QMJFORNIAI FTSH-GAME "CONSERVATION OF WILDLIFE THROUGH EDUCATION" California Fish and Game is a journal devoted to the conser- vation of wildlife. If its contents are reproduced elsewhere, the authors and the California Department of Fish and Game would appreciate being acknowledged. Effective January 1, 1975 The free mailing list will be limited by budgetary considera- tions to libraries, scientific institutions, and conservation agencies. Subscriptions must be renewed annually by returning the post- card enclosed with each October issue. Subscribers are asked to report changes in address without delay. Please direct correspondence to: Robson A. Collins, Editor California Fish and Game 350 Golden Shore Long Beach, California 90802 Individuals and organizations who do not qualify for the free mailing list may subscribe at a rote of $5 per year or obtain individual issues for $1.50 per copy by placing their orders with California Department of Fish and Game, 1416 Ninth Street, Sacramento, California 95814. Money orders or checks should be made out to California Department of Fish and Game, 1416 Ninth Street, Sacramento, California 95814. Inquiries regarding paid subscriptions should be directed to the editor. u 1 1 VOLUME 61 JANUARY 1975 NUMBER 1 Published Quarterly by STATE OF CALIFORNIA THE RESOURCES AGENCY DEPARTMENT OF FISH AND GAME STATE OF CALIFORNIA EDMUND G. BROWN JR., Governor THE RESOURCES AGENCY CLAIRE T. DEDRICK, Secretary for Resources FISH AND GAME COMMISSION TIMOTHY M. DOHENY, President, Los Angeles JOSEPH RUSS III, Vice President PETER T. FLETCHER, Member Ferndole Roncho Santa Fe BERGER C. BENSON, Member SHERMAN CHICKERING, Member San Mateo San Francisco DEPARTMENT OF FISH AND GAME G. RAY ARNETT, Director 1416 9th Street Sacramento 95814 CALIFORNIA FISH AND GAME Editorial Staff ROBSON A. COLLINS, Editor-In-Chlef long Beach KENNETH A. HASHAGEN, Editor for Inland Flsheriei Sacramento CAROL M. FERREL, Editor for Wildlife Sacramento ROBERT N. TASTO, Editor for Marine Resources Menio Park PAUL M. HUBBELL, Editor for Salmon and Steeiheod Sacramento HAROLD K. CHADWICK, Editor for Striped Bass, Sturgeon, and Shod Stockton (2) CONTENTS A Black Bear Population Study in Northern California William Piekielek and Timothy S. Burton 4 Early Larvae of the Diamond Turbot, Hypsopsetta guttulata Maxwell B. Eldridge 26 The Food of Neomysis mercedis Holmes in the Sacramento-San Joaquin Estuary Angela L. Baldo Kost and Allen W. Knight 35 Note on the Ecology of the Ratfish, Hydrolagus collei, in the Gulf of California C. P. Mathews 47 Notes An Unusually Fast Growth Bate for Tilapia zillii William, J. Hauser 54 Notes on Some Fishes Collected off the Outer Coast of Baja Cali- fornia Eric H. Knaggs, John S. Sunada, and Robert N. Lea 56 Occurrence of the Prowfish, Zaprora silenus Jordan, 1896 in Mon- terey Bay, California Gregor M. Calliet and M. Eric Anderson 60 Book Reviews 63 (3) Calif. Fish and Game 61(1) : 4-25. 1975. A BLACK BEAR POPULATION STUDY IN NORTHERN CALIFORNIA^ WILLIAM PIEKIELEK School of Forestry and Conservation, University of California, Berkeley and TIMOTHY S. BURTON Wildlife Management Branch California Department of Fish and Game Forty-three wild bears were culvert trapped, immobilized, and tagged in a limited area in Trinity County, California, during the summer and fall of 1972. Eleven depredation bears were trapped and tagged throughout the county. Sex and age distribution and physical charac- teristics of these 54 animals are summarized. Summer movements and home ranges of the marked bears were small. Average known maximum summer movement was 1.85 miles (2.97 km), increasing in fall to 6.1 miles (9.8 km). Adult females with cubs appeared to have smaller yearly ranges than other sex and age classes. Summer density of the bear population in the study area was approximately two bears per square mile (2.6 km^). Thirty-six percent of the adult females were with cubs, the average litter 1.67. Summer food habits are reported, based on analysis of 106 scats. INTRODUCTION The black bear, Ursiis amcricanus, is receivinjr inereasint; recognition as an integral part of our forest environment and as an important game species. Improved methods of handling and tagging large animals have facilitated black bear population studies in the last 2 decades. This paper reports the initial phase of a long term black bear population study in California. Emphasis in the first year of the project was on determining population composition and density, movements, food habits, and individual physical characteristics of black bears in a rep- resentative habitat in northern California. STUDY AREA A study area of approximately 115 square miles (298 km^) was selected east and south of Clair Engle Lake, Trinity County (Figure 1). Most of the study area is contained within the Shasta-Trinity Na- tional Forest. This part of the national forest is in "checker board" ownership; alternate sections are privately owned. The study area sup- ports a relatively high density of bears and is intersected by numerous logging roads providing easy access. Although major emphasis was given to tlie study area outlined, depredation bears (garbage dump, campground, and other nuisance bears) captured elsewehere in Trinity County are included in the analyses. The study area lies at the south base of the Trinity Alps, one of the principal mountain ranges of this area. Elevations range from 1,800 ft (549 m) in the Lewiston area to 8,091 ft (2,468 m) at Granite Peak. The area consists almost entirely of timbered or brushy gulches divided ^ This study was supported in part by Federal aid in Wildlife Restoration projects W-51-R "Big Game Studies" and W-52-R "Wildlife Investigations Laboratory." Accepted for publication July 1974. (4) BLACK BEAR STUDY Lewiston Lake Lewiston FIGURE 1. Principal bear study area west of Clair Engle Lake, Trinity County, California, showing summer trapping sites (o), and fall trapping sites (•) near Lewiston. by sharp ridges, with local elevation changes of 1,000 (305 m) to 2,000 ft (610 m). At the immediate base of the Trinity Alps, precipitous local elevation changes approach 6,000 ft (1,830 m). The climate of the area is typical of the Pacific Coast with local con- ditions influenced by elevation and exposure. Summers are dry and warm ; winters are cool and wet. Snowfall may vary greatly from year to year with a range of 10 (25.4 cm) to 70 (177.8 cm) inches recorded at Weaverville. Higher elevations receive greater amounts of precipi- 6 CALIFORNIA FISH AND GAME tation in the form of snow. The spring of 1972 was unusually dry and the fall months of 1972 were unusually wet. Most of the study area is covered by a pine-fir forest; dominant species are Douglas fir {Pseudotsuga menziesii) and yellow pine (Pniws pondcrosa) with lesser numbers of sugar pine (P. lamhrrfifina) and incense cedar {Lihocedrus dccurrens) (Figure 2). Understory trees in the conifer forest include Pacific madrone (Arbutus menziesii) , bigleaf maple {Acer macrophyllus) and Pacific dogwood (Cornus nutiallii). Oak woodland and manzanita communities are on some soutli facing slopes; principal species are Oregon white oak (Qucrcus garryana), California black oak {Q. kelloggii), interior live oak {Q. wislizcnii), green leaf manzanita {Arctostaphylos patula), and white leaf man- zanita (A. viscida). Some stands of digger pine (P. sahiniay^a) are at lower elevations. A few small wet meadows occur at higher elevations, about 4,000 ft (1,220 m). Scientific names of plants were taken from Munz and Keck (1959). FIGURE 2. General view of part of the bear study area, showing intermixture of conifer timber and brush fields (largely manzanita). Commercial logging plays a major role in the ecology of the study area. An estimated 40 to 50% of the study area has been at least par- tially logged since 1950. The completion of tlie Trinity and Lewiston dams in 1962 had an important effect on the physical aspects of the area. Clair Engle Lake, formed by the Trinity Dam, inundated much of the lowland watershed of the Trinity River and some of its major tributaries, which were previously winter deer range. Tlie upstream spawning run of the king salmon {Oncorhytichus tshawytscha) was stopped at the breast of the Lewiston Dam. Another recent impact on the study area is the great influx of summer recreationists. Within the study area there are 11 national BLACK BEAR STUDY forest campgrounds and one major private resort. However, there are few year-round residents in the study area. METHODS Trapping Methods Trapping took place in two different time periods. A summer period, using 18 trapsites (Figure 1), extended from June 29 to September 6, 1972. Limited fall trapping was undertaken at a salmon spawning area near Lewiston between October 2 and October 13, 1972. Depredation bear trapping was done throughout the summer and into the fall. Essentially all trapping was done with culvert traps. Emphasis was placed on capturing bears in natural settings in a defined local area. Traps were located on or near old logging roads. "Call baits," consist- ing of fish (wrapped in burlap) or road killed deer hanging in trees, were used at these trapsites. Trapsites were chosen on the basis of bear sign in the area or the response to a test "call bait" placed in the area. Traps for nuisance bears were set when needed at campgrounds, private homes and resorts throughout the county. Trap bait consisted of canned fish base catfood, strawberry jam and marshmallows. Aldrich snare settings were tested as a trapping method the last two nights of the summer trapping period. Trapping success was expressed in terms of bear captures per trap night. During the summer period 58 captures of 38 different bears were made in 156 culvert trap nights, for a 37% capture rate. During the fall period four captures of four different bears were made in 21 cul- vert trap nights, for a 19% capture rate. Fifteen depredation bear captures of 14 different bears were made in 94 culvert trap nights for a 16% capture rate. Eleven of the latter were immobilized, tagged, and transplanted. One bear was captured by a snare trap in six trap nights for a 17% capture rate. FIGURE 3. Immobilized bear being processed outside of trop. 8 CALIFORNIA FISH AND GAME Immobilization, Handling and Tagging Trapped bears were immobilized with Sernylan (phencyclidine hydrochloride) injected manually using a syringe with a 3 ft (0.9 m) fiberglass extension rod. Dosages were administered at the level of 1 mg of Sernylan per 3 (1.30 kg) to 4 lb. (1.81 kg) of estimated body weight. Once techniques were established, average time from first injec- tion to immobilization was approximately 30 min with a range of 3 to 85 min. Average time from bear immobilization to bear arousal was approximately 60 min and ranged from 20 to 154 min. No lasting ill effects of the drug were noted, and the immobilization method was con- sidered satisfactory. Once a bear was immobilized biological data were recorded (Figure 3). All animals were then marked in each ear with metal ear tags wdth attached colored plastic streamers which identified each bear individu- ally. Some bears were also tatooed in the ear. Retention of the metal ear tags and streamers was good; only one metal ear tag and four streamers were known lost. Six bears were also fitted with radio collars. After marking, bears were given an injection of Procaine Penicillin G as a general prophylaxis. INDIVIDUAL BLACK BEAR CHARACTERISTICS Color Of 54 bears handled and three cubs observed during the handling of their mothers, 33 (58%) Avere black or predominantly black with only small patches of another color, such as a white chest blaze. Twenty -one bears (37%) were predominantly a shade of bro\vn (Figure 5). One bear was about equally brown and black. Two bears were predominantly blonde. In all, eight bears, three of the black phase and five of the brown phase, had white breast marks. Color phases of the black bear vary from region to region. In the eastern United States most bears are of the black phase. Black (1958) reported that of 184 bears handled in New York all were black phase. In Pennsylvania the situation is similar with only a few cinnamon colored bears reported (Pennsylvania Game Commission 1952). In western