Lista de espécies comentada e estudo taxonômico de espécies de Drymaeus (Drymaeus) e Drymaeus (Mesembrinus) (Gastropoda, Bulimulidae) com ocorrência no Brasil

Abstract

Traditionally, terrestrial gastropods have been classified based only on shell characteristics. The anatomy of the soft parts has been neglected since them. Recently, the characterization of soft parts gained importance as a taxonomic feature for all taxonomic categories. Since then, species have been revisited for other traits besides the shell. Bulimulidae is a diverse group of land snails occuring in the tropical and subtropical regions of Central, North and South America, and Australia. In Brazil there are 19 genera with approximately 120 species. The genus Drymaeus has 58 species previously reported in Brazil. These species are divided into two subgenera; Drymaeus (Drymaeus) (42 species) and Drymaeus (Mesembrinus) (11 species). Information on the distribution of bulimulids in Brazil is fragmented and many species were last reported by European naturalists on their expeditions throughout the Americas in the 19th century. This study aimed to make a taxonomic revision of the genus Drymaeus, providing species occurrence data and searching for new diagnoses based on other characteristics besides the shell. The specimens examined were preserved in ethanol and deposited in the collections of the Museu de Malacologia Professor Maury Pinto de Oliveira of the Universidade Federal de Juiz de Fora and in the Malacological Collection of the Museu de Zoologia de São Paulo. Dissections were performed according to standard techniques. The soft parts were designed with the aid of a camera lucida and photographed to describe the soft parts. Malacological collections databases were used to obtain the occurrence points of the species. These points were georeferenced to build the distribution maps. The research in databases allowed to recognize a wider distribution for previously known species and to increase the number of species registered in Brazil. For Drymaeus (Drymaeus) 48 species were registered, increasing by 14.3% the number of species reposted to Brazil. Three new species were described for the Minas Gerais state. For Drymaeus (Mesembrinus) 16 species were registered, increasing by 45.5% the number of species reported to Brazil. Mollusks are highly endangered animals. The knowledge of Brazilian malacofauna and its distribution is essential to reinforce the arguments of conservation and establishment priority conservation areas, otherwise many species will become extinct even before they are known and described.