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ILLINOIS NATURAL HISTORY SURVEY | THE LIFE HISTORY OF THE TENNESSEE SNUBNOSE DARTER, Etheostoma simoterum IN BRUSH CREEK, TENNESSEE Lawrence M. Page and Richard L. Mayden Biological Notes No. 117 State of Illinois ae : Illinois Institute of Natural Resources Illinois Natural History Survey Natural History Survey Division Champaign, Illinois-August 1981 OS APNYS EY} OF SJUJOG MOB OY) “WNJeJOW/S BWOJSOeY)Z 4O UO!}NG\ySIG—'"|L ‘HI4 ji aha The Life History of the Tennessee Snubnose Darter, Etheostoma simoterum, in Brush Creek, Tennessee The Cumberland snubnose darter, described as Arlina atripinnis by D. S. Jordan in 1877 from specimens col- lected near Nashville, Tennessee, has been determined recently to be at most only intraspecifically distinct from the Tennessee snubnose darter, Etheostoma simoterum (Cope) (D. A. Etnier, personal communication), as sug- gested by Bouchard (1977:129). Etheostoma simoterum, described as Hyostoma simoterum from the Holston River, Virginia, by E. D. Cope in 1868 thus ranges throughout most of the Tennessee River system and much of the Cumberland River system (Fig. 1). The subgenus Nanostoma of Etheostoma encompasses Etheostoma zonale and all species previously referred to the subgenus Ulocentra (Page 1981), including E. simoterum. Except for E. zonale and E. coosae, all species in Nanostoma are poorly known ecologically. The lack of information on these species is in part because 9 of the 15 recognized species in the subgenus are undescribed taxonomically; without names, species remain unknown except to a few specialists. Ecological data on E. zonale are included in Forbes & Richardson 1908:306; Lachner et al. 1950; Miller & Robison 1973:216; Wehnes 1973; Adamson & Wissing 1977; Pflieger 1975:312; Lutterbie 1979:24; Bryant 1979; and Cordes & Page 1980. The life history of E. coosae was studied recently in Barbaree Creek, Clay County, Alabama (O’Neil & Boschung 1980:53). Bouchard (1977) discussed the habitats utilized by E. etniert. For aid in collecting specimens we are grateful to B. M. Burr and M. A. Morris. Illustrations were prepared by Illinois Natural History Survey Illustrator Lloyd LeMere and Survey Photographer Les Woodrum. The manuscript was typed by Alice Adams and Bernice Sweeney and edited for publication by Shirley McClellan, Assistant Technical Editor at the Survey. Dr. William J. Matthews, University of Oklahoma; Dr. Wayne C. Starnes, University of Tennessee; Dr. Glen C. Sanderson and Dr. John Tranquilli, Illinois Natural History Survey, reviewed and improved the manuscript. This study was supported in part by National Science Foundation grant DEB 76-15542. STUDY AREA AND METHODS Etheostoma simoterum was studied in Brush Creek, Smith County, Tennessee at the same site used in the life- This paper is published by authority of the State of Illinois, and is a contribution from the Section of Faunistic Surveys and Insect Identification of the Illinois Natural History Survey. Dr Lawrence M. Page is a taxonomist at the Survey. Richard L. Mayden, formerly a Research Assistant at the Survey, is a Graduate Assistant at the University of Kansas Museum of Natural History, Lawrence ted for publication in the Biological Notes series before it is accepted A minimum of two outside referees recommend cach manuscript submit Lawrence M. Page and Richard L. Mayden history study of E. olivaceum and described by Page (1980:3-5). The Brush Creek population of E. stmoterum is referred to by Page (1980) as E. atripinne. Methods of study were the same as those employed in the study of E. olivaceum (Page 1980:3-5). Minnow-seine collections were made at about 2-month intervals; the first collection was made on 3 March 1977, the last on 30 January 1979. A total of 10 collections were made and 425 specimens were preserved and examined. Specimens