Colpospira sinuata (Reeve, 1849)
Description: Protoconch 1½ whorls, teleoconch 12 whorls in adult shells. Whorls straight sided or convex, suture impressed. Whorls spirally ribbed, latter whorls sculptured with 10-20 spiral threads of different sizes, sometimes a few being much stronger than the rest. Axial sculpture of growth lines conforming to shape of outer lip sinus. Inner lip of aperture reflected outwards at base; outer lip thin, with a deep sinus, lip usually broken. Base flatly convex, with numerous spiral threads. Upper quarter of whorls coloured with diffuse alternating white and tan splashes, sometimes developing into irregular axial streaks on rest of whorl. Operculum circular, corneous.
Size: Up to 18 mm in length.
Distribution: Endemic to Australia; Fraser Island, Queensland, southwards to Victoria.
Habitat: Known from 9-110 m, and a few beach collected specimens. It has been dredged from Sydney Harbour at depths down to 20 m. Uncommon.
Comparison: Three species in the NSW fauna are of similar size with brown and white markings - C. sinuata, C. guillaumei, C. quadrata. C. sinuata has only fine spiral threads and the whorls are weakly convex or straight. C. guillaumei has broad, low ribs at the top and bottom of whorls but is smooth between. C. quadrata also has ribs at top and bottom of whorls but has spiral threads between.
Fig. 1: Disaster Bay, NSW, in 27 m (C.077330).
Copyright Des Beechey 2006