Fatal asphyxia due to laryngeal displacement by large-sized prey in a Guiana dolphin (Sotalia guianensis), Brazil / Asfixia por deslocamento laríngeo associado a consumo de presa de grande tamanho em boto-cinza (Sotalia guianensis), Brasil

The Guiana dolphin (Sotalia guianensis) is a small odontocete distributed from Santa Catarina state, Brazil, to Honduras. Although it is currently considered “near threatened” by the International Union for Conservation of Nature, considerable knowledge on health and disease aspects of this species has been gained over the last decade. The main threats for the species are represented by multiple anthropic factors. Guiana dolphins feed on a variety of taxa, primarily teleosts, crustaceans, and cephalopods. Herein, we reported a case of severe laryngeal displacement and esophageal impaction with ulceration associated with a deglutted adult leatherjacket (Oligoplites sp.). This fish species is not a common prey item of Guiana dolphins diet. Severe upper aerodigestive compromise likely led to death by mechanical asphyxia (choke) in this dolphin. This report attested the occurrence of upper aerodigestive dysfunction due to overzealous feeding in Guiana dolphin and contributed to general knowledge on pathology of the species.(AU)

O boto-cinza (Sotalia guianensis) é um pequeno odontoceto que ocorre desde o estado de Santa Catarina, Brasil, até Honduras. Embora esta espécie seja considerada “quase ameaçada” pela União Internacional para a Conservação da Natureza, um considerável conhecimento sobre diversos aspectos de saúde e doença nesta espécie foi adquirido na última década. As principais ameaças para a espécie são representadas por múltiplos fatores antrópicos. Os botos-cinza se alimentam de uma variedade de táxons, incluindo principalmente teleósteos, crustáceos e cefalópodes. No presente estudo relatamos um caso de deslocamento laríngeo grave e impactação esofágica com ulceração pela deglutição de um peixe adulto do gênero Oligoplites. Esta espécie de peixe não é um elemento comum da dieta dos botos-cinza. É possível que o comprometimento aerodigestivo grave tenha levado o animal à morte por asfixia mecânica. Este relato atesta a ocorrência de disfunção aerodigestiva superior devido à alimentação de tamanho excessivo por um boto-cinza, e contribui para o conhecimento geral de patologias na espécie.(AU)

Ontogeny of the skull of Sotalia guianensis (Cetartiodactyla: Delphinidae) on the Northern coast of Brazil

This study aimed to investigate the ontogenetic development of the skull in the Guiana dolphin (Sotalia guianensis Van Bénéden, 1864 ) through the comparison of 29 morphological non-metrical characters together with the estimated age of 54 specimens derived from four areas on the northern coast of Brazil. The state of each character was associated with the age of each specimen to assess the formation of bone structures, and the degree of fusion of the sutures in each state of the character studied. Nineteen qualitative morphological characters presenting state ontogenetic variations have been analyzed statistically. The analysis depicted that the characters associated with the parietal-frontal suture, parietosupraoccipital, parietoexoccipital, supraoccipital-exoccipital and basioccipital-pterygoid varied according with the age. The results suggest that the physical maturity of the cranium was more premature in the specimens from the Northern Coast, suggesting a geographical adjustment of the species, or a biological response to an intense pressure of by-catch in fisheries over decades on the populations.(AU)

O objetivo do estudo foi investigar o desenvolvimento ontogenético craniano do boto-cinza (Sotalia guianensis Van Bénéden, 1864), comparando 29 caracteres morfológicos não métricos aliados às estimativas de idade de 54 espécimes provenientes de quatro áreas da Costa Norte do Brasil. Cada estado de caráter foi associado à idade de cada espécime para avaliar a formação de estruturas ósseas e o grau de fusionamento das suturas em cada estado de caráter analisado. Foram analisados estatisticamente 19 caracteres morfológicos qualitativos que apresentaram variação nos estados de caráter. A análise revelou que os caracteres que diferiram de acordo com a idade foram aqueles ligados à sutura parietal-frontal, parietal-supraoccipital, parietal-exoccipital, supraoccipital-exoccipital e basioccipital-pterigóide. Os resultados indicaram que a maturidade física do crânio foi mais precoce nos espécimes da Costa Norte, sugerindo uma estruturação geográfica da espécie ou uma resposta biológica a uma intensa pressão de captura acidental em redes de pesca sobre as populações.(AU)

Ontogeny of the skull of Sotalia guianensis (Cetartiodactyla: Delphinidae) on the Northern coast of Brazil

This study aimed to investigate the ontogenetic development of the skull in the Guiana dolphin (Sotalia guianensis Van Bénéden, 1864 ) through the comparison of 29 morphological non-metrical characters together with the estimated age of 54 specimens derived from four areas on the northern coast of Brazil. The state of each character was associated with the age of each specimen to assess the formation of bone structures, and the degree of fusion of the sutures in each state of the character studied. Nineteen qualitative morphological characters presenting state ontogenetic variations have been analyzed statistically. The analysis depicted that the characters associated with the parietal-frontal suture, parietosupraoccipital, parietoexoccipital, supraoccipital-exoccipital and basioccipital-pterygoid varied according with the age. The results suggest that the physical maturity of the cranium was more premature in the specimens from the Northern Coast, suggesting a geographical adjustment of the species, or a biological response to an intense pressure of by-catch in fisheries over decades on the populations.

