The family Phoxocephalopsidae (Crustacea: Amphipoda) from Brazilian coastal waters with description of four new species.

Phoxocephalopsids are fossorial amphipods endemic to the Southern Hemisphere and currently encompass five genera and 15 species, including the four new species herein described. Previous records of the family along the Brazilian coast are limited to Phoxocephalopsis zimmeri Schellenberg, 1931. Based on material from the Crustacean Collection of Museu Nacional/UFRJ four new species of Phoxocephalopsidae areherein described: Phoxocephalopsis ruffoi sp. nov. from Rio de Janeiro, São Paulo, Paraná and Rio Grande do Sul (23o-30oS); Puelche irenae sp. nov. from Espírito Santo and Rio de Janeiro (19o-23oS); Puelche longidactylus sp. nov. from Bahia, Espírito Santo and Rio de Janeiro (12o-23oS) and Puelche mourae sp. nov. found only at Rio de Janeiro. High diversity was recorded from the Campos Basin region, which extends from the north of Rio de Janeiro to south of Espírito Santo (21o-23oS), with the presence of all four phoxocephalid species. A key to Phoxocephalopsidae species from Brazil, including P. orensanzi Barnard and Clark, 1982 is provided.

A new Munidopsis species (Galatheoidea, Munidopsidae) from the Southwestern Atlantic.

Six Munidopsis species are recorded to the Southwestern Atlantic: M. barbarae; M. erinacea; M. nitida; M. sigsbei; M. riveroi and M. transtridens. Herein a new Munidopsis species from Southwestern Atlantic is described: Munidopsis trindadensis sp.nov., was sampled off Trindade Island (Espírito Santo, Brazil) at 360 m depth and differs from all six species previously recorded in this region by the telson with seven plates.

New findings of the family Pardaliscidae from the deep-sea southwestern Atlantic: the genus Caleidoscopsis Karaman, 1974.

Caleidoscopsis is a deep-sea pardaliscid genus known previously only from the SE Atlantic Ocean (Angola Basin), NE Pacific Ocean (Mexico, Cedros Trench) and Indian Ocean (Madagascar). This is the first record of Caleidoscopsis from off the Brazilian coast, SW Atlantic Ocean. Samples were collected with box core and/or van veen grabs between Espírito Santo, Campos and Santos Basin (19o-27o S), and around 417-1974 m depths. Two new species is herein described, Caleidoscopsis carlosi sp. nov., which differs from all Caleidoscopsis species by antenna 1 geniculate; maxilliped palp, article 4 shorter than 3; pereopods 5-7, propodus shorter than dactylus; and pereopod 7 with propodus 7x longer than wide; and Caleidoscopsis karamani sp. nov., which can be distinguished by rostrum more developed, reaching half-length of article 1 of peduncle of antenna 1; antenna 2, peduncle, article 5 longer than 3 and 4; pereopod 7, propodus 13x longer than wide, subequal to dactylus; urosomite 1 covering part of urosomite 2, with 1 long dorsal tooth; urosomite 2 with 1 very long and thin dorsal tooth almost reaching the end of urosomite 3. Further on, Caleidoscopsis carlosi sp. nov. turn out to be a very common and abundant species along the study area, being found in 126 samples with a total of 146 specimens examined, when comparing with C. karamani sp. nov. that was found in only 5 samples with one individual each. A table of comparison and an identification key of the currently six known species of the genus are provided. The present study is an effort in understanding and unrevealing the deep-sea macrofauna from the Brazilian margin bringing new data on the family Pardaliscidae found in the slope of the Campos, Santos and Espírito Santo Basins.

Leuconidae Sars, 1878 (Crustacea: Cumacea) from the southwestern Atlantic, filling the distribution gap along the Brazilian coast.

