The Order Suberitida is defined as a group of marine sponges without an obvious cortex, a skeleton devoid of microscleres, and with a deletion of a small loop of 15 base pairs in the secondary structure of the 28S rDNA as a molecular synapomorphy. Suberitida comprises three families and 26 genera distributed worldwide, but mostly in temperate and polar waters. Twenty species were reported along the entire Brazilian coast, and although the north-eastern coast of Brazil seems to harbour a rich sponge fauna, our current knowledge is concentrated along the south-eastern Atlantic coast. A survey was implemented along the northern coast of Brazil, and the collection allowed the identification of six species belonging to the Order Suberitida. Two of them are considered new to science: Suberites purpura sp. nov., Hymeniacidon upaonassu sp. nov., and four, Halichondria (Halichondria) marianae Santos, Nascimento & Pinheiro, 2018, Halichondria (H.) melanadocia de Laubenfels, 1936, Suberites aurantiacus (Duchassaing & Michelotti, 1864), and Terpios fugax Duchassaing & Michelotti, 1864, are re-described. Taxonomic comparisons are made for Tropical Western Atlantic species and type species of the four genera. Finally, an identification key for the Western Atlantic Suberites species is provided.

In this study we revise the current knowledge on the biodiversity and distribution of the Class Homoscleromorpha in the Tropical Western Atlantic (TWA). Twenty-seven species are currently recognized in the TWA, belonging to the genera Oscarella (O. nathaliae), Plakortis (P. angulospiculatus, P. dariae, P. edwardsi, P. halichondrioides, P. insularis, P. microrhabdifera, P. myrae, P. petrupaulensis, P. potiguarensis, P. simplex, P. spinalis, P. zyggompha), Plakinastrella (P. globularis, P. microspiculifera, P. onkodes, P. stinapa), Plakina (P. coerulea, P. elisa, P. jamaicensis, P. monolopha, P. tetralopha, P. trilopha, P. versatilis), Corticium (C. diamantense, C. quadripartitum) and Tetralophophora (T. mesoamericana). Three of these ‘species’ are cosmopolitan and in fact represent complexes of cryptic species: Plakina monolopha, P. trilopha and Plakortis simplex. All other 24 species reported are TWA endemics. Only four species are found both in the Caribbean and in Brazil: Plakortis angulospiculatus, P. halichondrioides, Plakinastrella microspiculifera and P. onkodes, but these may also be species complexes. Seven species are Brazilian endemics: Plakina coerulea, Plakinastrella globularis, Plakortis insularis, P. microrhabdifera, P. petrupaulensis, P. potiguarensis and P. spinalis. Thirteen species are restricted to the Tropical North-western Atlantic: Corticium diamantense, C. quadripartitum, Oscarella nathaliae, Plakina elisa, P. jamaicensis, P. tetralopha, P. versatilis, Plakortis dariae, P. edwardsi, P. myrae, P. zyggompha, Plakinastrella stinapa and Tetralophophora mesoamericana. The Greater Antilles is the richest ecoregion, with 12 species reported. Only the Guianan ecoregion has no records of Homoscleromorpha. Several undescribed species of Oscarella and Plakina are also known from the TWA. We estimate that the biodiversity of Homoscleromorpha in the TWA is at least twice as high than currently known.

Haliclona is an unusually species-rich genus in Porifera, with more than 400 species described. In spite of many subgenera used in the taxonomic housekeeping of these sponges, over half of them remain unassigned to a subgenus, thus encouraging a wide range of redescriptions and taxonomic revisions of materials from all around the world. In this paper, we describe two new Haliclona spp. collected at Pernambuco, Alagoas and Bahia States (north-eastern Brazil, between 08°46′S and 13°56′S). Haliclona (Reniera) chlorilla sp. nov. is a dark green or black coloured, delicately-branched species; and Haliclona (Soestella) peixinhoae sp. nov., a beige-coloured, tubular species, where tubes frequently bear large thorns and possess a conspicuous sub-superficial meandering reticulation. These species highlight the importance of including ex-situ collections in compiling baseline data, as both were already present in scientific collections by the 1980s and 1990s.

This paper reports on four banded butterflyfish Chaetodon striatus cleaning a juvenile green turtle Chelonia mydas in a rocky shore located at Baía de Todos os Santos, Bahia State, north-east Brazil.