Study of the morphological and allozyme variation among three common catfishes: Macronus gulio, Ariusjella, Tachysurus maculates.

Abstract

Species characterization using morphological and allozyme genetic markers were attempted for three common morphologically close catfishes, namely Macronus gulio (Family Bagridae), Long whiskers cat fish, Ariusjella (Syn. Pseudariusje/la) or (Family Tachysuridae) Small eye cat fish and Tachysurus macularus (Family Tachysuridae), Spotted cat fish. The degree of morphological variation of three common catfishes was evaluated using selected morphometric and meristic characters. Results of the univariate ANOVA and multivariate analysis revealed highly significant heterogeneity among three groups of fishes, but only Macronus gulio can easily be separated from other two species. It can be identified easily externally by counting pairs of barbells which has four while other two species had three pairs. Six linear measures (HW, OL, POL, MG, MAX and NASAL) and one truss measure (anal to adepose) were found to be significantly different among the catfishes. Here also all the linear measures could differentiate only the M. gulio from the other two. Two tachysurids could not be distinguished from each other, j However the single truss character could distinguish all three from each other, j | Therefore that character seems to be the suitable character in diagnosing these | catfishes. The genetic analysis in the present study was not capable of supporting 1 the results of the morphological analysis due to various technical difficulties. Further genetic analyses are needed in this regard.