Elementos traza (HgT, Cd, Cu y Ag) en el delfín común de pico corto (Delphinus delphis) y el delfín de Fraser (Lagenodelphis hosei) del atlántico sudoccidental

Entre la amplia variedad de contaminantes encontramos, dentro de los denominados elementos traza, el mercurio total (HgT), el cadmio (Cd), el cobre (Cu) y la plata (Ag). Su principal vía de absorción para los vertebrados marinos es la dieta. Los odontocetos están en la cima de las cadenas tróficas y dado que acumulan gran cantidad de compuestos a lo largo de la vida, son considerados bioindicadores de contaminación del ecosistema. Algunos trabajos indican que no existe una acumulación diferencial de elementos traza entre sexos, pero sí una relación con la edad y la talla. El objetivo del presente estudio fue analizar las concentraciones de elementos traza en el hígado y riñón de 31 delfines comunes (Delphinus delphis) y 6 delfines de Fraser (Lagenodelphis hosei) varados en las costas de los Golfos norpatagónicos entre 1996 y 2012. Asimismo, evaluar las concentraciones de estos contaminantes en relación al sexo, la edad y el largo estándar.Fil: Durante, Cristian Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Manhães Moura Reis, B.. Universidad Estadual de Río de Janeiro; BrasilFil: Loizaga de Castro, Rocio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Lailson Brito Jr, J.. Universidad Estadual de Río de Janeiro; BrasilFil: Crespo, Enrique Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaXI Congreso de la Sociedad Latinoamericana de Especialistas Mamíferos AcuáticosValparaisoChileSociedad Latinoamericana De Especialistas Mamíferos Acuático

Trace metals in liver and kidney of the franciscana (Pontoporia blainvillei) from the northern coast of Rio de Janeiro State, Brazil

In the Southwestern Atlantic few studies have documented trace metal concentrations in cetacean tissues. This study presents both hepatic and renal trace metal concentrations (Fe, Cu, Zn, Mn, Hg and Cd), in franciscana (n=17), inhabiting the waters of Rio de Janeiro State, southeastern Brazil. The concentrations of Fe, Cu, Zn, Mn and Hg generally were highest in the liver and Cd levels in liver and kidney were comparable. Hepatic and renal essential metal (Fe, Cu, Zn and Mn) concentrations were similar to those documented elsewhere for other species. THg and Cd concentrations were found to increase with age. The low concentrations of trace metals determined in the franciscana tissues in this study reflect its dietary habits, trophic position and the low bioavailability of metals in northern Rio de Janeiro

Morphology of the Guiana dolphin (Sotalia guianensis) off southeastern Brazil: growth and geographic variation

The objective of this study was to analyze the morphology of Guiana dolphin (Sotalia guianensis) to evaluate the existence of geographical variation along southeastern Brazil. Body length and 39 cranial variables were measured of specimens stranded or accidentally captured to consider ontogenetic and geographic variations. The areas studied were Espírito Santo (ES; 18°30’S-20°40’S), northern Rio de Janeiro (NRJ; 21°35’S-22°25’S), southern Rio de Janeiro (SRJ; 23°00’S-23°07’S) and São Paulo (SP; 23°30’S-25°30’S). Body length at age zero predicted by a non-linear Gompertz model for the Guiana dolphin was 148.3cm for area ES, 108.97cm for area NRJ, 98.4cm for area SRJ and 90.9cm for area SP. Asymptotic values were reached at about six years of age for total body length and cranial variations. These results indicate that Guiana dolphins reach adult size and sexual maturity simultaneously at six to seven years of age, when specimens cease to grow. The growth pattern for body and skull size indicated that there is variation between geographic areas. Guiana dolphins found in São Paulo are smaller than those analyzed in northern Rio de Janeiro and Espírito Santo, which implies a different growth rate. A canonical discriminant analysis of the cranial metric characters indicated significant differences between the four geographic areas. Differences between areas NRJ, SRJ and SP were responsible for 54% (axis 1) and 34% (axis 2) of the variation, respectively. The third axis depicted a difference between the area ES and the others. A partial overlap between geographic areas was observed in the projection of the species on the canonical axes, suggesting parapatry. Geographic variation recorded in this study is likely to be related to environmental adaptations. One of the areas that could play a role in the distribution of Guiana dolphin in the surveyed area is the central coast of Rio de Janeiro, which is characterized by the absence of river discharges, a narrowing of the continental shelf and upwelling influence that might be limiting the species occurrence in this area

Comparative histopathologic and viral immunohistochemical studies on CeMV infection among Western Mediterranean, Northeast-Central, and Southwestern Atlantic cetaceans

Cetacean morbillivirus (CeMV) is a major natural cause of morbidity and mortality in cetaceans worldwide and results in epidemic and endemic fatalities. The pathogenesis of CeMV has not been fully elucidated, and questions remain regarding tissue tropism and the mechanisms of immunosuppression. We compared the histopathologic and viral immunohistochemical features in molecularly confirmed CeMV-infected Guiana dolphins (Sotalia guianensis) from the Southwestern Atlantic (Brazil) and striped dolphins (Stenella coeruleoalba) and bottlenose dolphins (Tursiops truncatus) from the Northeast-Central Atlantic (Canary Islands, Spain) and the Western Mediterranean Sea (Italy). Major emphasis was placed on the central nervous system (CNS), including neuroanatomical distribution of lesions, and the lymphoid system and lung were also examined. Eleven Guiana dolphins, 13 striped dolphins, and 3 bottlenose dolphins were selected by defined criteria. CeMV infections showed a remarkable neurotropism in striped dolphins and bottlenose dolphins, while this was a rare feature in CeMV-infected Guiana dolphins. Neuroanatomical distribution of lesions in dolphins stranded in the Canary Islands revealed a consistent involvement of the cerebrum, thalamus, and cerebellum, followed by caudal brainstem and spinal cord. In most cases, Guiana dolphins had more severe lung lesions. The lymphoid system involved in all three species, with consistent lymphoid depletion. Multinucleate giant cells/syncytia and characteristic viral inclusion bodies were variably observed in these organs. Overall, there was widespread lymphohistiocytic, epithelial, and neuronal/neuroglial viral antigen immunolabeling with some individual, host species, and CeMV strain differences. Preexisting and opportunistic infections were common, particularly endoparasitism, followed by bacterial, fungal, and viral infections. These results contribute to understanding CeMV infections in susceptible cetacean hosts in relation to factors such as CeMV strains and geographic locations, thereby establishing the basis for future neuro- and immunopathological comparative investigations