O objetivo do estudo foi investigar o desenvolvimento ontogenético craniano do boto-cinza (Sotalia guianensis Van Bénéden, 1864), comparando 29 caracteres morfológicos não métricos aliados às estimativas de idade de 54 espécimes provenientes de quatro áreas da Costa Norte do Brasil. Cada estado de caráter foi associado à idade de cada espécime para avaliar a formação de estruturas ósseas e o grau de fusionamento das suturas em cada estado de caráter analisado. Foram analisados estatisticamente 19 caracteres morfológicos qualitativos que apresentaram variação nos estados de caráter. A análise revelou que os caracteres que diferiram de acordo com a idade foram aqueles ligados à sutura parietal-frontal, parietal-supraoccipital, parietal-exoccipital, supraoccipital-exoccipital e basioccipital-pterigóide. Os resultados indicaram que a maturidade física do crânio foi mais precoce nos espécimes da Costa Norte, sugerindo uma estruturação geográfica da espécie ou uma resposta biológica a uma intensa pressão de captura acidental em redes de pesca sobre as populações.

Ontogeny of the skull of Sotalia guianensis (Cetartiodactyla: Delphinidae) on the Northern coast of Brazil

ABSTRACT This study aimed to investigate the ontogenetic development of the skull in the Guiana dolphin (Sotalia guianensis Van Bénéden, 1864 ) through the comparison of 29 morphological non-metrical characters together with the estimated age of 54 specimens derived from four areas on the northern coast of Brazil. The state of each character was associated with the age of each specimen to assess the formation of bone structures, and the degree of fusion of the sutures in each state of the character studied. Nineteen qualitative morphological characters presenting state ontogenetic variations have been analyzed statistically. The analysis depicted that the characters associated with the parietal-frontal suture, parietosupraoccipital, parietoexoccipital, supraoccipital-exoccipital and basioccipital-pterygoid varied according with the age. The results suggest that the physical maturity of the cranium was more premature in the specimens from the Northern Coast, suggesting a geographical adjustment of the species, or a biological response to an intense pressure of by-catch in fisheries over decades on the populations.

RESUMO O objetivo do estudo foi investigar o desenvolvimento ontogenético craniano do boto-cinza (Sotalia guianensis Van Bénéden, 1864), comparando 29 caracteres morfológicos não métricos aliados às estimativas de idade de 54 espécimes provenientes de quatro áreas da Costa Norte do Brasil. Cada estado de caráter foi associado à idade de cada espécime para avaliar a formação de estruturas ósseas e o grau de fusionamento das suturas em cada estado de caráter analisado. Foram analisados estatisticamente 19 caracteres morfológicos qualitativos que apresentaram variação nos estados de caráter. A análise revelou que os caracteres que diferiram de acordo com a idade foram aqueles ligados à sutura parietal-frontal, parietal-supraoccipital, parietal-exoccipital, supraoccipital-exoccipital e basioccipital-pterigóide. Os resultados indicaram que a maturidade física do crânio foi mais precoce nos espécimes da Costa Norte, sugerindo uma estruturação geográfica da espécie ou uma resposta biológica a uma intensa pressão de captura acidental em redes de pesca sobre as populações.

Toxoplasma gondii in cetaceans of Brazil: a histopathological and immunohistochemical survey / Toxoplasma gondii em cetáceos do Brasil: estudo histopatológico e imuno-histoquímico

Toxoplasmosis is a parasitic disease caused by the protozoan Toxoplasma gondii. In cetaceans, T. gondii infection is a significant cause of morbidity and mortality. Despite the worldwide range and broad cetacean host record of T. gondii infection, there is limited information on toxoplasmosis in cetaceans from the Southern hemisphere. We investigated the occurrence of T. gondii by histopathology and immunohistochemistry in tissue samples of 185 animals comprising 20 different cetacean species from Brazil. Three out of 185 (1.6%) animals presented T. gondii-associated lesions: a captive killer whale Orcinus orca, a free-ranging common bottlenose dolphin Tursiops truncatus and a free-ranging Guiana dolphin Sotalia guianensis. The main lesions observed in these animals were necrotizing hepatitis, adrenalitis and lymphadenitis associated with protozoal cysts or extracellular tachyzoites presenting immunolabeling with anti-T. gondii antibodies. This study widens the spectrum of species and the geographic range of this agent in Brazil, and provides the first reports of T. gondii infection in a captive killer whale and in a free-ranging common bottlenose dolphin in South America.(AU)

Toxoplasmose é uma doença parasitária causada pelo protozoário Toxoplasma gondii. A infecção por T. gondii é uma causa significativa de morbidade e mortalidade, nos cetáceos. Apesar da abrangência mundial e amplo registro de espécies de cetáceos infectadas por T. gondii, informações sobre toxoplasmose em cetáceos do hemisfério sul são limitadas. Neste estudo pesquisou-se por meio de histopatologia e imuno-histoquímica a ocorrência de T. gondii em amostras de tecido de 185 animais, compreendendo 20 diferentes espécies de cetáceos que ocorrem no Brasil. Três dos 185 (1,6%) animais apresentaram lesões associadas a T. gondii: uma orca Orcinus orca mantida em cativeiro, um golfinho-nariz-de-garrafa Tursiops truncatus e um boto-cinza Sotalia guianensis de vida livre. As principais lesões observadas nesses animais foram hepatite, adrenalite e linfadenite necrotizantes associadas a cistos protozoários ou taquizoítos extracelulares, marcados com anticorpos anti-T. gondii. O presente estudo amplia o espectro de espécies susceptíveis a esse agente e o seu alcance geográfico no Brasil, fornecendo o primeiro relato da infecção por T. gondii em uma orca mantida em cativeiro e em um golfinho-nariz-de-garrafa de vida livre na América do Sul.(AU)

Variation of age and total length in Sotalia guianensis (Van Bénéden, 1864) (Cetacea, Delphinidae), on the coast of Espírito Santo state, Brazil

Abstract Variations of age and total length of Sotalia guianensis from the state of Espírito Santo, Brazil, were evaluated. Specimens were found stranded. Age and total length of 44 Guiana dolphins were assessed based on tooth analysis. Age varied between 0.5 year and 33 years (mean = 8.23 years). Most specimens were between zero and 6 years old (47%). Total length varied from 119 cm to 198 cm, with mean of 172.52 cm. Asymptotic length was reached at 185 cm and approximately 5-6 years of age. Mean total length and age were higher than in other regions of the distribution range of the species. Nevertheless, more studies have to be carried out to evaluate the morphological variations in S. guianensis populations in the study area and Brazil.

