Nassarius nigellus (Reeve, 1854)
Description: Shell light to medium weight, often translucent. Sculptured with coarse, nodulose axial ribs which become obsolete on dorsal surface of body whorl. Wide spiral ribs overide axials. A broad, smooth channel separates the row of ribs at the suture from remainder of whorl. Outer lip smooth or denticulate, columella callus expanded, but not reaching the body whorl suture. Columella with small denticles anteriorly, sometimes obsolete, and a strong tooth anteriorly in mature shells. Uniform cream to dark brown in colour, occasionally banded with brown.
Size: Up to 13 mm in length.
Distribution: Endemic to Australia; Cairns, Qld, to Cockburn Sound, WA, including Tas.
Habitat: On mud and sand flats, or in sand, low tide level to 180 m. Common.
Comparison: Superficially similar to N. pauperatus, but smaller, lighter in weight and less bulbous at the body whorl, with finer and more discrete sculpture. Cernohorsky (1972) describes protoconch differences. Although N. pauperatus occurs as far north as Sydney, it is rare and appears to be restricted to deeper water in NSW.
Synonyms: This species is quite variable, in terms of size, the presence of absence of denticles on the inside of the outer lip, the presence or absence of a varix on the body whorl, and in colour banding. A number of forms have been given specific names:
Figs. 1,2: Simpsons Bay, Port Hacking, NSW (DLB4965)
Copyright Des Beechey 2000