Investigation of morphometric and meristic characters of the Caspian Lamprey (Caspiomyzon wagneri) during migration season in Shirud and Talar Rivers

Abstract

We studied the morphological characteristics of the Caspian Lamprey (Caspiomyzon wagneri) in two rivers of Shirud and Talar during the spring migration in 2006. A total of 91 specimens were collected using hand and cast net. Relative morphometric characters including disc length, head depth, eye length, prebranchial length, head length, distance between disc and posterior end of the first dorsal fin, distance between disc and base of second dorsal fin, distance between disc and anus, post branchial length, tail length, interocular distance, and post ocular length showed significant differences between the two populations (P less than or equal to 0.05), but meristic characters showed no significant differences (P greater than or equal to 0.05). Although some of the relative morphometric characters showed differences between the two populations of the rivers, but the populations were not different based on the principal components analysis (PCA) and had a relatively high overlap.