Picture By Chad Thomas, Texas State University-San Marcos



Percina phoxocephala

slenderhead darter



Type Locality

Illinois River and tributaries, Illinois (Nelson 1876).


Etymology/Derivation of Scientific Name

Percina – Latin diminutive of perca, “perch”; phoxocephala – Greek phoxos, “pointed” and kephale (Latinized stem cephal), “head” (Boschung and Mayden 2004).



Etheostoma phoxocephalum Nelson 1876:35.

Hadropterus phoxocephalus



Maximum size: 96 mm TL (Page and Burr 1991).


Coloration: Sides with large black rectangular blotches (Hubbs et al. 2008). Yellow-brown above with dark brown wavy lines; 10-16 round brown-black blotches along side; white to yellow below; black teardrop; orange band on 1st dorsal fin; small but distinct black spot on caudal fin base (Page and Burr 1991). Males darken during breeding season (large males darken earliest and most intensely) and are distinguishable from females by overall duskiness; in the breeding males, rays of the second dorsal fin are boldly outlined by yellow (Page and Smith 1971; Page and Burr 1983).


Counts: Usually 9 anal rays; preopercle serrae 0 to 3; 61-76 lateral line scales (Hubbs et al. 2008).


Mouth position: Terminal (Goldstein and Simon 1999).


Body shape: Long snout and head; head length contained in standard length less than 4 times; upper jaw reaches to no more than anterior one-third of eye; snout less conical, not extending beyond upper lip; body depth contained in standard length less than 7 times (Hubbs et al. 2008).


External morphology: Nape scaled; upper lip connected to snout by a broad frenum; midline of belly with a series of enlarged scales or naked; preopercle smooth or weakly serrated (Hubbs et al. 2008).


Distribution (Native and Introduced)

U.S. distribution: Occurs throughout the central Ohio and Mississippi river basins, as far south as the Red River in eastern Oklahoma and northeast Texas (Hubbs et al. 2008).


Texas distribution: Red River in northeast Texas (Hubbs et al. 2008).


Abundance/Conservation status (Federal, State, NGO)

Luttrell et al. (2007) suggested that an introduced population of Percina phoxocephala in the Kansas River basin had become established and recommended further monitoring in order to evaluate potential impacts on native fish communities. Brewer et al. (2006) reported that P. phoxocephala was one of the four most abundant species collected from the Marais des Cygnes River. In the Neosho River, Kansas, Tiemann et al. (2004) found that abundance of this species was influenced by dams and was highest in downstream sites. Boschung and Mayden (2004) recommended Threatened status for Percina phoxocephala in Alabama, noting that the species is becoming rarer in the state and attributing this change to loss of habitat, resulting from the impoundment of creek systems. Currently Stable (Warren et al. 2000) in the southern United States.


Habitat Associations

Macrohabitat: Moderate-sized rivers (Thomas 1970; Page and Smith 1971; Page 1983). Few records of this species in lakes or reservoirs (Thompson 1980).


Mesohabitat: Somewhat plastic in habitat preference, but most common in gravel or rocky bottom riffles in fairly swift current; moderately intolerant of silt; can become fairly abundant in gravel and rubble runs below dams (Thompson 1980). Principal habitat gravel raceways; juveniles inhabit gravel riffles (Page and Smith 1971). In the Kaskaskia River, Illinois, species was fairly abundant in the middle-river, rare in the headwaters, and found only occasionally in the rest of the river; fish were found most often over fine gravel with moderate to fast current in fairly shallow water; collected frequently from riffles in one area, and most often over rubble substrate in another (Thomas 1970). In the Des Moines River (Boones Co.), Iowa, most collections of this species were made in faster moving rapids in association with larger rocks (Karr 1963). In Ohio, largest numbers of specimens collected from extensive bars and riffles which contained clean sand and small gravel that was almost free of silt (Trautman 1957). In the Fox River system, Wisconsin, species prefers riffle areas over sand or fine gravel (Auer 1982).