North America there is a greater mixture of color phases. Records compiled from fur posts in British Columbia, Washington, Oregon and Idaho between 1825 and 1857 (Cowan 1938) indicated color phase ratios from 63% brown — 37% black in Idaho to 100% black on Vancouver Island (Figure 4). In the Northwest Pacific area there was a pronounced increase in the proportion of black phase bears from south to north and also from east to west. In California, Grinnell et al. (1937) reported that bears in the Sierra Nevada were predominantly of the brown phase. The Trinity County ratio of 37% brown — 58% black corresponds with the geographic trends in color reported by Cowan. There was no correlation between color phase and sex in the Trinity study area. However, there did seem to be an unexplained correlation between color and age. Of five cubs handled or se^n by the authors, all were black. Of six yearlings handled, five were black. Thus, of 11 cubs and yearlings 91% were black while of the total sampled population 58% were black, and of the sampled adult bears only 39% were black or predominantly black. If these samples are representative of the popu- BLACK BEAR STUDY FIGURE 5. Sub-adult bear of brown phase recovering from immobilizing drug. Note ear markings, lation, the question is raised whether a portion of the population changes with age from black to a lighter color phase. We have no proof that such change occurs. Measurements The following measurements were taken (in inches) from immobilized bears: body length, from nose tip to tail bone end; shoulder height, from top of shoulder to base of ankle; tail length-, from base of tail to end of tail bone ; neck girth ; chest girth ; head length ; head width ; head circumference ; hind foot length ; hind foot width ; hind toe width ; forefoot length; forefoot width; fore toe width, (see Figure 3 for il- lustration of foot measurements) ; ear height from notch ; and ear height from crown. A summary of all measurements is given in the senior au- thor's unpublished M. S. thesis, 1973, University of California, Berkeley. Sexual dimorphism in size among the bears in the Trinity study area was pronounced. There was little overlap in any of the linear measure- ments of adult males and females, and where present was largely at- tributed to age differences. The average chest girth for adult male bears 10 CALIFORNIA FISH AND GAME Black color phase r~^ Brown color phase FIGURE 4. Color composition of black bear populations in the Pacific northwest. Data largely from Cowan, 1938. was 41.7 (105.9 cm) inches compared to 34.5 (87.6 cm) inches for adult female bears. Size dimorphism apparently starts soon after birth, as yearlings exhibited a size difference between sexes. Adult male depredation bears averaged larger than other adult male bears. A part of this average size difference was probably due to a BLACK BEAR STUDY 11 larger percentage of older males in the depredation sample than in the wild bear sample. A strong positive correlation was found between bear weight and composite foot measurements (Figures 6 and 7). The log-log form of plotting the data fit well to a straight line of the equation : FIGURE 6. Foot measurements of black bears. A + B + C + D-I-E+ F gives the sum of composite foot measurements plotted in Figure 7. Log (weight) = — 2.73 + 3.5 log (sum of foot measurements). The correlation coefficient for this plot is 0.974. Several field observations showed that a composite foot measurement sum obtained from a track in light dust was about 10% less than the true sum, obtained from the animal. Track measurements thus might be used to derive rough estimates of population composition. Weights The average weight of the adult male depredation bear is more than other wild males (Table 1). Bears captured in the fall appeared by 12 CALIFORNIA FISH AND GAME C O o CD -r \^\y / o 0 / ° o <^o° o ^8 200 — oA° ■ / o ■ y o ■ / o4o K 100 — ■f ■ 80- / ° / o 60- 40- /■ o-Males / ■- Females 30- o < > 1 1 1 20 30 Sum of composite foot measurements (inches) FIGURE 7. Correlation of body weight and composite foot measurements of Trinity County bears. visual inspection to be fatter than summer captured bears. However, no bear captured in the summer was recaptured in the fall, so no actual weight gain could be determined. Trinity County bears are similar in weight to those reported by Jonkel and Cowan (1971) in Montana, but are considerably lighter than those found in the eastern United States (Table 2). Because some of the weights given for the eastern states are probably late fall weights, it is difficult to make exact comparisons. Nevertheless, it seems apparent that Trinity County bears are smaller. Of 149 bears that Black (1958) handled in one summer, six male bears exceeded 400 lb. (181.6 kg) with BLACK BEAE STUDY 13 the largest two weighing 562 (255.1 kg) and 599 lb. (271.9 kg). His maximum weight for a female was 361 lb. (163.9 kg). None of the Trinity bears approach these figures. The largest male, weighed 324 lb. (147.1 kg) and the largest female 162 lb. (73.5 kg). TABLE 1.— Average Weights (pounds) of Trinity County Black Bears, 1972 Class No. Range X SD All adult males 30 8 11 2 1 3 2 116-324 190-295 112-162 99-104 87 58-64 43-44 215.0 243.6 127.6 101.5 87.0 61.0 43.5 55.0 Depredation adult males Adult females 38.8 18.0 Sub-adult males Sub-adult females Male yearlings Female yearlings TABLE 2. — Average Black Bear Weights from Several Different Localities Location Average weights (pounds) Adults Year- lings Source Males Females Cubs Jonkel and Cowan (1971) Montana 211 304 324 276 215 125 189 200 196 128 45 94 54 22 Harlow (1961) Florida - Harlow (1961).. New Hampshire New York Black (1958) 38 This study.. ... Trinity County 29 LIFE HISTORY Summer Movements and Home Range Recaptures and radio locations of 13 bears (6 males and 7 female) yielded data on summer movements. All movements were computed as minimum linear distances between known location points. The average movement shown by male bears was 1.7 miles (2.7 km), while for females the average was 2.0 miles (3.2 km). The overall average summer movement was 1.9 (3.1 km) miles, both sexes included. The maximum movement recorded by recapture was 2.8 miles (4.5 km). During sum- mer, the maximum distances moved by three radio-collared bears were 2.2 (3.5 km), 3.0 (4.8 km) and 4.5 miles (7.2 km). The average maxi- mum number of days between known locations for bears showing move- ment was 24.5 days. Trapsites were not located in such a pattern or in adequate numbers that a reliable home range size could be plotted on the basis of recap- tures alone. However, two radio-collared bears — number 10, an adult male, and number 61, an adult female with cubs — were located fre- 14 CALIFORNIA FISH AND GAME quently enough to enable an accurate estimation of their summer home range (Figure 8). A third bear, number 14, an adult female, was located only a few times before losing her collar. FIGURE 8. Movements of three Trinity County bears fitted with radio collars. Bear number 10 was located 20 times over 56 days in an area of less than 5 square miles (12.9 km-) before he moved a distance of approxi- mately 7 miles (11.3 km) from his summer range. The latter movement was considered a seasonal migration. Bear number 61 was located six times over a period of 15 days in an area of less than 7 square miles BLACK BEAR STUDY 15 (18.1 km^). Bear number 14 was located four times in a period of 28 days in an area of less than 4 square miles (10.4 km^). Her collar was then recovered 23 days after the last known location approximately 3.5 miles (5.6 km) from the center of the area of her previously known locations. From these data, summer home ranges were estimated to be fairly FIGURE 9. Seasonal movements of Trinity County bears as shown by recapture, sighting, and hunter kill. One kill site (SW corner) was actually 7 miles (11.3 km) farther to the Southwest, ofF the map. 16 CALIFORNIA FISH AND GAME small, most being approximately 5 (12.9 km-) to 10 square miles (25.9 km-) in size. Summer home range size did not appear to be different- iated by sex or age class. Fall Movements On the basis of radio collar locations, sightings, trapping, and hunter tag returns, fall movements of 10 bears were known (Figure 9). The average movement of nine bears trapped in the s\immer and located in the fall was 6.1 miles (9.8 km) from the original summer capture site. Movements fell into two distinct categories. Four of the bears apparently had not, at the time of the fall location, left or moved far from their summer home range. Eadio-collar bear number 61, a female with cubs, stayed in the area of her summer home range until she was shot on October 18. On October 17, an adult female with a cub was sighted 2.0 miles (3.2 km) from her capture site of September 1. On September 23, an adult male was shot illegally 1.5 miles (2.4 km) from his original summer (July 25) capture site. On October 24, a yearling female was sighted 0.5 miles (.8 km) from her original summer (July 26) point of capture. It is not known if any of these bears would have moved or did move from their summer home ranges later in the fall. The other five bears, captured in the summer and located in the fall, were found an average of 9.0 miles (14.5 km) from their original cap- ture site. These fall locations were determined between September 11 and November 4. Eadio-coUared bear number 10 moved from his sum- mer home range and then stayed on a small fall home range for at least 30 days (Figure 8). It is not known whether other bears located a relatively large distance from their original capture sites were staying in a newly defined home range or were wandering. In summary, average fall movements were greater than average sum- mer movements, but not all of the animals moved from their summer home ranges. Comparison With Other Studies of Black Bear Mobility Movement data from other reports (Table 3) show two important trends in bear movement habits. First, most studies report a larger average movement in the faU than in the summer. And second, male bears show larger average movement than females. TABLE 3. — Average Movements of Black Bears According to Season and Sex Minimum average movement (miles) Summer Fall All year Location and source Males Females Michigan — Erickson and Petrides (1964).. Montana — Jonkel and Cowan (1971) Virginia — Stickley (1961) 2.1 1.3 1.85 6.7 7.6 6.10 5.4 3.9 10.0 3.67 1.4 1.6 1.8 Trinity County (1972) ... 