Cymbiola pulchra (Sowerby, 1825)
Description: Shell solid, smooth and glossy. Spire moderately tall, concave. Whorls shouldered, concave above shoulder, convex below; shoulder usually with nodules or upwardly pointing spines, 7 to 12 on body whorl. Columella with four strong plaits. Outer lip simple, smooth. Background colour white, fawn or salmon, usually with three darker spiral bands on body whorl, and a superimposed pattern of dark dots and white tent-shaped markings, and axial lines descending from suture.
Size: Adults 41-110 mm.
Distribution: Endemic to Australia; Undine Reef (north of Mossman), Queensland, to Bulli, NSW.
Habitat: Intertidal to about 200 metres. Common in Queensland, uncommon in NSW.
Remarks: Cymbiola pulchra is a very variable species, with a long range from northern Queensland to southern NSW, from the coast to beyond the eastern edge of the Great Barrier Reef. It appears to be a species which is in the process of evolving into many new species, driven by the reproductive isolation of populations. The species, or species complex, has been monographed by Bail & Limpus (1998), who provide excellent illustrations of the various forms, which they prefer to regard as subspecies. They report two of the subspecies as occurring in NSW:
Cymbiola pulchra complexa (Iredale, 1924) (Figs.1, 3a)
Shells of this subspecies are large for the species, 45-110 mm in length, but smaller at the southern end of the range; specimens from off Sydney are typically 60 mm. The background colour is violet-brown to salmon. The pattern is of dark brown, elongated dots over larger irregular white dots, with three spiral bands of large irregular brown patches, below suture, below shoulder and middle of body whorl. The protoconch has broad, low axial ridges (Fig. 3a). The range of this subspecies is Sandy Cape, Fraser Island, Queensland, to Bulli, NSW. NSW specimens are recorded from 46 - 110 metres, plus a few beach specimens.
Cymbiola pulchra moretonensis Bail & Limpus, 1998 (Figs. 2, 3b)
This subspecies differs by being smaller, having a different pattern, and a different protoconch. (The protoconch difference may be justification for elevating this taxon to species level). The background colouration is the same as C. pulchra complexa, but the banding and dots are different. There is no band of brown patches below the suture; on the body whorl there are three spiral bands of darker background colour - below the shoulder, at midbody and at base - in which the brown spots are concentrated. The protoconch has weak spiral threads instead of the axial ridges of C. pulchra complexa. The size range is 41-62 mm for adults. The range of this subspecies is Cape Moreton, Queensland, to Sydney, NSW. NSW specimens are recorded from 100-183 metres.
Fig. 1 Cymbiola pulchra complexa. Off Newcastle Bight, NSW, 46 m (C.065376)
Fig. 2 Cymbiola pulchra moretonensis. Off Danger Point, NSW, 132-135 m (C.117874).
Fig. 3 a. Protoconch of C. pulchra complexa. (C.065376) b. C. pulchra moretonensis (C.117874)
Copyright Des Beechey 2003