Morfologia, taxonomia e sistemática das espécies de Scolodontidae (Baker, 1925) (Gastropoda, Heterobranchia, Pulmonata, Stylommatophora) do Estado do Rio de Janeiro

Abstract

Scolodontidae encompasses 14 genera of land snails widely distributed in the Neotropical region, although they are scarcely known. The goal of this study was to describe shells, external morphology, palial complex, reproductive system and radula of the scolodontid species from the State of Rio de Janeiro, in order to contribute to the systematic of the family. The species Happia vitrina (Wagner, 1827), Happia nana (Wagner, 1827), Prohappia besckei (Dunker, 1847), Tamayoa banghaasi (Thiele, 1927), Happiella aff. grata (Thiele, 1927), Guestieria sp., Entodina sp., Scolodonta aff. spirorbis (Deshayes, 1850), Wayampia sp., Miradiscops brasiliensis (Thiele, 1927) and Miradiscops sp. were analyzed. The cladistics analysis was carried out using Haplotrema sportella (Gould, 1846) as outgroup. The selected species, Happiella aff. grata, Entodina sp., Prohappia besckei, Happia vitrina, Tamayoa banghaasi e Guestieria sp., were studied by hand. For the other species, Zilchistrophia tridentata Weyrauch, 1960; Systrophiella eudiscus (Baker, 1925), Systrophia systropha (Albers, 1854); Scolodonta semperi (Döring, 1875); Wayampia lutea Tillier, 1981, Miradiscops opal (Pilsbry, 1920); Hirtudiscus comatus Hausdorf, 2003 e Drepanostomella tucma Hylton Scott, 1948, literature data were used. The data matrix was built with 14 taxa and 40 characters and it was run with the Traditional search algorithm of the software TNT version 1.1. The analysis produced two equally parsimonious trees (L = 120 steps, CI = 0.483 and RI = 0.415), that were compared. The family Scolodontidae was not monophyletic, since it lacks synapomorphies. The subfamilies Systrophiinae and Tamayoinae were not supported as monophyletic units. Systrophia + the clade (Zilchistrophia + Entodina) is defined by a not exclusive synapomorphy, the subdiscoidal shell. The clade (Zilchistrophia + Entodina) is supported by the following synapomorphy: crescent-shaped shell aperture with denticulated callum. Based on literature data, the sister group (Drepanostomella + Guestieria) possesses as not exclusive synapomorphies: nautiloid shell, thin growth lines, short kidney obliquely positioned in relation to the rectum. Hirtudiscus plus the sister group (Guestieria + Drepanostomella) form a clade sustained by one synapomorphy: presence of an incision at the peristomium parietal angle. In the second tree, the clade (Prohappia + (Tamayoa + (Scolodonta + (Happia + (Wayampia + (Miradiscops + (Systrophiella + (Hirtudiscus + (Guestieria + Drepanostomella))))))))) was recovered on the basis of the following not exclusive synapomorphies: aulacopod foot without truncature in the caudal end, ratio seminal vesicle/hermaphrodite duct between 1/5 and half, phallum more calibrous than epiphallum. In the first tree, this clade does not have the aulacopod foot without truncature in the caudal end as synapomorphy. The sister group (Scolodonta + Happia) possesses as not exclusive synapomorphy the presence of the suspensor muscle of vagina.