3.13 BLACK BEAR STUDY 17 A greater average movement in the fall suggests an extension of the summer home range, or movement to a different fall home range, or possibly fall nomadism. Increased fall movement can be a result of bears taking advantage of local food abundance (Spencer 1955). In Montana, Jonkel and Cowan (1971) reported that throughout the year a small home range was used by all bears, except transient sub-adults. They believed that the large diversity of climate, topography and veg- etation in a small area made it possible for bears in the Montana area to maintain small yearly home ranges. In this study, bears seemed to have an extremely small summer home range, but part of the population moved in fall to new food supplies. By the latter half of September the supply of manzanita berries, the major summer food, had been exhausted in the summer trapping area. There appeared to be no mast crops, berry crops, or other easily avail- able or plentiful food sources in the area to replace manzanita berries. There were plentiful food sources in the form of spawning salmon, acorn crops and manzanita berries in the areas to which bears were known to move. Despite poor food conditions a segment of the study population did not move far from their summer home range, or possibly they moved later in the fall. That portion of the study population that stayed close to their summer home range was largely made up of sows with cubs or immature bears. Sows with cubs are generally expected to stay on small home ranges. Jonkel and Cowan (1971) reported that dis- persal was pronounced in yearling bears in Montana. However, there was no evidence that this was the case with yearling bears in the Trinity study area. Contrary to other reports, movement data from the Trinity study area were not clearly differentiated according to sex. The average max- imum known summer movement of females was slightly greater than that of males. However, it appears that adult females with cubs make significantly shorter fall movements than either lone adult females or adult males. Food Habits Seats were collected from July through October of 1972. All scat samples were analyzed, most in the dry state, at the California Fish and Game laboratory. Scat samples usually were not collected unless they could be dated to within approximately a week. During July and August most samples were collected along roads, around trapsites and bait stations, and from traps during regular trapping activities. Trap bait did not appear in scats taken from traps. All of the samples in July and August came from the summer trapping area. In September and October a system of trails and roads was checked periodically for scats. Part of this system was within the summer trapping area. The remainder was around Lewiston Lake, in an area with a high proportion of Manzanita thickets and oak woodland. Table 4 summarizes the major food items found in 106 scat samples. Volumes of food items were estimated, but because volume composition in a scat is not necessarily indicative of the volume eaten, final data 18 CALIFORNIA FISH AND GAME "were expressed in terms of frequency of occurrence, with general vol- ume trands noted. These data are presented only as a food index and a supplement to other data in the study. Many of the September and October samples came from a king salmon [Oncorhxjnclxus tshawtscha) spawning area on the Trinity River near the breast of Lewiston Dam. Although bears were seen feeding on salmon, scats dropped in the area contained mostly acorns and manzanita berries apparently eaten in the surrounding area. Bears in the study area depended primarily on manzanita berries from July through August (Table 4). Thirty four of 35 scat samples contained manzanita berries, and a large majority of these samples were essentially 100% manzanita berries with other items in trace amounts. Grasses and forbs were the next most common food item in July and August, but they were a relatively small volume of the samples in which they occurred. Dogwood seed occurred in 14% of the August scats, usually as a major volume item. In September and October manzanita berries remained a major food. By late September and into October acorns became a dominant food item in the Lewiston Lake area. Although acorns were found in 38% of the October scats, none occurred in any of the scats from the summer trapping area. Grasses and forbes continued to be found frequently but in small amounts. Deer hair was found in 5 of 106 samples. Reproduction Of all adult female bears examined during the summer trapping period, two were in estrus. These bears were captured on July 17 and July 18. Of three adult female bears captured after July 18 that were believed to be without cubs, none were observed in heat. The beginning of the breeding season could not be estimated because trapping did not begin until the last week in June. Four of the 11 adult females captured (36%) were known to have a litter of the year. Three of these litters were either handled or seen. The other litter was not observed during the handling of the mother, but was sighted with the mother several weeks later. Two other females unaccompanied by cubs during capture were lactating. The average litter size in Trinity County was 1.67 cubs, based on six litters handled or seen. The female black bear has seasonally constant estrus with ovulation induced following mating. The mating season can vary but usually occurs during June and July (Erickson and Nellor 1964). Grinnell et al. (1937) reported a pair of California black bears mating on June 25. Of eight females trapped by Stickley (1961) in Virginia in one summer, three were in heat in June, three in July and two in August. Jonkel and Cowan (1971) found in Montana that bears were in estrus as early as May 25 and as late as August 10, with a peak in June. Data indicated that most mating in Trinity County is over by mid-July. Black bear litters seem to run slightly over two cubs in the eastern United States. Average litter size was reported as 2.4 in Maine (Spencer 1955), 2.2 in Florida (Harlow 1961) and 2.15 in Michigan (Erickson 1964). In the western United States reported average litter size is usually below two cubs. Average cubs per litter has been reported as BLACK BEAR STUDY 19 « o "9 e ^ M — e • 3 o 0 e E V 0 u k « 3 u w e w k 0 ^ «^ c 0 s X X ^ w « C k V 0 3 E o- « 0) k k «*• 01 M ^ 3 w 41 Tl CI Ik U =■ W O rj 01 0 ^£ M o B U k o II W sP si u « ^ «k s e lA u S ■»^ Ik k 0) a E it Ul GO < M ^ fe ^ fe ^ fe ^ ^ fe T3 O O o to o o ^ t^ lO t^ OS CO C^ CO I CO I • IN O O O CD cot^o^-^r^t^t^Tfoo COCOt^rt|>fOCOfOI>-* oi CO r^ t^ 05 CO CO * * I 00 ■* 00 o I Tj< >-l * o t^ o O CO o O CD O 1 O CD O CD CO rtH CD 1 CO ^ C3 c3 « CO S =8 -4^ 6 01 V d -^:> > c3 TI N Wl « C ■^■1 ■** o3 ffS o > _ o Jo - si/ O O 6«= D. O, o, -l Tjl t- CO I t^ CO CD CO CD "-I CO CO CD CO Tj* 1-1 Tj* IN I 03 Q, =! P. -a G 03 a « .t>.t>.t^tOt^ 01 < 0 s A 1 kOiOiO>0>AiCtO>A s cocococococococo S. > > « i 1 fc f 1i CQ3 ' _; iH fH 1-! ci 1 ci ci e —1 (N e 1 E 1 D ia -►> _ 0 « o'*sl3 ^ 1 • . 1 t-( 1^ «5 OS «0 O b- ■* T)< t>. % 1-H CO •^ ■o e 0 1 $ a t-OSONOlfl i«o r-l»H(NNMCO ITJHIO ■.oo>eo ^^ •^ s 0 w c S s •M QQ x ■1 "S M COfOTjtiOCoS iMOO U3 Tjj to I,- < +» -< t CQ 0 Z fc,-0 « 2 iJ i I'i eotO^Ji-iMcc irHN 1 ^S 1, ^ H ^ €0 a J2 — 1 OS OS OS OS OS O O) I 02 •^05-*'o5T) 1 1 i-i ea CO Ti* ic OS OS 1 1 1-H »— 1 t-H t-( t— 1 t— ( -^ 1 iiooooqoo O »C O ifl O iC o »o O 1 ii-c(NC0'-l.^t-lr-tOIUi 0. o « 32 CALIFORNIA FISH AND GAME decreased slightly as the body deepened (Fip:ure 2). The mouth was inferior in position until 3.5-3.9 mm when it became terminal. The larvae around 5.8 mm exhibited asymmetric growth, with the left eye 20-1 10- 40- 30- 20- 10- 0 ^ 60H Ctl 50H 40-1 ^30H I 20 i5 10- 0 80- 70- 60- 50- 40- 30- 20- 10- 0 ,1 _ ---+-■• * + ^ -. EYE DIAMETER 0.1 FIGURE 3. T ' 1 — ' I ' I ' r —I — 0.2 1 — ' I • I •! I • I • I ' I • * 4. I I f f *+ - HEAD LENGTH I ■ I — ' t ' I ' I ' I < I < I i..-i ii it.-- .. 1-- ♦ BODY DEPTH I ' I ' I M 1 "— T — " I ' I M I ' 1 • I ' I ' \ ■ H-f- + 1 "^ SNOUT TO ANUS LENGTH T — ' I MM T ' 1 — ' I ' I '! 0.4 0£ 0.8 1.0 2.0 4.0 6.0aOIO —I • — I MM' 20 40 60 80 (mm) Morphometric proportions (in logorithmic scale) of the diamond turbot, plotted OS percentages of standard length. DIAMOND TURBOT LARVAE 33 in the midst of migration to the right side. Eye diameters remained much the same in relation to body length throughout development (Figures). The finfold began at the forehead and extended posteriorly around the tail and forward to the yolk-sac or gut. It remained complete and translucent throughout development until around 3.8 mm when the anlagen of the dorsal and anal fins and the caudal fin were seen form- ing. At hatching the pectoral fin bud was visible on the dorsal aspects of the yolk-sac. By approximately 2.4 mm, the pectoral fins appeared as small lateral projections. The 4.9 mm larvae possessed nearly developed dorsal and anal fins but the fin ray counts were not complete. Likewise, the metamorphosing larvae did not have complete dorsal and anal fin development, but the rays were more discernible. The caudal fin developed simultaneously with the dorsal and anal fins. The upward flexion of the caudal noto- chord occurs at about 4.0 mm s.l. The hypural cartilages and the full complement of caudal rays were visible in the metamorphic specimens (Figure 2c). In these advanced larvae, the pterygiophore primordia appeared as longitudinal ridges along the bases of these fins. The smallest juvenile specimen (11.5 mm) did show complete vertical fin ray development. DISCUSSION From occurrences of the larvae, Hypsopsetta guttulata appeared to have an extended spawning period. Larvae, and what I believe to be the pelagic eggs of the diamond turbot, were collected from early June through mid-October. These eggs averaged 0.80 mm in diameter with usually one large oil globule (average 0.14 mm diameter) and numerous other globules scattered throughout the yolk. They can easily be distinguished from Pletoronichthys eggs by the absence of the hexagonal pattern on the chorion and the presence of oil globules. It is very easy to confuse H. guttulata larvae with Pleuronichthys larvae, especially with the similarity in pigmentation and morphology. There are no other known larvae in this geographical area which have such heavy pigmentation and which might be confused with turbot larvae. So differentiation needs to be made between the larvae of the different turbots which might occur in the San Francisco Bay area. In general, the Pleuronichthys larvae are larger than Hypsopsetta larvae in the early stages of development. P. verticalis is the smallest at hatching being 3.16 mm (0.12 inch) long (Budd 1940). Even allow- ing for shrinkage during preservation, Hypsopsetta larvae would not exceed about 2.00 mm (0.08) at hatching. Yolk-sac larvae of P. verticalis have a notable crest not as pronounced in the diamond turbot. Another distinguishing characteristic for the young is the presence of oil globules in the yolk. The finfold pigment patches found in both P. verticalis and P. decurrens are not as developed or as consistently present in the diamond turbot. Only the very small Hypsopsetta larvae (2.4 mm) had finfold patches. The mottled turbot, P. coenosus, is separated most easily because it is very large at hatching (5.54 mm) and has heavy pigmentation throughout its finfold. 34 CALIFORNIA FISH AND GAME It can be seen that various turbot larvae are best separated by pig- mentation (especially in the finfold), and relative size at which struc- tures develop in post yolk-sac larvae. ACKNOWLEDGEMENTS I wish to acknowledge the valuable advice, instruction, and generous time E. H. Ahlstrom and H. G. Moser of the Southwest Fisheries Oceanography Center oiTered me during the course of this study. I also would like to thank the California Academy of Sciences, especially Lillian Dempster, for providing equipment and specimens. REFERENCES Ahlstrom, E. H.. and O. P. Ball. 1954. Description of eggs and larvae of jack mackerel (Trachurus symmetricus) and distribution and abundance of larvae in 1950 and 1951. U.S. Fish Wildl. Serv., Fish. Bull. 56(97) : 209-245. Baxter, J. L. 1960. Inshore fishes of California. Calif. Dep. Fish and Game. Sacramento : 80 p. Budd, P. L. 1940. Development of the eggs and early larvae of six California fishes. Calif. Dep. Fish and Game, Fish. Bull. (56) : 1-50. Jordan, D. S., and C. H. Gilbert. 1880. List of the fishes of the Pacific coast of the United States, with a table showing the distribution of species. Proc. U.S. Nat. Mus., 3(1880) : 452-458. Lewis, R. M., W. F. Hettler, Jr., E. P. H. Wilkens, and G. N. Johnson. 1970. A channel net for catching larval fishes. Ches. Sci., 11(3) : 196-197. Limbaugh, C. 1955. Fish life in the kelp beds and the effects of kelp harvesting. Univ. of Calif., Institute of Marine Resources, Ref. 55-9, 158 p. Orton, G. L., and C. Limbaugh. 1953. Occurrence of an oil globule in eggs of pleuronectid flatfishes. Copeia 1953 (2) : 114-115. Calif. Fish and Game 61(1) : 35-46. 