Minytrema melanops 

spotted sucker



Type Locality

Ohio River, at Louisville, Kentucky (Rafinesque 1820).


Etymology/Derivation of Scientific Name

Minytrema: reduced aperture, in reference to the incomplete lateral line; melanops: black appearance (Ross 2001).



Catostomus melanops Rafinesque 1820:57.

Minytrema melanops Cook 1959:86.



Maximum size:  495 mm TL (Lambou 1961); 270 mm SL, in Texas (Edwards 1997).


Coloration: Color pattern (except in the pale, obscurely mottled young) consists of rows of black spots (one on each scale; Hubbs et al. 1991). Back and upper sides dark gray to olive with a coppery iridescence. Lower sides are brassy, lighter gray or olive, and undersides are white. Scales have distinct dark pigmentation at base, lending the appearance of parallel lines on sides. Pectoral, pelvic, and caudal fins often have red tinting, and all fins have heavy dark pigmentation along rays. Usually has a light band through the middle of dorsal fin, running parallel to fin margin. Caudal fin often has darker melanophores lining rays of the lower lobe. Pectoral, pelvic, and anal fins sometimes have thin, unpigmented areas surrounding fin (Ross 2001). Males exhibited two dark, almost black, mid-lateral stripes, separated by a pinkish-red band; the dark bands sometimes extending across the nape and nose of male (McSwain and Gennings 1972). Peritoneum is colorless to white (Goldstein and Simon 1999).


Teeth count: 75-91 pharyngeal teeth (Eastman 1977); 101-104 reported for fish measuring 361 mm SL (R.E. Jenkins, pers. comm.1996 In: Ross 2001).


Counts: 4-18 dorsal fin rays (Hubbs et al. 1991).


Body shape: Slim-bodied, nearly terete (Miller and Robison 1973); body depth goes into standard length 4-6 times, large fish becoming proportionately deeper bodied (Ross 2001).


Mouth position: Inferior and horizontal (Hubbs et al. 1991).


External morphology: Lateral line somewhat developed in adults (with only 4 unpored scales; Ross 2001); dorsal fin base less than one-fourth standard length (Hubbs et al. 1991); lips fairly thin and plicate (Miller and Robison 1973). Forked caudal fin, lateral line absent in small fish; snout extending well beyond upper lip; dorsal fin is quite short and the anterior rays are longer than the posterior rays, producing slightly-moderately concave profile (Ross 2001). Males with large nuptial tubercles present on snout (Jackson 1958) and anal fins, occasionally with smaller tubercles on other fins and dorsal scales. Small tubercles may be present on anal fin of breeding females (McSwain and Gennings 1972).


Internal morphology: Air bladder with two chambers (Hubbs et al. 1991). Intestine is long, little differentiated (Goldstein and Simon 1999).


Distribution (Native and Introduced)

U.S. distribution: Lower Great Lakes basin (lakes Erie, Huron, and Michigan) of PA, OH, MI, WS, and Ontario, Canada; upper Mississippi Valley in WS, MN, and IA; south to Gulf slope drainages from TX (Colorado River drainage) to FL (Suwannee River drainage); and north on Atlantic coast to Cape Fear drainage of NC (Gilbert and Burgess 1980).


Texas distribution: Found primarily in eastern streams from the Red to the Brazos basins; disjunct population occurs in the Llano River (Colorado River Basin) near Junction downstream about to Mason (Hubbs et al. 1991). Warren et al. (2000) list the following drainage units for distribution of Minytrema melanops in the state: Red River (from the mouth upstream to and including the Kiamichi River), Sabine Lake (including minor coastal drainages west to Galveston Bay), Galveston Bay (including minor coastal drainages west to mouth of Brazos River), Brazos River, and possibly the Colorado River. 


Abundance/Conservation status (Federal, State, NGO)

Populations in the southern United States are currently stable (Warren et al. 2000).

Often moderately common, though species has disappeared in areas (as in much of Illinois), due to extensive siltation (Smith 1965; Gilbert and Burgess 1980); authors have suggested that increased siltation, as well as other environmental changes negatively impacting populations, have resulted in declining numbers in Ohio (Trautman 1957) and Kansas (Cross 1967).


Habitat Associations

Macrohabitat: Species found in some creeks, small rivers, overflow lakes, and impoundments (Gilbert and Burgess 1980). According to Jackson (1958), species is commonly found in reservoirs, and Beecher et al. (1977) report that it is abundant in oxbow lakes.


