First record of sharksucker Echeneis naucrates (Perciformes, Echeneidae) associated to a young Guiana dolphin Sotalia guianensis (Cetartiodactyla, Delphinidae) in north-eastern Brazil

Funding: Conselho Nacional de Desenvolvimento Científico e Tecnológico - 208203/2014-1.Suckerfish attached to dolphin species have been extensively reported worldwide, yet such association has been rarely seen in the tropical and shallow waters of South America. In Brazil, the Guiana dolphin Sotalia guianensis is distributed along almost the entire coastal extension and only one case of association with suckerfish has been published. Here we report on a sharksucker Echeneis naucrates associated with a young Guiana dolphin for north-eastern coast of Brazil. The juvenile dolphin with an attached sharksucker was observed in two occasions separated by a 47-day period; we hypothesize the occurrence of host attachment fidelity. The present report adds information to better discuss the ecological interactions between echeneids and dolphins, and expands the baseline information on cetacean species serving as host to suckerfish.Publisher PDFPeer reviewe

Anthropogenic impact on a pregnant Cuvier's beaked whale (Ziphius cavirostris) stranded in Brazil

Background: Because of their usually cryptic behaviour, most knowledge on the biology of beaked whales are from records of stranded animals. Although the Cuvier’s beaked whale (Ziphius cavirostris) is the best known species of the ziphiidae family, little information on its reproduction is available. Results: Here we report on the stranding of a dead pregnant female with clear signs of anthropogenic impact, including the presence of a fishing artefact in the stomach. Conclusions: The region of the stranding (north-eastern coast of Brazil) is an area of increasing interest for oil and gas exploitation. Conservation concerns may arise from findings such as the one presented and discussed here.Publisher PDFPeer reviewe

Sincraniometria do cachalote-pigmeu, Kogia breviceps (Odontoceti, Kogiidae), no litoral da Bahia, Nordeste do Brasil

The present work analyzes the sincranio of an adult male of pygmy sperm whale, Kogia breviceps, stranded in the state of Bahia. The cranial measures were taken with aid of a caliper accurately of 0,05mm. The condylobasal length (CCB) found was of 426mm. The relationship between the length of the rostrum and CCB was below the expected (58%) and it can be a consequence of geographical differences. The symphysis mandibular came no fused, measuring 123,8mm. The branches mandibles with the broken extremities presented, respectively, 11 and 9 alveolus in the left and right sides. This is the first record syncranial of K. breviceps for the state of Bahia, contributing like this, with information about the species in Atlantic Ocean Western South.O presente trabalho analisa o sincrânio de um macho adulto de cachalote-pigmeu, Kogia breviceps encalhado no Estado da Bahia. As medidas cranianas foram tomadas com auxílio de um paquímetro com precisão de 0,05mm. O comprimento côndilo-basal (CCB) encontrado foi de 426mm. A relação entre o comprimento do rostro e o CCB ficou abaixo do esperado (58%) e pode ser decorrente de diferenças geográficas. A sínfise mandibular apresentava-se não fusionada, medindo 123,8mm. Os ramos mandibulares com as extremidades quebradas apresentavam, respectivamente, 11 e 9 alvéolos nos lados esquerdo e direito respectivamente. Este é o primeiro registro sincraniano de K. breviceps para o estado da Bahia, contribuindo assim, com informações sobre a espécie no Atlântico Sul Ocidental

Anthropogenic impact on a pregnant Cuvier's beaked whale (<i>Ziphius cavirostris</i>) stranded in Brazil

Background: Because of their usually cryptic behaviour, most knowledge on the biology of beaked whales are from records of stranded animals. Although the Cuvier’s beaked whale (Ziphius cavirostris) is the best known species of the ziphiidae family, little information on its reproduction is available. Results: Here we report on the stranding of a dead pregnant female with clear signs of anthropogenic impact, including the presence of a fishing artefact in the stomach. Conclusions: The region of the stranding (north-eastern coast of Brazil) is an area of increasing interest for oil and gas exploitation. Conservation concerns may arise from findings such as the one presented and discussed here

Analysis of Cookiecutter shark Isistius spp. (Squaliformes; Dalatiidae) bites in cetaceans (Mammalia; Cetacea) on the Bahia coast, northeastern Brazil

Few studies have registered signs of mutilation on cetaceans in Brazil, especially from shark attacks. This work describes interactions between cookiecutter sharks Isistius spp. and cetaceans through the analysis of bite records for cetacean carcasses washed ashore on the Bahia coast between 1996 and 2005. Twenty bite records were analyzed in 13 cetacean species, of which the Delphinidae family was the most frequent. After the analysis, Isistius plutodus was identified as the aggressor species on 80% of the records, followed by I. brasiliensis (20%), based on the characteristic shape of the mutilations. The areas most subject to attack in cetaceans were: flanks 40%; head and abdomen 20% each; dorsal 15%; and genital with 5%. The relatively high number of bites on the flanks was probably due to its larger area, which offered greater opportunities to the cookiecutter shark. At least three bite records were related to the possible causes of strandings in delphinids. We recommend further studies on interactions between sharks and cetaceans along the Brazilian coast

Mitochondrial diversity and inter-specific phylogeny among dolphins of the genus Stenella in the Southwest Atlantic Ocean.

The genus Stenella is comprised of five species occurring in all oceans. Despite its wide distribution, genetic diversity information on these species is still scarce especially in the Southwest Atlantic Ocean. Some features of this genus can enhance opportunities for potential introgressive hybridization, e.g. sympatric distibution along the Brazilian coast, mixed known associations among species, karyotype uniformity and genome permeability. In this study we analyzed three genes of the mitochondrial genome to investigate the genetic diversity and occurrence of genetic mixture among eighty specimens of Stenella. All species exhibited moderate to high levels of genetic diversity (h = 0.833 to h = 1.000 and π = 0.006 to π = 0.015). Specimens of S. longirostris, S. attenuata and S. frontalis were clustered into differentiated haplogroups, in contrast, haplotypes of S. coeruleoalba and S. clymene were clustered together. We detected phylogenetic structure of mixed clades for S. clymene and S. coeruleoalba specimens, in the Southwest Atlantic Ocean, and also between S. frontalis and S. attenuata in the Northeast Atlantic Ocean, and between S. frontalis and S. longirostris in the Northwest Atlantic Ocean. These specimes were morphologically identified as one species but exhibited the maternal lineage of another species, by mitochondrial DNA. Our results demonstrate that ongoing gene flow is occurring among species of the genus Stenella reinforcing that this process could be one of the reasons for the confusing taxonomy and difficulties in elucidating phylogenetic relationships within this group

Anthropogenic impact on a pregnant Cuvier’s beaked whale (Ziphius cavirostris) stranded in Brazil

Background: Because of their usually cryptic behaviour, most knowledge on the biology of beaked whales are from records of stranded animals. Although the Cuvier’s beaked whale (Ziphius cavirostris) is the best known species of the ziphiidae family, little information on its reproduction is available. Results: Here we report on the stranding of a dead pregnant female with clear signs of anthropogenic impact, including the presence of a fishing artefact in the stomach. Conclusions: The region of the stranding (north-eastern coast of Brazil) is an area of increasing interest for oil and gas exploitation. Conservation concerns may arise from findings such as the one presented and discussed here