COMPARATIVE MORPHOLOGY AND REDESCRIPTION OF THREE SPECIES OF CALLIOSTOMA (GASTROPODA, TROCHOIDEA) FROM BRAZILIAN COAST

The morphology of Calliostoma adspersum, C. depictum and C. hassler, from the Brazilian coast, were studied in detail. Their anatomy has particularities that may be unique to the genus, such as: presence of an ampulla in the female; reduction or loss of the cephalic lappets; presence of a pseudoproboscis; occurrence of the intestinal loop outside the head-foot haemocoel. At species level, we conclude that C. vinosum is a synonym of C. hassler, because specimens identifiable as both species occur within a single ontogenetic series. Calliostoma hassler can be distinguished by: lack of the left dorsal esophageal fold, absence of a gastric spiral caecum and presence of an intestine with two wide loops. Based on anatomical evidence, we concluded that C. depictum is not a synonym of C. adspersum, differing by strongly convex whorls and a distinct suture; a marked groove near the columella; an odontophore partially covered by the mid-esophagus; absence of the pair of odontophore muscles m8a; a ventral esophageal fold of the same size as the dorsal folds; and a reduced spiral caecum with 0.5 whorl.