Resumo Foram avaliadas variações de comprimento total e etárias de Sotalia guianensis provenientes do estado do Espírito Santo. Os espécimes foram encontrados encalhados. Idade e comprimento total de 44 S. guianensis foram avaliados com base na análise dentária. A idade variou entre 0,5 e 33 anos (média = 8,23 anos). A maioria dos exemplares tinha entre zero e seis anos de idade (47%). O comprimento total variou de 119 a 198 centímetros, com média de 172,52 centímetros. O comprimento assintótico foi atingido com 185 cm, aproximadamente entre 5-6 anos de idade. O comprimento total médio e a idade foram maiores que outras regiões de distribuição da espécie. No entanto, mais estudos devem ser realizados para avaliar as variações morfológicas em populações de S. guianensis na região e no Brasil.

Review of thirty-two years of toothed whale strandings in Santa Catarina, southern Brazil (Cetacea: Odontoceti)

Marine mammal strandings provide valuable insights into local biodiversity. Strandings can be caused by both natural and anthropogenic factors. In the state of Santa Catarina, Southern Brazil, organized marine mammal collections started in the 1980s through opportunistic and non-systematic collection efforts, representing a record of over 30 years of marine biodiversity. This study aimed to perform a preliminary review of 32 years of stranding records within this region. The secondary aim was to elucidate the stranding dynamics of the three most commonly recorded species. A total of 460 records were obtained, representing 17 species of odontocetes. The species registered most frequently were the franciscana, Pontoporia blainvillei (Gervais & d' Orbigny, 1844) (n = 173), bottlenose dolphin, Tursiops truncatus (Montagu, 1821) (n = 100), and Guiana dolphin Sotalia guianensis (Van Bénéden, 1864) (n = 97). Most of the stranding records were observed in the second half of the year during the austral winter and spring. The apparent causes of death could not be determined for most of the specimens due to carcass decomposition. For the specimens in which the apparent cause of death could be determined, 27% of the strandings were compatible with anthropogenic interactions. While the focus of this study was a preliminary assessment of stranding data obtained through opportunistic collection, it is evident that future systematic monitoring efforts and stable networks of collaborators will generate more reliable coastal biodiversity inventories and will allow the knowledge of population dynamics of marine mammal species. In particular, for threatened and vulnerable species, or species with poor natural history data, strandings are a fundamental tool for the understanding of marine biodiversity. Ideally, future more refined analyses of stranding data should be used to inform conservation and management policies and to elucidate the biology and ecology of marine and coastal...

Review of thirty-two years of toothed whale strandings in Santa Catarina, southern Brazil (Cetacea: Odontoceti)

Marine mammal strandings provide valuable insights into local biodiversity. Strandings can be caused by both natural and anthropogenic factors. In the state of Santa Catarina, Southern Brazil, organized marine mammal collections started in the 1980s through opportunistic and non-systematic collection efforts, representing a record of over 30 years of marine biodiversity. This study aimed to perform a preliminary review of 32 years of stranding records within this region. The secondary aim was to elucidate the stranding dynamics of the three most commonly recorded species. A total of 460 records were obtained, representing 17 species of odontocetes. The species registered most frequently were the franciscana, Pontoporia blainvillei (Gervais & d' Orbigny, 1844) (n = 173), bottlenose dolphin, Tursiops truncatus (Montagu, 1821) (n = 100), and Guiana dolphin Sotalia guianensis (Van Bénéden, 1864) (n = 97). Most of the stranding records were observed in the second half of the year during the austral winter and spring. The apparent causes of death could not be determined for most of the specimens due to carcass decomposition. For the specimens in which the apparent cause of death could be determined, 27% of the strandings were compatible with anthropogenic interactions. While the focus of this study was a preliminary assessment of stranding data obtained through opportunistic collection, it is evident that future systematic monitoring efforts and stable networks of collaborators will generate more reliable coastal biodiversity inventories and will allow the knowledge of population dynamics of marine mammal species. In particular, for threatened and vulnerable species, or species with poor natural history data, strandings are a fundamental tool for the understanding of marine biodiversity. Ideally, future more refined analyses of stranding data should be used to inform conservation and management policies and to elucidate the biology and ecology of marine and coastal...(AU)

Alterações vertebrais em botos-cinza, Sotalia guianensis, do litoral amazônico, Brasil

O presente estudo tem como objetivo descrever as alterações ósseas da coluna vertebral de 169 Sotalia guianensis da coleção osteológica de mamíferos aquáticos depositada de janeiro de 2005 a dezembro de 2017 na Coleção de Mamíferos do Museu Paraense Emílio Goeldi (MPEG). Os animais foram coletados no litoral do Estado do Pará, nos municípios de Soure, Salvaterra, Maracanã, Marapanim, Curuçá e Bragança. Os animais foram classificados em imaturos e maduros. A faixa etária foi estimada pela análise das vértebras, considerando que os imaturos apresentavam pelo menos uma sínfise não consolidada. As alterações macroscópicas foram classificadas em malformação (congênita), degenerativa (senil), inflamatória/infecciosa e hiperostose (remodelação óssea): Alterações congênitas foram observadas em 47 (27,8%), incluindo 24 animais maduros e 23 imaturos. Alterações degenerativas foram observadas em 7,7% (13/169) dos animais, todos na categoria madura. Lesões inflamatórias ou líticas estiveram presentes em 6,5% (11/169) dos S. guianensis, afetando 7 animais maduros e 6 imaturos. Alterações na remodelação óssea foram observadas em 4,1% (7/169), envolvendo 5 animais maduros e 2 imaturos. Dois desses casos eram compatíveis com lesão de origem traumática. As demais alterações desse grupo foram classificadas como hiperostose esquelética idiopática. Os achados deste estudo contribuem para um melhor entendimento das ameaças à saúde do boto-da-guiana da região Norte do Brasil, principalmente no que diz respeito às lesões vertebrais

