Differentiation de juveniles de Chlamys varia et Chlamys opercularis

The recent developments in collecting techniques for spat of Chlamys operoularis and Chlamys varia make it necessary to find criteria for separating these two species at early life stages. Biométrie criteria for differenciating between species have been found to be usable on individuals of a height superior to 3 mm. A quick différenciation of smaller individuals is possible by observation, under light microscope, of the périostracum external morphology on left valves.