The genus Antimargarita (Gastropoda: Trochidae) in the Southern Ocean

TRONCOSO J. S., C. ALDEA Y D. G. ZELAYA

Valdivia

Congreso; VII Congreso Latinoamericano de Malacología; 2008

Universidad Austral de Chile - Asociación Latinoamericana de Malacología

Although Trochidae seems to be a widely diversified gastropod family in the Southern Ocean, very few studies foccoused particularly on this group. To date, most of the trochid species / genera described for the area remain mainly known from their original descriptions, in the 18th or early 19th centuries, often laking of relevant details for distinguishing them. This is the case, for instance, of Antimargarita Powell, 1951, a genus revised herein. The type material of the three species previously asigned to the genus (Valvatella dulcis Smith, 1907: type species; Submargarita smithiana Hedley, 1916; and Minolia thielei Hedley, 1916), specimens from several museum collections, and additional specimens collected during the Spanish BENTART Expeditions to the Antarctica, were examined as part of this study. Both morphological and anatomical characters, particularly the radula morphology, were examined. Based on this information, the diagnostic characters for Antimargarita are enlarged, and a comparison of this with other similar genera occurring in the area is provided. In addition, the existence of two new species from the West Antarctica, is noticed.