The present study aims to describe bone alterations in the vertebral column of 169 Sotalia guianensis from the osteological collection of aquatic mammals deposited from January 2005 to December 2017 in the Mammal Collection of the Museu Paraense Emílio Goeldi (MPEG). The animals were collected from the coast of Pará State, in the municipalities of Soure, Salvaterra, Maracanã, Marapanim, Curuçá and Bragança. The animals were classified as immature and mature. The age range was estimated by the vertebrae analysis, considering that the immature ones had at least one non-consolidated symphysis. The macroscopic alterations were classified into malformation (congenital), degenerative (senile), inflammatory/infectious, and hyperostosis (bone remodeling): Congenital alterations were observed in 47 (27.8%), including 24 mature and 23 immature animals. Degenerative alterations were observed in 7.7% (13/169) of the animals, all of them in the mature category. Inflammatory or lithic lesions were present in 6.5% (11/169) of the S. guianensis, affecting 7 mature and 6 immature animals. Alterations of bone remodeling were observed in 4.1% (7/169), involving 5 mature and 2 immature animals. Two of these cases were compatible with injury of traumatic origin. The other alterations from this group were classified as idiopathic skeletal hyperostosis. The findings of this study contribute to a better understanding of the health threats of the Guiana dolphin of the Northern region of Brazil, particularly concerning to vertebral injuries.

Caracterização histopatológica, imuno-histoquímica e molecular de doenças emergentes em cetáceos no litoral do Paraná

Há evidências crescentes sobre a importância dos mamíferos aquáticos para os ecossistemas e sobre as consequências das atividades humanas. As alterações no ecossistema causadas pelas atividades humanas geram impactos à biodiversidade e inúmeras consequências, incluindo o aumento da suscetibilidade a patógenos e doenças emergentes. Entre as doenças infecciosas emergentes, a morbilivirose de cetáceos, a toxoplasmose e a brucelose, representam, de fato, um potencial risco para a conservação e preservação dos cetáceos. Essas doenças podem desencadear mortalidade massiva, restringir o crescimento de indivíduos, aumentar o risco de extinção e provocar perda da biodiversidade. Ademais, a frequente detecção de novas cepas virais de morbillivírus de cetáceos (CeMV) aumenta a preocupação com a preservação de cetáceos em todo o mundo. Portanto, o objetivo do presente estudo foi verificar a prevalência e os achados patológicos associados ao CeMV e outros patógenos em cetáceos encalhados no litoral do Estado do Paraná sob condições naturais e a possível relação com impactos antrópicos e naturais. O estudo foi realizado no litoral do Paraná e no Complexo Estuarino de Paranaguá compreendendo uma área total de 618 km2. A base de dados do Programa de Monitoramento de Praias da Bacia de Santos foi consultada para verificar os registros de todos os cetáceos encalhados entre fevereiro, 2016 a novembro, 2018, de onde todas as amostras foram obtidas. Como critério de inclusão, apenas animais em boa ou moderada condição de preservação post-mortem e com amostras suficientes para análise molecular, histopatológica e imuno-histoquímica (IHQ) foram avaliados. Amostras de pulmão, sistema nervoso central (SNC) e linfonodos foram imersas em solução de formalina tamponada a 10% e rotineiramente processadas para avaliação histopatológica e imuno-histoquímica anti-CDV e anti-Toxoplasma gondii. Um anticorpo monoclonal anti-CDV foi utilizado para a pesquisa de CeMV devido a reação cruzada entre diferentes cepas de morbillivírus demonstradas por estudos sorológicos. Amostras de pulmão e SNC foram congeladas a -20º para posterior transcrição reversa e reação em cadeia da polimerase (RT-PCR). Do total de 325 registros de cetáceos autopsiados, 40 animais apresentaram todos os critérios de inclusão. A espécie mais comumente observada foi o boto-cinza (Sotalia guianensis, 30/40; 75%) e a interação antrópica mais frequente foi a interação com a pesca (21/40; 52,5%). Na histopatologia, foi observado infiltrado inflamatório linfoplasmocitário peribronquial ou peribronquiolar e encefalite discreta com manguitos de até duas camadas foram os principais achados patológicos associados à infecção por CeMV. A sobreposição de lesões típicas de CeMV por agentes secundários, como o nematoide Halocercus brasiliensis, foi observada em cinco (12,5%) animais. Na avaliação imuno-histoquímica, foi observada a prevalência de antígenos de CeMV em 11 (11/40; 27,5%) animais. A maioria dos animais apresentaram imunomarcação intracitoplasmática apenas no pulmão e um animal apresentou imunorreatividade em todos os órgãos avaliados. Todas as amostras foram negativas para CeMV na análise molecular usando a RT-PCR. A negatividade da análise molecular é multifatorial e provavelmente incluem-se (i) distribuição heterogênea do vírus nos órgãos, (ii) degradação do RNA devido à baixa preservação do tecido frequentemente observada em animais encalhados, ou degradação do RNA nas amostras por RNases e/ou mudanças térmicas, (iii) baixa carga viral, (iv) alvos diferentes na IHQ e na RT-PCR. Em conclusão, o diagnóstico de CeMV é desafiador em áreas em que episódios epidêmicos não foram registrados ainda e devido às alterações post-mortem. Entretanto, observamos uma prevalência de 27,5% de CeMV com predominância de alterações pulmonares associadas por meio de uma combinação de análise histopatológica e imuno-histoquímica. Esse vírus pode desempenhar um papel importante no encalhe de cetáceos, assim como, agir como um agente imunossupressor causando e/ou facilitando infecções secundárias. Os resultados aqui descritos ampliam o conhecimento sobre CeMV na nossa região e este é o primeiro estudo realizado sob condições naturais no Brasil.

