Patterns of the growth of soft-shell clam Mya arenaria L. (Bivalvia) in shallow water estuaries of the southern Baltic Sea

We explored the shell shape and growth performance of the soft-shell clam Mya arenaria L. in two shallow brackish water estuaries of the southern Baltic Sea – Darss-Zingst and Ruegen lagoons. Observed clams ranged from 2 to 50.1 mm in length with detected age up to 6 years old. The growth patterns of the clams were analyzed using the von Bertalanffy growth function (VBGF). An isometric relationship was found between shell length and shell height or shell thickness. Asymptotic length and weight were predicted according to von Bertalanffy equation as L∞ = 82.75 mm and W∞ = 10.9 g. The relationship of wet weight to length was allometric, with exponent b = 3.09. Observed shell lengths were close to values predicted by the model. Our study distinguished patterns of the molluscan growth in estuarine transitional environment of the southern Baltic Sea in comparison with other coastal habitats with pronounced spatial environmental heterogeneity.