Mesohabitat: Found in clear, creeks with firm substrate, and sometimes in small turbid creeks (Gilbert and Burgess 1980). In Goose Creek, Kentucky, White and Haag (1977) observed adults in deep pools, during the day, and over sand bars in early morning hours and at dusk; larval and juvenile fish were found in shallower pools. Species inhabits sluggish, turbid, low-gradient streams having soft substrates of silt, organic debris, or sand, with submerged vegetation usually present; typically lowland ditches, oxbows, borrow pits and quiet backwater areas without strong currents (Edwards 1997). Minytrema melanops was more numerous in downstream sections of Big Sandy Creek, Texas (Evans and Noble 1979).



Spawning season: In Georgia, early March – early May at water temperatures of 12-19.5°C (McSwain and Gennings 1972); in Oklahoma, late April and May at 15-18 degrees C (Jackson 1958); in Ichetucknee Spring Run, Florida, early March (R.E. Jenkins, pers. comm. In: Gilbert and Burgess 1980). Based on the presence of small specimens, measuring less than 40 mm SL, in research museum collections from April – July, spawning probably occurs from about March – June, in Texas (Edwards 1997).


Spawning habitat: Lithopelagophils – rock and gravel spawners with pelagic free embryos (Simon 1999). In Oklahoma, riffle areas above pools (Jackson 1958); in Georgia, on shallow riffles with coarse substrata (McSwain and Gennins 1972).


Reproductive strategy: Nonguarders; open substratum spawners (Simon 1999). A group of 3 – 7 males, facing upstream, held loosely defined territories covering a 6 m by 3 m range in the riffle area. As a female appeared, the nearest males proceeded directly to her; and with their snouts, bumped and prodded the female about the abdomen, dorsum, and head. Usually, two males and one female participated in spawning, with the female positioned on the bottom and a male on either side of her, all fish facing upstream. The males clasped the posterior half of the female between their posterior halves, vibrating caudal portions for a period of 2 – 6 seconds, during which all three moved toward the surface.  Semibouyant eggs were shed as just before this act ended, with the eggs drifting downstream directly below and immediately following union, while debris from the substrate is disturbed by spawning fish. Males spawn several times; both the short duration of the spawning act, and collection of females examined and found to have spent ovaries suggests that females may spawn on multiple occasions as well (McSwain and Gennings 1972).


Fecundity: In Oklahoma, eggs hatched in 7-12 days, depending on water temperature (Jackson 1958). Immediately prior to hatching, eggs measure 3.1 mm (White 1977). Hogue and Buchanan (1977) reported that eggs reared in laboratory at 16.1-20.0 degrees C hatched between 108-156 hours after fertilization; unfertilized eggs averaged 2.0 mm diameter; fertilized, water hardened eggs averaged 2.5 mm diameter; fertile eggs were demersal and adhesive.


Age at maturation: Jackson (1958) noted that majority of specimens collected were mature by 3rd year of life (Age-group II).


Migration: In Oklahoma, annual spawning migration begins in late January, with fish moving into stream in great numbers from deeper water (Jackson 1958).


Longevity: 6 year maximum lifespan reported from MN (Gilbert and Burgess 1980), although southeastern fish may live only 5 years (Carlander 1969; Edwards 1997).


Food habits: Invertivore (Goldstein and Simon 1999), based on food items of copepods and ostracods (19.4% volume), and cladocerans (77.2% volume) found in digestive tracts of specimens examined by Bur (1976). As fish develop, they change from middepth water predators to bottom foragers (by 50 mm TL); larvae begin feeding at 12-15 mm TL, while yolk sac is still present, consuming zooplankton and large diatoms, feeding in schools during the day; with shift to bottom feeding, adults feed during dusk and dawn, primarily consuming sand, organic fragments, diatoms, small crustaceans (copepods and cladocerans), and midge larvae, which fish efficiently separate from bottom materials by finely spaced gill rakers; zooplankton mainly ingested in spring, summer, and fall; midges are mostly taken in the summer and fall; in winter, majority of fish feed on organic detritus (White and Haag 1977). Species actively feeds during breeding season (McSwain and Gennins 1972). Miller and Evans (1965) considered species a mouth taster based on the brain pattern. In laboratory culture vats, postlarvae 15.0 mm TL and smaller fed at surface and at mid-region; fish greater than 15.0 mm TL fed in mid-region and bottom of the culture tanks; bottom feeding became prevalent at the juvenile stage, when the mouth was distinctly inferior (Hogue and Buchanan 1977).


