Astralium squamiferum Philippi, 1844
Description: Shell height less than width; ratio of height to width 0.64-0.82. Whorls sharply angled, weakly to strongly keeled, keel projecting laterally, with keels of early whorls sometimes overhanging lower whorls; keel usually smooth edged, sometimes irregularly scalloped or extended into rounded spines in juvenile shells; base whorls flat or slightly concave or convex. Sculptured with any of three components, each variable in strength, usually eroded: (1) granular spiral threads (2) curved oblique axial ribs, about 60 on last whorl, which may cross the entire whorl or be restricted to the upper part (3) fine or coarse growth ridges parallel to the aperture lip. Base with fine, scaly riblets, apertural callous on base no more than one-third of whorl in mature shells. Outer lip thin, simple. Exterior white, grey or fawn; interior nacreous. Operculum calcareous, white, with a raised spiral ridge.
Size: NSW specimens up to 26 mm high, commonly about 15 mm.
Distribution: Endemic to Australia: Angourie, NSW, to south-western WA, possibly extending further up the WA coast; northern Tasmania.
Habitat: On rocky shores, in lower intertidal and subtidal zone. In NSW, uncommon intertidally, more common subtidally.
Comparison: Smaller and flatter than A. tentoriiformis, without the large nodules on the lower half of whorls of that species; operculum white, blue or purple in A. tentoriiformis (Fig. 3). The variation in height to width ratio and strength of sculpture results in many specimens of the two species being indistinguishable except for the operculum.
Synonymy: Trochus fimbriatus Lamarck, 1822 was preoccupied. Bellastraea kesteveni Iredale, 1924 was applied "to the common Sydney shell" on the assumption that it was a different species to that in Western Australia, but it is now regarded as the same species.
Figs. 1,2: Balmoral, Middle Harbour, NSW (C.076217)
Fig. 3: Opercula a. Astralium tentoriiformis (C.072717) b. Astralium squamiferum (DLB2282)
Fig. 4: a. Off Eden, NSW (C.099776) b. Port Jackson, NSW (C.072717)
Copyright Des Beechey 2005