Streptopinna

Streptopinna is an Indo-Pacific genus of bivalve molluscs characterized by a roughly triangular outline. There is only one species, Streptopinna saccata.

Description

No two "baggy pen shells" are alike; they grow into unexpected shapes, conforming to the shape and position of other hard structures in their immediate environment.

Distribution

Warm waters of the tropical Indian and western Pacific oceans.

Habitat

Buried in sandy bottoms.