Taxonomy of Placospongia Gray, 1867 from Northern and Northeastern Brazil, with description of two new species (Porifera: Demospongiae: Clionaida).

The demosponge genus Placospongia includes 13 valid species, of which six occur in the Brazilian Exclusive Economic Zone. In the present study, we describe two new species of Placospongia from Northern (off the Amazon River mouth) and Northeastern Brazilian continental shelf and oceanic islands (i.e., Fernando de Noronha Archipelago), viz., Placospongia beatrizae sp. nov. and Placospongia amphinolastra sp. nov., and redescribe the holotype of Placospongia cristata Boury-Esnault, 1973, a poorly known species. In addition, we revise the Brazilian records of the allegedly cosmopolitan species P. carinata, P. melobesioides and P. intermedia, and provide new records of P. colombiensis and P. ruetzleri from Brazil. We demonstrate that P. carinata sensu Coelho & Mello-Leito and P. intermedia sensu Muricy & Moraes and Jimenez et al. belong in fact to P. ruetzleri, and that P. melobesioides sensu Mothes et al. and Gonzlez-Faras is a new species, described here as Placospongia beatrizae sp. nov. With the description of the two new species and synonymyzation of previous records, six species of Placospongia are currently known in Brazilian waters, two of which are endemic. A key to Placospongia species is also provided.

New records of Neopetrosia carbonaria (Lamarck, 1814) from the Brazilian coast reveal new morphological features and spicule types.

Sponges of the family Petrosiidae have usually a stony and brittle texture due the high silica content of the mineral skeleton that is formed by a more-or-less regular isotropic reticulation of undefined primary and secondary tracts. Neopetrosia species are distributed worldwide and twelve species are found in the Tropical Western Atlantic Ocean, of which four are recorded from the Brazilian coast. Here, we describe new Neopetrosia carbonaria specimens from several localities along the NE Brazilian coast, analyze the Neopetrosia carbonaria holotype and review the previous record of N. carbonaria from the Brazilian coast. Our study reveals new morphological features and spicule types in the Brazilian populations of N. carbonaria. Now, Neopetrosia carbonaria is defined by a thick encrusting to repent or ramose sponge, with reddish brown to brown color or dark green to black color in vivo, two categories of oxeas as megascleres and raphidiform toxas as microscleres. These toxas are quite rare and occur in both black and brown sponges. Due the absence and rarity of raphidiform toxas in some specimens, unrelated to its color, we assume that these differences are intraspecific. However, we suggest that all records of Neopetrosia carbonaria should be reevaluated, since toxas can be easily overlooked, added to the use of molecular methods to investigate the relationship between the Caribbean and Brazilian populations.

Taxonomy of Geodia and Rhabdastrella from the Brazilian coast: a new species, new synonyms and redescription of Geodia tylastra (Demospongiae: Astrophorina: Geodiidae and Ancorinidae).

In this contribution we revise the type specimens of Geodia tylastra, Rhabdastrella fibrosa and Geodia corticostylifera, adding new photographs of preserved specimens, skeleton sections, and scanning electron micrographs of the spicules. We demonstrate that the three species are synonyms, with priority to the older name G. tylastra Boury-Esnault, 1973. We also show that Rhabdastrella fibrosa sensu Van Soest (2017) differs from the holotype in spicule composition and is here given a new name, Rhabdastrella vansoesti sp. nov. In addition, we describe a new species of Geodia, G. polytriaena sp. nov., and new records of G. glariosa and G. tylastra from Sergipe State, in the Northeast Brazilian coast. With the description of Geodia polytriaena sp. nov. and the synonymyzation of G. corticostylifera, 20 species of Geodia are now known in the Tropical Western Atlantic Ocean.

New records of Endectyon (Endectyon) xerampelina (Lamarck, 1814 (Demospongiae: Axinellida: Raspailiidae) from the Tropical Western Atlantic Ocean, with comments on its distribution and type locality.