1975. THE FOOD OF NEOMYSIS MERCEDIS HOLMES IN THE SACRAMENTO-SAN JOAQUIN ESTUARY ANGELA L. BALDO KOST ^ and ALLEN W. KNIGHT Deportment of Water Science and Engineering University of California, Davis ABSTRACT Gut contents were determined in approximately 1500 opossum shrimp, Neomysis mercedis Holmes, from the Sacramento-San Joaquin Estuary. The shrimp, obtained from 12 stations over a 13-month period, were 2 to 17 mm (0.08 to 0.67 inch) long. The most abundant items in the gut were detritus and diatoms. The percentage of detritus relative to diatoms was greater in winter than in summer, and increased with shrimp size. Forty kinds of diatoms were found in the gut. Certain diatom genera predominated in shrimp from particular locations and in shrimp col- lected during particular times of the year. Animal fragments and other items also encountered were much less abundant than detritus and diatoms. Thus, the shrimp appears to eat a variety of food items. INTRODUCTION This study was initiated, along with others on the opossum shrimp, Neomysis mercedis Holmes, to improve understanding of environmental relationships in the Sacramento-San Joaquin Estuary which might be affected by water development projects. The present study is an im- portant component of an extensive investigation into many aspects of the biology and ecology of N. mercedis and the striped bass, Morone saxatilis. N. mercedis is an important component of the trophic structure of the Sacramento-San Joaquin Estuary. This shrimp is the major food item in the diet of young striped bass in all seasons of the year (Stevens 1966). This study involved the gut contents of approximately 1500 opossum shrimp collected from Suisun Bay and the Delta from March 1970 through March 1971. Very little previous information was avail- able on the feeding habits of this shrimp. MATERIALS AND METHODS Sampling Stations The opossum shrimp were collected by the California Department of Fish and Game, Bay-Delta Fishery Project, from 12 stations extendin^ from Suisun Bay up the Sacramento River to Rio Vista, and up the San Joaquin River almost to Stockton (Figure 1). The station numbers used in this study are those of the California Department of Fish and Game. 1 Present address: 9321 Discovery Way, Apt. H, La Jolla, California 92037. Accepted August 1974. ( 35 ) 36 CALIFORNIA FISH AND GAME Sampling Procedure Each month from March 1970 to March 1971 a sample was obtained from each of the 12 stations, for a total of 156 samples. Monthly- sampling was conducted during three consecutive days between one- half hour before and one hour after high neap tide. Samples were taken with a cone-shaped plankton net of silk bolting cloth with 23 meshes per inch. The net opening was 0.1 m- (1.07 ft^). A diagonal tow was made from the bottom to the surface, and each tow took approximately 10 minutes. Each sample was preserved with 5-10% formalin, along with enough Rose Bengal dye to stain the shrimp. Five pair of shrimp were selected from each sample. The shrimp were selected to obtain a wide range of sizes (2-17 mm from the anterior STOCKTON SACRAMENTO -SAN JOAQUIN BAY DELTA NEOMYSIS SAMPLING STATIONS FIGURE 1. Sacramento-San Joaquin Bay-Delta Estuary System, Neomysis sampling stations. NEOMYSIS MERCEDIS FOOD 37 end of the eyestalk to the base of the telson). The sex was determined for each organism 7 mm and longer. Shrimp shorter than 7 mm could not be sexed and were considered as juveniles. Shrimp of the same size and sex were chosen for each pair, and their gut contents were pooled. Shrimp Dissection and Slide Preparation The stomach and intestine were removed from each shrimp with two fine needles under a dissecting microscope. The full gut was located readily since it did not take up the stain. The thin exoskeleton was teased apart along the dorsal surface of the organism from the head to the base of the telson, and the gut was then carefully lifted out. Each pair of pooled guts was placed on a glass microscope slide in a drop of water. The stomach and intestine were gently broken open with the needles, and the contents were dispersed and stirred in the water. The slide was then air-dried, a drop of Permount mounting medium was applied, and a 1 cm^ glass coverslip was placed on the slide. The preparation was dried overnight. Enumeration of Gut Contents Items present in the mounted gut contents were counted and iden- tified with a compound microscope at 400 X- Every item was enumerated except when more than 1000 algal cells were present on a slide. In such cases (about half of the total), enumeration was terminated at 1000 cells. According to Javornicky (1958) counting 1000 cells limits the expected error to ±6.3% (with a probability of 0.95). TABLE 1. — Diatoms Encountered in Neomysis Gut Contents Diatom Total number counted Diatom Total number counted Coscinodiscus sp. - _- 196,633 166.380 57.206 16,893 11,882 7,173 6,450 4.661 4,412 3,547 2,002 1.808 1,182 446 414 288 285 250 223 174 Rhopalodia sp. 159 Melosira sp. _- Gomphonema sp. No. 1 Surirella sp. No. 2 143 Cvclotella ST>. _ 96 Nitzschia paradoxa Nitzschia sp. No. 4 88 Tabellaria sp. Pinnularia sp. 85 Diatoma sp. . _ Stauroneis sp 45 Fragilaria sp. No. 1 Eunotia sp. . _. .- 32 Stephanodiscus sp. Fragilaria sp. No. 2 22 Synedra sp. ..--. .--. Actinoptychus sp 18 Asterionella sp. Pleurosigma sp. 15 Epithemia sp. . Meridian sp. 13 Naviciila sp.. . Acnanthes sp -- 9 Triceratium sp. _ Gyrosigma sp. 6 Cocconeis sp. Amphora sp. _ . 5 Cymbella sp. . . .. Fragilaria arcus 5 Nitzschia sp. No. 2 . Skeletonema sp.. 4 Surirella sp. No. 1 . Lepidodiscus sp. 3 Rhoicosphenia sp .. Frust ula sp 1 Nitzschia sp. No. 3 _. __ Gomphonema sp. No. 2 Nedium 9p. 1 Diploneis sp. 1 38 CALIFORNIA FISH AND GAME Algae were identified to the generic level, but many animal fragments could not be identified and were included in the general category "animal fragments". Detritus was enumerated by using a microscope ocular attachment which divided the field into 100 squares, 0.0258 mm on a side, at 400 X- The quantity of detritus was approximated by counting the number of squares filled in each field examined. The portion of the field occupied by diatoms was also estimated, according to the detailed procedure described elsewhere (Baldo, 1972). RESULTS The most abundant of the materials found in the gut were detritus and diatoms. Each varied in importance with station, time of year, and size of shrimp. Of the identifiable material, a total of 40 diatoms were encountered (Table 1). In addition there were 2 genera of green algae, one dinoflagellate, rotifer loricas, tintinid loricas, crustacean fragments, sponge spicules, pollen grains, and (apparently) fragments of higher plants (Table 2). TABLE 2. — Additionol Items Encountered in Neomysis Gut Contents Item Total number counted Green algae Scenedesmus Pediastrum Dinoflagellate Ceralium Rotifer loricas Tintined lociras Crustacean fragments. . Sponge spicules Pollen grains Higher-plant fragments 38 20 252 129 739 129 252 10 Detritus The majority of the guts examined contained a significant amount of unidentifiable material. This unidentifiable material was classified as detritus. It was usually a gold-brown color. Some of this material ap- peared to be homogeneous, but it was generally mixed with particles or objects of different sizes and shapes of unknown origin. This material was probably either organic debris (e.g., peat or plant material) that the shrimp had ingested, or partially digested algal material. Its actual origin was not determined. Comparison of the relative amounts of detritus and diatoms in the guts showed that detritus was more important during the winter (De- cember to March), while diatoms were more important during the sum- mer and early fall (Figure 2). NEOMYSIS MERCEDIS FOOD 39 DETRITUS DIATOMS 8 9 1.0 MONTHS 11 12 FIGURE 2. The percentage of total diatoms and detritus relative to each other. Gut contents from all 12 stations combined for each month from March 1970 through March 1971. Over the shrimp size range evaluated, the relative amounts of detritus and diatoms differed markedly. Diatoms were more plentiful in small shrimp than in large ones. On the other hand, detritus was more abundant in the larger shrimp (Figure 3). Shrimp 16 to 17 mm long were excluded because only one of each was examined. Calculations for most of the other sizes were based on more than 80 individuals. The increase in percentage of detritus with size was rather uniform except for 2 mm shrimp (which included only 9 individuals). % lOOn SO- SO- 70 60 50- 40- iO\ 20 lOJ 0 lllllllllll DIATOMS ■1^ DETRITUS 5 6 7 8 9 SHRIMP SIZE IN MM 10 12 15 FIGURE 3. The percentage of total diatoms and detritus relative to each other in the gut of shrimp of different sizes (2 to 15 mm), all stations and months combined. 40 CALIFORNIA FISH AND GAME Diatoms Of the 40 kinds of diatoms t'lieountorod in tho guts of N. mercedis, certain genera predominated (Table 1). Two diatoms, Coscinodiscus and Melosira, were far more abundant than the rest. Coscinodiscus was MEL05IRA CYCLOTELLA TABELLARIA NITZSCHIA PARADOXA DIATOMA FRAGILARIA STEPHANOOISCUS SYNEORA ASTEHIONELLA EPITHEMIA NAVICULA THICERATIUM 24 44 34 52 58 62 68 STATIONS 74 80 88 92 102 FIGURE 4. Variation in the 13 most common diatom genera encountered in the gut of shrimp from each of the 12 Bay-Delta stations, oil months combined. Each genus is represented as its percent of total diatoms. Diatoms not included con- stituted less than 1% of the total. NEOMYSIS MERCEDIS FOOD 41 CYCLOTELLA TABELLARIA NITZSCHIA PARADOXA DIATOMA FRAGILARIA STEPHANODISCUS SYNEDRA ASTERIONELLA TRICERATIUM 3456789 10 11 12 1 23 MONTHS FIGURE 5. Variation in the 13 most common diatom genera encountered in the gut of shrimp from March 1970 through March T977, all stations combined. Each genus is represented as its percent of the total diatoms. the most important diatom in guts of shrimp from the lower Delta and Suisun Bay stations (Figure 4). At these downstream stations it often constituted 90 to 99% of the total diatoms. The diatom Melosira replaced Coscinodiscns as the most abundant diatom in shrimp from upper Delta stations during most of the year. Cyclotella was also im- 42 CALIFORNIA FISH AND GAME portant at eastern stations, especially at station 92, near Stockton. These geographical variations in the relative abundance of the various diatoms were greater than seasonal variations in relative abundance (Figures). Coscincxiiscus 7 8 9 MONTHS FIGURE 6. Variation in the diatom Coscinodiscus sp., represented as its percent of the total diatoms in the gut for each month from March 1970 through March 1971 at 12 Bay-Delta stations. Figures 6, 7, and 8 are three-dimensional graphs showing the spatial and temporal distribution of the 3 most common diatoms. Each diatom is represented as its percent of the total diatoms in all the guts ex- amined from each station and each month. It is again evident that Coscinodiscus was the most abundant diatom in the gut from the lower Delta. It was replaced by Melosira as the most common diatom in the upper Delta. The percentage of Coscinodiscus in shrimp from stations in the upper Delta is greater from June to August than during the Melosira 3 4 5 6 7 8 9 10 11 12 1 2 ._ MONTHS FIGURE 7. Variation in the diatom Melosira sp., represented as its percent of the total diatoms in the gut for each month from March 1970 through March 1971 at 12 Boy-Delta stations. NEOMYSIS MERCEDIS FOOD 43 rest of the year (Figure 6). This increase appears to be related to the salinity, which increases upstream during the summer when the flow in the rivers is decreased (Figure 9). Distribution of the remaining diatoms in the guts also varied geo- graphically and seasonally. For example, Triceratium appeared pre- dominantly at station 102 during most of the year whereas Tdbellaria appeared at station 68 during the late spring and early summer. For a more complete description of the distribution of the less common dia- toms, seeBaldo (1972). Animal Fragments and Other Gut Contents Many guts contained fragments (mostly appendages) of unidentified crustaceans. A copepod was encountered which was nearly intact. The Cyclotella MONTHS FIGURE 8. Variation in the diatom Cyclofella sp., represented as its percent of the total diatoms in the gut for each month from March 1970 through March 1971 at 12 Bay-Delta stations. 1(^000 ELECTRICAL CONDUCTIVITY MONTHS FIGURE 9. Variation in electrical conductivity in umhos of water at 12 Bay-Delta stations for each month from May 1970 through March 1971. Data are from Knight, Biggar, and Tanji, 1972. 