col- lected for study were preserved in 10-percent formalin. Collections were recorded as being made in riffles, bedrock pools, or slab pools. Potential predators captured during seining operations were preserved for later ex- amination of stomach contents. Ambient stream condi- tions were recorded at each visit. In the laboratory each specimen was measured (unless stated otherwise, all lengths given in the text are standard lengths), sexed by examining the genital papilla or when necessary the gonads, and aged. Aging to year class was done by counting annuli on scales removed from the dor- sum; aging to month was done by using April, the month of the greatest breeding activity, as month zero. Thus a darter collected in July and having one scale annulus was estimated to be 15 months old. For some comparisons, darters were divided into young (through 12 months) and adult (over 12 months) age groups. Ninety-seven specimens of various lengths were weighed to the nearest 0.001 g; functional regressions of weight on standard length were computed following Ricker (1973). A representative sample of each collection was dissected to identify stomach contents and endoparasites and to note the conditions of the gonads. Weights of the ovaries of 34 females and of the testes of 14 males collected in various months were obtained and recorded as propor- tions of the total body (including the gonads) weights and of the adjusted body weights (the specimen minus the ovaries, stomach, intestine, and liver); the latter weight is intended to remove variation resulting from the weights of recently ingested food. Mature ova in 10 breeding females were counted. The relative survival of the second- year class was calculated by expressing the number of in- dividuals in that year class as a proportion of the number of individuals in the first-year class. Breeding behavior was observed in individuals transferred to aquaria during the breeding season. HABITAT E. simoterum lives in rock- and gravel-bottomed pools, often near riffles and with moderate current, in small to medium-sized streams. In Brush Creek, individuals were Cover Illustration.—Etheostoma simoterum collected in Brush Creek, Smith County, Tennessee, 16 April 1978. Upper, 52-mm male; lower, 51-mm female. 3 most common in bedrock pools below riffles and in deep (to 20 cm) crevices in the bedrock (Fig. 2). Few in- Fig. 2.—Gravel-strewn crevice in bedrock substrate of Brush Creek, Smith County, Tennessee, 16 April 1978. Crevices are occupied by Etheostoma simoterum. dividuals were found in riffles or in slab-rock pools along the margins of the stream. Clean pools with moderate current over bedrock, cob- ble, or gravel are the characteristic habitat of the adults of most species of Nanostoma although Bouchard (1977:124) found E. etnieri to be most common in riffles and runs, and E. zonale inhabits rocky and usually vegetated riffles. O’Neil & Boschung (1980) stated that E. coosae occupies raceways, riffles, and pools over cobble or gravel. REPRODUCTION Reproductive Cycle of the Male During most of the year, the genital papilla of the male is a small conical structure. Between January and April the papilla gradually elongates and becomes tubular (Fig. 3). Testes of breeding males are large, white, and spongy; those of nonbreeding males are small and translu- cent. The mean testes-to-total-body (including the testes) weight ratio increased from 0.002 (N = 3 males) in October to a high of 0.017 (N = 3) in April. From June to September, when males were postreproductive, the testes were too small to weigh accurately (i.e., less than 0.001 g). The relationship between the mean weight of the testes divided by the adjusted body weight (specimen’s body weight after removal of the gonads, stomach, intestine, and liver) and the month, with October = 6 and April = 12, was log Y = 0.697 + 