The Helminthological Collection of the Oswaldo Cruz Institute is the biggest in Latin America and it is among the largest collections at worldwide reference level, with around 40,000 sets of specimens and approximately one million individual specimens. It contains helminths parasites of vertebrate and invertebrate animals that form part of the fauna of Brazil and other countries. The samples comprise holotypes, paratypes and representative specimens of Platyhelminthes, Acanthocephala, Nematoda and other non-helminth phyla, such as Annelida and Arthropoda. Some of the samples preserved in liquid media were found to have dried out. This made it impossible to analyze these samples morphologically for taxonomic purposes. The aim of this study was to test techniques used for rehydration of the tegument of specimens that had been found to have dried out and present protocols for such techniques. A total of 528 specimens that either no longer were immersed in preservatives or had already dried out were analyzed: 96 digenetic trematodes, 45 cestodes, 22 acanthocephalans, 357 nematodes, four hirudineans and four pentastomid crustaceans. The technique of rehydration using only distilled water on the specimens proved to be efficient for recovering tegument malleability, for all samples analyzed in this present study.

Long overlooked, sponge grounds are now recognised as important habitats which support high biodiversity. Some of these deep-sea sponge aggregations are formed by hexactinellids, in varying densities, which can occur on both soft and hard substrates. Despite their ecological importance as habitat framework building taxa, hexactinellids have been little studied and only 33 species in this Class were reported from the entire South Atlantic until now. Most of this knowledge was gained from studies conducted on the eastern South America continental slope. Here we report a new hexactinellid sponge garden found by the Shinkai 6500 manned submersible on the Rio Grande Rise, a prominent topographic feature of the deep SW Atlantic. This is the first sponge garden worldwide found to be dominated by the stiff, often dichotomously branching, Sarostegia oculata which may occur in densities of over 5 individuals per square meter. This sponge, of uncertain familial allocation, seems to always carry epibiotic zoanthids, thus mimicking the 3D skeletal framework of actual coral gardens

The second part of the catalogue of type material deposited in the Helminthological Collection of the Oswaldo Cruz Institute/ FIOCRUZ (CHIOC), between 1979 and 2016, is presented, to complement the first list of all types that was published in 1979. This part includes Platyhelminthes other than monogenoids, which were covered in the first part published in September 2016. The present catalogue comprises type material for 104 species, distributed across three classes, 40 families and 75 genera. Species names are listed systematically, followed by type host, infection site, type locality and specimens with their collection numbers and references. The classification and the nomenclature of the species have been updated.

Deep-sea reefs and coral banks are increasingly known as highly biodiverse ecosystems where sponges constitute a significant proportion of builders and inhabitants. Albeit smaller in dimensions, Campos Basin coral mounds also harbor a rich associated fauna, whence only 16 species of sponges had been fully identified this far. Seven new species are described here, viz. Geodia garoupa sp. nov., Vulcanella stylifera sp. nov., Trachyteleia australis sp. nov., Echinostylinos brasiliensis sp. nov., Xestospongia kapne sp. nov., Sympagella tabachnicki sp. nov., and Leucopsacus barracuda sp. nov. Of the 24 species of sponges known from the area, only seven were found elsewhere too, thus suggesting a possible high endemism in Campos Basin. Nevertheless, the widespread occurrence of deep reef-framework building corals along a large sector of the Brazilian coast suggests these habitats and their associated fauna may be more widespread than currently appreciated. Echinostylinos patriciae nom. nov. is proposed for the New Zealand record of E. reticulatus.

Abstract Four specimens of Farrea herdendorfi Duplessis & Reiswig, 2004 are described from the depth 2428–2630 m in the Charlie-Gibbs Fracture Zone area, northern Mid-Atlantic Ridge. Specimens were collected on cruises of the RRS James Cook (in 2007 and 2010) as part of the ECOMAR project. The species was originally reported from off South Carolina (USA), and subsequently from Campos Basin (SE Brazil). New specimens slightly deviate from specimens in the type series, apparently owing to complete lack of onychohexasters, which are considered here to be of minor importance.

Species of Cladorhizidae are most frequently found associated with hard substrates in the deep sea, close to hydrothermal vents or cold water reefs. Deep sea coral mounds were recently found to occur at Campos Basin, and the ongoing study of these ecosystems has shown that they harbour a diverse sponge fauna. Further results along these lines are reported here, with a (re)description of Asbestopluma (A.) cf. calyx, and six new species from 605 to 1141 m depth: Abyssocladia sp. nov., Asbestopluma (A.) sp. nov. 1-4 and Cladorhiza sp. nov. The fact that all Cladorhizidae come from a relatively small sector of the SE South American slope suggests the diversity of these sponges may still be considerably larger in this area than known so far. The known diversity of cladorhizids in the SW Atlantic ranks intermediate between the richest areas of the NW Pacific (27 species) and the NE Atlantic (23 species), and the poorest ones such as the Mediterranean, the Southeast Atlantic and the whole of the Indian Ocean (1-6 species). Campos Basin yields over 1.5x10(6) barrels of oil/day, thus generating much concern on the preservation of these ecosystems.

