Taxonomia morfológica e análise morfométrica de Chlamydotheca iheringi (Sars, 1901) (Crustacea, Ostracoda) da planície de inundação do alto rio Paraná, Brasil.

Abstract

The genus Chlamydotheca comprises large-bodied ostracods, exceeding 2 mm in length, belonging to the family Cyprididae, with a distribution mainly restricted to the Neotropical region and the southern portion of the Nearctic. This genus, Chlamydotheca iheringi (Sars, 1901) was long considered an exclusively parthenogenetic species. This study presents the first record and morphological description of the male of C. iheringi. In addition, two distinct morphological forms were identified within a single population from the upper Paraná River floodplain: the typical form of C. iheringi, with a straight dorsal margin, and a morphologically distinct form, referred to as Chlamydotheca cf. iheringi, characterized by a more rounded dorsal margin and a slight dorsal overlap of the right valve. To investigate these differences, morphometric analyses of the valves and comparisons of body appendages were conducted. Accordingly, this study provides a morphological description of male individuals of C. iheringi, as well as a redescription of the female. Moreover, individuals of both sexes of C. cf. iheringi were described. The results indicated that, although there are morphological differences in the dorsal valve margins, these variations are not sufficient to confirm the existence of two distinct species, given the presence of intermediate specimens.