44 CALIFORNIA FISH AND GAME crustacean fragments found increased in number with shrimp size, but so few crustaceans were found that the validity of this observation is questionable. Rotifer loricas which appeared to be of the genus Kcratella were found in a number of shrimp. Tintinid loricas were less common. The number of rotifers or tintinids present was not correlated with shrimp size. At least two varieties of sponge spicules were present in the gut of a number of shrimp. Two genera of green algae, Scenedesmus and Pcdiastrum, were en- countered in very small numbers. A single dinoflagellate, Ceratiiim, was found in a shrimp from Suisun Bay. Pollen grains were present in very small numbers at every station. Fragments of higher plants were only minor contributions. For more information on the spatial and temporal distribution of these items, see Baldo (1972). DISCUSSION Many investigators (e.g., Esterly 1916, Wilson 1951, Mecom and Cummins 1964, Hart 1934) have noted that recognizable items in the gut may not be the sole source of nutrition. In some cases the items may not even be a source of nutrition. The hard skeletons of items such as diatoms and crustaceans may be the main reason for their retention and recognition in the gut. Many kinds of algae such as greens and blue-greens would be less likely to retain their original structure after being eaten and partially or totally digested. Items such as bacteria, either free in the water or surrounding detritus particles, and other nanoplankters which would be difficult to identify in the guts, may or may not play a significant role in the nutrition of these shrimp. Data were obtained from the Federal Bureau of Reclamation in Sacramento on the phytoplankton present at Delta stations during the same period. Many of the diatoms found in the shrimp guts were similar to those in the phytoplankton samples. A number of Chloro- phyta, Cyanophyta, and Crytophyta. however, which were present in the phytoplankton samples were not in the shrimp guts. It was not possible to determine from the gut contents examined whether the shrimp ingested these green algae and other forms and digested them beyond identification, or whether they selected against these forms. The seasonal changes in the relative occurrence of detritus and dia- toms in the guts noted in this study presumably reflect changes in their relative availability. Diatoms are several times more abundant in the environment during the summer than in the winter (Delta Fish and Wildlife Protection Study, 1972). Conversely, detritus may be more abundant during the winter, when increased runoff likely carries greater amounts of organic debris into the Estuary. Both of these probable changes parallel the changes in relative abundance observed in the shrimp guts. This study does indicate that N. mercedis is able to ingest a wide variety of foods. It is reasonable to assume that it utilizes whatever food is available at any particular place or time, whether it be detritus or one kind of diatom or another. NEOMYSIS MERCEDIS FOOD 45 Mauchline (1967) indicated similar results for the mysid Schistomysis spiritis. That shrimp extracts suspended matter indiscriminately from the water and must therefore use a large variety of foods. In guts of S. spiritis he found fine particulate matter mixed with sand grains, various diatoms, dinoflagellates, filamentous algae, some leaf fragments, spores, and seeds of terrestrial origin. In addition, Mauchline (1971a, b) found that the mysid, Paramysis arenosa and Neomysis inte- ger could utilize many food types when available, including plant and animal matter, detritus, and inorganic particles. I?aymont et al (1964) stated that mysids take whatever food is more or less immediately available. They indicated that detritus is important in the nutrition of N. integer, especially in estuarine conditions where there is normally a constant supply of organic matter. They observed Neomysis stirring up detritus on the bottom with its appendages and ingesting it. Lasenby and Langford (1973) found that My sis relicta in two Canadian lakes is potentially omnivorous. Wilson (1951) examined the stomach contents of Neomysis mercedis Holmes in British Columbia, and found diatoms, dinoflagellates, blue- green algae, vascular plant material, and animal material consisting of mainly copepod and mysidacean remains. Tattersall (1951) indicates that most mysidacea, including N. integer, filter-feed microscopic plants and animals and detritus. They are able to pounce on living copepods and ingest them and have been seen carry- ing around dead mysids and amphipods of their own size while eating them. Acanthomysis scidpta will readily eat injured or freshly killed members of its own species and anything else it can capture (Green 1970). N. mercedis has been seen in the lab eating dead or weak mem- bers of its own species. It is probable that shifts in environmental quality would alter the food supply available to A'^. mercedis. Changes in water chemistry (salinity, pollutants, etc.) would favor certain forms of algae rather than others. Increased turbidity could inhibit algal growth. However, since N. mercedis appears to utilize a diversity of items, food will probably not be limiting to the shrimp as long as either detritus or some form of algae is present in sufficient quantity. SUMAAARY 1. Detritus and diatoms were the major food items found in the gut of N. mercedis from the Sacramento-San Joaquin Delta. Animal frag- ments and other items were less abundant. 2. The relative abundance of detritus and diatoms in the gut varied during the year. Diatoms increased in relative amounts in summer, and detritus increased in the winter months. 3. The relative importance of detritus increased in the gut of larger shrimp, and, conversely the relative importance of diatoms increased in the gut of smaller shrimp. 4. Previous reports indicate that mysid shrimp are capable of utiliz- ing a wide variety of foods. The results of this study are consistent with those reports. The shrimp N. mercedis appears to be omnivorous. ACKNOWLEDGEMENTS This research was supported in part by a grant from the Water Resources Center, project number W243. We thank Harold Chadwick 46 CALIFORNIA FISH AND GAME and staff of the California Fish and Game Department-Delta Study group for providing the opossum shrimp and extending many courtesies and conveniences. Gerald J. Kost was of considerable assistance in computer analysis of these data. The authors are grateful to Mary Ann Simmons for her assistance in preparation of this manuscript. REFERENCES Baldo, A. L. 1972. The food of Neotnysis aicatschensis in the Sacramento-San Joaquin Delta. Masters Thesis, University of California at Davis. Davis, Cali- fornia. Delta Fish and Wildlife Protection Study. 1972. Dissolved Oxygen Dynamics Sacramento-San Joaquin Delta and Suisun Bay. California Departments of Water Resources and Fish and Game. 129 pp. Esterly, J. L. 1916. Feeding habits and food of pelagic copepods and the question of nutrition by organic substances in solution in water. Universitv of California Publ. Zool. 16 : 171-184. Green, J. W. 1970. Observations on the behavior and larval development of Acanthomysis sculpta (Tattersall) (Mysidacea). Canadian J. Zool. 48:289-292. Hart, T. J. 1934. On the phytoplankton of the south west Atlantic and Belling- shaussen Sea 1929-1931. Discovery Rep. 8 : 1-268. Javornicky, Pavel. 1958. Revision of some methods of quantative estimation of phvtoplankton. Scientific papers of the Chemical Engineering School. 1958. Fac. Technol. Fuels and Water 2 : 283-367. Knight, A. W., J. W. Biggar and K. K. Tanji. 1972. Bay Delta Water Chemistry Study, unpublished data. Dept. of Water Science and Engineering, U. C. Davis, Davis, California. Lasenby, D. C, and R. R. Langford. 1973. Feeding and assimilation of Mysis relicta. Limnol. Oceanogr. 18 : 280-285. Mauchline, J. 1967. The biology of Schistomysis spiritus (Crustacea, Mysidacea). J. Mar. Biol. Assoc. U. K. 47 : 383-396. Mauchline, J. 1971a. The biology of Paramysis arenosa (Crustacea, Mysidacea). J. Mar. Biol. Assoc. U. K. 51 : 339-346. Mauchline, J. 1971b. The biology of Neomysis integer (Crustacea. Mysidacea). J. Mar. Biol. Assoc. U. K. 51 : 347-354. Mecom, J. O., and K. W. Cummins. 19(>4. A preliminary study of the trophic relationships of the larvae of Brachycentrus americanus (Banks). Trans. Amer. Microscop. Soc. 83 : 239-250. Raymont, J. E. C, J. Austin and E. Linford. 1964. Biochemical studies on marine zooplankton. I. The biochemical composition of Neomysis integer. J. Conseil Perm. Intern. Exploration Mer. 28 : 354-363. Stevens, Donald E. 1966. Food habits of striped bass, Roccus saxatilis, in the Sacramento-San Joaquin Delta. Calif. Dept. Fish and Game, Fish Bull. 136 : 68-96. Tattersall, W. M., and O. S. Tattersall. 1951. The British Mysidacea. Lond. Ray Society. 460 p. Wilson, R. R. 1951. Distribution, growth, feeding habits, abundance, thermal and salinitj' relations of Neomysis mercedes (Holmes) from Xicomekl and Serpentine Rivers, British Columbia. M. A. Thesis, U. of British Columbia, Vancouver, Calif. Fish and Game 61(1) : 47-53. 1975. NOTE ON THE ECOLOGY OF THE RATFISH, HYDROLAGUS COLLEI, IN THE GULF OF CALIFORNIA^ C. p. MATHEWS FAO/INP AP M-10, 778 Mexico (1) D.F. Mexico^ Hydrolagus collei, the ratflsh, has been taken frequently in the north- ern Gulf of California. This species shows a marked migratory pattern being relatively abundant and widely distributed in this area in Febru- ary-March, and found at few stations and in low numbers in June and August. Males appear to grow more slowly than females and are less frequent in the catches. The breeding season must be several months before or after the period of spring abundance in the northern Gulf. Hydrolagus coffei, el pez llamado pez rata de California, ha side capturado frecuentemente en el norte del Golfo de California. Esta especie demuestra un patr6n migratorio; es relativamente abundante en esta zona en febrero y marzo y muy restringido en su distribuci6n y en abundancias muy bajas en junio y en agosto. La estaci6n de repro- duccion debe de estar varies meses antes a despuis del periodo de abundancias altas en el norte del Golfo de California. INTRODUCTION Hydrolagus collei has been known to occur in eastern Pacific tropical waters from western Alaska to northern Baja California ; Johnson and Horton (1972) have described some aspects of the ecology of this species. It is the object of this paper to present some of the results of the exploratory and prospective fishing cruises of the Alejandro de Humboldt, during which Hydrolagus collei was found to be fairly widespread although usually in low abundances, at certain times of the year in the northern Gulf of California. During a series of cruises con- ducted by the K/V Alejandro de Humboldt of the Instituto Nacional de Pesca of Mexico, between June, 1971 and March, 1972, suflScient data were gathered for the bathymetric and geographic distributions of this species to be known in the area from Guaymas to Isla Tiburon and in the zone north of Isla Tiburon and Isla Angel de la Guarda. During cruises conducted from April 1971 to December 1971, in other parts of the Gulf of California no ratfish were taken although on all cruises the same depths (100-600 m) (328-1,968 ft) were sampled. METHODS The Alejandro de Humboldt is a 42 m (138 foot), 450 gross ton stern trawler equipped as a research vessel. The usual sampling tool was an otter-trawl net, with a 41 m (136 feet) headline, and cod-ends with mesh sizes of 4.5 cm (1.8 inches) and 5.5 cm (2.2 inches). The smaller 1 These views do not necessarily reflect those of FAO. Accepted for publication June 1974. * Present address : Department of Fisheries Oceanography, Escuela Superior de Ciencias Marinas, Ensenada, B.C., Mexico. (47) 48 CALIFORNIA FISH AND GAME mesh cod-end was employed only from July 1971 onwards, but is not thought to have increased the vulnerability of ratfish to the net during this period. Specimens of ratfish were separated from the catch, and were usually measured (total body length in cm) and sexed. RESULTS Ratfish were taken from the mid-Gulf northward, but the area of greatest concentration was to the north of Isla Angel de la Guarda. rJune 1S71 August 19 71 a February-March 19 72 30° Lot N 100 fathom Isobath (183 m) 200 fathom isobath (366 m) — . - • 400 fathom Isobath (732 m) SCALC in nautical MItC S . FIGURE 1. Distribution of Hydrolagus colUi in the Northern Gulf of California. GULF OF CALIFORNIA RATFISH 49 TABLE 1 . — Stations at Which Hydrolagus eollei was Captured by the "Alejandro de Humboldt" Number of specimens Total length in cms. Depth (m) Date 1971 19 June 20 June 21 June 23 August... 1 September Date 1972 23 February. 23 February. 23 February. 23 February. 24 February. 25 February. 28 February. 28 February. 28 February. 28 February. 29 February, 29 February. 