Taxonomic review of Inella and Strobiligera (Gastropoda: Triphoridae) from Brazil

摘要

The triphorid genera Inella and Strobiligera are historically considered to represent one or two distinct groups, with recent studies claiming that Strobiligera comprises species with paucispiral or multispiral protoconchs, whereas only species with paucispiral protoconch occur in Inella. The present study aims to update the taxonomy of Inella and Strobiligera (with paucispiral protoconchs) from Brazil. Three main groups are recognized: Inella s.s. and Strobiligera show a simultaneous emergence of the three spiral cords of the teleoconch, the former possessing a discrete nucleus and the latter bearing a distinct globose protoconch; the "pseudo Inella" group has a late emergence of the median spiral cord of teleoconch. Four species were previously recorded from Brazil: I. unicornium, I. longissima, S. pompona and S. compsa, of which the three latter records are disregarded for being based on shells with broken apices and consequent uncertainty of identification. Twenty species in fact occur in Brazil: Inella s.s. is represented by I. apexbilirata and one possible new species; "pseudo Inella" includes "Inella" differens,"Inella" faberi, "Inella" galo sp. nov., "Inella" euconfio sp. nov., "Inella" leucocephala sp. nov., "Inella" faceta sp. nov., "Inella" maculata sp. nov., "Inella" vanilla sp. nov., and three possible new species: Strobiligera is represented by S. unicornium comb. nov., S. gaesona, S. dinea, Strobiligera campista sp. nov., Strobiligera santista sp. nov., and two possible new species. The "pseudo Inella" group is probably derived from unrelated lineages that converged to a simple type of paucispiral protoconch, requiring the examination of radular morphology to properly reallocate those species. The supposed restricted geographical range of triphorids with lecithotrophic development requires future investigations of the five species from the northwestern Atlantic/Caribbean that are herein recorded to Brazil.