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Nineteen species of darters (family Percidae, subfamily Etheostomatinae) were found in that part of Oklahoma north and east of the Arkansas River. Of these, four are species of limited distribution, whereas 15 are wide-ranging species in the United States. Sixty-one species-pair combinations were never found in the same collection; other species-pair combinations were found associated with various degrees of frequency. The biotic districts of W. F. Blair and Hubbell were found, in general, to have reality as regards darter distribution. During the period 1948-55 an effort was made to gain an accurate picture of the distribution of the darters in that part of Oklahoma north and east of the Arkansas River (Fig. 1). No effort was made to include man-made lakes or the Arkansas River proper, where I have

The orangebelly darter, Etheostoma radiosum cyanorum, is found only in the Blue River system of south central Oklahoma. Adult fish exhibited very little movement within the stream. It was found that few of the adults showed intra- raceway movement and none exhibited inter-raceway movement. Larval and young- of-year darters exhibited stream movement. Postlarval fish were found in the quiet water or pool areas of the stream. As the fish increased in size they moved into progressively swifter water. At approximately 25 mm total length they were found in the raceway areas of the stream, their adult habitat. Approximately 2.66 adult orangebelly darters were found for every square meter of raceway in the study area. The orangebelly darter, Etheostoma radiosum cyanorum (Moore and Rigney), is found only in the Blue River and its tributaries in south central Oklahoma. This fish is primarily associated with clear, flowing, rocky-bottomed raceways in the upper two-thirds of the river system. Many stream fishes live in very restricted areas during most, if not all, of their lifetimes. Gerking (1953) studied the concepts of home range and territory of stream fishes and found that the longear sun- fish, Lepomis megalotis, the green sunfish, L. cyanellus, and the rock bass, Ambloplites rupestris, limited their activities to rather small areas. Larimore (1952) obtained similar results for the smallmouth bass, Micropterus dolomieui, though these fish had larger ranges than did the previously mentioned species. Reed (1968) found that the rain- bow darter, Etheostoma caeruleum, the greenside darter, E. blen- nioides, the fantail darter, E. flabellare, and the banded darter, E. zonale, remained in rather confined areas of the stream. The present work was undertaken to determine the degree of movement which the orangebelly darter exhibited during the various stages of its life his

Stanford Univ. Publ., Univ. Ser. Biol. Sci. 3(2):77-243. AND C. H. EIGENMANN. 1885. Notes on skeletons of Etheostomatinae. Proc. U. S. Natl. Mus. 8(484):68-72. AND B. W. EVERMANN. 1896. The fishes of North and Middle America. Bull. U. S. Natl. Mus. 47, part 1 1240 p. LACEPEDE, BERNHARD. 1802 (Vol. 3), 1803 (Vol. 4). Histoire naturelle des poissons. Plassan 558 p. (Vol. 3), 728 p. (Vol. 4). MORGAN, G. D. 1936. A study of the vestigial air bladder in the darter (Catonotis [sic] flabellaris Rafinesque). J. Sci. Labs. Denison Univ. 31(4-6):143-58. NIKOLSKY, G. V. AND N. A. EVTUKHOV. 1940. The fishes of the middle and lower courses of the Ili River. Bull. Mosk. Obsch. Isp. Prir., Biol. 49(5-6):57-70. (In Russian.) OKEN, LORENZ. 1816. Lehrbuch der Naturgeschichte. Theil 3, Zool., Abth. 2, Fleischthiere. Jena 1270 p. . 1817. Cuvier's und Oken's zoologien naben einander gestellt. Isis, Encyclo. Zeitung 8(148):1179-85. RAFINESQUE, C. S. 1820. Ichthyologia Ohiensis. Reprinted in Richard E. Call, 1899, Burrows Brothers Co., Cleveland p. 40-162. tanford Univ. Publ., Univ. Ser. Biol. Sci REGAN, C. T. 1913. The classification of the percoid fishes. Ann. & Mag. Nat. Hist. ser. 8 12:111-45.