Growth and Population structure: Fish from lower Spavinaw Lake, Oklahoma, attained an average TL of at the end of the 1st year of life, and 10.2, 12.7, 14.7, and 16.5 inches TL by the end of the 2nd – 5th years of life, respectively; in upper Spavinaw Lake, Oklahoma, fish attained an approximate TL of 6.1 inches the 1st year of life, and 11.3, 13.3, 16.1, and 17.3 inches TL by the end of the 2nd – 5th years, respectively (Jackson 1958). Bur (1976) collected 122 fish, ranging from 130 – 495 mm TL, from the upper Mississippi, during the summer of 1975; calculated lengths at annuli from 1 – 6 years old were 63 mm, 169 mm, 270 mm, 348 mm, 391 mm, and 450 mm, respectively. Hogue and Buchanan (1977) reported that newly hatched larvae averaged 6.0 mm TL, and reached an average of 10.5 mm eight days after hatching; at 7-9 weeks, juveniles measured from 20-23 mm. White (1977) reported that larvae ranged from 8.0-9.2 mm TL at hatching.


Phylogeny and morphologically similar fishes

Minytrema melanops is member of subfamily Catostominae (Gilbert and Burgess 1980), and is the only species of the genus Minytrema (Tomelleri and Eberle 1990). Most similar in body shape to redhorses (Moxostoma) and chubsuckers (Erimyzon). It can be distinguished from both groups by its absent or incomplete lateral line (versus complete, well developed) and narrow dark-dashed lines along the sides. All other suckers, except chubsuckers, have complete lateral lines. Spotted suckers differ from chubsuckers in having generally higher lateral scale counts (44-47 versus 45 or fewer). Chubsuckers also lack dusky spots on the base of the scales (Ross 2001).


Host Records

Trematoda: Posthodiplostomum minimum (Mayberry et al. 2000). In Alabama, three species of Pseudomurraytrema (Trematoda: Monogenea) described from the gills of Minytrema melanops: Pseudomurraytrema alabarrum sp. n., P. etowanum sp. n., and P. swinglei sp. n. (Rogers 1966).


Commercial or Environmental Importance

Species considered pollution intolerant (Karr et al. 1986; USEPA 1983). In the nineteenth-century, Minytrema melanops was recommended for domestication by ichthyologist, Edward Drinker Cope, based on its hardiness in the aquarium (Tomelerri and Eberle 1990).


[Additional literature noting collection of this species from Texas locations includes, but is not limited to the following: Hubbs (1954;1957); Riggs and Bonn (1959); Pine Island bayou (Kleinsasser and Linam 1987); Cow Bayou (Linam and Kleinsasser 1987); Linam et al. (1994); Sister Grove Creek (Trinity River basin; Matthews et al. 1996); Village Creek (Hardin Co.; Moriarty and Winemiller 1997).]



Beecher, H.A., W.C. Hixson, and T.S Hopkins. 1977. Fishes of a Florida oxbow lake and its parent river. Fla. Sci. 40(2):140-148.

Bur, M.T. 1976. Age, growth and food habits of Catstomidae in Pool 8 of the upper Mississippi River. M.S. Thesis. Univ. Wis., LaCrosse. 107 pp.

Carlander, K.D. 1969. Handbook of freshwater fishery biology. Vol. 1. The Iowa State University Press, Ames. 752 pp.

Cook, F.A. 1959. Freshwater fishes in Mississippi. Mississippi Game and Fish Commission, Jackson.

Eastman, J.T. 1977. The pharyngeal bones and teeth of catostomid fishes. Amer. Midl. Nat. 97(1):68-88.

Edwards, R.J. 1997. Ecological profiles for selected stream-dwelling Texas freshwater fishes. Report to the Texas Water Development Board. 89 pp.

Evans, J.W., and R. L. Noble. 1979. The longitudinal distribution of fishes in an east Texas stream. American Midland Naturalist 101(2):333-343.

Gilbert, C.R. and G.H. Burgess. 1980.  Minytrema melanops (Rafinesque), Spotted sucker, p. 408 in D. S. Lee, et al.  Atlas of North American Fishes.  N. C. State Mus. Nat. Hist., Raleigh, i-r+854 pp.