Spawning season: Spawning occurred in early April to late June, in the Marais des Cygnes River; peak spawning occurred April to May with water temperatures between 12-21°C (most fish spawned between temperatures of 19-21°C; Brewer et al. 2006, 2007). In Wisconsin, females were in readiness to spawn in June (Lutterbie 1979). Occurs late April into May, in central Missouri (Pflieger 1975). May to early July, in Illinois, with peak spawning in early June (Page and Smith 1971). In Kansas, spawning occurs between late May and early March (Cross 1967). Thomas (1970) suggested that species may have spawned as late as August (1965), when ripe females were present in the Kaskaskia River, Illinois, but no ripe males were collected at this time; however, Brewer et al. (2006) noted that August spawning in the Kaskaskia River was unlikely and that the August specimens were probably postspawn fish. Page and Simon (1988) observed spawning, in aquaria, in early May and late June.


Spawning habitat: Swift-flowing water 15-60 cm deep over gravel (Cross 1967; Page and Smith 1971; Page 1983). In the Marais des Cygnes River, spawning occurred in high-velocity microhabitats containing cobble (Brewer et al. 2006).


Spawning behavior: Nonguarder; brood hider; lithophils – rock and gravel spawners that do not guard eggs (Simon 1999). Males move into spawning habitat well before females and presumably establish territories (Page and Smith 1971). In aquaria, males schooled until near spawning time and then dispersed more evenly about the aquarium, suggesting establishment of territories (Page and Simon 1988).Page and Simon (1988) observed spawning in aquaria: female buried her papilla about 1 cm beneath surface of substrate; male mounted female, forming an S-shape, with his head on one side and his tail on the other side of the female; each spawning act occurred in about 4 seconds; eggs buried in mixed gravel and sand substrate behind (relative to current) large rocks.


Fecundity: Karr (1963) reported egg counts from six specimens from the Des Moines River, Iowa, ranging from 186-365 eggs (mean 288). Embarras River, Illinois specimens contained 50-720 mature; mature eggs from ripe females were transparent and adhesive, averaged 1.3 mm in diameter, and contained one large oil droplet (Page and Smith 1971). In aquaria, eggs were 1.7-1.8 mm in diameter, transparent, spherical, demersal, and nonadhesive, with moderate perivitelline spaces, pale yelloe yolks and unpigmented chorions; eggs hatched in 120-124 hours at 22°C (Page and Simon 1988).


Age/size at maturation: Individuals reach sexual maturity at about 40 mm SL; all males and most females were sexually mature during the first spring following hatching (Page and Smith 1971). Minimum standard length of sexually mature females was 39 mm SL (Brewer 2007).


Migration: Breeding; hiemal; apparent downstream movement into deeper habitats during the colder months, fish return upstream in the spring (Page and Smith 1971; Page 1983; Brewer et al. 2006).


Growth and Population structure: Calculated total length at annulus for specimens from the Des Moines River, Iowa: 34.1 mm for age class I fish, 46.6 mm for age class II, 49.4 mm for age class III, and 56.0 mm TL for age class IV fish (Karr 1963). In the Kaskaskia River, Illinois, year I fish averaged 45.3 mm TL, year II fish averaged 60.6 mm TL, and year III fish averaged 67.6 mm TL; no influence of sex on growth rate indicated (Thomas 1970). Calculated total lengths were reported for 98 specimens captured in Wisconsin: 39-44 mm at first annulus, 54-56 at second annulus, 67-68 at third annulus, and 74-80 mm at fourth annulus (Lutterbie 1979; Page 1983). Page and Smith (1971) reported young-of-the-year fish (74%), 1-year-old fish (25%), and 2-year-old fish (1%) present in the Embarras River, Illinois; there was little indication of sex influence on size; sex ratio was 1.4 males to 1 female; adult morphology nearly complete at 3 weeks.


Longevity: 4 years, in Iowa (Karr 1963); 3 years, in Illinois (Thomas 1970).


