The Mass-Dimension Relationships in the Mussels Mytilus Galloprovincialis (Mollusca, Bivalvia) from Different Phenotypical Groups in Periphyton Populations near Odessa Coast, the North-Western Part of Black Sea

Abstract

Abstract The data of the size-mass indices in the mussels Mytilus galloprovincialis (Lamarck, 1819) from three phenotypic groups - brown, dark violet (black) and “zebra” (brown with radial black stripes) shells in the periphyton settlements on the concrete traverses near Odessa coast, the North-western part of Black Sea (Ukraine), in March-November 2014-2015 are presented. A comparative evaluation has been made on the relationships of total mass of the mollusks, wet and dry mass of their soft body and mass of the shells on the one hand, and the size of animals (length of its shells) on the other hand, in the each of phenotypical groups from the five marine beach areas. It is shown, that in the marine areas with different degrees of isolation from the open sea by coast-protection engineering constructions, the mussels from different phenotypes have almost the same size-mass characteristics. Only the dry weight of soft animal body, which indicated to fatness of mollusk and therefore demonstrated his biological prosperity in specific hydrological conditions, can serve as a reliable criterion which can mark the shellfish habitats with different gradients of environmental factors.