The present study reports three species of Farrea Bowerbank, 1862 from Campos Basin (southwestern Atlantic): Farrea herdendorfi Duplessis and Reiswig, 2004, Farrea occa Bowerbank, 1862, and Farrea campossinus sp. nov. This is the first record of F. herdendorfi for the South Atlantic and only the second record of the species worldwide. Farrea occa is described and reported to form mass occurrences in the area's sponge and coral banks, as seen in extensive video recording undertaken between 900 and 1100 m depth. The new species approaches Farrea foliascens Topsent, 1906 very closely, but differs in that its hooked anchorate clavules are much larger and the meshes of its dictyonal framework rather more irregular. Our thoughts on whether the proposed new species deserved species or subspecies rank led to an investigation on the usage of subspecies rank in Porifera. A historical overview, mainly contrasting Demospongiae and Hexactinellida is offered here. We concluded that no rule of thumb is readily made out from the comparative analysis of various authors' taxonomic decisions. Until one such agreement is achieved, it appears to us that naming new subspecies should be objectively argued for, or better, totally avoided, as a useless further dimension to taxonomic uncertainty in poriferan classification.

Eight new species of carnivorous sponges are described from southern South America, off Diego Ramírez Archipelago (south Chile): Abyssocladia diegoramirezensis, sp. nov., A. umbellata, sp. nov., Asbestopluma (Asbestopluma) bitrichela, sp. nov., A. (A.) magnifica, sp. nov., A. (A.) microstrongyla, sp. nov., A. (Helophloeina) delicata, sp. nov., Chondrocladia (Chondrocladia) schlatteri, sp. nov. and C. (Meliiderma) latrunculioides, sp. nov. Most of these sponges were sampled from an antipatharian coral collected accidentaly by demersal fisheries, which indicates an unexpected high diversity and abundance of carnivorous sponges in this area. The taxonomy and biogeography of the family Cladorhizidae is discussed, with an emphasis on cladorhizid versus phellodermid affinities of Abyssocladia, and on the possibility that species bearing either cleistochelae or arcuate chelae as the sole chelae morphotype may belong in this genus. A synthesis of the geographic as well as bathymetric distribution of cladorhizids is presented.

Descriptions of hexactinellid sponges collected by the RV ‘Marion Dufresne’ MD55 expedition on the Vitória–Trindade seamounts chain (off Espírito Santo State, south-eastern Brazil) in 1987 and stored in the MNHN (Muséum National d'Histoire Naturelle in Paris) are presented. Hyalonema (Cyliconema) conqueror sp. nov. (the first finding of this subgenus in the Atlantic Ocean) and H. (Prionema) dufresnei sp. nov. (the second record of this subgenus for the Atlantic Ocean) are described as new species. The holotype of H. (C.) conqueror sp. nov. was collected with a ROV at Campos Basin (off Rio de Janeiro State, south-eastern Brazil), while the paratypes originated from Vitória–Trindade seamounts chain and off Bahía State (eastern Brazil). Other hexactinellids reported here, Farrea sp., Sarostegia aff. oculata, Aphrocallistes aff. beatrix, Dactylocalyx aff. subglobosus and Euplectella suberea were known before to be widely distributed in the Atlantic Ocean. The total number of hexactinellid sponges known from Brazil has risen to 15 and from the south-western Atlantic to 23.

A comprehensive revision of literature dealing with Brazilian marine sponges has been undertaken. One hundred and ten sponges were found to occur deeper than 100 m, and are here considered deep-sea sponges. These species were reported upon in 18 papers, starting from Polejaeff (1884) on the 'Keratosa' collected by the H.M.S. 'Challenger'. For each deep-sea species, its distribution in terms of Brazilian states off which it has been found, its depth range, original literature and expedition, are given.

Fourteen species of hexactinellid sponges have been known from the southwestern Atlantic, 11 of which belong to the subclass Hexasterophora. Among these, only two belong to Hexactinosida Schrammen, 1903, namely Aphrocallistes beatrix Gray, 1858, Dactylocalyx pumiceus Stutchbury, 1841. The present study increases the number of southwestern Atlantic Hexasterophora to 13 species, adding two additional Hexactinosida, namely Chonelasma choanoides Schulze & Kirkpatrick, 1910 and Eurete atlantica sp. nov. The latter species is the first record of Eurete for the Atlantic Ocean, differing from the remaining 11 known species most conspicuously by the heavy spination of its pentactines.