Lepomis megalotis

longear sunfish

Type Locality

Kentucky, Licking, and Sandy Rivers, Kentucky (Rafinesque 1820).

Etymology/Derivation of Scientific Name

Lepomis, Greek, meaning “scaled gill cover”, megalotis, Greek, meaning “great ear” (Pflieger 1975).

Synonymy

Ichthelis megalotis:  Rafinesque 1820a:29; Nelson 1876:38.

Lepomis fallax Hay 1881:499.

Lepomis megalotis Hildebrand and Towers 1928:132; Cook 1959:180.

Characters

Maximum size: 200 mm SL (Bauer 1980).

Life colors:  Back is brown to olive green. Scales on sides have brownish spots resulting in a brown background overlain with bright blue spots. Fins are olive with a tinge of orange or red, and belly is white to orange. Irregular blue lines on head; pupil is blue, with reddish iris (Ross 2001); opercle not dark to its margin (Hubbs et al. 1991). Colors are much more intense in breeding males, which also have blue to charcoal-colored pelvic fins and bright orange or red sides and belly. The head in breeding males is orange or red with bright blue stripes, the stripes extending onto the body in back of the head, but not onto the throat region. The membranes of median fins of breeding males are orange or red (Ross 2001). “Sneaker” males do not develop breeding coloration; instead they are cryptically colored (Jennings and Philipp 1992a). Young fish lack distinct bands on the side (Ross 2001).

Counts: 5-7 cheek scales; 13-15 pectoral rays; 38-49 lateral line scales; 3 anal spines (rarely 2 or 4); 6-13 dorsal fin spines; 6 or 7 branchiostegals (Hubbs et al 1991); 10-11 dorsal rays; 8-10 anal rays (Ross 2001).

Body shape:  Deep-bodied (Ross 2001); body depth usually contained two to two and one-half times in standard length (Hubbs et al 1991).

Mouth position: Terminal, slightly oblique (Goldstein and Simon 1999).

External morphology: Anal base nearly straight; opercle produced into a thin flexible projection lying within the opercular membrane; posterior edge of opercle within opercular membrane fimbriate; pectoral fins short and rounded; pectoral fin contained 3.75 or more times in standard length; supramaxilla absent or shorter than breadth of maxilla; maxillary width less than suborbital; lateral line present; scales ctenoid (Hubbs et al. 1991).

Internal morphology: Intestine well differentiated; silvery peritoneum; pyloric caeca present (Goldstein and Simon 1999). No teeth on tongue or pterygoid; palatine teeth absent (Hubbs et al 1991). “Sneaker” males have significantly larger testes than parental males (Jennings and Philipp 1992a).

Distribution (Native and Introduced)

U.S. distribution: Wide ranging throughout much of the central United States (Hubbs et al. 1991). Restricted to fresh waters of east-central North America; west of Appalachians, occurs from southern Québec south to Gulf of Mexico in Alabama and western Florida; extends west through Texas and Rio Grande tributaries in northeast Mexico, north through eastern parts of the states from Oklahoma to southern Ontario (Bauer 1980).

Texas distribution: Found statewide in Texas except in the headwaters of the Canadian and Brazos rivers; a number of populations have been introduced in the state (Hubbs et al 1991). Warren et al. (2000) list the following drainage units for distribution of Lepomis megalotis 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, Colorado River, San Antonio Bay (including minor coastal drainages west of mouth of Colorado River to mouth of Nueces River), Nueces River.

Abundance/Conservation status (Federal, State, NGO)

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

Habitat Associations

Macrohabitat: Reservoirs, small streams; generally absent from downstream lowland sections (Bauer 1980).

Mesohabitat: Abundant in clear, small upland streams with rocky bottoms and permanent or semi-permanent flows (Robison and Buchanan 1988). In upper reaches of Black Creek, Mississippi, habitats averaged 61 cm deep, had slow current flow (5.2 cm/s) and a silt, mud, or sand substratum (Ross et al. 1987). Species generally shows little movement in streams; however, when movements do occur they are more often downstream than upstream and average 17 km (Funk 1955).

Biology

Spawning season: Occurs during the late spring and early summer (Huck and Gunning 1967; Bietz 1981).