AND B. W. EVERMANN. 1896. The fishes of North and Middle America. Pt. 1. Bull. U. S. Natl. Mus. 47:1-1240. LINCK, H. F. 1790. Versuch einer Eintheilung der Fische nach den Zahnen. Mag. Neu. Phys. Naturges. 6(1):28-38. LINNAEUS, C. 1758. Systema Naturae. Tom. 1, Ed. 10. ii-824 pp. MILLER, R. R. 1957. Origin and dispersal of the alewife, Alosa pseudoharengus, and gizzard shad, Dorosoma cepedianum, in the Great Lakes. Trans. Am. Fish. Soc. 86(1956): 97-111. REGAN, C. T. 1916. The British fishes of the subfamily Clupeinae and related species in other seas. Ann. Mag. Nat. Hist. Ser. 8, 18: 1-19. 1917. A revision of the clupeoid fishes of the genera Pomolobus, Brevoortia and Dorosoma and their allies. Ibid. 19:297-316. SVETOVIDOV, A. N. 1932. Sur le rapport entre le caractere de la nourriture et la nombre des appendices pyloriques chez les harengs. Comp. Rend. Acad. Sci. URSS A (8):202-204. 1952a. O zavisimosti mezhdu colichestvom pulorichescikh pridatcov i kharacteram pitanya ryb. (On the correlation between the number of pyloric caeca and the character of food in fishes.) Ocherki po obschim voprosam ikhtyologyi. Akad. Nauk SSSR:282-289. 1952b. Seldevye (Clupeidae). Fauna SSSR. Ryby 2(1), 331 pp.

More than 1500 measurements were made of mature eggs from females obtained from two populations of central Texas darters (Etheostoma spect- abile from the Llano River at Junction and Etheostoma lepidum from the South Concho River 4 miles south of Christoval). Junction eggs averaged 1.515 + 0.002 mm and those from the South Concho 1.301 ? 0.031 mm. Female size did not seem to influence egg size, with small eggs as likely in large as in small females. Eggs from females collected in November and April were smaller than those from fish of the same population collected in December through March. More than 2500 counts were made of egg complements of females from the same two populations. The number of eggs increased geometrically with female size, and the rate of increase approximates a squared relationship. Apparently digestive absorptive surface is more limiting than coelomic space. The largest females may have fewer eggs than medium sized females, especially toward the end of the breed- ing season. Females collected in February and adjacent months have more eggs than those obtained in other months. The difference is caused by more eggs in equivalent sized females. The fecundity of an animal is the product of frequency of spawn- ing and number of eggs produced per spawning interval. Although egg number would appear to be rather easily ascertained, little is known about spawn variability or factors causing it. The potential maximum number of eggs in a female is the result of available dis- tended coelomic space divided by average egg volume. Either volume varies among females or maximum potential is seldom achieved, be- cause spawn variation has been demonstrated and is obvious in our counts. Therefore, egg number in fishes may be limited by several factors including available coelomic space and nutrition. Sviirdson (1949) pointed out that equivalent-sized females can pro- duce large numbers of small eggs or small numbers of large eggs. A female could concentrate her nutrients in a few eggs, each of which would have a high survival potential, or spread them over many small eggs, each with low survival potential. Genetically controlled differ- 301

A survey of snails from streams in central Ohio revealed that Cercaria kentuckiensis was common in one of the prosobranch snails, Goniobasis livescens. C. kentuckiensis was first reported by Cable (1935), and later described by him (1938) from cercariae obtained from Goniobasis semicarinata which he collected from Scaffold Cane Creek in Madison County, Kentucky. Cable reported that the cercariae encysted in several species of cyprinid fishes. C. kentuckiensis was again reported by Cable (1937) and by Anderson (1944) in Goniobasis sp. and Goniobasis depygis, respectively, from McCormicks Creek, Indiana. It was again reported by Vernberg (1952) from Goniobasis livescens collected from Clifty Creek in southern Indiana. She found that, although the cercariae penetrate several species of fish, they encyst only in a single species of darter, the name of which was not given. C. kentuckiensis was observed by me to penetrate and encyst in laboratory raised guppies, Lebistes reticulatus. The metacercariae were fed later to a starved 1-day-old chick. Seven days after the feeding, eggs of a trematode appeared in the feces of the chick and 3 days later 13 adult worms of the genus Mesostephanus were recovered from the small intestine of the chick. Other chicks fed this

The systematics of Etheostoma rufilineatum (Cope), a riffle-inhabiting species of the subgenus Nothonotus, is considered by com- paring meristic data and coloration from various geographic localities. Although geographic variation in characters exists, none of these differ- ences warrants subspecific designation of the populations. This species occurs widely in the Cumberland and Tennessee river systems where it frequently is the most abundant darter. The coloration of some Hiwas- see River populations has diverged from the usual patterns. A distribu- tion map and pictures are included.