The family Leuconidae Sars, 1878 is one of the eight widely recognized families of Cumacea and can be found in all oceans, but often in deeper waters (> 200 m). Despite its worldwide distribution, Southwestern Atlantic records were restricted to Argentina and Uruguay, indicating a gap in the knowledge of the group along the Brazilian coast. Samples were collected in the Campos, Esprito Santo and Santos Basins with box core and/or van Veen grabs between 163000 m in depth. A total of five new species and a new genus are described herein. Leucon (Alytoleucon) rhuanae sp. nov., Leucon (Crymoleucon) pseudograndidentatus sp. nov., Leucon (Macrauloleucon) watlingi sp. nov., Eudorella helenae sp. nov. and Gyneleucon tripedium gen. et sp. nov. The lack of knowledge on cumacean leuconids along the Brazilian coast is clearly a result of taxonomic impediment. The present study is an effort towards understanding and revealing the Cumacea fauna from the Brazilian margin, bringing new data on the family Leuconidae found in the continental shelf and slope of the Esprito Santo, Campos and Santos Basins, areas with high oil and gas exploration. Promoting the characterization of these areas is essential to a wide understanding of the local species richness and consequently provides tools for preservation and monitoring activities.

Coevolutionary Implications of Obligate Commensalism in Sea Turtles: the Case of the Genus Hyachelia Barnard, 1967 (Crustacea, Amphipoda).

Obligate commensalism in the marine environment and its evolutionary role are still poorly understood. Although sea turtles may serve as ideal substrates for epibionts, within amphipods, only the genus Hyachelia evolved in obligate commensalism with turtles. Here, we report a new host record for Hyachelia lowryi on the hawksbill turtle and describe a larger distribution of the genus in the Atlantic Ocean on green and loggerhead turtles. Hyachelia spp. were sampled from nesting sites of Caretta caretta and feeding grounds of Eretmochelys imbricata and Chelonia mydas along the Brazilian coast. Insights regarding the coevolution of this remarkable genus with its hosts based on molecular analyses are inferred based on mitochondrial (COI) and nuclear (18SrRNA) genes using new and previously available sequences from the infraorder Talitrida. Divergence times for Hyachelia are around the Cretaceous (~127.66 Mya), corresponding to an ancient origin and in agreement with modern green turtle (Chelonioidea) radiation. Later, diversification of Hyachelia species is dated at about 26 Mya, suggesting a coevolutionary association between amphipods and Carettini/Chelonini sea turtles.

A new pattern of dendrobranch gill within the family Solenoceridae (Crustacea: Decapoda: Dendrobranchiata).

Mostly, gills are simple lamellate structures, but in decapods they can assume three elaborate morphologies: trichobranchiate, phyllobranchiate and dendrobranchiate. The dendrobranchiate gill, typically found among the suborder Dendrobranchiata, primarily consists of a long central axis, from which arises a series of paired secondary branches. Each secondary branch is subdivided into smaller fingerlike tertiary processes, and each fingerlike process is also branched (dendritic). The family Solenoceridae is known for having the dendrobranchiate type. Examen of 50 species of Solenoceridae from all nine genera, revealed a new pattern to the classic dendrobranchiate type in 14 species of Solenocera and in Mesopenaeus tropicalis. This new pattern consists of the flattening of the secondary and tertiary processes, with tertiary processes also having a wide, flattened, lamella-like base. This new pattern is herein described as a dendrolamellate gill.

New species of Typhlotanaidae (Crustacea, Tanaidacea) from the Brazilian coast: genera Hamatipeda, Meromonakantha and Paratyphlotanais, with description of Targaryenella gen. nov.

Benthic samples collected along the Brazilian coast yielded the description of four new species from three genera of Typhlotanaidae: one Hamatipeda (H. prolata), one Meromonakantha (M. mauri) and two Paratyphlotanais (P. apletos and P. bessai). A new genus Targaryenella is erected to accommodate Meromonakantha anarsios and differences between Targaryenella and Meromonakantha are given. This study increases the total number of Tanaidacea species known for Brazil by 8% (50 to 54 species); the family Typhlotanaidae off the coast of Brazil is now represented by four known genera. Identification keys to the three genera are provided.

Taxonomic status of the amphi-Atlantic species Plesionika acanthonotus (Caridea: Pandalidae): a multi-locus and morphological approach.