Spawning location:  Polyphils; miscellaneous substrate and material nesters that have adhesive eggs either attached or occur in clusters on any available substrate (Simon 1999). Spawning occurs in shallow water with gravel bottom, shallow water and little current (Bietz 1981; Hubbs and Cooper 1935; Hankinson 1919).

Reproductive strategy:  Guarders; nest spawners (Simon 1999). In preparation for spawning, males fan out a depression in shallow water, using vigorous motion of the caudal fin. Nest diameter is about twice the length of the fish (Huck and Gunning 1967; Bietz 1981). Males actively court females by quickly rushing back and forth from nest to the female, while making distinctive grunts (Gerald 1971). During spawning, male and female swim in circles around the nest, the female always nearer the center. After spawning, the male chases the female from the nests, then guards and aerates the eggs (by fanning water with pectoral and caudal fins) until hatching (Huck and Gunning 1967). Lepomis megalotis is more active in defense of nest than other sunfishes (Hankinson 1919). Nests are often built close together, forming large groups of territorial males during the spawning season (Jennings and Philipp 1992b), which allows for "sneaker" male behavior. “Sneaker” males, individuals of 40-85 mm TL,  attempt to steal fertilizations from a normal, nesting male by darting into nest and fertilizing eggs when resident male is spawning with a female (Jennings and Philipp 1992a). Some nesting/parental males will opportunistically engage in sneaker behavior with neighboring males that may be more attractive to females (larger males, with centrally located nesting sites in the spawning area; Keenleyside 1972; Jennings and Philipp 1992b).

Fecundity: Fertilized eggs demersal, adhesive, and average about 1.0 mm in diameter (Anjard 1974).

Age/Length at maturation: Both “sneaker” and parental males both mature after 2nd year. However, “sneaker” males are at about 40 mm TL when mature and parental males are at about 75 mm TL when mature due to different growth rates (Carlander 1977; Jennings and Philipp 1992b).

Migration:

Growth and population structure: In Bull Shoals Reservoir, Arkansas and Missouri, individuals reached 43.2 mm TL after one year, 81.3 mm TL after two, 104.1 mm TL after three, and 114.3 mm TL after four (Applegate et al 1967). Growth rates are generally faster in reservoir habitats than in streams, although, even in reservoirs, although fish may require five growing seasons to reach a minimum catch size of 127 mm TL. Fish in northern areas may have smaller body size (Carlander 1977). “Sneaker” males have significantly slower growth rates after 1^st year due to majority of energy utilized in developing gonads rather than increasing length (Jennings and Philipp 1992a).

Longevity: 6 years in southern areas (Bacon and Kilambi 1968); fish in northern areas may live up to 9 years (Carlander 1977).

Food habits:  Invertivore/piscivore. Individuals ingest mainly aquatic and terrestrial insects, other invertebrates and occasional small fish (Robison and Buchanan 1988). Species feeds extensively at the surface (Goldstein and Simon 1999). Applegate et al. (1966) listed diet of individuals smaller than 48 mm as being 86 % aquatic insects and Entomostraca; individuals between 48 -99 mm fed primarily on aquatic insects (48 %), fish eggs (23%), terrestrial insects (9%) and bryzoans (9%); those longer than 102 mm ate terrestrial insects (37%), fish (29%), and aquatic insects (15%). Bryant and Moen (1980) show population in DeGray Reservoir, Arkansas consuming insects (52.6%), crayfish (12.5%), fish (7.4%), and plant material (6.7%). Smaller than 48 mm TL fed mainly on aquatic insects and small crustaceans (copepods and cladocerans), fish larger than 102 mm TL also feed on aquatic insects, but diet also included fish eggs, terrestrial insects, and bryozoans (moss animals; Applegate et al. 1967).

Phylogeny and morphologically similar fishes

Lepomis marginatus (dollar sunfish) is closest relative (sister species; Mabee 1993) to L. megalotis; these two species comprise subspecies Icthelis. L. megalotis hybridizes extensively with other Lepomis (Bauer 1980). L. megalotis easily mistaken for L. marginatus, from which it differs in having 5-7 rather than 3-4 rows of cheek scales, 13-14 rather than 12 pectoral rays, and an opercular tab that is usually not slanted upward in adult males (the opercular tab of females and of young fish has an upward slant). Habitat also distinguishes these two species, with L. megalotis generally occurring in flowing water rather than in swamps (Ross 2001).