The number of nominal species and subspecies described per year are compared with the cumulative summary of the number of forms considered valid. The history of darter descriptions is divided into four periods: "Beginnings" (1818-1840); "Golden Era" (1841-1892); "Doldrums" (1893-1931); and "Reawakening" (1932-present). The success of different ichthyologists in describing valid taxa is assessed. The number of specimens per type-series forms a strongly skewed distribution from 42 species based on only the holotype to the 1338 type-specimens of Boleosoma nigrum eulepis. The 25 repositories of the 4863 type-specimens of 185 nominal species of darters are divided into three groups based on the number of primary and secondary types. The present number of valid species and subspecies (139) is predicted to rise to about 160 by the year 2000.

The distribution of the Arkansas darter, Etheotomv cragini Gilbert ts limited to isolated populations (Cross, 1967; Metcalf, 1959) of the Arkansas River Basin in eastern Colorado (Ellis and Jaffa, 1918), southern Kansas (Cross, 1967), northeastern Oklahoma (Moore and Cross, 1950; Blair, 1959), and southwestern Missouri (Branson, Triplett, and HartmanS 196g). This localization of populations is due to the paucity of the optimum habitat for this species in the Arkansas River basin, which is a spring or spring-run filled with water cress (Blair and Windle, 1961). Because E. cragini is distributed in isolated populations, it is subject to extirpation during periods of drought. Cross (1967) suspected that much local extinction has occurred in the last century, and Blair (1959) stated that E. cragini might become extinct in northeastern Oklahoma because three of the Sve streams from which he collected E. craginz dried up in the summer of 1955 and another was reduced to poioles. This situation could desrelop in southwestern Kansas and eastern Colorado where the climate is typically arid and the streams are small. In view of the current distribution of E. cragini} I believe it should be considered an endangered species. Thus7 new records regarding the distribution and habits of E. cragini may be important in keeping it from becoming extinct. It is interesting to note that E. cragini is the only darter existing in southwestern Kansas west of 99° 30' west longitude. This indicates that E. cragini can tolerate the fluctuating water levels and sluggish currents of the streams in a dry climate. However, because iis species is usually found in a spring or spring-run which would tend to have clearer water ian the rest of a stream, I believe it cannot tolerate much turbidity. In the past century man has gradually cultivated more and more land in ie Arkansas River basin. This has caused more surface runoff to enter the streams than iat which would occur under natural conditions, thus the turbidit has increased in many of the streams in the Arkansas River basin. This in turn has caused E. crdgini to seek the clearer springs which are rare

Etheostoma (Catonotus) barbouri is described from 97 specimens collected from the Green River basin in Kentucky and Tennessee. It is most closely related to E. virgatum and E. obeyense which occur in the adjacent Cumberland River basin, but differs in size and body patterning. It also differs from many populations of the above species in the number of pores in the infraorbital and lateral line canals. The subgenus Catonotus is characterized and the range of E. barbouri mapped.

During the past two decades a number of Texas freshwater fishes have been recognized as meriting new taxonomic ranking. Recently four of these fishes have been named (Hubbs, 1951, and Hubbs and Bonham, 1951). In this paper a continuation of the series, a new darter is defined. The methods of counting and measuring used in this investigation are those proposed by Hubbs and Lagler (1947). The variational data are expressed by a simplified graphical scheme that follows the Hubbs and Perlmutter (1942) modification of the method proposed by Dice and Leraas (1936). In each unit of the graphs the extreme range is represented by the base line, the mean by the vertical line, two standard errors on each side of the mean by the solid area, and one standard deviation on each side of the mean by the outlined area. This further modification of the Dice and Leraas method for the graphical comparison of series of samples was developed jointly with Carl L. Hubbs and is discussed in another paper (Hubbs and Hubbs, 1953). The status and synonymy of the species Hadropterus scierus is being treated by Hubbs and Black (1954).