29 February. 29 February. 29 February. 1 March 2 March 3 March 10 March... 10 March 6 1 4 1 1 4 3 23 33 3 11 112 76 17 4 4 4 15 75 40-50 7 17 2 6 58 40 51 42-49 38-55 33-50 40-42 25-51 2&-49 36-45 38-50 39-51 46-48 39-49 30-50 38-51 43-55 50-51 36-44 36-44 412-446 502-506 290-310 540-560 294-296 196 304-307 390-394 309-312 192-220 366-415 288-292 304-332 250-298 201-226 300m 330 290 292-296 282-360 268-274 264-321 398-400 420-434 341-348 Barely some specimens were found between Guaymas and Isla Tiburon. Ratfish were far more abundant in February-March 1972 than in June or August 1971 (Figure 1, Table 1). In interpreting these data, it is important to remember that in June and August-September 1971, approximately 50 hours of fishing were spent in the area in which ratfish were subsequently found in February- March 1972, when about 60 hours were fished. Therefore, the amount of fishing effort expended in the summer of 1971 and early spring, 1972 was approximately equal and the marked differences in abundance and distribution are not caused by differences in fishing effort expended. They are probably due to migratory movements of the fish themselves, either towards depths the Alexandre de Humboldt could not sample, or out of the Gulf of California. Most stations (16 out of 19) at which ratfish were found were situated from 270-430 m deep. Abundances, expressed in numbers of fish per hectare, varied from 0.1 fish/ha to 2.9 fish/ha (Figure 2). These depths also contain all stations at which abundances exceeded two individuals per hectare. However, ratfish were found up to 196 m deep in low abundances (0.2 or less/ha). The envelope curve for the stations at which ratfish were found in summer 1971, is based on only five occurrences, but three of these were 50 CALIFORNIA FISH AND GAME ABUNDANCE. NUMBERS /ha. 100- 200- E Ql Q 3 00- 3 _i 500- FIGURE 2. Bathymetric distribution and abundance of Hydrolagus collei. GULF OP CALIFORNIA RATFISH 51 in deeper waters than any of the spring 1972 occurrences (Table 1), and all five occurrences were in low abundances (0.1-0.4 fish/ha). This suggests that in summer (June-September) ratfish move out of the northern Gulf of California into deeper waters and return at the latest by the end of winter (February), probably earlier. A total of 448 ratfish was measured and sexed on the Alexandre de Humboldt in February and March 1972 (Figure 3). Two modes are present, at 38-39 cm and at 47 cm, corresponding to the maximum occurrence of male and female fish. It is unlikely that there is any ques- tion of sex reversal in this species, so it may be concluded that females grow to a larger size than males. From 45-55 cm 10 fish were males and 168 females, giving a sex ratio of 94.4% females, with no males from 52-55 cm. On the other hand, from 35-44 cm, 131 males and 104 females were found, giving a sex ratio of 44.3% females. Females pre- dominate in the catch, of which 67.2% were females and 42.8% males. Twenty-seven females, all taken in spring 1971, from 36-55 cm in length, were opened and their gonads were examined. Two stages were recognized : i) Ovaries moderately developed, include at least one clear yellow, yolky egg 2.0-2.5 cm in diameter; frequently other, smaller and similar bodies were present. ii) Immature, when the ovaries are small and undeveloped (Table 2). TABLE 2.— Maturity in Female Ratfish Total body length (cm) State of ovaries Immature With eggs 36-40 Three immature fish 3 1 6 0 0 41-45 46-50* 51-55 One fish with eggs, one fish immature Five fish with eggs, six fish immature Eleven fish with eggs 1 5 11 * Longest immature female: 47 cm. These rather sparse data indicate that female ratfish mature at lengths between 41-47 cm, and that fish 51 cm and over are always mature. It was not possible to distinguish any stages of maturation in the male gonads : these were inconspicuous and showed no signs of sperm. The state of the female gonads, and especially the male gonads, sug- gests that reproduction takes place several months before or after the sampling period (February 1972). At any rate, no ripe animals were taken. Unfortunately, none of the fish taken in June or August 1972, were dissected. An attempt to examine the stomach contents was made, but this species has no clearly defined stomach and the area which corresponds to the stomach in other fish was empty in the fish examined. The spiral valves of four were opened ; while three of these were empty, the fourth contained what appeared to be some sand. 52 CALIFORNIA FISH AND GAME V o 9 o o E 3 Z n n 25 35 40 45 ToTol Body Length cms. 50 55 60 FIGURE 3. Size frequency distribution of the males and females of Hydrolagus collei. SHADED BARS = MALES DISCUSSION AND CONCLUSIONS Ratfish show a distinct migratory movement, being more abundant and more widespread in the northern Gulf of California in February- March, than in June-September. They do not appear to reproduce dur- ing the period of peak abundance, but this requires further investiga- tion. Females predominate in the catch and this could be because of greater vulnerability to the net, as females are on the average larger, but could also be due to females migrating more readily, or even to a natural difference in sex ratio. However, the pattern of an increasing proportion of females in larger fish is a very widespread one and on close investigation is usually found to be accompanied by increasing mortality selective against males. There is no good reason to believe this process does not operate on the Gulf of California population of ratfish. The cause of the migratory movements of ratfish is unknown, but most of the fish species in the northern Gulf of California are more abundant in early spring, so a casual agent with a rather generalized action should be looked for ; quite possibly temperature, oxygen con- centration and currents are of great importance. A different mesh size was used in spring 1972 (4.5 cm) and June 1971 (5.5 cm), so the ratfish caught were subject to different net vul- nerabilities at different sampling periods. However, there is no reason to believe that the marked seasonal differences in distribution are caused by biased sampling arising from the different equipment used, GULP OF CALIFORNIA RATFISH 53 as the material collected in August-September 1971 was also collected with the finer mesh cod-end (4.5 cm) as opposed to the courser mesh used to gather the material collected in June 1971. There were no sig- nificant differences in distribution or abundance recorded between June and August 1971 ; therefore, the change in mesh size did not signifi- cantly affect the vulnerability to the net of the fish present. ACKNOWLEDGEMENTS I wish to acknowledge the help of the Captain, F. Hernandez Ascensio, and crew of the Alejandro de Humboldt who made the work of collection so much easier and more agreeable by their friendly participation. I also wish to acknowledge the help of Biol. H. Chavez, Sr. Humberto Pedraza and T. P. Armando Arias, who were instru- mental in helping to collect the data on which this paper is based. REFERENCES Johnson, A. G., and Horton, H. F. (1972). "Length, weight, relationships, food- habits, parasite and sex and age determinations of the ratfish, Hydrolagus collei (Lay and Bernett)" Fishery Bulletin 70 (2) : 1972. Calif. Fish and Game 61(1) : 54-63. 1975. NOTES AN UNUSUALLY FAST GROWTH RATE FOR TILAPIA ZILLII TUapia zillii is an herbivorous cichlid from East Africa, and it is one of many species of TUapia introduced into the United States for the biological control of aquatic weeds (SchefPer 1960; Avault, Smith- erman, and Shell 1968). It was authorized for introduction into Cali- fornia waters in 1971 (Pelzman 1973). Any successful method of bio- logical control of aquatic weeds in the irrigation systems in southern California would be welcomed. Large sums of money are spent annually for the mechanical removal of aquatic weeds since chemical controls cannot be applied because irrigation water also provides the potable water supply. On 5 May 1972, the California Department of Fish and Game re- leased 250 T. zillii in an irrigation drainage ditch near the southeastern edge of Imperial Valley, approximately 15 miles east of Calexico, Cali- fornia. No other T. zillii have been stocked in this drainage ditch since the initial introduction. At the time of stocking, the fish averaged 5.7 g (5 per oz) (F. G. Hoover, California Department of Fish and Game, personal communication) and approximately 70 mm (2.75 inches) (un- published data). Eecently, nine large T. zillii were captured in this drain, probably individuals from the original introduction. They were collected on 16 January and 13 March 1974 by seining and throw-netting. Scale samples were taken from a dorso-lateral location near the base of the caudal peduncle. The scales were mounted between two glass slides and examined with a binocular microscope at 10 power magnification. Distances between annuli were measured at least twice with an ocular micrometer. The specimens ranged from 257 to 315 mm (10.1 to 12.4 inches) tl and weighed 380 to 709 g (0.84 to 1.56 lb) (Table 1). All were 2 years old. Back-calculated lengths ranged from 133 to 185 mm (5.2 to 7.3 inches) and averaged 164 mm (6.5 inches) at the end of the first year. At the end of the second year of growth, the range w^as 225-300 mm (8.9 to 11.8 inches) and the average, 249 mm (9.8 inches). Chimits (1957) reported a faster growth rate for T zillii, but most reports indicate that this species requires 4 to 6 years to reach approxi- mately 300 mm (11.8 inches) in length (El Zarka 1961; Fryer and lies 1972). Lowe (McConnell) (1955) reported a 2-year old T. zillii weighing 765 g (1.69 lb), but she does not indicate whether the fish grew under wild or cultured conditions. The maximum reported length and weight for T. zillii is 350 mm (13.8 inches) and 800 g (1.76 lb), respectively, (Chimits 1957) although there is a single report of one which weighed 2948 g (6.50 lb) (Anon. 1955). In addition, the fish I collected grew faster than nearly all TUapia sp. reported by lies (1971) and Fryer and lies ( 1972 ) . (54) NOTES 55 The largest fish I collected were males. Ben-Tuvia (1959), El Bolock and Koura (1960), El Zarka (1961) and Fryer and lies (1972) also reported that males were usually longer than females, particularly after they matured. Unfortunately, this growth rate does not represent the growth rate of all T. zillii in California waters, but rather, is an example of the growth potential of this species when released into an environment with a long growing season, little competition, and abundant food. This growth rate most likely will not be sustained as the population in- creases. TABLE 1. — Size at the time of capture, sex, and growth of Tilapla zillii in a south- ern California irrigation drainage ditch. Sex Length (mm) Weight (g) Length at age Date I II 13 Mtrch 1974 M M M F M F F 315 301 297 290 285 280 278 271 257 286 (11.3 inches) 709 608 595 572 522 508 587 438 380 547 (1.201b.) 185 161 178 133 174 171 173 157 140 164 (6.5 inches) 300 13 March 1974 244 13 March 1974 242 13 March 1974 240 13 March 1974 253 16 January 1974. 245 16 January 1974 244 13 March 1974 244 13 March 1974 225 Average 249 (9.8 inches) REFERENCES Anonymous. 1955. East African Freshwater Fisheries Research Organization Annual Report 1954/1955. Uganda Argus, Ltd., Kampala. 1-40. Avault, J., Jr., R. Smitherman, and E. Shell. 1968. Evaluation of eight species of fish for aquatic weed control. FAO Fisheries Report 44. VII/E3 : 109-122. Ben-Tuvia, A. 1959. The biology of the cichlid fishes of Lakes Tiberias and Huleh. Bull. Res. Counc. Israel. 8B : 153-188. Chimits, P. 1957. The tilapias and their culture. FAO Fisheries Bull. 10(1) : 1-24. El Bolock, A., and R. Koura. 1960. Age, growth and breeding season of Tilapia zillii Gervais in Egyptian experimental ponds. Notes and Memoirs No. 49. Alex- andria Institute of Hydrobiology : 1-36. El Zarka, S. 1961. Tilapia fisheries investigation in Egyptian lakes. II. A biological study of Tilapia zillii G. in Lake Quarum, Egypt, U.A.R. Notes and Memoirs No. 66. Alexandria Institute of Hydrobiology : 1-44. Fryer, G., and T. lies. 1972. The cichlid fishes of the great lakes of Africa. Oliver and Boyd, Edinburgh. 