0.169X, with r = 0.986 (Fig. 4). All April-collected males (N = 19) were 1 year old, had enlarged testes and were considered sexually mature. They ranged from 40.1 to 55.7 and averaged 49.1 mm in length. Sexual maturity at 1 year is usual among darters, although in some species a few individuals may not be large enough by the first breeding season to mature sex- ually, and in northern populations of some species (e.g., E. zonale) individuals may not mature until their second year (Lutterbie 1979:24). Breeding colors began developing in the largest males in January and by April all males were brightly colored. The breeding male is deep green or blue-green with bright red or red-orange spots on the body and bright red dorsal fins. The red spots on the body sometimes coalesce into suffusions of red or red-orange. Breeding tubercles do not develop. Fig. 3.—Genital papillae of Etheostoma simoterum col- lected in Brush Creek on 16 April 1978. Upper, breeding male; lower, breeding female. Both specimens were 1 year old. 500 Log Y = 0,421 + 0,139X 100 50 10 WEIGHT OF GONADS X 1000 PER ADJUSTED BODY WEIGHT Log Y =-0,697 + 0.169X MAY JULY SEPT. JAN. MAR. JUNE AUG, OcT. DEC. FEB. APR. Fig. 4.—Monthly variations in ovarian (dots) and testicular (open circles) weights relative to adjusted body weights in Etheostoma simoterum. Reproductive Cycle of the Female The genital papilla of the nonbreeding female is a short thick tube. During spring the tube elongates into a structure (Fig. 3) used to attach the adhesive eggs to a suitable substrate (Fig. 5). The breeding female is slightly brighter but nearly identical in color to the nonbreeding female. Ovaries of June-collected 1-year-old females were in a state of reabsorption and had no mature ova. From July to September the ovaries contained only undifferentiated (clear) ova and were small and translucent. In October the largest females (1 + age class) contained a few dif- ferentiated (white) ova. By February yellow ova were pre- sent, and in March large, dark yellow, nearly mature ova were present (only -1 age class females were collected after October). All April-collected females (N = 48) were 1 year old, contained mature ova, and presumably would have spawned within a few weeks. They ranged from 38.5 to 50.8 and averaged 44.1 mm in length. Fully mature ova averaged 1.2 mm in diameter and were transparent with one to several oil droplets and deeply indented on one side. Indented eggs have been described for darters of the subgenera Microperca (= Boleichthyes — see Page 1981) and Catonotus (Burr & Page 1978:6, 1979:5; Page 1980:7) but are not known in other freshwater fishes (Burr & Ellinger 1980). In 10 females collected on 16 April 1978 the number of mature ova ranged from 110 to 240 (Table 1). As in other darters living through only one breeding season (Burr & Page 1978:6-7, 1979:5-6; Page 1980:7), no significant correlation exists between the number of mature ova produced by a female and the standard length, nor between the number of mature ova and the body weight or adjusted body weight; for all relationships the correlation coefficients (r) were less than 0.32. Table 1.—Relationship between female size, weight of ovaries, and number of mature ova in Etheostoma simoterum. All females were collected in April 1978 and estimated to be 12 months old. Standard Body Adjusted Weight of Number of Length Weight Body Weight Ovaries Mature (Orange inmm inGrams inGrams@ inGrams or Translucent) Ova 42 1.44 1.07 0.18 122 43 1.46 1.15 0.15 110 43 1.41 1.05 0.17 144 43 1.53 1.11 0.20 170 43 1.88 1.27 0.45 240 45 1.60 te 20 0.20 128 47 i ev) 1.34 0.28 112 48 2.07 1.57 0.22 188 49 1.93 1.49 0.24 128 51 2.52 2.03 0.38 182 4 Adjusted body weight is the specimen’s weight after removal of the ovaries, stomach, intestine, and liver wo The relationship between the mean weight of the ovaries