Estéfane Cardinot Reis

Genetic composition, population structure and phylogeography of the loggerhead sea turtle: colonization hypothesis for the Brazilian rookeries

The loggerhead sea turtle, Caretta caretta, is the most common species of sea turtle nesting in Brazil and is listed as endangered by the IUCN. Our study characterizes the genetic structure of loggerheads in Brazil based on mitochondrial DNA control region variability and presents a hypothesis for the colonization of Brazilian rookeries. We analyzed 329 samples from Brazilian rookeries and an oceanic foraging ground, and we compared our results with previously published data for other loggerhead populations. Brazilian rookeries had four haplotypes, none of which have been reported for rookeries outside Brazil. Six haplotypes were found in the foraging aggregation. The presence of the CC-A4 haplotype at all sampled sites and the low nucleotide diversity suggest a common origin for all rookeries, with CC-A4 being the ancestral haplotype of the Brazilian populations. The occurrence of three haplotypes in the foraging aggregation that are known only from rookeries outside of Brazil is consistent with the transoceanic migratory behavior of loggerheads. Our results indicated that the colonization of Brazilian rookeries probably occurred from the southern USA stock. This recent colonization most likely followed a north to south route along the Brazilian coastline, influenced by the Brazilian warm current. Our results further suggest the existence of two genetic population units of loggerheads in Brazil and corroborate natal homing behavior in loggerheads.

Nuclear markers reveal a complex introgression pattern among marine turtle species on the Brazilian coast

Surprisingly, a high frequency of interspecific sea turtle hybrids has been previously recorded in a nesting site along a short stretch of the Brazilian coast. Mitochondrial DNA data indicated that as much as 43% of the females identified as Eretmochelys imbricata are hybrids in this area (Bahia State of Brazil). It is a remarkable find, because most of the nesting sites surveyed worldwide, including some in northern Brazil, presents no hybrids, and rare Caribbean sites present no more than 2% of hybrids. Thus, a detailed understanding of the hybridization process is needed to evaluate natural or anthropogenic causes of this regional phenomenon in Brazil, which could be an important factor affecting the conservation of this population. We analysed a set of 12 nuclear markers to investigate the pattern of hybridization involving three species of sea turtles: hawksbill (E. imbricata), loggerhead (Caretta caretta) and olive ridley (Lepidochelys olivacea). Our data indicate that most of the individuals in the crossings L. olivacea × E. imbricata and L. olivacea × C. caretta are F1 hybrids, whereas C. caretta × E. imbricata crossings present F1 and backcrosses with both parental species. In addition, the C. caretta × E. imbricata hybridization seems to be gender and species biased, and we also found one individual with evidence of multispecies hybridization among C. caretta × E. imbricata × Chelonia mydas. The overall results also indicate that hybridization in this area is a recent phenomenon, spanning at least two generations or ∼40 years.

Evidence of migratory movements of olive ridley turtles (Lepidochelys olivacea) along the Brazilian coast

