Complexo Littorina ziczac (Gmelin) (Mollusca, Gastropoda, Caenogastropoda) no litoral fluminense: análise morfométrica, distribuição vertical e bioquímica

Abstract

ABSTRACT. The Littorilla ziczac (Gmelin) complex (Mollusca, Gastropoda, Caenogastropoda) in the Rio de Janeiro coast: morphometric analysis, vertical distribution and biochemistry. The UI/orina ziezae (Gmelin, 179 1) spec ies complex was studied in Rio de Janeiro State, southeastern Brazil. The occurrence of three species was confirmed, through the analysis of penis morphology: L. ziezae (Gmelin, 1791), L. lineata d'Orbigny, 1841 and L. lineolata d'Orbigny, 1840. There is a correlation between the morphology ofthe penis and shell shape, thus it was possible to make a discrimination model based in conchologic data, with an efficiency of75%. However, this model cannot be applied to others samples that weren't included in its formulation, due to phenotypic plasticity of the shell caused by biotic and abiotic factors . ln the 9 areas studied L. lilleolata was always the most abundant species. No vel1ical stratitication in the distribution of the species was veritied. From the nine enzymatic systems examined, only Pgi, Pgm e Mpi , presented identitiable patterns and no diagnostic loeus was identified in any species. Nevertheless, S and I suggest the individualization of L. 2iezac and L. lilleata, respective ly. KEY WORDS. UI/orina, spec ies complex, vertical distribution , biochemistlY, Rio de Janeiro, Brazil Os litorinídeos são caenogastrópodes que habitam, tipicamente, os substratos conso lidados da zona entre marés em todo o mundo e, particularmente, a zona supralitora/. No Brasil se distribuem do Cabo Orange ao Chuí (RIos 1994), desde que o substrato apropriado esteja presente.Apesar da ampla distribuição e da abundância numérica dos litorinídeos, eles não têm sido bem estudados no Brasil, com exceção de MARCUS & MARCUS (1963). Por outro lado, em escala mundial, são relativamente abundantes os estudos sobre sua taxonomia, ecologia e biologia.Um problema comum que parte cons iderável desses estudos tem enfrentado é o de espécies crípticas ou, como é comumente chamado entre os malacologistas, um complexo de espécies. Um complexo de espécies deve ser entendido como a existência de duas ou mais espécies com características semelhantes e geralmente associados a um habitat ou conjunto de habitats. Assim, pode-se esperar dificuldades relacionadas à identificação das espécies integrantes de complexos desta natureza.

Morphometric analysis of the shell of the intertidal gastropod Echinolittorina lineolata (d'Orbigny, 1840) at different latitudes along the Brazilian coast

“…Individuals of E. lineolata were collected by hand from the supralittoral zone of each consolidated environment in order to standardize sampling in the different areas. Collection during low tide was performed during daytime (Stephenson & Stephenson, 1949; Magalhães, 1998; Absalão et al ., 1999). The biological material was collected with authorization from IBAMA/SISBIO (No.…”

Shell morphometry of three species of the genus Nuculana Link, 1807 (Bivalvia, Protobranchia, Nuculanidae) from continental shelf and slope Northeastern Brazil

“…23 (ABSALÃO;ROBERG, 1999). Studies based on morphometrical techniques may help in these cases (FUIMAN et al, 1999;RUGGIERO et al, 2008;ASTÚA, 2009).…”