divided by the total body (including the ovaries) weight (Y) and the month of collection (X), with May = 1 and April = 12, was log Y = 0.402 + 0.133X, with r = 0.963. The relationship between the mean weight of the ovaries divided by the adjusted body weight (Y) and the month of collection (X) was log Y = 0.421 + 0.139X, with r = 0.963 (Fig. 4). The proportionally largest ovaries, equalling 24.0 percent of the body weight or 35.5 percent of the adjusted body weight, were found in a 43,2-mm female collected on 16 April 1978. In the 10 females represented in Table 1, ovary-weight-to-adjusted- body-weight ratios ranged from 0.128 to 0.355 and averaged 0.185. Spawning In Brush Creek in 1978, E. simoterum spawned in April and probably in early May. Ripe individuals transferred from Brush Creek (19°C) on 16 April 1978 to a laboratory aquarium were observed spawning the next 2 days (at 25°-27 °C). Three males and five females were held in an aquarium on 17-18 April 1978; the two largest males and at least three of the females were observed spawning. Aquarium-held breeding males did not defend stationary territories, but were combative toward one another when in close proximity (within 10 cm). A male courted a near- by female by laterally displaying his erect median fins. During displays the blue-green and red-orange on the side of the body and in the fins were at their greatest intensity. When receptive to the courting of a male, a female led the male to a site selected for egg deposition. The male fol- lowed closely behind the female and at the selected site mounted the female (Fig. 5). The pair vibrated and one or two eggs were released and fertilized. Characteristically the pair then moved to another site and repeated the spawning act. However, males and females were pro- miscuous and repeatedly switched from one spawning partner to another. Usually eggs were attached to the side of a large stone; less often they were laid on top of a stone. On a few occa- sions eggs were buried in gravel (Fig. 5); however, the female did not bury her body as deeply into the gravel as do more typical egg-burying species (e.g., E. caeruleum — Winn 1958:177). Eggs were not guarded by the parents. Often after laying the eggs in gravel the female immed- iately turned and ingested them. The related E. coosae and two undescribed species of Nanostoma also deposit eggs on the surfaces of large stones (Winn 1985:160, O’Neil & Buschung 1980); E. zonale lays eggs among filamentous algae in riffles (Pflieger 1975:312). DEVELOPMENT AND GROWTH A series of 40 young E. simoterum ranging in length from 14 to 32 mm was collected at the study area on 18 June 1977. At 14 mm, the pigmentation was essentially the same as that of the adult and squamation was com- plete except on the nape and anterior half of the belly. Head canals were complete but the lateral line had not yet Fig. 5.—Etheostoma simoterum spawning in an aquarium. Usually eggs were deposited on the sides of boulders (right and left photos), although some were buried in gravel (bottom photo). begun to form. On specimens 17-18 mm, the lateral line extended to near the junction of the first and second dor- sal fins. At 20 mm the lateral line was complete but the nape and anterior portion of the belly were still unscaled. At 25 mm squamation was complete. For males, the relationship between mean standard length (Y) and age in months (X) is Y = 18.4 + 27.66 log X, with r = 0.924, and for females is Y = 19.2 + 22.48 log X, with r = 0.933 (Fig. 6). At 1 year (12 55 45 = = 35 &S Fra] pa | 2 a 25 = 5 ——= Y = 18,4 + 27.66 log X (males) 15 —--- = Y = 19,2 + 22.48 log X (females) Pie 8 10) 12914 16 18 MONTHS OF AGE Fig. 6.