Greenside Darter
Etheostoma blennioides
Summary 3
The greenside darter (Etheostoma blennioides) is a species of fish in the family Percidae. Etheostoma blennioides is a large percid than inhabits swift riffles in Alabama, Arkansas, the District of Columbia, Georgia, Illinois, Indiana, Kansas, Kentucky, Maryland, Michigan, Missouri, Massachusetts, North Carolina, New York, Ohio, Oklahoma, Pennsylvania, Tennessee, Virginia, and West Virginia.
Distribution 4
Global Range: (200,000-2,500,000 square km (about 80,000-1,000,000 square miles)) Range includes the Great Lakes and Mississippi River basins from eastern Kansas and Oklahoma east to New York and western Maryland, and from southwestern Ontario south to Arkansas, Alabama, and Georgia (excluding the range of former subspecies gutselli, now regarded as a distinct species; Nelson et al. 2004); also the Atlantic slope in Mohawk, Susquehanna, and Potomac drainages, New York to Virginia; a range hiatus exists in the Former Mississippi Embayment and lowlands of Illinois and southwestern Indiana (Page and Burr 2011).
Habitat 5
Greenside darters are benthic organisms and spend their lives associated with the substrate. They live in deep riffle habitats consisting of cobble and loose boulders covered by filamentous green algae, upon which they lay their eggs (Bunt et al., 1998). These fish also prefer moderate to fast-moving water of low turbidity (Dalton, 1991).
Habitat Regions: temperate ; freshwater
Aquatic Biomes: benthic ; lakes and ponds; rivers and streams
Morphology 6
Etheostoma blennioides are small members of the perch family, first discovered by naturalist Constantine Rafenesque in 1819 (Dalton, 1991). Like all darters, greensides lack a swim bladder and live on the bottom substrate (Jenkins and Burkhead, 1993). They average 76 mm in total length, with a cylindrical body (Dalton, 1991) covered with ctenoid scales (Scott and Grossman, 1998) and a broad, triangular head (Dalton, 1991). Their eyes are large and located on each side of the apex (Discover Life in America, 2004). The snout is bluntly rounded, with a small terminal mouth (Dalton, 1991). They have two separate but closely-spaced dorsal fins (Dalton, 1991); the first dorsal fin is edged in white and has 12-14 hard spines, while the second has streaks of black and contains 13-16 soft rays and extends above the first fin (Jenkins and Burkhead, 1993; Bailey et al., 2004). There is also a small sharp spine on the posterior of the opercle. The pectoral fins are large and well-developed, the pelvic fins are located anteriorly, and the caudal fin is often slightly indented (Jenkins and Burkhead, 1993). The caudal, anal, and pelvic fins are all light green in color (Dalton, 1991).
The dorsal surface is olive-green or brown with dark red spots on the upper sides and at the base of the dorsal fins (Dalton, 1991). There are also two dark lines on the face, one extending downward from the eye to the snout and one extending from the eye to the maxillary (Scott and Grossman, 1998). The dark lateral patterning lightens to pale green down the sides, and gradually fades into a white ventral surface. The lower lateral sides have a dark green pattern of five to seven V-shaped bars. These bars are especially dark and visible on juveniles, who also have more pointed pelvic fins than adults (Scott and Grossman, 1998). Males are generally larger overall and also have larger anal, pectoral, pelvic, and first dorsal fins than females (Miller, 1986). Coloration also differs between sexes during the breeding season; males develop intense green to blue-green coloration on the lower sides, anal fins, pelvic fins, and head. The spiny dorsal fin, soft dorsal fin, caudal fins, and lower portions of the pectoral fins in male greenside darters may also become bright green, while the V-shaped lateral pattern turns into green vertical bars (Discover Life In America, 2004 ).
There are 4 different subspecies of Etheostoma blennioides: Etheostoma blennioides, E. b. newmanii, E. b. gutselli, and E. b. pholidotum. The best way to tell them apart is through scale counts and number of dorsal rays. E. b. newmanii has the highest scale count, the most dorsal rays, a fully scaled belly, and a well-developed upper lip. E. b. blennioides has fewer scales and dorsal rays than pholidotum. They also have more lateral blothes and a naked (scaleless) belly. E. b. gutselli has low scale counts, an anteriorally naked belly, no upper lip tip, and lack opercle scales. E. b. pholidotum has lower scale counts than E. b. newmanii and E. b. blennioides, as well as a small lip tip, and a completely scaled belly. E. b. newmanii and E. b. gutselli are considered to be more primitive forms of darter (Miller, 1968).
Greenside darters can be distinguished from other darters by their larger size, rounded snout, and coloration pattern: the rainbow darter (Etheostoma caeruleum) is bright blue and orange and has a pointy snout, while the johnny darter (Etheostoma nigricans) is brown and tan (Bailey et al., 2004).
Average length: 76 mm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: male larger; male more colorful
Nature serve conservation status 7
Rounded Global Status Rank: G5 - Secure
Nature serve conservation status 7
Rounded Global Status Rank: G5 - Secure
Sources and Credits
- (c) Brian Wulker, some rights reserved (CC BY-NC), https://www.flickr.com/photos/bdwulker/15351932386/
- (c) Kent Miller, some rights reserved (CC BY-ND), uploaded by Kent Miller
- Adapted by rkkessler from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Etheostoma_blennioides
- (c) NatureServe, some rights reserved (CC BY-NC), http://eol.org/data_objects/28763654
- (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31393681
- (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31393682
- (c) NatureServe, some rights reserved (CC BY-NC), http://eol.org/data_objects/28763647
