ta ee poperen era coat at eve entice acl ered at eeaave aileets ormsre listoerer near roa n Grlagrob usta ee ony ke eT aerate le eetcr apa crea eee Setar