A new species of Stelletta (Demospongiae, Astrophorida) without microscleres from Abrolhos Archipelago, northeastern Brazil

Abstract

Stelletta anasteria sp. nov., a new species of Stelletta without microscleres from Abrolhos archipelago, northeastern Brazil, is described. The new species is best classified in Stelletta due to its growth habit, the shape of its triaenes and oxeas, presence of a cortex and a disorganized choanosomal skeleton. Besides the absence of microscleres, that set it apart from all other species of the genus, it differs from all other tropical Atlantic species of Stelletta in presenting at the same time all megascleres smaller than 590 µm long, the clads of plagiotriaenes smaller than 70 µm long, and those of anatriaenes smaller than 20 µm long. Additionally, anatriaenes with ill-formed and/or additional clads along the rhabdome are common in the new species.