There is growing evidence about the importance of aquatic mammals to ecosystems and the consequences of human activities. The changes in the ecosystem caused by human activities have impacts on biodiversity and countless consequences, including increased susceptibility to pathogens and emerging diseases. Among the emerging infectious diseases, cetacean morbidity, toxoplasmosis and brucellosis, in fact, represent a potential risk for the conservation and preservation of cetaceans. These diseases can trigger massive mortality, restrict the growth of individuals, increase the risk of extinction and cause loss of biodiversity. In addition, the frequent detection of new viral strains of cetacean morbillivirus (CeMV) raises concerns about the preservation of cetaceans worldwide. Therefore, the objective of the present study was to verify the prevalence and pathological findings associated with CeMV and other pathogens in stranded cetaceans on the coast of the State of Paraná under natural conditions and the possible relationship with anthropic and natural impacts. The study was carried out on the coast of Paraná and in the Estuarine Paranaguá Complex, comprising a total area of 618 km2. The database of the Santos Basin Beach Monitoring Program was consulted to verify the records of all stranded cetaceans between February 2016 to November 2018, from where all samples were obtained. As an inclusion criterion, only animals in good or moderate condition of post-mortem preservation and with sufficient samples for molecular, histopathological and immunohistochemical (IHC) analysis were evaluated. Samples of lung, central nervous system (CNS) and lymph nodes were immersed in 10% buffered formalin solution and routinely processed for histopathological and anti-CDV immunohistochemistry and anti-Toxoplasma gondii. An anti-CDV monoclonal antibody was used for CeMV screening due to the cross reaction between different strains of morbillivirus demonstrated by serological studies. Lung and CNS samples were frozen at -20º for subsequent reverse transcription and polymerase chain reaction (RT-PCR). Of the total of 325 autopsied cetacean records, 40 animals met all inclusion criteria. The species most observed was the Guiana dolphin (Sotalia guianensis, 30/40; 75%) and the most frequent anthropogenic interaction was bycatch (21/40; 52.5%). In histopathology, peribronchial or peribronchiolar lymphoplasmacytic inflammatory infiltrate and mild encephalitis with cuffs of up to two layers were observed as the main pathological findings associated with infection by CeMV. The overlapping of typical CeMV lesions by secondary agents, such as the nematode Halocercus brasiliensis, was observed in five (12.5%) animals. In the immunohistochemical evaluation, the prevalence of CeMV antigens was observed in 11 (11/40; 27.5%) animals. Most animals presented intracytoplasmic immunostaining only in the lung and one animal showed immunoreactivity in all organs evaluated. All samples were negative for CeMV in the molecular analysis using RT-PCR. The negativity of the molecular analysis is multifactorial and probably includes (i) heterogeneous distribution of the virus in the organs, (ii) degradation of the RNA due to the low tissue preservation frequently observed in stranded animals, or degradation of the RNA in the samples by RNases and / or thermal changes, (iii) low viral load, (iv) different targets in IHC and RT-PCR. In conclusion, the diagnosis of CeMV is challenging in areas where epidemic episodes have not been recorded yet and due to post-mortem changes. However, we observed a 27.5% prevalence of CeMV with a predominance of associated pulmonary changes through a combination of histopathological and immunohistochemical analysis. This virus can play an important role in stranding cetaceans, as well as acting as an immunosuppressive agent causing and / or facilitating secondary infections. The results described here expand the knowledge about CeMV in our region and this is the first study carried out under natural conditions in Brazil.

Behavioral event occurrence differs between behavioral states in Sotalia guianensis (Cetarctiodactyla: Delphinidae) dolphins: a multivariate approach

Difficulties in quantifying behavioral events can cause loss of information about cetacean behavior, especially behaviors whose functions are still debated. The lack of knowledge is greater for South American species such as Sotalia guianensis (Van Benédén, 1864). Our objective was to contextualize the behavioral events inside behavioral states using a Permutational Multivariate Analysis of Variance (MANOVA). Three events occurred in the Feeding, Socio-Sexual and Travelling states (Porpoising, Side flop, Tail out dive), and five events occurred in the Feeding and Travelling states (Back flop, Horizontal jump, Lobtail, Spy-hop, Partial flop ahead). Three events (Belly exposure, Club, and Heading) occurred exclusively in the Socio-sexual state. Partial Back flop and Head flop occurred exclusively in the Feeding state. For the events that occurred in multiple states, we observed that some events occurred more frequently in one of the states (p 0.001), such as Lobtail, Tail out dive horizontal Jump, Partial flop ahead and Side flop. Our multivariate analysis, which separated Socio-sexual behavior from Feeding and Travelling, showed that the abundance of behavioral events differs between states. This differentiation indicates that some events are associated with specific behavioral states. Almost 40% of the events observed were exclusively performed in one state, which indicates a high specialization for some events. Proper discrimination and contextualization of behavioral events may be efficient tools to better understand dolphin behaviors. Similar studies in other habitats and with other species, will help build a broader scenario to aid our understanding of the functions of dolphin behavioral events.