641 p. ' lies, T. 1971. Ecological aspects of growth in African cichlid fishes. J. Cons. Int. Explor. Mer. 33(3) : 363-385. Lowe (McConnell), R. 1955. Species of tilapia in East African dams, with a key for their identification. East African Agric. Jour. 20(4) : 256-262. Pelzman, R. 1973. A review of the life history of Tilapia zillii with a reassess- ment of its desirability in California. Inland Fisheries Admin. Rep. 74-1 : 1-9. Scheffer, P. 1960. Factual information concerning the use of tilapia in the bio- logical control of algae and aquatic weeds in Arizona farm ponds, reservoirs and ditches. U. S. Dep. of Agric. Soil Conserv. Service. Technical Notes. 21 p. 56 CALIFORNIA FISH AND GAME William J. Hauscr, University of Califortiia-Riverside, Imperial Valley Field Station, 1004 East Bolton Road, El Centro, CA 92243. Funds for this and related research were provided hy Imperial Irrigation District, Coachella Valley County Irrigation District, and Palo Verde Irrigation District, Research Grant Number CAL/ICP. Accepted June 1974. NOTES ON SOME FISHES COLLECTED OFF THE OUTER COAST OF BAJA CALIFORNIA The 12 fishes listed in this report represent geographic range ex- tensions, definite collection localities, or they are taken so infrequently as to warrant a published record. The fishes were collected by the au- thors aboard the Department of Fish and Game research vessel Alaska. Previously unpublished data, from fish collected during other Depart- mental research cruises, are also included. Latitudes and longitudes have been included for all collecting localities (Table 1). Miles are in nautical miles. TABLE 1. — Latitudes and Longitudes of Localities of Capture (Arranged from North to South) Locality Latitude Longitude Baja California Todos Santos Bay San Martin Island Pt. Canoas rt. Canoas (33.3 km W) Playa Maria Bay Sebastidn Vizcaino Bay (27.8 km SW of Playa Maria Bay) Cedros Island (12.9 km W. of northern end) Cedros Island (17.6 km NNW of northern end) San Benito Islands Lagoon Head Sebastidn Vizcaino Bay (22 fathom spot) Sebastidn Vizcaino Bay (27.8 km E. of Pt. Eugenia) Turtle Bay (14.8 km SW of Turtle Bay) San Cristobal Bay San Pablo Point San Hipoiito Point (11.1 km SE) 31° 46.6' N. 30° 28.8' N. 29° 44.0' N. 29° 27.8' N. 28° 56.2' N. 28° 49.7' N. 28° 23.7' N. 28° 21.2' N. 28° 20.3' N. 28° 14.9' N. 28° 6.0' N. 27° 50.0' N. 27° 36.2' N. 27° 22.4' N. 27° 12.9' N. 26° 52.0' N. 116° 45.3' W. 116° 2.7' W. 115° 50.0' W. 115° 31.5' W. 114° 31.7' W. 114° 115° 115° 115° 114° 114° 114° 115" 114° 114° 113° 48.2' W. 21.0' W. 17.9' W. 31.6' W. 5.5' W. 23.0' W. 50.0' W. 1.0' W. 37.8' W. 30.5' W. 52.0' W. Eptatretus stoutii (Lockington) — Pacific hagfish On three separate occasions, a total of four Pacific hagfish was cap- tured off the coast of central Baja California: (i) 27.8 km (15 miles) SW of Plava Maria Bav on October 2, 1970, (ii) 33.3 km (18 miles) W of Pt. Canoas on October 3, 1970, and (iii) on June 21, 1971 o& San Pablo Point. These fish ranged from 178 to 420 mm (7.0 to 16.5 inches) total length (tl). Our identification was confirmed by Carl L. Hubbs, Scripps Institution of Oceanography, La Jolla, California. Two of these hagfish taken on October 2 and 3, 1970, are now in the ichthyological collection at Scripps Institution of Oceanography (SIO 73-373 and SIO 73-374). The hagfish, taken on June 21, 1971, is catalogued as SIO 71-164. E. stoutii also was captured 12.9 km (7 miles) W of the northern end of Cedros Island in 278 to 281.6 m (152 to 154 fm) of water on Janu- ary 17, 1959 by John Seapin. This previous southern limit to the range NOTES 57 was never published. The hagfish captured off San Pablo Point extends the range south a distance of approximately 148.3 km (80 miles) from off Cedros Island to San Pablo Point. Hexanchus griseus (Bonnaterre) — Sixgill shark On October 6, 1970, a sixgill shark measuring 850 mm (33.6 inches) TL was captured in a midwater trawl in Todos Santos Bay. The trawl was fished from surface to a depth of 14.6 m (48 ft) in water 38.1 m (125 ft) deep. This is the first record of H. griseus from Mexican waters. The specimen is deposited in the Natural History Museum of Los Angeles County (LACM 31679-1). Hydrolagus collie'i (Lay and Bennett) — Raffish Six raffish were collected in a bottom trawl off Point Canoas on June 26, 1971, in 58.5 m (32 fm) of water. These fish ranged from 370 to 450 mm (14.6 to 17.7 inches) tl. The vertebral column of a small Hydrolagus had been found in the stomach of a giant sea bass, Stereo- lepis gigas, taken at the "22 fathom spot" in Sebastian Vizcaino Bay, two days earlier. Unfortunately, our evidence was inadvertently washed overboard. Two H. colliei were captured on January 17, 1959, approxi- mately 17.6 km (9.5 miles) NNW of northern end Cedros Island in 182.9 to 183.2 m (100 to 101 fm) of water. These two specimens were 360 and 462 mm (14.2 and 18.2 inches) tl. The occurrence of the raffish off Cedros Island extends the range south along the outer coast of Baja California 389.2 km (210 miles) from Santo Tomas to Cedros Island and evidently Sebastian Vizcaino Bay. Although the specimens captured off Point Canoas are now de- posited at the Natural History Museum of Los Angeles County, they have not been catalogued at this time. Anchoa exigua (Jordan and Gilbert) — "Anchovy" A number of these engraulids was collected at three separate localities in Sebastian Vizcaino Bay. Our first collection was made 27.8 km (15 miles) E of Point Eugenia in Sebastian Vizcaino Bay on October 1, 1970, where the fish were dip-netted from tide pools. The subsequent capture localities were at Lagoon Head (Oct. 2, 1970) and Playa Maria Bay (Oct. 3, 1970). These fish were captured by beach seine and ranged in size from 52 to 60 mm (2.0 to 2.4 inches) standard length (sl). Clearing and staining facilitated identification of these fishes and meristics corroborated with those given by Hildebrand (1943). Speci- mens from the above collections are deposited at California Academy of Sciences (CAS 28745 and 28746). These fish extend the known range northward approximately 370.6 km (200 miles) from San Juanico Bay (McHugh and Fitch 1951) to Playa Maria Bay. Physiculus rasfrelliger Gilbert — Hundred-fathom codling Eight Physiculus rastrelliger, ranging from 127 to 178 mm (5.0 to 7.0 inches) sl, were captured in prawn traps on June 21, 1971, from a depth of 182.9 m (100 fm) off San Pablo Point. This collection is near the type locality for this species as reported by Fitch and Barker (1972). Their occurrence seems noteworthy, however, because this 58 CALIFORNIA FISH AND GAME species is by no means common. All eight specimens (2 whole and 6 skeletonized) are now deposited at the Natural History Museum of Los Angeles County ( LACM 32755-1 ) . Anoplopoma fimbria (Pallas) — Sablefish Two sablefish were captured on June 23, 1971, in prawn traps off San Benito Islands. The traps were set in 219.4 m (120 fm) of water and these fish measured 380 and 403 mm (14.9 and 15.9 inches) sl. Fitch and Lavenberg (1971) note Cedros Island as the southern limit for this species. San Benito Islands are at a latitude equivalent to Cedros Island. These specimens are deposited at the Natural History Museum of Los Angeles County (LACM 32700-1). Zaniolepis latipinnis Girard — Longspine combfish Eleven longspine combfish were collected in a bottom trawl off San Cristobal Bay on June 22, 1971. The specimens ranged from 65 to 150 mm (2.6 to 5.9 inches) sl. Fitch (1953) recorded the southern limits as 2.8 km (1.5 miles) southwest of San Martin Island; thus, the present specimens extend the southern limits 222 km (120 miles). Zaniolepis frenata Eigenmann — Shortspine combfish A single shortspine combfish, 57 mm (2.2 inches) sl, was taken 14.8 km (8 miles) SW of Turtle Bay in a midwater trawl on June 22, 1971. The specimen captured off Turtle Bay extends the range southward a distance of 105.5 km (57 miles). Agonopsis sterletus (Gilbert) — Southern spearnose Two southern spearnose poachers were taken in a bottom trawl SE of San Martin Island. These fish were captured at a depth of 4.2 m (23 fm) on June 28, 1971, and measured 56 and 123 mm (2.2 and 4.8 inches) sl. While searching for other individuals of this species, we found an A. sterletus deposited at the Natural History Museum of Los Angeles County (LACM 20819) which had been captured 11.1 km (6 miles) SE of San Hipolito Point. This fish measured 106.5 mm (4.2 inches) sl and was netted in 65.8 to 71.3 m (36 to 39 fm) of water on April 29, 1950. Jordan and Everman (1896) report the southern limit for this species to be Los Coronados Islands. The capture at San Hipolito Point extends the range southward 685.6 km (370 miles). Epinephelus niveatus (Valenciennes) — Snowy grouper A snowy grouper was captured with a bottom trawl in San Cristobal Bay. This fish, netted at a depth of 67.7 m (37 fm) on June 22, 1971, measured 104 mm (4.1 inches) sl. Although this capture is within E. niveatus range, it is captured so infrequently, that this netting satis- fies much needed catch localities of this species. This fish is deposited at California Academy of Sciences (CAS 28420). Parophrys vetulus Girard — English sole Four English sole were caught in a bottom trawl fished at a depth of 67.7 m (37 fm) in San Cristobal Bay on June 22, 1971. These fish ranged from 119 to 147 mm (4.7 to 5.8 inches) sl. The southern limit is extended from Cedros Island approximately 92.5 km (50 miles) south- ward by this collection. NOTES 59 Microstomus pacificus (Lockington) — Dover sole Two dover sole, 158 and 203 mm (6.2 and 8.0 inches) sl, were cap- tured in a bottom trawl on June 22, 1971, in San Cristobal Bay. The southern limit of this speci'^s has been recorded as San Quintin Bay, Baja California (Fitch and Lavenberg 1971), and Guadalupe Island (Roedel 1953). The specimens caught in San Cristobal Bay extend the known range over 185.3 km (100 miles) southward. ACKNOWLEDGEMENTS The authors gratefully acknowledge the assistance of Andrew Felando, Frank McCumiskey, Earl Andreassen, and the rest of the crew on the ALASKA. We especially wish to express our thanks to John Fitch for his field notes of previously unpublished material and his suggestions concerning the manuscript. Mickey Wolfe, Pat Barnett, and Gayle Jones are to be commended for their patience in typing our many versions of this paper. REFERENCES Fitch, John E. 1953. Extensions to known geographical distributions of some marine fishes on the Pacific coast. Calif. Fish Game 39 (4) : 539-552. Fitch, John E., and L. W. Barker. 1972. The fish family Moridae in the eastern north Pacific with notes on morid otoliths, caudal skeletons, and the fossil record. U. S. Nat. Mar. Fish. Serv., Fish. Bull. 70(3) : 565-584. Fitch, John E., and R. J. Lavenberg. 1971. Marine food and game fishes of Cali- fornia. Univ. of Calif. Press, Berkeley. 179 p. Hildebrand, Samuel F. 1943. A review of the American anchovies (family En- graulidae). Bingham Oceanogr. Collection, Bull. 8(2) : 1-165. Jordan, David S., and B. W. Evermann. 1896. A check-list of the fishes and fish-like vertebrates of North and Middle America. U. S. Comm. Fish. Kept, for 1895 : 207-584. McHugh, J. L., and J. E. Fitch. 1951. An annotated list of the clupeoid fishes of the Pacific coast, from Alaska to Cape San Lucas, Baja California. Calif. Fish Game 37(4) : 491-495. Roedel, Phil M. 1953. Common ocean fishes of the California coast. Calif. Dep. Fish and Game, Fish Bull. (91) : 1-184. Eric H. Knaggs, John S. Sunada and Robert N. Lea, Marine Resources Region, California Dcpariment of Fish and Game, 350 Golden Shore, Long Beach, Calif. 