Deep-sea shrimps of the species Plesionika acanthonotus (Smith, 1882) and P. holthuisi Crosnier Forest, 1968 are morphologically similar and exhibit overlapping amphi-Atlantic distributions. In the literature, through morphological studies, there are reports of doubts about the validity of P. holthuisi and some authors believe that the eastern and western Atlantic populations of P. acanthonothus could represent two distinct species. The objective of the present study was to use molecular data to elucidate the taxonomic status of the two populations of P. acanthonothus. DNA sequences of two mitochondrial genes (16S rDNA and Cytochrome Oxidase subunit I) and a nuclear gene (Histone 3) were obtained for both species and for both populations of P. acanthonotus. The sequences were also obtained from Genbank for comparison. The trees (separate and multi-locus/partitioned genes) were generated by Bayesian Inference analyzes, and genetic divergence (Kimura-2-parameters) was also calculated. All specimens that had their DNA sequenced were examined morphologically to confirm their identification; morphological variations were noted. The genetic data showed that Plesionika holthuisi is closely related to P. acanthonotus, but clearly separated, indicating that P. holthuisi is a valid species. In the multi-locus analysis, the P. acanthonothus specimens were divided into two clades, one with the eastern Atlantic specimens and another with the western Atlantic specimens. However, this genetic separation was considered to be a population structuring for three reasons: (1) the genetic divergences of the two mitochondrial genes between these two groups (eastern Atlantic X western Atlantic) were smaller than the interspecific divergence for Plesionika; (2) the P. acanthonothus sequences of the Histone 3 gene showed no genetic variation; (3) in the analyzed individuals, no valid morphological character was found to support this separation. Thus, the conclusion of this study is that P. holthuisi probably is a valid species and P. acanthonothus presents two populations with mitochondrial divergences that could be in the process of speciation, but which currently represent only one species.

Organochlorine pesticides (OCs) and polychlorinated biphenyls (PCBs) in sediments and crabs (Chasmagnathus granulata, Dana, 1851) from mangroves of Guanabara Bay, Rio de Janeiro State, Brazil.

Organochlorinated compounds, seven indicator PCB congeners, DDT and its main metabolites, were determined in sediment and crab (Chasmagnathus granulata) samples collected from mangrove areas near Rio de Janeiro, Brazil. Samples were analysed according to the FAO/SIDA protocols using continuous non-polar solvent extraction and a conventional GC-ECD apparatus. The highest levels of total PCB congeners and total DDT metabolites in sediments (184.16 and 37.40 ng g(-1)d.w. respectively) and crab eggs (570.62 and 98.22 ng g(-1)d.w. respectively) were found at impacted mangroves. The higher PCB congeners than DDT metabolites levels suggesting a stronger industrial impact in this area. The results indicate that the population density of crab is negatively affected by sediment contamination that is reflected basically by the organochlorine content in the female eggs. The organochlorine concentration in eggs is more significant to evaluate or estimate an impact of these pollutants upon C. granulata population than the organochlorine concentration in sediment samples.

The family Caprellidae (Amphipoda: Caprelloidea: Caprellidae) from Campos Basin, Southwestern Atlantic, with a key of species occurring in Brazil.

Caprellid material of the present study was collected between 25-3000 m depth from the Campos Basin area, Southwestern Atlantic. As a result, Deutella incerta was found as a new record to the Southwestern Atlantic and two new species are described: Liropus guerragarciai sp. nov. and Mayerella sittropiae sp. nov. Besides, Paracaprella pusilla is herein redescribed as a common component of the Campos Basin amphipod community. Caprellids are a diverse and abundant group that can be found among algae and general biological substrates of the continental shelf area. As more deep sea samples are coming into light, they are turning out to be also a common component in this habitat. Including the present data, there are 25 caprellid species recorded in Brazil, being four of them restricted to the slope areas and 14 endemic to the Brazilian coast. A key to the Caprellidae species from Brazil is provided.

Cheirimedon foscae sp. nov. (Amphipoda: Lysianassidae: Tryphosinae) from the deep sea Campos Basin, Southwestern Atlantic Ocean.

A new species of lysianassid amphipod belonging to the genus Cheirimedon was collected on the continental slope of the Campos Basin, the largest oil reserve in Brazilian waters. This is the first record of the genus Cheirimedon from the Atlantic Ocean, which was previously restricted to the Antarctic and Tasmanian sea. The new species is fully illustrated and compared with related species. Additionally, a world key to the Cheirimedon species is provided.