Behavioral event occurrence differs between behavioral states in Sotalia guianensis (Cetarctiodactyla: Delphinidae) dolphins: a multivariate approach

Difficulties in quantifying behavioral events can cause loss of information about cetacean behavior, especially behaviors whose functions are still debated. The lack of knowledge is greater for South American species such as Sotalia guianensis (Van Benédén, 1864). Our objective was to contextualize the behavioral events inside behavioral states using a Permutational Multivariate Analysis of Variance (MANOVA). Three events occurred in the Feeding, Socio-Sexual and Travelling states (Porpoising, Side flop, Tail out dive), and five events occurred in the Feeding and Travelling states (Back flop, Horizontal jump, Lobtail, Spy-hop, Partial flop ahead). Three events (Belly exposure, Club, and Heading) occurred exclusively in the Socio-sexual state. Partial Back flop and Head flop occurred exclusively in the Feeding state. For the events that occurred in multiple states, we observed that some events occurred more frequently in one of the states (p 0.001), such as Lobtail, Tail out dive horizontal Jump, Partial flop ahead and Side flop. Our multivariate analysis, which separated Socio-sexual behavior from Feeding and Travelling, showed that the abundance of behavioral events differs between states. This differentiation indicates that some events are associated with specific behavioral states. Almost 40% of the events observed were exclusively performed in one state, which indicates a high specialization for some events. Proper discrimination and contextualization of behavioral events may be efficient tools to better understand dolphin behaviors. Similar studies in other habitats and with other species, will help build a broader scenario to aid our understanding of the functions of dolphin behavioral events.(AU)

Investigação de infecções por Brucella e Morbillivirus em cetáceos e sirênios nas regiões Norte e Nordeste do Brasil

Os mamíferos aquáticos são susceptíveis a infecções por uma ampla variedade de microrganismos, incluindo bactérias, fungos, vírus e parasitas, cabendo destaque às infecções por Brucella e Morbillivirus, as quais vêm sendo evidenciadas em uma ampla variedade de espécies de mamíferos marinhos em diversas localidades geográficas. Nos mamíferos marinhos, a brucelose é causada pelas espécies Brucella ceti e Brucella pinnipedialis, tendo os cetáceos e os pinípedes como hospedeiros preferenciais, respectivamente. Algumas estirpes foram associadas a infecções zoonóticas. Nos cetáceos e pinípedes, os morbillivirus têm o potencial de causar grandes epidemias com mortalidade em massa das espécies acometidas, podendo ocasionar extinções locais em virtude da tendência cíclica desta infecção. Ambas as infecções já foram registradas em cetáceos marinhos no Brasil, incluindo a recente descrição de epizootia associada a alta mortalidade de botos-cinza (Sotalia guianensis) no Rio de Janeiro, RJ, Brasil. Até o momento, infecções por Brucella e Morbillivirus não foram descritas em golfinhos de rio e em sirênios. Assim, o objetivo do presente trabalho foi investigar a ocorrência de infecções por Brucella spp. e Morbillivirus em cetáceos e sirênios nas regiões Norte e Nordeste do Brasil. Foram analisados 57 peixes-boi marinhos (Trichechus manatus) incluindo animais cativos, reintroduzidos e de vida livre, 84 peixes-boi amazônicos cativos (Trichechus inunguis) e 23 cetáceos, compreendendo amostras de animais vivos e provenientes do banco de amostras de instituições responsáveis pela reabilitação e monitoramento destas espécies. Foram obtidas amostras de tecidos, swabs nasais, genitais, orais e anais e sangue, as quais foram utilizadas para o diagnóstico direto das infecções, pela reação em cadeia pela polimerase (PCR). Amostras de soro foram submetidas ao teste sorológico do antígeno acidificado tamponado (AAT) para detecção de anticorpos anti-Brucella. Os animais com resultados positivos nos testes sorológicos e/ou moleculares para brucelose, tiveram suas amostras analisadas pelo cultivo microbiológico. Amostras positivas nas reações moleculares foram submetidas à caracterização molecular para a confirmação do resultado e caracterização da estirpe bacteriana e/ou viral. Todos os sirênios analisados apresentaram resultado negativo no teste do AAT para sorodiagnóstico de Brucella, bem como nas reações moleculares para detecção de Brucella e morbilivírus em amostras de swabs, tecidos e sangue. Dentre os cetáceos analisados, um espécime de boto-cinza (Sotalia guianensis), macho, encontrado encalhado em Pernambuco, apresentou resultado positivo na PCR para detecção de Brucella spp. em amostra de rim, tendo sido identificada a espécie B. ceti. O isolamento bacteriano não foi bem-sucedido. Num segundo espécime de boto-cinza (S. guianensis), fêmea, encalhada em Alagoas, foi detectado morbillivirus em amostras de fígado e rim. De acordo com os resultados obtidos, não foram verificadas evidência de infecções por Brucella e Morbillivirus em sirênios no Brasil. Quanto aos cetáceos, este corresponde ao segundo relato no Brasil de infecção por Brucella nessa espécie de cetáceo, sendo o primeiro relato de infecção por morbillivirus em boto-cinza na região nordeste do Brasil. Estes resultados alertam para a importância do monitoramento sanitário sistemático desses patógenos, particularmente nesta espécie de golfinho.

