Morphological comparisons of Lefua costata (Teleostei: Nemacheilidae), L. pleskei and L. nikkonis, with notes on morphological variations in L. costata introduced to Japan.

Morphological comparisons of Lefua costata (Kessler, 1876) with related congeners, L. pleskei (Herzenstein in Warpachowski & Herzenstein, 1888) and L. nikkonis (Jordan & Fowler, 1903), resulted in a revision of diagnostic features for L. costata, including: a rhomboidal or triangular dark blotch in the middle of the caudal-fin base; a dark lateral stripe along the body in mature males; pre-dorsal vertebrae 16-18 (modally 17); abdominal vertebrae 18-22 (21); longitudinal scales 101-136; body depth 12.3-21.7% SL (mean 16.5% SL); body width 12.0-15.3% SL (13.8% SL); head depth 9.1-12.4% SL (10.9% SL); and interorbital width 7.3-9.6% SL (8.5% SL). Morphological differences between native populations of L. costata and introduced Japanese populations are also discussed. [ABSTRACT FROM AUTHOR]