—Size distribution by age of Etheostoma simoterum collected in Brush Creek between 3 March 1977 and 30 January 1979. Black dots represent sample means for males; circles represent sample means for females. A total of 425 specimens is represented. months) males (N_ = 19) were significantly (t.4] = 5.66, df = 65) longer (X = 49.1 mm) than females(N = 48, X = 44.1 mm). E. simoterum reached one-half of the first year’s mean growth in about 8 weeks. The largest specimen examined from Brush Creek was a 55.7-mm male collected on 16 April 1978; the largest female was 50.6 mm and collected on the same date. The largest specimen known for the species is 64 mm. For males (N = 45) the functional regression (Ricker 1973) of total weight (W) on standard length (L) was log W = -5.116 + 3.196 log L, with r = 0.995; for females (N = 52) was log W = -5.209 + 3.255 log L, withr = 0.983; and for both sexes (N = 97) was log W = -5.149 + 3.216 log L, with r = 0.990. A slope above 3 means that the fish grows proportionally heavier as it grows longer (Ricker 1968). Among darters, the largest slopes are found in deep-bodied riffle-inhabiting species such as E. tippecanoe (slope = 3.9 — Page & Burr 1979) and E. caeruleum (3.4 — Lutterbie 1979:7); the smallest values are found in slender, quiet-water species such as E. exile(2.6 — Copes 1976:9) and E. striatulum (2.7 — Page 1980:9). The value of 3.2 for E. stmoterum corresponds to its typical occupation of habitats having moderate but not swift cur- rent. DEMOGRAPHY Density Density estimates were made on two dates by repeatedly seining an area of Brush Creek until no E£. stmoterum were present in two consecutive seine hauls. On 10 August 1977, the density of E. stmoterum in bedrock pool, the preferred habitat, was 5.38 individuals per m?. On 30 January 1979, densities per m? were: in slab pools, 0.0; in riffles, 0.0; and in bedrock pools, 2.61. Density values given for E. olivaceum in Brush Creek (Page 1980:10) were incorrect. Those values should have been, for 10 August 1977: in slab pools, 4.04 individuals per m?; for 30 January 1979: in slab pools, 8.07; in riffles, 1.79; and in bedrock pools, 1.47. For E. striatulum the value should have been 1.34 per m?. Composition Of the 425 specimens collected in Brush Creek be- tween 3 March 1977 and 30 January 1979, 90.1 percent were up to 1 year of age and 9.9 percent were between 1 and 2 years of age (Table 2). Table 2.—Distribution of sexes and year classes in samples of Etheostoma simoterum collected in Brush Creek between 3 March 1977 and 30 January 1979. Sex Number by Year Class Total -1 +1 Males 139 12 151 Females 244 30 274 Total 383 42 425 Females significantly outnumbered males in the first year (-1) age class [1.75 to 1 (X* = 28.79; P< 0.001)] and in the second year (1 +) age class [2.5 to 1 (X?_ = 35.59; P <0.001)]. Among all specimens collected, females were 1.81 times as abundant as males (X?_ = 35.59; P <0.001). Although females often predominate in the highly ter- ritorial species of the subgenus Catonotus (Lake 1936:829; Schwartz 1965:100; Page 1974:13, 1975:10; Page & Burr 1976:9), most sex ratios among darters have not deviated significantly from 1:1. More data are needed on E. stmoterum and on other species of the subgenus Nanostoma to determine if the Brush Creek ratio is typical. Survival Of the 151 males collected, 92.1 percent were up to 1 year of age and 7.9 percent were between 13 and 18 months of age. Of the 274 females, 89.1 percent were up to 1 year old, and 10.9 percent were between 13 and 18 months of age. Assuming that each year class was col- lected in proportion to its relative number in the popula- tion, only 8.6 percent of the first-year males and 12.3 per- cent of the first-year females survived to a second year. For males and females combined, survival to a second year was 11.0 percent. From this 2-year study, it appears that in Brush Creek, E. simoterum does not live beyond 18 months and experiences only one spawning season. A maximum longevity of 18 months and a survival rate to a second