Aquatic mammals are susceptible to infections by a variety of microorganisms, including bacteria, fungi, viruses and parasites, with emphasis on Brucella and Morbillvirus infections, which have been evidenced in a wide variety of marine mammal species in several geographical locations. In marine mammals, brucellosis is caused by Brucella ceti and Brucella pinnipedialis, having the cetaceans and pinnipeds as the preferred hosts, respectively. Some Brucella strains have been associated with zoonotic infections. In cetaceans and pinnipeds, morbiliviruses have the potential to cause large epidemics with mass mortality of the affected species with potential to cause local extinctions due to the cyclic tendency of this infection. Both infections have been reported in marine cetaceans in Brazil, including a recent described morbillivirus infection associated with an unusual mass mortality of Guiana dolphins (Sotalia guianensis) in Rio de Janeiro, RJ, Brazil. Until now, Brucella and Morbillivirus infections have not been reported in river dolphins and sirenian. The objective of the present study was to investigate the occurrence of Brucella spp. and Morbillivirus infections in cetaceans and sirenians in the northern and north-eastern regions of Brazil. Fifty-seven marine manatees (Trichechus manatus) were analyzed including captive, reintroduced and free-living animals, 84 captive Amazonian manatees (Trichechus inunguis) and 23 cetaceans were analysed, comprising samples from live animals and from the bank of samples from institutions involved in the rehabilitation and monitoring of these species. Tissue samples, nasal, genital, oral and anal swabs and blood, which were used for direct diagnosis of the infections using the polymerase chain reaction (PCR). Sera was used to detect anti-Brucella antibodies through the buffered acidified antigen test (BAAT). The animals with positive results in serological and/or molecular tests for brucellosis had their samples analysed by microbiological culturing. Positive samples in the molecular reactions were subjected to the sequencing of amplified products to confirm the result and characterize the detected bacterial and/or viral strain detected. All the sirenians analysed were negative in the BAAT test for Brucella serodiagnosis, as well as through the PCR for the detection of Brucella and morbilivirus. Among the cetaceans analysed, a specimen of male Guiana dolphin (S. guianensis), found stranded in Pernambuco, had a Brucella positive PCR result in a kidney sample, with the identification of B. ceti. Bacterial isolation was not successful. In a second specimen of female Guiana dolphin found stranded in Alagoas, morbillivirus was detected in liver and kidney samples. According to the results obtained, there was no evidence of Brucella and Morbillivirus infections in manatees in Brazil. Regarding the cetaceans, this is the second report in Brazil of Brucella infection in this cetacean species, and the first report of morbillivirus infection in Guiana dolphin in the north-eastern Brazilian regions. These results highlight for the importance of conducting systematic health monitoring of these pathogens, particularly in this dolphin species.

Parental care behavior in the Guiana dolphin, Sotalia guianensis (Cetacea: Delphinidae), in Ilha Grande Bay, southeastern Brazil

Parental care is any form of parental behavior that increases offspring fitness. To the authors' knowledge, this study is the first to analyze the intensity of parental care in the Guiana dolphin, Sotalia guianensis (van Bénéden, 1864). The objectives of this study are as follows: 1) to quantify the degree of parental care in S. guianensis in Ilha Grande Bay, Rio de Janeiro; 2) to investigate the influence of behavioral state and group size on the degree of parental care; and 3) to evaluate the differences between the intensity of parental care provided to calves and juveniles. Our results indicate that the intensity of parental care is high in S. guianensis and that care is more intense in larger groups. It is possible that these differences serve to maximize hydrodynamic gains and to minimize risks. Our results suggest that parental care is more intense during travel. A possible reason for this greater intensity is that the feeding dynamics show a more random pattern than other behavioral states. Moreover, the results indicate that calves receive more intense care than juveniles. These results suggest that parent-offspring conflict is possible in the study population.

Parental care behavior in the Guiana dolphin, Sotalia guianensis (Cetacea: Delphinidae), in Ilha Grande Bay, southeastern Brazil

Parental care is any form of parental behavior that increases offspring fitness. To the authors' knowledge, this study is the first to analyze the intensity of parental care in the Guiana dolphin, Sotalia guianensis (van Bénéden, 1864). The objectives of this study are as follows: 1) to quantify the degree of parental care in S. guianensis in Ilha Grande Bay, Rio de Janeiro; 2) to investigate the influence of behavioral state and group size on the degree of parental care; and 3) to evaluate the differences between the intensity of parental care provided to calves and juveniles. Our results indicate that the intensity of parental care is high in S. guianensis and that care is more intense in larger groups. It is possible that these differences serve to maximize hydrodynamic gains and to minimize risks. Our results suggest that parental care is more intense during travel. A possible reason for this greater intensity is that the feeding dynamics show a more random pattern than other behavioral states. Moreover, the results indicate that calves receive more intense care than juveniles. These results suggest that parent-offspring conflict is possible in the study population.

Parental care behavior in the Guiana dolphin, Sotalia guianensis (Cetacea: Delphinidae), in Ilha Grande Bay, southeastern Brazil

Parental care is any form of parental behavior that increases offspring fitness. To the authors' knowledge, this study is the first to analyze the intensity of parental care in the Guiana dolphin, Sotalia guianensis (van Bénéden, 1864). The objectives of this study are as follows: 1) to quantify the degree of parental care in S. guianensis in Ilha Grande Bay, Rio de Janeiro; 2) to investigate the influence of behavioral state and group size on the degree of parental care; and 3) to evaluate the differences between the intensity of parental care provided to calves and juveniles. Our results indicate that the intensity of parental care is high in S. guianensis and that care is more intense in larger groups. It is possible that these differences serve to maximize hydrodynamic gains and to minimize risks. Our results suggest that parental care is more intense during travel. A possible reason for this greater intensity is that the feeding dynamics show a more random pattern than other behavioral states. Moreover, the results indicate that calves receive more intense care than juveniles. These results suggest that parent-offspring conflict is possible in the study population.(AU)

Coordinated feeding behavior of the Guiana dolphin, Sotalia guianensis (Cetacea: Delphinidae), in southeastern Brazil: a comparison between populations

The coordinated feeding tactics used by delphinids are influenced by differences in the distribution of prey species, season, and opportunities for social learning. In the present study, we compared the coordinated feeding behavior of two populations of the Guiana dolphin, Sotalia guianensis, in southeastern Brazil, and how these feeding tactics vary seasonality and in the presence of calves. We observed eight types of coordinated feeding tactics, which differed in frequency and in the mean number of individuals engaged in them, and between both areas. Feeding tactics used to herd and capture prey were the most frequent and engaged a greater number of individuals, suggesting that these tactics are better for capturing fish that gather in larger schools. Furthermore, the seasons influenced the occurrence of different prey items, which in turn modified the feeding tactics of the dolphins. In the Ilha Grande Bay we observed that bouts lasted longer and larger groups engaged in the feeding tactics, which may be associated with the seasonal spawning of larger schooling fish such as Sardinella brasiliensis (Steindachner, 1879) (Teleostei: Clupeidae). However, in the Sepetiba Bay, we observed longer feeding bouts and a smaller number of individuals engaged in the feeding tactics during autumn-winter. This may be associated with the fact that the most abundant prey species, Micropogonias furnieri (Desmarest, 1823) (Teleostei: Sciaenidae), gathers in small schools. Calves were present in 95% of all coordinated feeding tactics that occurred in the Ilha Grande Bay and in approximately 61% of feeding tactics in the Sepetiba Bay, suggesting that these areas are important for social learning. This study provides more information about feeding tactics and improves knowledge of the coordinated behavior of Sotalia guianensis (Van Benéden, 1864).