Within recent years considerable work has been concentrated upon the study of the life histories of our larger percid fishes that provide both sport and food for man. The life histories of most of our smaller Percidae, the darters, are still not completely known. Several studies have revealed some of their spawning habits, such as those of Adams and Hankinson (1928), Atz (1940), Hankinson (1932), Jaffa (1917), Lake (1936), J. J. Petravicz (1936), W. P. Petravicz (1938), Reeves (1907), Reighard (1913) and Seal (1892). In this study we have attempted to make known several of the main features of the life history of three species of darters, mainly by scale analysis. These species, the variegated darter, Poecilichthys variatus (Kirtland), the eastern banded darter, Poecilichthys zonalis zonalis Cope, and the northern grecnside darter, Etieostoma blennoides blennoides Rafinesque, are quite common in the upper Allegheny River system of western Pennsylvania. Their ranges are given by Hubbs and Black (1940: 7) and Hubbs and Lagler (1947: 88, 89). These darters have remained in such obscurity that even brief generalizations of their life histories are not available. Such discussions of blennoides by Evermann and Clark (1920: 440-442, colored plate) and Forbes and Richardson (1920: 292-294, colored plate) and of zonalis by Forbes and Richardson (1920: 304306, fig. 73) are mainly descriptional. Their habitat and associates, abundance and density, sexual dimorphism, sex ratio, longevity and comparative rates of growth are discussed and tabulated, herein.

The orangebelly darter, Etheostoma racdiosum cyanorum, changed its food habits as it increased in size. The young fed primarily on copepods and cladocerans. When the darters reached approximately 16 mm in total length their primary source of food consisted of ephemerids and dipteran larvae. Darters from 22 to 30 mm in total length relied mainly on small ephemerids, dipteran larvae, hydropsychids and baetids. The food of the adult darters consisted primarily of the aquatic larvae and naiads of five families of insects: Tendipedidae (= Chironomidae), Baetidae, Hydropsychidae, Ephemeridae and Simuliidae. The food eaten by the various sizes of darters appeared to be dependent upon the preferability, availability and vulnerability of the food organisms present in the stream. INTRODUCTION The orangebelly darter, Etheostoma radiosum (Hubbs and Black), inhabits streams of southwestern Arkansas and southeastern Oklahoma. There are three subspecies of this darter; one of these subspecies, E. r. cyanorum, is found only in the Blue River and its tributaries in southeastern Oklahoma. No work has previously been reported conceming its food habits. The present study was conducted to determine the food organisms utilized Iby the darters in the various stages of their life cycle and also their relative utilization of the food organisms present in the stream. DESCRIPTION OF THE STUDY AREA The Blue River is located in Bryan, Johnston and Pontotoc counties, Oklahoma. It rises in Pontotoc Co. 6 miles W of Fittstown and flows in a southeasterly direction for approx 110 miles to where it joins the Red River. It is primarily spring-fed. The study darters were collected at two locations. The first location was on the Blue River itself, at a low-water bridge, 1 mile E of Connerville, Okla. The second location was on a tributary of the Blue River, the Diamond Spring Branch, 3 miles S and 1 mile E of Connerville. MATERIALS AND METHODS For 1 year, August 1968 through July 1969, bimonthly collections of orangebelly darters were made with a 6 x 4 ft, one-eighth inch mesh seine and a 4 x 3 ft habitat seine. The fish collected ranged in size from young stages, when they were present, to large adult darters. All fish were initially preserved in 10% formalin; they were later washed and put into 70% ethyl alcohol. In the laboratory, stomachs were excised and their contents identified under a binocular dissecting scope. In order to obtain relative volumes for the types of food organisms present, a displacement tech