Food habits: Invertivore; benthic (Goldstein and Simon 1999). Main food items included mayfly nymphs, midge larvae and caddisfly larvae (Karr 1963; Thomas 1970; Goldstein and Simon 1999). In the Des Moines River (Boones Co.), Iowa, insects were the principle food (Diptera, Ephemeroptra, and Tricoptera in order of importance); the small stones and plant material present in stomachs were probably ingested incidentally in normal feeding (Karr 1963). Stomach contents of specimens from the Embarras River, Illinois contained midge larvae and pupae, black fly larvae, caddisfly larvae, and mayfly naiads (forming over 99% of food items); less frequent items encountered were amphipods, fish eggs, and terrestrial insects (Page and Smith 1971). In the Kaskaskis River, Illinois, diet items included Diptera, Ephemeroptera, Trichoptera, Collembola, and fish eggs; fish fed mainly during daylight hours, but stomach contents suggested some feeding just after dark (Thomas 1970). Cross (1967) reported diet items from specimens examined: mainly bloodworms, blackfly larvae, dragonfly larvae, and mayfly larvae; some specimens contained fish eggs, and a single specimen contained a leafhopper, while another contained a small stone. Turner (1921) listed principal food items as midge larvae, mayfly larvae and copepods for Ohio specimens.


Phylogeny and morphologically similar fishes

Subgenus Swainia (Mayden 1985). Percina phoxocephala differs from P. maculata (blackside darter) in having a long acute snout; P. caprodes (logperch) differs from P. phoxocephala in that its snout is conical and extends well past the upper jaw, and it lacks orange in the spinous dorsal fin and has more vertical bars on the side; P. phoxocephala differs from P. shumardi (river darter) in having a long acute snout, and in having a much smaller anal fin and a frenum (vs. large anal fin and the absence of or weakly developed frenum); P. phoxocephala differs from P. sciera (dusky darter) in having a long acute snout and a single small, intense basicaudal spot (Boschung and Mayden 2004). P. phoxocephala differs from P. apristis (Guadalupe darter) in that it has usually 9 anal fin rays, has a long snout and head, and the head length is contained in standard length less than 4 times, whereas P. apristis has usually 10 anal fin rays, has a short snout and head, and head length is contained in standard length more than 4.5 times; also, in Texas, P. phoxocephala is found only in the Red River, while P. apristis is endemic to the Guadalupe, San Marcos, and Comal rivers in the state (Hubbs et al. 2008). P. phoxocephala has 61-76 lateral line scales, while P carbonaria (Texas logperch) and P. macrolepida (bigscale logperch) have more than 77 scales in the lateral line; also, P. phoxocephala has a long snout and head, while P. carbonaria and P. macrolepida have a conical snout extending beyond the upper lip (Hubbs et al. 2008).


Percina maculata (blackside darter) x Percina phoxocephala hybrids reported from the Kaskaskia River, Illinois (Thomas 1970) and the Salt River, Missouri (Page 1976). Leeches, nematodes, and acanthocephalans reported from Illinois specimens (Page and Smith 1971).


Host Records

Karr (1963) reported a single specimen from the Des Moines River, Iowa, having a leech of the family Piscicolidae attached to the caudal fin. External parasites present on specimens from the Kaskaskia River, Illinois (Thomas 1970).


Commercial or Environmental Importance

Trautman (1957) believed that silting of larger southern Ohio streams produced an unsuitable habitat for this species (and its food supply) and resulted in its recent decrease in abundance.



Auer, N.A. 1982. Identification of larval fishes of the Great Lakes basin with emphasis on the Lake Michigan drainage. Great Lakes Fishery Commission, Ann Arbor, Michigan. Special Publication 82-3:744 pp.

Boschung, H.T., Jr., and R.L. Mayden. 2004. Fishes of Alabama. Smithsonian Books, Washington. 736 pp.

Brewer, S.K., D.M. Papoulias, and C.F. Rabeni 2006. Spawning habitat associations and selection by fishes in a flow regulated prairie river. Transactions of the American Fisheries Society 135:763-778.

Brewer, S.K., D.M. Papoulias, and C.F. Rabeni 2007. Comparing histology and gonadosomatic index for determining spawning condition of small-bodied riverine fishes. Ecology of Freshwater Fish 17(1):54-58.