Coordinated feeding behavior of the Guiana dolphin, Sotalia guianensis (Cetacea: Delphinidae), in southeastern Brazil: a comparison between populations

The coordinated feeding tactics used by delphinids are influenced by differences in the distribution of prey species, season, and opportunities for social learning. In the present study, we compared the coordinated feeding behavior of two populations of the Guiana dolphin, Sotalia guianensis, in southeastern Brazil, and how these feeding tactics vary seasonality and in the presence of calves. We observed eight types of coordinated feeding tactics, which differed in frequency and in the mean number of individuals engaged in them, and between both areas. Feeding tactics used to herd and capture prey were the most frequent and engaged a greater number of individuals, suggesting that these tactics are better for capturing fish that gather in larger schools. Furthermore, the seasons influenced the occurrence of different prey items, which in turn modified the feeding tactics of the dolphins. In the Ilha Grande Bay we observed that bouts lasted longer and larger groups engaged in the feeding tactics, which may be associated with the seasonal spawning of larger schooling fish such as Sardinella brasiliensis (Steindachner, 1879) (Teleostei: Clupeidae). However, in the Sepetiba Bay, we observed longer feeding bouts and a smaller number of individuals engaged in the feeding tactics during autumn-winter. This may be associated with the fact that the most abundant prey species, Micropogonias furnieri (Desmarest, 1823) (Teleostei: Sciaenidae), gathers in small schools. Calves were present in 95% of all coordinated feeding tactics that occurred in the Ilha Grande Bay and in approximately 61% of feeding tactics in the Sepetiba Bay, suggesting that these areas are important for social learning. This study provides more information about feeding tactics and improves knowledge of the coordinated behavior of Sotalia guianensis (Van Benéden, 1864).

Coordinated feeding behavior of the Guiana dolphin, Sotalia guianensis (Cetacea: Delphinidae), in southeastern Brazil: a comparison between populations

The coordinated feeding tactics used by delphinids are influenced by differences in the distribution of prey species, season, and opportunities for social learning. In the present study, we compared the coordinated feeding behavior of two populations of the Guiana dolphin, Sotalia guianensis, in southeastern Brazil, and how these feeding tactics vary seasonality and in the presence of calves. We observed eight types of coordinated feeding tactics, which differed in frequency and in the mean number of individuals engaged in them, and between both areas. Feeding tactics used to herd and capture prey were the most frequent and engaged a greater number of individuals, suggesting that these tactics are better for capturing fish that gather in larger schools. Furthermore, the seasons influenced the occurrence of different prey items, which in turn modified the feeding tactics of the dolphins. In the Ilha Grande Bay we observed that bouts lasted longer and larger groups engaged in the feeding tactics, which may be associated with the seasonal spawning of larger schooling fish such as Sardinella brasiliensis (Steindachner, 1879) (Teleostei: Clupeidae). However, in the Sepetiba Bay, we observed longer feeding bouts and a smaller number of individuals engaged in the feeding tactics during autumn-winter. This may be associated with the fact that the most abundant prey species, Micropogonias furnieri (Desmarest, 1823) (Teleostei: Sciaenidae), gathers in small schools. Calves were present in 95% of all coordinated feeding tactics that occurred in the Ilha Grande Bay and in approximately 61% of feeding tactics in the Sepetiba Bay, suggesting that these areas are important for social learning. This study provides more information about feeding tactics and improves knowledge of the coordinated behavior of Sotalia guianensis (Van Benéden, 1864).

Coordinated feeding behavior of the Guiana dolphin, Sotalia guianensis (Cetacea: Delphinidae), in southeastern Brazil: a comparison between populations

The coordinated feeding tactics used by delphinids are influenced by differences in the distribution of prey species, season, and opportunities for social learning. In the present study, we compared the coordinated feeding behavior of two populations of the Guiana dolphin, Sotalia guianensis, in southeastern Brazil, and how these feeding tactics vary seasonality and in the presence of calves. We observed eight types of coordinated feeding tactics, which differed in frequency and in the mean number of individuals engaged in them, and between both areas. Feeding tactics used to herd and capture prey were the most frequent and engaged a greater number of individuals, suggesting that these tactics are better for capturing fish that gather in larger schools. Furthermore, the seasons influenced the occurrence of different prey items, which in turn modified the feeding tactics of the dolphins. In the Ilha Grande Bay we observed that bouts lasted longer and larger groups engaged in the feeding tactics, which may be associated with the seasonal spawning of larger schooling fish such as Sardinella brasiliensis (Steindachner, 1879) (Teleostei: Clupeidae). However, in the Sepetiba Bay, we observed longer feeding bouts and a smaller number of individuals engaged in the feeding tactics during autumn-winter. This may be associated with the fact that the most abundant prey species, Micropogonias furnieri (Desmarest, 1823) (Teleostei: Sciaenidae), gathers in small schools. Calves were present in 95% of all coordinated feeding tactics that occurred in the Ilha Grande Bay and in approximately 61% of feeding tactics in the Sepetiba Bay, suggesting that these areas are important for social learning. This study provides more information about feeding tactics and improves knowledge of the coordinated behavior of Sotalia guianensis (Van Benéden, 1864).