Colpospira moretonensis Garrard, 1972
Description: Protoconch 1½ whorls, teleoconch at least 8 whorls, shell translucent when fresh. Whorls straight-sided overall, suture incised. Whorls spirally ribbed; latter whorls with two primary spiral ribs; upper rib broad, low, rounded, at ? or ¼ whorl's height from top; lower rib at bottom of whorl, usually stronger, sharp edged above, smoothly sloping to suture below; zone between ribs weakly concave; whole surface with about 10 weak threads or lirae. 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. Body whorl angled, base with weak spiral threads. Colour fawn. Operculum unknown.
Size: Up to 6.5 mm in length.
Distribution: Endemic to Australia; Swain Reefs, Queensland, southwards to Port Stephens, NSW.
Habitat: Known from 70-201 m. Rare.
Comparison: This small shell may be separated by its small size - up to only 6.5 mm - and its sculpture. There are only two other species as small as this in NSW - C. wollumbi and C. yarramundi. Both of these are strongly spirally keeled, while C. moretonensis has two low, broad ribs.
Remarks: The strength of the spiral ribs varies in this species; the upper rib may be absent, or occasionally nearly as strong as the lower.
Fig. 1: Off Moreton Bay, Queensland, in 75-80 m (C.380988).
Copyright Des Beechey 2006