Ambloplites rupestris 

rock bass



Type Locality

Lakes of New York, Vermont, and Canada (Rafinesque 1817).


Etymology/Derivation of Scientific Name

Ambloplites: blunt armature; rupestris: living among the rocks (Ross 2001).



Bodianus ruprestris  Rafinesque 1817:120.

Cichla aenea  Lesueur 1822:214.

Centrarchus aeneus   Richardson 1936:20.

Ambloplites rupestris  Jordan and Gilbert 1883:466.



Maximum size:  305 mm TL (Robison and Buchanan 1988). 


Coloration: Head, back, and sides of adult dark brown to olive; red eye; small reddish orange spot on opercle; 4-7 yellowish dorsolateral blotches terminating at the level of the lateral line; darkly spotted scales below lateral line forming 8-10 horizontal rows; abdomen silvery white. The young are darker with more distinct mottling than in adults (Sublette et al. 1990). Red intensified in eye of breeding male; body of male temporarily darkens to black during spawning; males have a dark band bordering anal and pelvic fins which is prominent during the nesting period but less so during spawning (Gross and Nowell 1980).


Counts: 6 anal spines, and 10-11 soft rays; fewer than 20 gill rakers on 1st arch; 11-13 dorsal fin spines; 6 or 7 branchiostegals (Hubbs et al. 1991); 36-44 lateral line scales; 10-11 dorsal rays; 14-15 pectoral rays (Ross 2001).


Body shape: Strongly compressed; depth greatest at origin of dorsal fin (Sublette et al. 1990).


Mouth position: Terminal, slightly oblique (Goldstein and Simon 1999); large mouth; lower jaw slightly protruding (Sublette et al. 1990).


External morphology: Preopercle entire or weakly crenate; lateral line present; scales ctenoid (Hubbs et al. 1991).


Distribution (Native and Introduced)

U.S. distribution: Wide-ranging in the central northeastern region of North America, found from southern Ontario, the Great Lakes and St. Lawrence River to Quebec and Lake Champlain; found west of the Appalachians south to the Tennessee River drainage and in tributaries of the middle and upper Mississippi River valley; introduced in other areas, including Atlantic Slope drainages (Cashner 1980; Cashner and Jenkins 1982).


Texas distribution: Introduced into the state from Neosho, Missouri, in the late 1800’s, this species now occurs in the San Marcos, Comal, and upper Guadalupe rivers (Hubbs et al. 1991). Warren et al. (2000) list the following drainage units for distribution of Ambloplites rupestris in the state: Colorado River, San Antonio Bay (including minor coastal drainages west of mouth of Colorado River to mouth of Nueces River).


Abundance/Conservation status (Federal, State, NGO)

Populations in southern drainages are currently stable (Warren et al. 2000).


Habitat Associations

Macrohabitat: Common in streams (George and Hadley 1979; Probst et al. 1984) and lakes (Cashner 1980). Found in small to moderate-sized clear streams of the western Ozarks, in Arkansas (Robison and Buchanan 1988). Although found in reservoirs, numbers generally decline after the first few years of impoundment (Carlander 1977).


Mesohabitat: In northern areas, species occurs in small, cool, weedy lakes or littoral regions of larger lakes (Cashner 1980). Found in warm water and slow current in streams of Ontario, Canada (Hallam 1959). Young of year found in shallow littoral zones of lakes and streams; prefer a heavily vegetated substrate (George and Hadley 1979). Species is intolerant of turbidity and siltation (Robison and Buchanan 1988; Bunt et al. 2004).



Spawning season: May - July (Carlander 1977); spawning occurs at temperatures ranging from 15.6-27 degrees C (Neill and Magnusen 1974; Gross and Nowell 1980; Tin 1982).


Spawning habitat: Utilizing anal and pectoral fins to loosen and remove substrate, the male will excavate a nest in shallow water over gravel or coarse sand substrata (Gross and Nowell 1980; Noltie and Keenleyside 1986). Polyphils; miscellaneous substrate and material nesters that have adhesive eggs either attached or occur in clusters on any available substrate (Simon 1999).