The demosponge genus Endectyon is characterized by the presence of acanthostyles with recurved or clavulate spines. Two subgenera are recognized, Endectyon and Hemectyon, distinguished mainly by the acanthostyles being located only in the periphery of the axial skeleton in Endectyon, or forming the ectosomal brushes in Hemectyon. Sixteen species are known worldwide, of which only two were reported from the Western Atlantic Ocean. However, the type locality of Endectyon xerampelina is uncertain, and it could be located either in the Western Atlantic or in Australia. In the present study, we describe new records of E. xerampelina from the Brazilian coast and propose that Raspailia (R.) johnhooperi from the Guyana shelf is a junior synonym of E. xerampelina. Our results support the hypothesis that the type locality of E. xerampelina is located somewhere in the Tropical Western Atlantic Ocean and also that the species belongs to the subgenus Endectyon (Endectyon). We amended the diagnosis of the subgenus Endectyon (Endectyon) to account for the variability of acanthostyle shape in E. (E.) xerampelina, assigning greater taxonomic value to the position of the echinating megascleres than to their shape and pattern of spination.

Thorectinae (Porifera: Demospongiae: Dictyoceratida) from Northeastern Brazil: two new species and transfer of Scalarispongia cincta (Boury-Esnault, 1973) to the genus Thorecta Lendenfeld, 1888.

The genus Scalarispongia was raised to gather species formerly allocated in Cacospongia with rectangular fibrous skeleton of cored primary fibers and uncored secondary fibers. Species of the genus Thorecta have a similar skeletal architecture, but the presence of a dermal armour distinguishes them from Scalarispongia. Here we describe two new species of Scalarispongia from northeastern Brazil and transfer Scalarispongia cincta to Thorecta cincta. Scalarispongia tubulata sp. nov. is thick encrusting to cushion-shaped, has tubular projections with thin walls, and surface irregularly microconulose. Scalarispongia cooki sp. nov. is massive lobate, with digitiform projections and irregular surface. Thorecta cincta n. comb. is pear-shaped with conulose surface, one large apical oscule and a belt of small oscula around the body. Its skeleton is composed by a regular and granular dermal armour and by a ladder-like network of concentrically laminated primary and secondary fibers. Cacospongia amorpha and Cacospongia levis are now the only species of the genus Cacospongia known to occur in the Brazillian coast, but both records need to be reassessed. A key to species of Thorectinae from the Tropical Western Atlantic is provided.

Neopetrosia de Laubenfels, 1949 from Brazil: description of a new species and a review of records (Haplosclerida: Demospongiae: Porifera).

The genus Neopetrosia was characterized by has fine brushes of oxeas issued from subectosomal tracts and compact choanosomal network. We report and describe here specimens collected in the coast of Brazil: Neopetrosia sulcata sp. nov. and Neopetrosia proxima. The first was previously recorded from Brazil as Neopetrosia proxima, but it was found that these specimens corresponded to a new species. Thus, we provide here the characterization of N. proxima from Brazilian coast. A taxonomic study of Brazilian samples is given, including description, illustrations and geographic distribution, combined with the comparison of the new species with all other descriptions of Neopetrosia from Atlantic.

Dictyoceratida (Porifera: Demospongiae) from Tropical Southwestern Atlantic (Northeastern Brazil, Sergipe State) and the description of three new species.

Five species of dictyoceratid sponges were collected from trawling on the continental shelf of Sergipe State, Northeastern Brazil, of which three are new to science: Ircinia sergipana sp. nov., Ircinia repens sp. nov., Ircinia strobilina, Hyattella cavernosa and Smenospongia ramosa sp. nov., the latter the first record of the genus Smenospongia from Brazil. 

Two new species of Haliclona Grant, 1836 (Haplosclerida: Chalinidae) from Sergipe State, Brazil.

Haliclona is one of the most species-rich genera among Demospongiae, but with only 11 species recorded for the Brazilian coast. Here we describe two new species of Haliclona collected by trawling at Sergipe State (Northeastern Brazil). Haliclona (Halichoclona) dura sp. nov. is distinguished by the combination of confused choanosome with dense reticulation, oxeas with stepped and mucronate points, color dark brown externally and light beige internally, consistency firm and incompressible. Haliclona (Soestella) brassica sp. nov. is set apart by the combination of a choanosomal skeleton with rounded meshes, strongyles, raphides, color beige and consistency soft.

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.