The Adaptive Morphology of Byssus in Mytilus coruscus, Crenomytilus grayanus, and Modiolus modiolus (Mytilidae, Bivalvia) from the Sea of Japan

Abstract

The adaptation of sessile bivalves to the attached mode of life has been studied using three common mytilid species, Mytilus coruscus, Crenomytilus grayanus, and Modiolus modiolus. This study has shown similar features of organization of byssus and some of its structures associated with their functional significance in these bivalves. Myt. coruscus has the shortest and thickest byssal threads with the largest, reinforced attachment disks, which indicates the species’ adaptation to a habitat in the coastal zone with active hydrodynamics. In contrast, the threads of C. grayanus and Mod. modiolus are thinner, longer, and smaller in size, with weakly reinforced attachment disks, which is evidence that these species have adapted to biotopes sheltered from direct wave action.