year of only 11 percent are smaller than the values found for other darters, including E. proeliare and E. microperca for which short life spans were thought to be a distinctive feature among darters (Burr & Page 1978:11, 1979:11). The largest E. simoterum in the fish collection of the Illinois Natural History Survey is a 63-mm male collected in East Fork Stones River, Rutherford County, Tennes- see, on 14 March 1976. Scale readings suggest that this specimen, which is only 1 mm less than the length of the largest specimen known for the species, was 2 years (23-24 months) old when captured. The consubgeneric species, E. coosae and E. zonale, live to 3 and 3 + years, respectively (O’Neil & Boschung 1980; Lachner et al. 1950:101). DIET AND PARASITISM Stomach contents of 45 E. simoterum were identified and tabulated by size class of darter (Table 3) and month of collection (Table 4). Midge larvae (Chironomidae) formed the bulk of the diet of all size classes. Other major items were mayfly naiads, caddisfly larvae, copepods, and cladocerans. The smallest darters fed mainly on midges, copepods, and cladocerans. With an increase in size, the darters shifted to larger food items, eating fewer crusta- ceans and more mayflies and caddisflies (Table 3). Food consumption was high in spring and fall, and highest in April (Table 4), the month of peak spawning activity. Consumption was lowest in January, February, and July, months of temperature extremes and probably of reduced activity by the darters. In the 45 stomachs examined, 6 contained a total of 12 flukes and 2 contained a total of 3 parasitic nematodes. Flukes were present in individuals collected in February, March, and April; nematodes were present in January and February. All flukes and nematodes were found in large darters (42 mm and longer). External parasites found on E. simoterum from Brush Creek were fluke metacercariae (black-spot disease) and piscicolid leeches. The leeches were found only on darters collected in April 1977, and were present on 7 of 19 darters collected. The metacercariae were present in most months but only on darters 35 mm and longer. CONTRASTS WITH ETHEOSTOMA OLIVACEUM E. simoterum and E. olivaceum are rivaled in abundance in Brush Creek only by midwater minnows (Pimephales notatus and an undescribed species of Notropis) which do not compete with the darters for space and probably not for food. The only species of darter other than £. stmoterum and E. olivaceum encountered at the Brush Creek study site was E. flabellare and it was extremely uncom- mon. Cottus carolinae, the banded sculpin, is a benthic species which might compete with the darters but also was uncommon. In Brush Creek, the most likely competitors for E. sitmoterum and E. olivaceum are each other. However, their life-history characteristics suggest a low probability of competition between the two species for resources likely to be in limited supply. Although sharing the same small stream the two darters occupy different habitats and are not in direct competition for space or food. E. olivaceum lives and breeds in the slab-rock pools along the margins of Brush Creek and only rarely is found in bedrock pools. £. Table 3.—Stomach contents of Etheostoma simoterum from Brush Creek, by size class of darter. Figures in parentheses are numbers of stomachs examined. a Percent of Stomachs in Which Food Organisms Occurred Food Organism 17=25 26-35 36-45 46-55 mm mm mm mm (6) (7) (20) (12) Gastropoda 14.3 Arachnida Acarina eta behte a de ans 8.3 Crustacea Cladocera 16.7 28.6 15.0 8.3 Copepoda 33.3 42.9 10.0 8.3 Insecta Ephemeroptera 42.9 25.0 33.3 Trichoptera 14.3 5 16.7 Diptera Chironomidae 100.0 85.7 80.0 91.7 Mean Number of Food Organisms per Stomach 17-25 26-35 36-45 46-55 mm mm mm mm (6) (7) (20) (12) 0.14 0.16 0.17 atin 0.35 0.08 0.50 4.00 0.15 0.08 0.71 0.70 0.42 0.14 1.45 0.50 