Host Records

Commercial or Environmental Importance

References

Anjard, C.A. 1974. Centrarchidae, pp. 178-195. In: Manual for identification of early developmental stages of fishes of the Potomac River estuary. A.J. Lippson and R.L. Moran, eds. Environmental Technology Center, Martin Marietta Corp., Baltimore, Md.

Applegate, R. L. 1966. The use of a Bryozoan, Fredericella sultana, as Food by Sunfish in Bull Shoals Reservoir. Limnology and Oceanography 11(1): 129-130.

Applegate, R. L., J. W. Mullan, D. I. Morais. 1967. Food and growth of six centrarchids from shoreline areas of Bull Shoals Reservoir. Proc. S.E. Assoc. Game Fish Comm. 20:469-482.

Bacon E. J., Jr., and R. V. Kilambi. 1968. Some aspects of the age and growth of the longear sunfish, Lepomis megalotis, in Arkansas waters. Proc. Ark. Acad. Sci. 22:44-56.

Bauer, B. H. 1980.  Lepomis megalotis (Rafinesque), Longear sunfish.  pp. 600 in D. S. Lee, et al.  Atlas of North American Freshwater Fishes. N. C. State Mus. Nat. Hist., Raleigh, i-r+854 pp.

Bietz, Brian F.  1981.  Habitat availability, social attraction and nest distribution patterns in longear sunfish (Lepomis megalotis peltastes). Environmental Biology of Fishes 6(2):193-200.

Bryant, H. E. and T. E. Moen. 1980. Food of Bluegill and Longear sunfish in DeGray reservoir, Arkansas. Arkansas Academy of Science Proceedings 34: 31-33.

Carlander, K. D. 1977. Handbook of freshwater fishery biology. Vol. 2. Iowa State Univ. Press, Ames. 431 pp.

Cook. F. A. 1959. Freshwater fishes in Mississippi. Mississippi Fame and Fish Commission, Jackson. 239 pp.

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

Gerald J. W. 1971. Sound production during courtship in six species of sunfish (Centrarchidae). Evolution 25(1):75-87.

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.

Hankinson, T. L. 1920. Notes of life histories of Illinois fish. Trans. Ill. State. Acad. Sci. 12:132-150.

Hay, O. P. 1881. On a collection of fishes from eastern Mississippi. Proc. U.S. Nat. Mus. 3:488-515.

Hildebrand S. F. and I. L. Towers. 1928. Annotated list of fishes collected in the vicinity of Greenwood, Mississippi, with descriptions of three new species. Bull. U.S. Bur. Fish. 43(2):105-136.

Hubbs, C. L. and G. P. Cooper, 1935. Age and growth of the longeared and the green sunfishes in Michigan. Pap. Mich. Acad. Sci. Arts Lett. 20:669-696.

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, Supplement 43(4):1-56.

Huck, L. L. and G. E. Gunning. 1967. Behavior of the longear sunfish, Lepomis megalotis (Rafinesque). Tulane Stud. Zool. 14(3):121-131.

Jennings, M. J. and D. P. Philipp. 1992a. Reproductive investment and somatic growth rates in longear sunfish. Env. Biol. Fish. 35:257-271.

Jennings, M. J. and D. P. Philipp. 1992b. Females choice and male competition in longear sunfish. Behav. Ecol. 3(1):84-94.

Keenleyside, M. H. A. 1972. Intraspecific intrusions into nests of spawning longear sunfish (Pisces: Centrarchidae). Copeia 1972(2):272-278.

Mabee, P.M. 1993. Phylogenetic interpretation of ontogenetic change: sorting out the actual and artefactual in an empirical case study or centrarchid fishes. Zoological Journal of the Linnean Society 107:175-291.

Nelson, E. W. 1876. A partial catalogue of the fishes of Illinois. Bull. Ill. Mus. Nat. Hist. 1(1):33-52.

Pflieger, W. L. 1975.  The Fishes of Missouri. Missouri Department of Conversation, Jefferson City. 343pp.

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

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

Ross, S.T., J.A. Baker, and K.E. Clark. 1987. Microhabitat partitioning of southeastern stream fishes: temporal and spatial predictability, pp. 42-51. In: Evolutionary and community ecology of North American stream fishes. W.J. Matthews and D.C. Heins, eds. Univ. Oklahoma Press, Norman. 299 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 Biological Notes 54.12p.

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.