title: Variability in the number of rays and specification of the dorsal fin formula of the black scorpionfish Scorpaena porcus Linnaeus, 1758 (Pisces: Scorpaenidae) from the Black Sea
abstract: Out of the morphological criteria for the fish species, the meristic (countable) characters are of the key role, in particular the number of rays in the fins. It is one of the stable signs of fish morphotype not subjected to size and age variability. At the same time, it is a clear taxonomic criterion. The aim of the work was to study the variability in the number of rays in the dorsal fin and to specify its formula for the black scorpionfish inhabiting the Black Sea off the coasts of the North 
journal: Marine Biological Journal