90802. Robert N. Lea's present address, University of Miami, Rosenstiel School of Marine and Atmospheric Sciences, 10 Rickenhacker Causeway, Miami, Florida 33149. This study was conducted in cooperation with the Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisher- ies Service, under Public Law 88-309, Project 6-3-R. Accepted Au- gust 1974. OCCURRENCE OF THE PROWFISH ZAPRORA SILENUS JORDAN, 1896 IN MONTEREY BAY, CALIFORNIA On the morning of October 15, 1973, a 50.1 cm (19.8 inch) Standard Length (sl) specimen of the rare proA\-fish, Zaprora silcnus Jordan, 1896 was collected by John Fumotara on the trawler New Janet Ann. It was taken at 118 m (390 ft) on the north shelf of the Monterey- Submarine Canyon at lat 36° 50' N, long 121° 59' W. This represents a southward range extension of approximately 161 km (100 miles) since it has recently been reported from Bodega Bay (Fitch and Laven- berg 1971 ; Miller and Lea 1972) . The specimen was brought to the vertebrate museum at the Moss Landing Marine Laboratories where all measurements, counts and photographs were taken. It has subsequently been deposited in the ichthyology collection at the California Academy of Sciences (CAS 30693). Information on the monotypic prowfish is scarce because most refer- ences consist chiefly of notes on range extensions, some with meristic and morphometric data presented (Kendall 1914; Dymond 1928; Schultz 1934; Scheffer 1940; Schultz and Haryey 1945). However, Chapman and Townsend (1938) reviewed the osteology and early life history of the prowfish based on 36 specimens collected in the north- east Pacific off Washington, British Columbia and Alaska. Fitch and Lavenberg (1971) presented natural history notes summarizing the TABLE 1. — Meristic and morphometric data from Zaprora silenus (CAS 30693). Measurements Total length.- ..- Standard length (SL) Head length (HL) Body depth Bony interorbital space Snout length Orbit diameter - Maxillary length Depth caudal peduncle Predorsal length Preanal length Length longest pectoral ray cm 50.1 41.8 8.7 11 3 2 1 3 4 7 23 8.0 %SL 119.9 20.8 27.8 8. 4. 4. 7. 11, 17.0 56.5 19.1 .9 .8 .1 .9 .2 %HL 575.9 480.5 133.3 42.5 23.0 19.5 37.9 54.0 81.6 271.3 91.6 Counts Dorsal fin rays. . Anal fin rays Pelvic fin rays.. Pectoral fm rays Branchiostegals. Gill rakers LVI IV 26 absent 23 6 8-18 (60) NOTES 61 known information on this species. McAllister and Krejsa (1961) reviewed its enigmatic taxonomic position, finally placing the family Zaproridae in the superfamily Stichaeoidae. Greenwood et al. (1966) have further placed the family in the suborder Blennioidei. Because little is known of this fish, even where it is more abundant to the north, the specimen was examined in detail to contribute as much information to its life history as possible. The meristic and morphometric data (Table 1) compare favorably with published information on northern specimens (Kendall 1914; Dy- mond 1928; Chapman and Townsend 1938; Scheffer 1940) with the exception that our specimen, when carefully dissected and examined by X-ray, had four anal spines and 26 soft rays. The right sagitta (otolith) was removed and measured 4.1 mm across its longest axis and exhibited three winter rings, with the last on the distal margin not quite complete, indicating that this fish was in its third year. As determined by serial sections of the gonad, our specimen was found to be an immature female with developing ova, indicating the possibility of spawning during the next season. Thus our specimen would probably have spawned in its fourth year, which agrees with growth zone readings on the otolith from a 33-inch male by Fitch and Lavenberg (1971). All of the juvenile specimens of Zaprora caught by Chapman and Townsend (1938) off Alaska were taken during the months of May, June and July, which may indicate a seasonality to their spawning habits, and thus a seasonality in the abundance of young prowfish in the plankton. The stomach of our specimen was empty but the intestine contained the remains of nine hyperiid amphipods. No trace was found of jelly- fish remains as reported by Fitch and Lavenberg (1971). No external or gill parasites were present. The specimen showed no unusual colora- tion, appearing uniform grayish blue with a slightly lighter ventral surface, and very noticeable light blue head pores, ACKNOWLEDGEMENTS We wish to thank John Fumotara for bringing us this interesting fish, and James Gordon, California Academy of Sciences, for providing a radiograph of the specimen for our counts. REFERENCES Chapman, W. M., and L. D. Townsend. 1938. The osteology of Zaprora silenus Jordan, with notes on its distribution and early life-history. Ann. Mag. Xatur. Hist. Ser. 11. 2(8) : 89-117. Dymond, J. R. 1928. Another prowfish {Zaprora silenus) record. Copeia (169) : 88-89. Fitch, J. E., and R. J. Lavenberg. 1971. Marine food and game fishes of Cali- fornia. Univ. of Calif. Press, Berkeley and Los Angeles, 179 pp. Greenwood, P. H., D. E. Rosen, S. H. Weitzman, and G. S. Myers. 1966. Phy- letic studies of teleostean fishes, with a provisional classification of living forms. Am. Mus. Nat. Hist., Bull., 131(4) : 341^55. Kendall, W. C. 1914. A new record for the prowfish. Copeia (12) : 1-2. McAllister, D. E., and R. J. Krejsa. 1961. Placement of the prowfishes, Zapro- ridae, in the superfamily Stichaeoidae. Can. Nat. Mus., Natur. Hist. Pap. (11): 1-4. Miller, D. J., and R. N. Lea. 1972. Guide to the coastal marine fishes of Cali- fornia. Calif. Dept. Fish and Game, Fish Bull. (157) : 1-235. 62 CALIFORNIA FISH AND GAME Scheffer, V. B. 1940. Two recent records of Zaprora siletius Jordan from the Aleutian Islands. Copeia 1940(3) : 203. Schultz, L. P. 1934. Zaprora silenus Jordan from Alaska. Copeia 1934(2) : 98. Schultz, L. P., and E. W. Harvey. 1945. The flaccid fish, Zaprora silenus, from off Newport, Oregon. Copeia 1945(4) : 237. — Gregor M. Cailliet and M. Eric Anderson, Moss Landing Marine Laboratories, Moss Landing, California 95039. Accepted September, 1974. BOOK REVIEWS Endemism in Fishes of the Clear Lake Region of Central California By John D. Hopkirk; University of California Press, Berkeley, 1973; 135 p., illustrated in black-and-white photos. The largest freshwatfer fish province within California is the Sacramento province. The Clear Lake region studied by Hopkirk encompasses all or part of 7 of the 10 districts within this province. It extends from 50-60 miles north and east of Clear Lake, to the Golden Gate on the south and the Pacific Coast on the west. Citing fluviolacustine speciation, the Clear Lake minnow {Endemichthys grandi- pinnis), the Clear Lake splittail (Pogonichthys ciscoides), the Clear Lake hitch {Lavinia exilicauda chi) , and the Clear Lake tuleperch {Hysterocarpus traskii lagunae) are described from the Clear Lake basin, as is an unnamed subspecies of Cottus asper. In addition, the tuleperch of the Russian River subprovince is now recognized as a new subspecies, H. t. porno. According to the author, the evidence from the fish fauna can now be added to that of the moUuscan fauna, and that of the flora, in support of the thesis that the Clear Lake area is a center of endemism. There will be arguments, however, as to the strength of this evidence. The differences between these "endemics" and that of their extrabasin congeners is small and the argument can be raised that, for example, P. ciscoides deserves no more than subspecific recognition. Endemichthys grandipinnis. a new genus and species, is based upon 12 specimens collected in 1939 and 1940. The characteristics that distinguish this taxon from re- lated taxa are minor indeed, and one might conclude we are dealing with hybrids grandipinnis, between Lavinia exilicauda and Orthodon microlepidotus, as earlier workers who examined this material have done. No less an authority than Dr. Carl L. Hubbs, however, reportedly agrees with the author's diagnosis. In any event, the author has compiled a considerable amount of data on native fishes of the Clear Lake region and their distribution. Particularly valuable is a listing of these fish (exclusive of Petromyzontidac, Acipenseridae, and Salmonidae) in the collections of 7 ichthyological museums through about 1966. The systematic discussion of each genus and species is especially detailed, but I would like to have seen more graphical and statistical treatment of the data presented, particularly where the new species and subspecies are concerned. The sections on geology, bio- geography and zonation of fishes are brief but informative. Not since Snyder's work on the fishes of the Lahontan system has there been a comprehensive treatment ©f the native fishes of a major California region. Regard- less of whether or not one agrees with its taxonomic conclusions, it is a welcome addition to the sparce taxonomic literature on California's native freshwater fishes. — Stephen J. Nicola Western Trout Fly Tying Manual By Jack Dennis; Snake River Books, Jackson Hole, WY 1974; 258 p., illustrated. $6.95 Finally, a book about western fly patterns ! The "west" in this case means Mon- tana, Wyoming, Idaho, and Colorado but the patterns described include many pat- terns commonly used in California. Jack Dennis has written an extremely useful "How-to" book for both the beginner and the more advanced tyer. Over sixty patterns are detailed in the Manual : Drys, wets, streamers, nymphs, and a special section on hair flies for our more turbulent western waters. The origin of each fly is briefly described, the most commonly used sizes listed, and information on how it would be fished is often illustrated with a personal experience. A detailed list of materials is provided and finally, step-by-step photo- graphs (black and white) of the actual tying process. As always, a picture is worth a thousand words ; the photos are clear, the proportions obvious, and the photo of the finished fly gives the novice tyer something to shoot at. The Manual also has a brief chapter on materials and tools, a chapter on special fly tying techniques, and a special section on the use of the whip finishing tool. The author explains what equipment and hooks he prefers, and tells where they can be obtained. Far too infrequently do authors provide enough information on brand names and sources of supply ; this feature will be appreciated by the beginning tyer. The Western Trout Fly Tying Manual is available in paperback at a price of $6.95 ; there is also a special limited edition, signed and numbered by the author for $35.00. — K. A. Hashagen, Jr. (63) A87003 — 800 11-74 5M INSTRUCTIONS TO AUTHORS EDITORIAL POLICY The editorial staff will consider for publication original articles and notes dealing with the conservation of the fauna and flora of California and its adjacent ocean waters. Authors may submit two copies, each, of manuscript, tables, and figures for consideration at any time, MANUSCRIPTS: Authors should refer to the CBE Style Mamial (third edition) for general guidance in preparing their manuscripts. Some major points are given below. 1. Typing — ^All material submitted, including headings, footnotes, and references must be typewritten double-spaced on white bond paper. Papers shorter than 10 typewriten pages, including tables, should follow the format for notes. 2. Citations — ^All citations should follow the name-and-year system. The "library style" will be followed in listing references. 3. Abstracts — Each paper will be introduced by a short, concise abstract. It should immediately follow the title and author's name and be indented at both margins to set it off from the body of the paper. 4. Abbreviations and numerals — ^Use approved abbreviations as listed in the CBE Style Mamwil, In all other cases speU out the entire word, TABLES: Each table should be typewritten double-spaced throughout with the heading centered at the top. Number tables with arable numerals and place them together in the manuscript following the references. Use only horizontal rules. See a recent issue of California Fish and Game for format. FIGURES: Submit figures at least twice final size so they may be reduced for publication. Usable page size is 4f inches by 7f inches. All figures should be tailored to this proportion. Photographs should be sub- mitted on glossy paper with strong contrasts. AU figures should be identified with the author's name in the upper left corner and the figure number in the upper right corner. Markings on figures should be in blue pencil or grease pencil, as this color does not reproduce on copyfilm. Figure captions must be typed on a separate sheet headed by the title of the paper and the author 's name. PROOF AND REPRINTS: Galley proof will be sent to authors approxi- mately 60 days before publication. Fifty reprints will be provided free of charge to authors. Additional copies may be ordered through the editor at the time the proof is submitted. s w c ii ■0 > §5 -o n -N Q > -t >o — m -i^