Marine Biology

Perna viridis

Species: Perna viridis

Family : Mytilidae

Common Name : Green mussel

Habitat : Intertidal to subtidal hard substrate

Description: shell thick and strong, equivalve, equilateral and elonge. Triangularly ovate in outline. Umbo terminal, pointed,beak-like and downturned. Single large hinge tooth in the right valve and two small hinge teeth on the left valve near the umbo. Anterior adductor muscle scar absent. Dorsal ligamental margin curved; mid dorsal margin arcuate; posterior margin rounded, ventral margin concave (ventral margin is straight in P. indica).

The green periostracum on the surface of the shell gives this species the common name ‘Green Mussel’ . Green mussels are found attached to hard substrata. They live in large clusters by attaching themselves by the proteinaceous byssal thread, secreted by a gland in the proximal part of the foot. They are suspension feeders and feed only when submerged. They do not tolerate prolonged exposure to air or freshwater consequently they are found mainly below mid tide level.

In addition to rocky open coasts and harbours, green mussels are found in the estuarine mouths where the salinity is almost equal to nearby neretic waters.

Size : 200mm.