The orangebelly darter, Etheostoma radiosum cyanorum, reaches sexual maturity and spawns when 1 year old. Numerous sexually dimorphic traits are exhibited by the fish, including body size and coloration; anal papillae size, shape and pigmentation; and the presence of breeding tubercles. Gonadal development is at its lowest point in September and reaches its peak in March, April and May. At the peak of gonadal development the ovaries of the females constitute approximately 10-15% of the body weight. The fecundity of the fish is quite low. Spawning occurs mainly b2tween the middle of March and the middle of April. The darters select arcas of small diam (3-5 mm) gravel as spawning sites. These sites are located in the moderate current portions of the raceway sections of the stream. Courtship behavior follows the entry of the female into the spawning area. If receptive to the male, she then initiates the actual spawning act by rising off the stream bottom and diving headlong into the gravel in an attempt to bury herself. If successful, the female fans the gravel partially away from herself. The male mounts and the spawning act, which lasts approximately 2-5 sec, begins. During this period, numerous other fish species can be in close proximity to the darters without disturbing their spawning activities. INTRODUCTION The orangebelly darter, Etheostoma radiosum cyanorum (Moore and Rigney), is one of many etheostomatine fishes about which little is known. The species radiosum is found in the southwestern quarter of Arkansas and the southeastern quarter of Oklahoma; the subspecies cyanorum is found only in the Blue River system of Oklahoma, and is the westernmost representative of this species. Little work has been reported concerning the reproduction of the orangebelly darter. Linder (1958) described the breeding behavior of this fish, but his work was done in the laboratory. Branson and Campbell (1969), Hubbs (1959) and Linder (1955, 1958) studied natural and laboratory hybridization of this darter with other darter species. No work, however, has been reported concerning the age at maturity of the orangebelly darter or its gonadal development, time of spawning or location of spawning sites. Also, no description of the spawning behavior of the fish in the natural environment has been reported. It is the purpose of this paper to report on the abovementioned unknown portions of the life history of this fish. AGE AT MATURITY Most orangebelly darters reach sexual maturity and spawn when 1 year old. Evidence of this maturity was obtained by examination 1 Present address: Department of Zoology and Entomology, Iowa State University, Ames 50010.

JAFFA, BERTRAM B. 1917 Notes on the breeding and incubation periods of the Iowa darter, Etheostoma iowae Jordan and Meek. COPEIA, 47: 71-72. JORDAN, D. S., and COPELAND, H. E. 1876 Johnny darters. Am. Nat., 10: 335-341, figs. 22-24. LAKE, CHARLES T. 1936 The life-history of the fan-tailed darter, Catonotus flabellaris flabellaris (Rafinesque). Am, Midl. Nat., 17: 816-830, figs. 1-3. PETRAVICZ, JOSEPH J. 1936 The breeding habits of the least darter, Microperca punctulata Putnam. CoPEIA, 1936: 77-82, figs. 1-4. PETRAVICZ, WALTER P. 1938 The breeding habits of the black-sided darter, Hadropterus maculatus. Ibid., 1938: 40-44, figs. 1-3. REEVES, CORA D. 1907 The breeding habits of the rainbow darter (Etheostoma coeruleum Storer), a study in sexual selection. Biol. Bull., 14: 35-59, figs. 1-3. REIGHARD, JACOB 1913 The breeding habits of the log-perch (Percina caprodes). Rep. Mich. Acad. Sci., 15: 104-105. SEAL, WILLIAM P. 1892 Observations on the aquaria of the U. S. Fish Commission at Central Station, Washington, D. C. Bull, U. S. Fish. Comm., 10, 1890: 1-12, figs. 1-2, pls. 1-4.

Misc. Publ. Mus. Zool. Univ. Mich., No. 35: 7-109. MANSUETI, R. 1951. Occurrence and habitat of the darter Hololepis fusiformis erochrous in Maryland. COPEIA (4): 301-02. RANEY, E. C. 1941. Records of the brook lamprey, Lampetra aepyptera (Abbott), from the Atlantic drainage of North Carolina and Virginia. Jour. Elisha Mitchell Soc., 57: 318-20. 1952. A new lamprey, Ichthyomyzon hubbsi, from the upper Tennessee River system. COPEIA (2): 93-99. REGAN, C. T. 1911. A synopsis of the Marsipobranchs of the Order Hyperoartii. Ann. and Mag. Nat. Hist., ser. 8, vol. 7: 193-204. VLADYKOV, V. D. 1950. Larvae of Eastern American lampreys (Petromyzonidae). I.-Species with two dorsal fins. Nat. Canadien, 77 (3-4): 73-94.

The two subspecies considered in this study, E. o. olmstedi and E. o. atromaculatum, have been separated previously by characters of squamation and lateral-line scale counts. Extensive collecting and an examination of museum collections pointed out difficulties in assigning subspecific names to some populations of E. olmstedi in southeastern Virginia. This study is intended to indicate some of the practical and theoretical taxonomic problems encountered.

Development of the neuston nets has been conducted under NSF grants GB-543 (19631965) and GB-4431 (1965-1967) (principal investigator Richard H. Backus) to the Woods Hole Oceanographic Institution. A part of the senior author's work was supported by NSF GB-3464 (principal investigator, Frank J. Mather III); NSF GA-810 (principal investigator Paul M. Fye) provided travel funds to join ATLANTIS II in the South Atlantic. We thank Richard H.