< Previous species


Next species  >

7853-1.jpg (781945 bytes)


7851-1.jpg (786876 bytes)

Streptopinna saccata (Linnaeus, 1758)

Description: Shell often distorted, thin to moderately heavy, sometimes translucent. Shape irregular, depending on habitat, varying from elongate to ovate, juvenile shells triangular. Dorsal margin initially straight, other margins variable and irregular. Hinge along straight section of dorsal margin. Interior with small nacreous area and adductor muscle scar at anterior end. Exterior very irregular, with 5-14 longitudinal ribs, always without spines. Shell variable in colour - pink, white, yellow, orange, brown, purple.

Size: Up to 200 mm in length in NSW.

Distribution: Indo-West Pacific. In NSW, as far south as Solitary Island, off Coffs Harbour, NSW.

Habitat: “Coral reefs, byssally attached to coral blocks or within branches of living corals, also on gravel, under or among rocks and on wrecks; subtidal 1-25 m” (Schultz & Huber, 2013). The larvae of this species must move into the uppermost zones of the oceans to disperse because juveniles are often found living attached to driftwood, drift nets and in niche spaces in vessels.

Comparison: The irregular shape of the shell comes about because of the shape of the space in which it lives. This irregular growth form in conjunction with the small internal nacreous area readily identifies this species.

Fig. 1: Split Solitary Island, NSW (C.156350)

Fig. 2: Top: Shelly Beach, south of Yamba, NSW (C.158079). Bottom: South West Solitary Island, NSW (C.087614)


Copyright Des Beechey 2024