Crepidula immersa Angas, 1865
Description: Shell oval in outline, very low, length greater than width. Apex a small beak overlapping posterior margin. Sculpture restricted to fine concentric growth lines. Interior with shelf, occupying about a third of base area. Exterior colour white or fawn, occasionally brown. Interior polished, usually white, occasionally fawn or tan.
Size: Up to 36 mm long, 4 mm high.
Distribution: Endemic to Australia; Sydney, NSW, around southern Australia to south-western WA.
Habitat: Lives attached to dead shells; subtidal, down to 350 m. Empty shells occasionally found in beach washup. Uncommon in NSW, more common in South Australia.
Synonymy: The name Crepidula unguiformis Lamarck, 1822, which is a European species, was used for this species in some early Australian literature.
Remarks: This species lives attached to other shells or occasionally to stones, and takes up the shape of the substrate surface. Those that live inside the host shell are concave, while those that live outside are convex. There is considerable variation in colour but the majority of specimens seen in NSW are white or fawn, although Victorian and South Australian shells may be chocolate brown in colour.
Fig. 1: Off Eden, NSW (C.359865)
Fig. 2: Same specimen as Fig. 1
Fig. 3: Same specimen as Fig. 1
Copyright Des Beechey 2007