7.50 2.14 24.15 12.17 O07 6I OFT OOF OFF 008 02°99 OF'ET 0% 02S 0o'00T 008 O08 O00! ODOT O00! O00! OOF 008 seprazouolgg) eraidiq OClOM a aaa ROGOER 2 ORO ea Sart Re tIOIOG., Seer od Oia ee ONO e etee essidoyouy UO ee OCG. see ee 0910) 8 0c.0) (0F10) s0ct0 00 OOF O08 “"** **** OOF 002 002% 0°02 ersidosrauoydy e}99su] OVO USO ROSS 0970) 0ci0! OGIO) al ae a ODO cree 0105 sO 0 Fm ONO cine O00 iiss eee thee epodsdop OC OMSAOPSOR DOR Taka me (Oct O metas ay Sy se satiate OOG RR O;O PE OFOS spa NOLO Gene ee een enn Rind ce eae BIQIOPE(D PaoRIsnin ORD Lr ee ene Ae! Telglalg) Legge ekagos pine sas tye th Nims an 1s 0s sigia euuesy epluypery ee a eae ee eee (G) Sc) = GG) cy) (ec), Gc) (eye GG) OY ©) OO) @ @ @) GG) @® . : dl ; . i ; ‘yo ida ‘Bny Ainf aunf sad “re ‘qoeq ‘ue 9Q dag -Sny Ajnf aunf{ -idy “sew ‘qaq ue{ O ) vy Aint f Vv Wd f wistue8iQ poog yorwmoig sad surstues1G, pasind90O suistuedIQ poo pooy jo saquinyy uray YPIYAA Ul SYDBUIOI JO JUdDIag a ee eee eee eee ‘Paulwexe SYORBWO}S 40 SiaquNU ae Sesayjuased U! SeuNB}4 ‘UO!}9e]}09 yo YJUOW Aq ‘yeeI9 Yysnig WO1j WNsJa}OW/S BWOJSOaY)Z JO SJU8}UOD YOBWO}S—'p aiqey 10 stmoterum lives and breeds in bedrock pools and crevices and seldom invades the smaller, more shallow slab-rock pools. The most striking ecological difference, other than habitat, between the two darters is their reproductive behavior. E. olivaceum males establish territories beneath slab stones and guard their nests of eggs until hatching. E. stmoterum does not establish stationary territories, lays eggs over a relatively large area, and immediately aban- dons them. As would be predicted by the reproductive ef- fort expended (Hoar 1957), E. olivaceum produces fewer (60-112) and larger (2.0 mm in diameter) eggs per female than does E. simoterum (110-240 eggs averaging 1.2 mm). E. olivaceum lives longer (to 27 months) than does E. simoterum (18 months) and gets larger (to 14 percent longer). Presumably as a result of its larger size, E. olivaceum eats a more varied diet, including some organisms generally too large for E. simoterum to ingest (e.g., stonefly naiads, beetle larvae, amphipods, and isopods). SUMMARY The life history information on E. simoterum collected in Brush Creek between 3 March 1977 and 30 January 1979 is summarized in Table 5. Table 5.—Summary of life-history information on Etheostoma simoterum in Brush Creek. Characteristic Life-history Data Principal habitat Age at reaching sexual maturity Age at first spawning Size at reaching sexual maturity Sexual dimorphism Number of mature ova counted Description of egg Spawning period Spawning position Egg deposition site Egg guarding Influence of sex on growth rate Sex ratio Longevity Maximum size Territoriality Principal diet Rock and gravel-bottomed pools with current 1 year 1 year All spring-collected individuals regardless of size were sexually mature. Males are larger and more colorful. 110-240 1.2 mm in diameter, translucent, and deeply indented on one side April and probably early May Male mounted on back of female Usually the sides and tops of large stones None At 1 year males are significantly larger than females. 1.8 females: 1 male 18 months 55.7 mm standard length for males; 50.6 mm for females Stationary territories not observed; moving territories may be established by males. Crustaceans and immature aquatic insects 11 LITERATURE CITED Adamson, S. W., and T. E. Wissing. 1977. Food habits and feeding periodicity of the rainbow, fantail, and banded darters in Four Mile Creek. Ohio Journal of Science 77:164-169. Bouchard, R. W. 1977. Etheostoma etniert, a new percid fish from the Caney Fork (Cumberland) River system, Tennessee, with a redescription of the subgenus Ulocentra. Tulane Studies in Zoology and Botany 19:105-130. Bryant, R. T. 1979. The life history and comparative ecology of the sharphead darter, Etheostoma acuticeps. Tennessee Wildlife Resources Agency Technical Report No. 79-50.60 p. Burr, B. M., and M.S. Ellinger. 