American ichthyologists Rebecca Blanton and Robert Jenkins have described three new species of darter belonging to the Etheostoma percnurum species complex.
Publishing the descriptions of the Citico darter (E. sitikuense), Marbled darter (E. marmorpinnum) and the Tuxedo darter (E. lemniscatum) in a recent issue of the journal Zootaxa, the authors separate the three new species from populations previously identified as the endangered Duskytail darter (E. percnurum).
Citico darter, E. sitikuenseThe Citico darter, Etheostoma sitikuense, is distinguished from other members of the E. percnurum species complex in having 34 pored lateral-line scales, anal-fin band 33"39% of height, 15 transverse scale rows, shorter pectoral and pelvic fins, and a wider, deeper body.
The Citico darter is known from the Tennessee River drainage and streams that this species inhabits are moderate-sized, with alternating riffles, runs, and pools with cobble and small boulders.
This species is named after the Cherokee Indian word ~sitiku for a place of clean fishing water and is the origin for the name of Citico Creek (the type locality).
Marbled darter, E. marmorpinnumThe Marbled darter, E. marmorpinnum, is distinguished from from other members of the E. percnurum species complex in having 60"80% of the belly covered by scales, the entire area along the first dorsal-fin base covered with scales, dark distinct marbling in the second dorsal fin of nuptial males, caudal-fin band width 12"15% of fin length, anal-fin band 29"33% of height, 25 scales around caudal peduncle, and higher first dorsal fin.
This species is named after the distinct marbled pattern of the second dorsal fin of nuptial males (from the Latin marmor, meaning marbled and pinna, meaning fin).
The marbled darter is known from the Tennessee River drainage, where it inhabits streams of moderate gradient with riffles, runs, and long pools.
The species is primarily associated with pools and moderate runs about 0.3"1.2 m deep with clean pebbles, cobble, and small boulders.
Tuxedo darter, E. lemniscatumThe Tuxedo darter, E. lemniscatum, is distinguished from other members of the E. percnurum species complex in having the anal fin positioned further back along the body, the pectoral fin of nuptial males with a dark, distal band confined to the rays of the dorsal half or less of the fin, and nuptial males with dark and distinctly defined black bands on the distal margin of the caudal, anal, and second dorsal fins.
The Tuxedo darter is known from the Cumberland River drainage, and where it occurs, the river is approximately 30"50 m wide and flows through a deep gorge; it is characterized by long, deep pools with large boulders and bedrock substrates, fast, well defined riffles with cobble, boulders, and gravel, and is completely forested along the main-stem.
The species was always observed in silt-free pools or runs with low flow, immediately above riffles where there were cobbles, boulders, and slab-rocks.
The specific name means adorned with ribbons, and refers to the black ribbon-like bands of the caudal, anal, and second dorsal fins.
For more information, see the paper: Blanton, RE and RE Jenkins (2008) Three new darter species of the Etheostoma percnurum species complex (Percidae, subgenus Catonotus) from the Tennessee and Cumberland river drainages. Zootaxa 1963, pp. 1"24.