Somatic Growth Parameters of Black Sea Bivalvia Mollusks – (Bruguiere, 1789), (Lamark, 1789) and (Gmelin, 1791) in Summer (Azov-Black Sea Basin)

The results of comparative analysis of morpho-physiological and biochemical indices of somatic growth for three Black Sea bivalve mollusks living in shallow waters near the Kerch Strait – cockle (Bruguiere, 1789), mussel (Lamark, 1789) and mytilaster (Gmelin, 1791) were presented. The length range from 15 to 20 mm were studied. The size-weight dependence was estimated as very high according to the Chaddock scale for , with the correlation coefficient R = 0.97, and high for (R = 0.73) and (R = 0.86). Linear regression models between total mussel mass and soft tissue mass illustrated a large proportion of explained variance, with determination coefficients from 0.70 to 0.87. Based on the values of total RNA content and the RNA/DNA growth index in and , it was shown that the level of synthesis of protein structures of somatic tissues in the juveniles of these species is estimated as average; in as high. Species specificity of somatic growth between species of different families was noted: the level of tissue biosynthesis was 2.3 times higher in (Mytilidae) than in (Cardiidae).