Insights into the generic affinities of Longiverena Pilsbry & Olsson, 1935 (Gastropoda: Thiaridae) based on partial sequences of the mitochondrial 12s rRNA gene

Abstract

Longiverena Pilsbry & Olsson, 1935 is a genus of freshwater snails included in the family Thiaridae Gill, 1871. The genus was created to accommodate several mid-Tertiary species, and currently has only one living species, Longiverena tuberculata Spix, 1827 described from southern Brazil. Several genus-group names are available for Neotropical thiarids, and includes Aylacostoma Spix, 1827, Hemisinus Swainson, 1840 and Longiverena, among others. Most of the South American representatives of these genera were described based solely on conchological features following the typological approaches of most of the 19th and the mid–20th centuries authors. Morphologically, Aylacostoma and Longiverena appear to be very similar except that the latter is strongly sculptured. Recently, mitochondrial DNA sequences for Aylacostoma were made available, thus providing new data for comparison. Here, we present the first molecular data for L. tuberculata. Total genomic DNA was obtained from museum material. Using information from the third domain of the 12S rRNA gene and a secondary structure model of this region, we assessed the evolutionary relationships among L. tuberculata and the three Aylacostoma species for which DNA sequences are available. Our result suggests that the morphological distinction of L. tuberculata is not of generic significance, and the species fit well within the genus Aylacostoma which has priority over Longiverena. Further anatomical and conchological evidence complementing the molecular data are required in order to make sound decisions regarding the generic status of L. tuberculata.