Abstract
Calliostoma tupinamba isa new species from Southeastern Brazil, ranging from southern Rio de Janeiro to northern São Paulo, and found only on coastal islands, on rocks and sessile invertebrates at 3 to 5 meters of depth. Shell and soft part morphology is described here in detail. Calliostoma tupinamba is mainly characterized by a depressed trochoid shell; eight slightly convex whorls; a sharply suprasutural carina starting on the third whorl and forming a peripheral rounded keel; and a whitish, funnel-shaped and deep umbilicus, measuring about 5%–10% of maximum shell width. Calliostoma tupinamba resembles Calliostoma bullisi Clench & Turner, 1960 in shape, but differs from it in being taller and wider, having a smaller umbilicus and lacking a strong and large innermost spiral cord at its base. Finally, an identification key of Brazilian Calliostoma species is presented.
Highlights
The speciose genus Calliostoma Swanson, 1840 has a worldwide distribution, occurring from the intertidal zone to depths of several hundred meters (Clench and Turner 1960)
The base of the shell of C. bullisi has a strongly and larger innermost spiral cord (Fig. 12). When it is present in C. tupinamba, this cord is half the size from that of C. bullisi
The umbilicus of C. tupinamba is much narrower, occupying only 5% to 10% of the maximum shell width, while in C. bullisi the umbilicus occupies 20%
Summary
The speciose genus Calliostoma Swanson, 1840 has a worldwide distribution, occurring from the intertidal zone to depths of several hundred meters (Clench and Turner 1960). An astounding diversity of Calliostoma species is found in the Western Atlantic: almost 100 species, 18 of which occur in Brazilian waters (Clench and Turner 1960; Quinn 1992; Rosenberg 2009). Calliostoma shells generally have spire typically straight-sided, but may be redounded, and the base ranges from flat to convex, umbilicate or imperforate, sculptured by spiral beaded cords, with a subquadrate aperture and an arched columella. Their ground colors usually are slightly yellowish or brownish, while their secondary coloration consists of white, red or reddish-brown blotches (Hickman and McLean 1990). An identification key, based on shell characters of fully grown Brazilian Calliostoma species is provided
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