New species of Myrmekioderma (Demospongiae: Halichondrida: Heteroxyidae) from Brazil.

The genus Myrmekioderma comprises eight species widely distributed, two of which occur in the Western Atlantic. We describe here a new species of Myrmekioderma from Northeastern Brazil with a discussion on the taxonomy of the Brazilian species. Samples were collected by trawling in the continental shelf of Sergipe and Alagoas States. Myrmekioderma intrastrongyla sp. nov. has strongyles in the choanosome, a single category of acanthoxea and two categories of trichodragmata. Regarding the external morphology, the closest species of M intrastrongyla sp. nov. are Myrmekioderma rea and M granulatum. However, the former differs from the new species by possessing oxeas and styles and the last by its unique category of trichodragmata. Myrmekioderma rea was the only species that was recorded for Brazil, occurring in Maranhão and Rio Grande do Sul States, but both records need to be reassessed.