Taxonomic position of Lovenella gracilis (Clarke, 1882) (Lovenellidae, Hydrozoa): new evidences of microanatomy justify its maintenance in the genus Lovenella (Hincks, 1868)

Abstract

Lovenella gracilis Clarke, 1882 is one of the 15 nominal species referred to the genus Lovenella Hincks, 1868, characterized by the presence of a basal line demarcating the separation between operculum and hydrotheca. However, Lovenella gracilis apparently does not have the demarcating line under light microscopy - therefore, the resurrection of the genus Dipleuron Brooks, 1882 was proposed to accommodate this species. The goal of this study is redescribe the polyp of L. gracilis trying to resolve this doubtful taxonomical status. Fertile colonies were collected in the intertidal zone of Rio Grande do Norte and Santa Catarina States, representing the first record of the species for the South Atlantic. Scanning electron microcopy of L. gracilis has shown a tenuous demarcation between operculum and hydrotheca, corroborating its position in the genus Lovenella. Considering the new evidences presented, we propose the maintenance of the species L. gracilis in the genus Lovenella, and corroborate the synonymy of Dipleuron and Lovenella.

Keywords

• Lovenella
• Dipleuron
• opérculo
• taxonomía
• Atlántico sur
• Brasil