Revalidation of Phyllocaulis renschi (Mollusca: Gastropoda: Veronicellidae) based on radula and mandible structures of taxonomic significance for the genus

Abstract

Phyllocaulis is a slug genus distributed throughout the south‐eastern and southern regions of Brazil, also Uruguay, Argentina and Chile. The determination of the species is almost exclusively based upon anatomical and morphological characters, mainly of the penis, spathe and the penial and pedal glands. Here we can show also that structure of the mandible and of the radula allow separation of the species P. boraceiensis, P. gayi, P. renschi, P. soleiformis (forms A, B, D and E), P. tuberculosus and P. variegatus. We present pictures obtained by scanning electronic microscopy of the taxonomically relevant details. Width and length of the central tooth and the width of the lateral tooth of the radula are regarded as most important for biometric differentiation between the species. This approach permitted the revalidation of Phyllocaulis renschi Thomé, 1965, a species which in the meantime had been placed under the synonymy of P. soleiformis (form C).

Phyllocaulis é um gênero de lesmas distribuído nas regiões sudeste e sul do Brasil, também no Uruguai, Argentina e Chile. A determinação das espécies de Phyllocaulis está baseada quase que exclusivamente na descrição de caracteres anatômicos e morfológicos, principalmente a forma do pênis, da espata, da glândula peniana e da glândula pediosa. As mandíbulas e os dentes da rádula das espécies P. boraceiensis, P. gayi, P. renschi, P. soleiformis (formas A, B, D e E), P. tuberculosus e P. variegatus, foram analisadas através da microscopia eletrônica de varredura. Os caracteres específicos mais importantes foram: largura e comprimento do dente central e largura do dente lateral da rádula. Os resultados evidenciaram que esses característicos possibilitam a diferenciação entre as espécies. Isto permitiu também revalidar a espécie Phyllocaulis renschi Thomé, 1965, que se achava sinonimizada sob P. soleiformis (forma C).

Keywords:

• Biometric analysis
• mandible
• Phyllocaulis renschi
• radula
• SEM pictures
• species revalidation
• Southern Neotropical

Acknowledgments

We would like to thank Giovanna Machado and Guacira Maria Gil for special advice and assistance in writing this paper. Our research was supported by scholarships and grants from CAPES and PUCRS.