Projeto Aves, Quelonios e Mamiferos Marinhos da Bacia de Campos, Grupo de Estudos de Mamiferos Marinhos da Regiao dos Lagos (GEMM-Lagos) / Oceanites, Departamento de Endemias, Escola Nacional de Saude Publica, FIOCRUZ (Rua Leopoldo Bulhoes, 1480 - 6o andar - Sala 620, 21041-210 Rio de Janeiro, RJ, Brasil) *Corresponding author: est.cardinot@gmail.com Sea turtles have a long and complex life cycle involving transoceanic migrations and marked changes in diet and habitat. Juveniles are believed to spend their first few years drifting passively in ocean current systems or on floating sargassum rafts (CARR, 1986; BOLTEN et al., 1998). Advanced juveniles subsequently shift to coastal feeding habitats (CARR, 1987). After reaching sexual maturity, some 20 or 30 years later (FRAZER; EHRHART, 1985; KLINGER; MUSICK, 1995), adults undertake reproductive migrations that range from tens to thousands of kilometers (MEYLAN, 1982; MEYLAN et al., 1983; HUGHES, 1989; LIMPUS et al., 1992). Nesting usually occurs in spring and summer. Tagging data suggest that sea turtles show maternal philopatry to their natal site (BJORNDAL et al., 1983; BOWEN et al., 1993). Five sea turtle species can be found in Brazil: Caretta caretta, Chelonia mydas, Eretmochelys imbricata, and Lepidochelys olivacea of the Cheloniidae family, and Dermochelys coriacea of the Dermochelyidae family (MARCOVALDI; MARCOVALDI, 1999) . L. olivacea (Eschscholtz 1829), known as olive ridley turtle, shows a great concentration of nests in Sergipe and northern Bahia states, on the north-eastern Brazilian coast (DA SILVA et al., 2007). Also, based on incidental catch by the Brazilian pelagic longline fishery, Sales et al. (2008) have suggested that the offshore waters of the north-eastern Brazilian coast are a preferential habitat for olive ridley turtles. Under the International Union for Conservation of Nature criteria, this species is currently considered endangered (IUCN Red List of Threatened Species, available at , December 2009). In addition, L. olivacea is listed in Appendix I of the Convention on International Trade in Endangered Species of Fauna and Flora (available at , December 2009). Here we discuss the possible existence of a translocation pattern of olive ridleys along the Brazilian coast based on reports of specimens stranded along the central-north coast of Rio de Janeiro state since 2005. These reports include an olive ridley tagged by the TAMAR Project in Sergipe and found by our research group in Quissama, northern Rio de Janeiro state. Since 2005, GEMM-Lagos / Oceanites staff has been regularly monitoring beaches along the central-north coast of Rio de Janeiro state, from Saquarema (22

Assessment of trace elements, POPs, 210Po and stable isotopes (15N and 13C) in a rare filter-feeding shark: The megamouth

With less than 60 records being reported worldwide, the megamouth (Megachasma pelagios) is today one of the least known shark species inhabiting our oceans. Therefore, information concerning the biology and ecology of this enigmatic organism is very scarce and limited to feeding behaviour and preferred habitat. The present work reports new data on the concentrations of trace elements, organic mercury, POPs and (210)Po in hepatic and muscular tissues of a specimen found stranded in the southeastern coast of Brazil. Additionally, we provide new evidence based on stable isotope analysis (δ(15)N and δ(13)C) confirming the preference for the pelagic habitat and the zooplanktivorous feeding behaviour of the megamouth. These results are consistent with the low concentrations of organic pollutant compounds and other elements measured in our samples.

Cytochrome b sequencing for the species identification of whale carcasses washed ashore in Brazil

Carcasses of whales provide much valuable information on their natural history. However, some specimens cannot be identified in the field due to the advanced state of decomposition. In this study, the DNA was extracted and the mitochondrial cytochrome b gene was amplified by polymerase chain reaction and sequenced for four carcasses of possible mysticeti (GEMM: 075, 088, 135 and GEMARS: 1302). A blast search using the nucleotide–nucleotide basic local alignment (blastn) search tool was conducted using the generated sequences. Samples GEMM 075 and GEMARS 1302 showed 98% identity to one sequence of Balaenoptera acutorostrata . Samples GEMM 088 and GEMM 135 showed 99% identity to sequences from Balaenoptera edeni and Megaptera novaeangliae , respectively. A neighbour-joining tree was generated using sequences from GenBank from all species of balaenopterid that occur on the coast of Brazil. The results showed that all carcasses analysed were correspondent to species from the family Balaenopteridae already recorded in Brazil.

Aplysina (Porifera: Demospongiae) species identification through SSCP-ITS patterns

Keratose sponges have no spicules and limited robust morphological characters, causing severe problems for taxonomic classification. Single-strand conformational polymorphism (SSCP) analysis of PCR amplified internal transcribed spacers (ITS) of nuclear ribosomal RNA (rRNA) genes was used to elucidate speciation patterns in marine sponges of the genus Aplysina. In this study, Aplysina species with non-ambiguous traditional morphological alpha taxonomy were used to generate standard SSCP-ITS patterns, which were compared with patterns from alleged new species. Our results show that ITS-SSCP patterns allowed the differentiation of Aplysina sponges, demonstrating the advantage of a method that explores the secondary structure compared to direct sequencing.