Reproductive strategy: Guarders; nest spawners (Simon 1999). Females swim through the spawning area to choose a nest without apparent courtship from the male; female approaches the male to initiate spawning act; the male vigorously chases the female from the nest after spawning; male guards the eggs and young for 9-18 days (Gross and Nowell 1980; Noltie and Keenleyside 1986).


Fecundity: In Lake Opinicon, Ontario, Canada, number of eggs ranging from 344-1758 per single nest; a single female releases about 400-500 eggs during each spawning; eggs hatched after 5 days (Gross and Nowell 1980). Tin (1982) reported fecundity, based on estimate from ovarian eggs count, between 2,000-11,000 eggs; eggs demersal and adhesive; eggs clear, pale yellow, or whitish; egg size 2.0-2.1 mm diameter, with single egg globule measuring 0.76 mm diameter; incubation is from 3-4 days at 20.5-21 degrees C.


Age at maturation: At the beginning of their 3rd year, both males and females reach maturity (Carlander 1977).


Migration: Funk (1955) reported that this species shows little movement.


Growth and Population structure: Fish inhabiting southern streams were found to average 120 mm TL at the end of their 2nd year (Carlander 1977). Average summer growth rate of upper Niagra River, NY population was 0.51 mm/day (George and Hadley 1979).  


Longevity: Maximum age of 13 years attained in a Wisconsin population; fish in Southeast may live 8 years. Fish in captivity reported to have reached 12 years and 18 years (Carlander 1977).


Food habits: Invertivore/carnivore (Goldstein and Simon 1999). The diets of juvenile and adult fish are dominated by crayfishes and small fishes; snails and aquatic insects, including mayflies and stoneflies, also consumed (Elrod et al. 1981; Probst et al. 1984); as individuals grow larger, consumption of crayfishes and fishes increases (Elrod et al. 1981). In the upper Niagara River, New York, young of year Ambloplites rupestris of all sizes fed on amphipods, copepods, and other aquatic invertebrates (George and Hadley 1979).


Phylogeny and morphologically similar fishes

Ambloplites rupestris differs from the crappies (Pomoxis) in having more than 10 dorsal spines and from other centrarchids in having 5-6 anal spines rather than 3 (in Lepomis) or 7-8 (in Centrarchus; Ross 2001).


Host Records

Hoffman (1967) listed parasites for Ambloplites rupestris: Protozoa (5), Trematoda (35), Cestoda (8), Nematoda (13), Acanthocephala (9), Leech (3), Mollusca (Glochidia), Crustacea (9). Underwood and Dronen (1984) reported infection of endohelminths in fish from the Upper San Marcos River, Texas. Mayberry et al. (2000) listed parasites found in Texas populations.


Commercial or Environmental Importance


[Additional literature noting collection of this species from Texas locations includes, but is not limited to the following: Cashner and Suttkus (1978).]



Bunt, C.M., S.J. Cooke, J.F. Schreer, and D.P. Philipp. 2004. Effects of incremental increases in silt load on the cardiovascular performance of riverine and lacustrine rock bass, Ambloplites rupestris. Environmental Pollution 128(3):437-444.

Carlander, K.D. 1977. Handbook of Freshwater Fishery Biology. Iowa State University Press, Ames. 431 pp.

Cashner, R.C. 1980. Ambloplites rupestris (Rafinesque), Rock bass, p.581. In: D. S. Lee, et al.  Atlas of North American Fishes.  N. C. State Mus. Nat. Hist., Raleigh, i-r+854 pp.

Cashner, R.C., and R.D. Suttkus. 1978. The status of the rock bass population in Blue Spring, New Mexico, with comments on the introduction of rock bass in the Western United States. The Southwestern Naturalist 23(3):463-472.

Cashner, R C., and R.E. Jenkins. 1982. Systematics of the Roanoke bass, Ambloplites cavifrons. Copeia 1982(3):581-594.

