Two Species of the GenusStrobiligera(Caenogastropoda: Triphoridae) with a Multispiral Protoconch in Southeastern Brazil

Abstract

The genus Strobiligera Dall, 1924, sometimes treated as a synonym of Inella Bayle, 1879, included up to now species geographically restricted to the North Atlantic Ocean, usually occurring at great depths. The present study records the genus Strobiligera in the South Atlantic Ocean, with the recognition of two species in Southeastern Brazil. The shell of Strobiligera delicata sp. nov., which has a white teleoconch and a light brown protoconch, is very similar in general coloration to the shells of Strobiligera georgiana (Dall, 1927) comb. nov. and Strobiligera indigena (Dall, 1927) comb, nov., both from the southeastern coast of the United States. However, S. delicata differs from those species in shell shape, number of axial cords on the teleoconch and earlier development of the adapical spiral cord of the teleoconch. Strobiligera inaudita (Rolán and Lee, 2008) comb, nov., previously known from the southern coast of the United States, is diagnosed by a teleoconch with adapical and abapical spiral cords tinted with brown and white nodules, and by a completely white median spiral cord. Strobiligera delicata, S. inaudita, S. georgiana and S. indigena have multispiral protoconchs, similar to those of their congeneric species from the East Atlantic (Europe and North Africa) and Mediterranean. Other species of Strobiligera from the Caribbean and neighboring areas, including the type species Triforis ibex Dall, 1881, have a paucispiral protoconch. Hence, the generic allocation of species with a multispiral protoconch to Strobiligera cannot be considered definitive, and should be confirmed by subsequent anatomical studies of species with different modes of development.