1980. Distinctive egg morphology and its relationship to development in the percid fish Etheostoma proeliare. Copeia 1980:556-559. , and L. M. Page. 1978. The life history of the cypress darter, Etheostoma proeliare, in Max Creek, Illinois. Illinois Natural History Survey Biological Notes 106. 15 p. , and . 1979. The life history of the least darter, Etheostoma microperca, in the Iroquois River, Illinois. Illinois Natural History Survey Biological Notes 112. 15 p. Copes, F. A. 1976. The Iowa darter Etheostoma exile Girard. American Currents 4:2-10. Cordes, L. E. and L. M. Page. 1980. Feeding chronology and diet composition of two darters (Percidae) in the Iroquois River system, Illinois. American Midland Naturalist 104:202-206. Forbes, S. A., and R. E. Richardson. 1908. The fishes of Illinois. Illinois State Laboratory of Natural History. cxxxi + 357 p. Hoar, W. S. 1957. The gonads and reproduction. Pages 287-321 in M. E. Brown, ed., The physiology of fishes. Academic Press, New York. Lachner, E. A., E. F. Westlake, and P. S. Handwerk. 1950. Studies on the biology of some percid fishes from western Pennsylvania. American Midland Naturalist 43:92-111. Lake, C. T. 1936. The life history of the fan-tailed darter Catonotus flabellaris flabellaris (Rafinesque). American Midland Naturalist 17:816-830. Lutterbie, G. W. 1979. Reproduction and age and growth in Wisconsin darters (Osteichthyes: Percidae). University of Wisconsin Museum of Natural History Reports on the Fauna and Flora of Wisconsin No. 15. 44 p. Miller, R. J., and H. W. Robison. 1973. The fishes of Oklahoma. Oklahoma State University Press, Stillwater. 246 p. O'Neil, P., and H. Boschung. 1980. Life history aspects of Etheostoma coosae (Pisces: Percidae) in Barbaree Creek, Clay County, Alabama. Association of Southeastern Biologists Bulletin 27:53. Page, L. M. 1974. The life history of the spottail darter, Etheostoma Squamiceps, in Big Creek, Illinois, and Ferguson Creek, Kentucky. Illinois Natural History Survey Biological Notes 89. 20 p. . 1975. The life history of the stripetail darter, Etheostoma kennt- cotti, in Big Creek, Illinois. Illinois Natural History Survey Biological Notes 93. 15 p. . 1980. The life histories of Etheostoma olivaceum and Etheostoma striatulum, two species of darters in central Tennessee. Illinois Natural History Survey Biological Notes 113. 14 p. 1981. The genera and subgenera of darters (Percidae, Etheostomatini). Occasional Papers of the Museum of Natural History of The University of Kansas 90. 69 p. , and B. M. Burr. 1976. The life history of the slabrock darter, Etheostoma smitht, in Ferguson Creek, Kentucky. Illinois Natural History Survey Biological Notes 99. 12 p. , and . 1979. The smallest species of darter (Pisces: Percidae). American Midland Naturalist 101:452-453. Pflieger, W. L. 1975. The fishes of Missouri. Missouri Department of Conservation. 343 p. Ricker, W. E. 1968. Methods for assessment of fish production in fresh waters. International Biological Program Handbook 3. 313 p. 1973. Linear regressions in fishery research. Canadian Fisheries Research Board Journal 30:409-434. Schwartz, F. J. 1965. Densities and ecology of the darters of the upper Allegheny River watershed i C. A. Tryon, Jr., R. T. Hartman, K. W. Cummins, eds., Studies on the aquatic ecology of the upper Ohio River system. Pymatuning Laboratory of Ecology, University of Pittsburg, Special Publication 3. Wehnes, R. A. 1973. The food and feeding interrelationships of five sympatric darter species (Pisces: Percidae) in Salt Creek, Hocking County, Ohio. M. S. Thesis, Ohio State University. 79 p. Winn, H. E. 1958. Comparative reproductive behavior and ecology of fourteen species of darters (Pisces-Percidae). 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