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.

Hogue, J.J., Jr., and J.P. Buchanan. 1977. Larval development of spotted sucker (Minytrema melanops). Trans. Amer. Fish. Soc. 106(4):347-353.

Hubbs, C. 1954. Corrected distributional patterns for Texas fresh-water fishes. Texas Journal of Science 1954(3):277-191.

Hubbs, C. 1957. Distributional patterns of Texas fresh-water fishes. The Southwestern Naturalist 2(2/3):89-104.

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.

Jackson, S.W., Jr. 1958. Comparison of the age and growth of four fishes from lower and upper Spavinaw Lakes, Oklahoma. Proc. S.E. Assoc. Game Fish Comm. 11:232-249.

Karr, J.R., K.D. Fausch, P.L. Angerneier, P.R. Yant, and L.J. Schlosser. 1986. Assessing biological integrity in running waters: a method and its rationale. Illinois Natural History Survey Special Publication 5, Champaign, Illinois.

Kleinsasser, L.J., and G.W. Linam. 1987. Fisheries use attainability study for Pine Island Bayou (Segment 0607). River Studies Report No. 6. Resource Protection Division, Texas Parks and Wildlife Department, Austin. 21 pp.

Lambou, V.W. 1961. Efficiency and selectivity of flag gillnets fished in Lake Bistineau, Louisiana. Proc. S.E. Assoc. Game Fish Comm. 15:319-359.

Linam, G.W., and L.J. Kleinsasser. 1987. Fisheries use attainability study for Cow Bayou (Segment 0511). River Studies Report No. 5. Resource Protection Division, Texas Parks and Wildlife Department, Austin. 14 pp.

Linam, G.W., J.C. Henson, and M.A. Webb. 1994. A fisheries inventory and assessment of Allens Creek and the Brazos River, Austin County, Texas. River Studies Report No. 12. Resource Protection Division, Texas Parks and Wildlife Department, Austin. 14 pp.

Matthews, W.J., M.S. Schorrs, and M.R. Meador. 1996. Effects of experimentally enhanced flows on fishes of a small Texas (U.S.A.) stream: assessing the impact of interbasin transfer. Freshwater Biology 1996(35):349-362.

Mayberry, L.F., A.G. Canaris, J.R. Bristol, and S.L. Gardner. 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, published on the World-Wide-Web. 100 pp.

McSwain, L.E., and R.M. Gennings. 1972. Spawning behavior of the spotted sucker, Minytrema melanops (Rafinesque). Trans. Amer. Fish. Soc. 101(4):738-740.

Miller, R.J., and H.E. Evans. 1965. External morphology of the brain and lips in catostomid fishes. Copeia 1965(4):467-487.

Miller, R.J., and H.W. Robison. 1973. The Fishes of Oklahoma. Oklahoma State University Press, Stillwater. 246 pp.

Moriarty, L.J., and K.O. Winemiller. 1997. Spatial and temporal variation in fish assemblage structure in Village Creek, Hardin County, Texas. Texas Journal of Science 49(3):85-110.

Rafinesque, C.S. 1820. Ichthyologia Ohiensis, or natural history of the fishes inhabiting the River Ohio and its tributary streams, preceded by a physical description of the Ohio and its branches. W. G. Hunt, Lexington, Ky.

Riggs, C.D., and E.W. Bonn. 1959. An annotated list of fishes of Lake Texoma, Oklahoma and Texas. The Southwestern Naturalist 4(4):157-168.

Rogers, W.A. 1966. Three new species of Pseudomurraytrema (Trematoda: Monogenea) from gills of catostomid fishes. The Journal of Parasitology 52(3):462-465.

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.

Smith, P.W. 1965. A preliminary annotated list of the lampreys and fishes of Illinois. Illinois Natural History Survey Biological Notes No. 54. 12 pp.


Tomelleri, J.R. and M.E. Eberle. 1990. Fishes of the Central United States. Univ. of Kansas Press, Lawrence. 226 pp.

United States Environmental Protection Agency. 1983. Technical support manual: waterbody surveys and assessments for conducting use attainability analyses. EPA Office of Water Regulations and Standards, Washington, D.C.

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.

White, D.S. and K.H. Haag. 1977. Foods and feeding habits of the spotted sucker, Minytrema melanops (Rafinesque). Amer. Midl. Nat. 98(1):137-146.