First morphometry, reproduction, and genetic data for Blennius ocellaris (Linnaeus, 1758) from the Black Sea

Two specimens of the butterfly blenny, Blennius ocellaris, were caught off coast Ordu (Black Sea, Turkey) in April 2021 by trammel net. The aim this paper is to further document occurrence and distribution blenny for Black Sea Turkish marine ichthyofauna provide first morphometric, reproduction, genetic data on species fauna species. Some morphometric meristic characters measured presented as percentage total length (TL%). All measurements except eye diameter, pre-anal length, maximum body depth higher male individual. It was observed that head makes up almost 1/4 body. determined ripe eggs their final stage development (Stage IV). Gonad’s weight a female individual 2.85 g number 2993. mean egg diameter 1070.7 ±15.63 μm (from 1050.2 1123.1 μm). mitochondrial DNA gene regions 16S rRNA COI sequenced analyzed. generated partial sequences 621 bp 551 bp, respectively. likelihood tree with retrieved from GenBank database demonstrated geographic region-based distinction nested reference specimen Western Mediterranean Marmara.