Elrod, J.H., W.N. Busch, B.L. Griswold, C.P. Schneider and D R. Wolfert. 1981. Food of white perch, rock bass and yellow perch in eastern Lake Ontario. New York Fish and Game J. 28(2):191-207.

Funk, J L. 1955. Movement of stream fishes in Missouri. Trans. Amer. Fish. Soc. 85: 39-57.

George, E.L., and W.F. Hadley. 1979. Food and habitat partitioning between rock bass (Ambloplites rupestris) and smallmouth bass (Micropterus dolomieui) young of the year. Trans. Amer. Fish. Soc. 108:253-261.

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.

Gross, M.R., and W.A. Nowell. 1980. The reproductive biology of rock bass, Ambloplites rupestris (Centrarchidae), in Lake Opinicon, Ontario. Copeia 1980(3):482-494.

Hallam, J.C. 1959. Habitat and associated fauna of four species of fish in Ontario streams. J. Fish. Res. Bd. Canada 16:147-173.

Hoffman, G.L. 1967. Parasites of North American Freshwater Fishes. University of California Press, Berkeley, 486 pp.

Hubbs, C., R.J. Edwards, and G.P. Garrett. 1991. An annotated checklist of the freshwater fishes of Texas, with keys to identification of species. Texas Journal of Science, Supplement 43(4):1-56.

Jordan, D.S., and C.H. Gilbert. 1883. A synopsis of the fishes of North America. Bull. U.S. Nat. Mus. 16:1-1018.

LeSueur, C.A. 1822. Descriptions of five new species of the genus Cichla of Cuvier. J. Acad. Nat. Sci. Philadelphia 2:214-221.

Mayberry, L. F., A. G. Canaris, and J. R. Bristol. 2000. Bibliography of parasites and vertebrate host in Arizona, New Mexico, and Texas (1893-1984). University of Nebraska Harold W. Manter Laboratory of Parasitology Web Server pp. 1-100.

Neill, W.H. and J.J. Magnuson. 1974. Distributional ecology and behavioral thermoregulation of fishes in relation to heated effluent from a power plant at Lake Winona, Wisconsin. Trans. Amer. Fish. Soc. 103(3):663-710.

Noltie, D.W., and M.H.A. Keenleyside. 1986. Correlates of reproductive success in stream-dwelling male rock bass, Ambloplites rupestris (Centrarchidae). Env. Biol. Fish. 17(1):61-70.

Probst, W.E., C.R. Rabeni, W.G. Covington, and R.E. Marteney. 1984. Resource use by stream-dwelling rock bass and smallmouth bass. Trans. Amer. Fish. Soc. 113(3):283-294.

Rafinesque, C.S. 1817. First decade of new North American fishes. Amer. Monthly Mag. Crit. Rev. 2(2):120-121.

Richardson, J. 1836. Fauna Boreali-Americana; or the zoology of the northern parts of British America: 3rd part The fish. Richard Bentley, London. 327 p.

Robison, H.W. and T.N. Buchanan. 1988. Fishes of Arkansas. University of Arkansas Press, Fayetteville. 536 pp.

Ross, S.T. 2001. The Inland Fishes of Mississippi. University Press of Mississippi, Jackson. 624 pp.

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.

Sublette, J. E., M. D. Hatch, and M. Sublette. 1990. The Fishes of New Mexico.  University of New Mexico Press, Albuquerque. 393 pp.

Tin, H.T. 1982. Family Centrarchidae, sunfishes, p. 524-580. In: Auer, N.A. (Ed.), Identification of larval fishes of the Great Lakes Basin with emphasis on the Lake Michigan Drainage. Great Lakes Fish. Comm. Spec. Publ. 82-83.

Underwood, H.T., and N.O. Dronan, Jr. 1984. Endohelminths of fishes from the Upper San Marcos River, Texas. The Southwestern Naturalist 29(4):377-385.

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.