Goldstein, R.M., and T.P. Simon. 1999. Toward a united definition of guild structure for feeding ecology of North American freshwater fishes. pp. 123-202 in T.P. Simon, editor. Assessing the sustainability and biological integrity of water resources using fish communities. CRC Press, Boca Raton, Florida. 671 pp.


Hubbs, C., R.J. Edwards, and G.P. Garrett. 2008. An annotated checklist of the freshwater fishes of Texas, with keys to identification of species. Texas Journal of Science, Supplement, 2nd edition 43(4):1-87.


Karr, J.R. 1963. Age, growth, and food habits of Johnny, slenderhead and blackside darters of Boone County, Iowa. Iowa Acad. Sci. 70:228-236.


Lutterbie, G.W. 1979. Reproduction and growth in Wisconsin darters (Osteichthyes: Percidae). Reports on the Fauna and Flora of Wisconsin, University of Wisconsin, Stevens Point. 44 pp.


Luttrell, G.R., F.R. Abe, M.P. Davis, and K.R. Anderson. 2007. Recent collections of the slenderhead darter, Percina phoxocephala (Nelson), from the Kansas River basin. Transactions of the Kansas Academy of Science 110(1/2):127-128.


Mayden, R.L. 1985. Biogeography of Ouachita Highland Fishes. The Southwestern Naturalist 30(2):195-211.


Nelson, E.W. 1876. A partial catalouge of the fishes of Illinois. Illinois Museum of Natural History Bulletin 1(1):33-52.


Page, L.M. 1976. Natural darter hybrids: Etheostoma gracile x Percina maculata, Percina caprodes x Percian maculata, and Percina phoxocephala x Percina maculata. The Southwestern Naturalist 21(2):161-168.


Page, L.M. 1983. Handbook of Darters. TFH Publications, Inc. Ltd., Neptune City, New Jersey. 271 pp.


Page, L. M., and B. M. Burr.  1991.  A field guide to freshwater fishes of North America north of Mexico.  Houghton Mifflin Company, Boston, Massachusetts. 432 pp.


Page, L.M., and P.W. Smith. 1971. The life history of the slenderhead darter, Percina phoxocephala, in the Embarras River, Illinois. Illinois Natural History Survey Biological Notes 74.


Page, L.M., and T.P. Simon. 1988. Observations on the reproductive behavior and eggs of four species of darters, with comments on Etheostoma tippecanoe and Etheostoma camurum. Trans. Illinois State Acad. Sci. 81(1-2):205-210.

Simon, T. P. 1999. Assessment of Balon’s reproductive guilds with application to Midwestern North American Freshwater Fishes, pp. 97-121. In: Simon, T.L. (ed.). Assessing the sustainability and biological integrity of water resources using fish communities. CRC Press. Boca Raton, Florida. 671 pp.

Thomas, D.L. 1970. An ecological study of four darter species of the genus Percina (Percidae) in the Kaskaskia River, Illinois. Illinois Natural History Survey, Biological Notes 70:1-18.

Thompson, B.A. 1980. Percina phoxocephala(Nelson), Slenderhead darter. pp. 737 in D. S. Lee et al., Atlas of North American Freshwater Fishes. N. C. State Mus. Nat. Hist., Raleigh, i-r+854 pp.


Tiemann, J.S., D.P. Gillette, M.L. Wildhaber, and D.R. Edds. 2004. Effects of lowhead dams on riffle-dwelling fishes and macroinvertebrates in a midwestern river. Trans. Amer. Fish. Soc. 133:705-717.

Turner, C.L. 1921. Food of the common Ohio darters. Ohio J. Sci. 22(2):41-62.


Warren, M.L., Jr., B.M. Burr, S.J. Walsh, H.L. Bart, Jr., R.C. Cashner, D.A. Etnier, B.J. Freeman, B.R. Kuhajda, R.L. Mayden, H.W. Robison, S.T. Ross, and W.C. Starnes. 2000. Diversity, Distribution, and Conservation status of the native freshwater fishes of the southern United States. Fisheries 25(10):7-29.