Length-weight relationships of ten fish species from the Bulgarian Black Sea waters

Length-weight relationships (LWRs) of 16,842 specimens of fish caught in the Bulgarian Black Sea waters, covering 9 families, 10 genera, and 10 species, were studied. Spiny dogfish (Squalus acanthias L.), thornback ray (Raja clavata L.), sprat (Sprattus sprattus L.), pontic shad (Alosa immaculata Eichwald), anchovy (Engraulis encrasicolus L.), whiting (Merlangius merlangus euxinus Pallas), horse mackerel (Trachurus mediterraneus Aleev), bonito (Sarda sarda Bloch), round goby (Neogobius melanostomus Pallas), and turbot (Psetta maxima L.) were collected from May 2006 to December 2008. The fishes were caught by different fishing techniques, such as gill net, trawl net, and trap nets. The slope or allometric coefficient (b) of the functional regression between length and weight values varied from between 2.302 and 3.839 with the mean b = 3.152. The LWRs for S. acanthias and R. clavata have been reported for the first time for the Bulgarian Black Sea waters.