Guitarra sepia n.sp. from the Southwestern Atlantic (Demospongiae, Poecilosclerida, Guitarridae) first record of a Guitarra without placochelae

This work reports on the first record of Guitarra Carter, 1874 for the
southern/southeastern Brazilian Coast. Guitarra sepia n. sp. is described from the coasts of Santa Catarina, São Paulo and Rio de Janeiro states, from depths of 3 - 25 m. The new species is devoid of placochelae. Its status as belonging to Guitarridae was derived from its
possession of spiny isochelae comparable to those in Guitarra and Tetrapocillon, followed by a cladistic analysis where a closer relationship to Guitarra indica Dendy, 1916 and Guitarra fimbriata Carter, 1874 was obtained. Reorganizing specimens kept for seven days in seawater enriched to 100 µm silica did not produce placochelae derived microscleres.