Aplicabilidade do Índice de Adiposidade para material de necropsia de baleias-jubarte (Megaptera novaeangliae)(Borowski, 1781)
Data
2024-07-19
Autores
Madureira, Lara Bennati 
Orientadores
Casas, André Luis da Silva
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Encalhes de carcaças de mamíferos marinhos são fontes de informações valiosas sobre a biologia geral das espécies, incluindo sua saúde populacional, ao evidenciar desde doenças até ameaças antrópicas. No entanto, nem todos os espécimes encalhados são adequados para análise, uma vez que a disponibilidade de alguns tipos de dados depende do nível de decomposição das carcaças. Um desses tipos de dados é o estado nutricional, que depende da integridade estrutural e química do corpo. Carcaças altamente decompostas perdem grande parte de suas propriedades teciduais e bioquímicas, dificultando a avaliação do nível nutricional do indivíduo. Ainda assim, algumas dessas propriedades podem estar suficientemente intactas para análise, como a estrutura celular. Nesses casos, metodologias baseadas no exame histológico, como o índice de adiposidade, podem ser utilizadas para o diagnóstico nutricional pré-óbito dos indivíduos. Este estudo teve como objetivo testar a aplicabilidade da metodologia do índice de adiposidade para diversos níveis de decomposição (COD 2, COD 3 e COD4) da gordura de carcaças de baleias-jubarte, Megaptera novaeangliae, (Borowski, 1781). Amostras coletadas de carcaças encalhadas foram analisadas histologicamente para testar a integridade celular. Diferentes níveis de preservação foram observados, desde adipócitos estruturalmente intactos até células de levemente à altamente deformadas. Amostras com bons níveis de preservação celular puderam ser observadas para todos os CODs, incluindo duas amostras COD4. Tecidos bem preservados de amostras coletadas em necropsia se mostram viáveis para a avaliação do índice de adiposidade. A necessidade de um método padronizado de coleta de gordura durante a necropsia também foi proposto, já que fatores como a forma de conservação do material foram determinantes para a qualidade amostral. Este estudo deve contribuir com as instituições de monitoramento e pesquisa da fauna marinha, otimizando a utilização dos materiais coletados com o refinamento das técnicas de coleta de amostras durante as necropsias.
Strandings of marine mammal carcasses are sources of valuable information about the general biology of species, including their population health, by highlighting factors such as diseases and anthropogenic threats. However, not all stranded specimens are suitable for analysis, as the availability of some types of data depends on the level of decomposition of the carcasses. One of these types of data is the nutritional status, which depends on structural and chemical integrity of the body. Highly decomposed carcasses lose a large part of their tissue and biochemical properties, making it difficult to assess the individual's nutritional level. Still, some of these properties may be sufficiently intact for analysis, such as cellular structure. In these cases, methodologies based on histological examination, such as the adiposity index, can be used for pre-death nutritional diagnosis of individuals. This study aimed to test the applicability of the adiposity index methodology for different levels of decomposition (CODE2, CODE3 and CODE4) of blubber from carcasses of humpback whales, Megaptera novaeangliae, (Borowski, 1781). Samples collected from stranded carcasses were analyzed histologically to test cellular integrity. Different levels of preservation were observed, from structurally intact adipocytes to slightly to highly deformed cells. Samples with good levels of cellular preservation could be observed for all CODEs, including two CODE4 samples. Well-preserved tissues from necropsy samples are viable for assessing the adiposity index. The need for a standardized method of blubber collection during necropsy was also proposed, as factors such as how the material was preserved were decisive for sample quality. This study should contribute to marine fauna monitoring and research institutions, optimizing the use of collected materials by refining sample collection techniques during necropsies.
Strandings of marine mammal carcasses are sources of valuable information about the general biology of species, including their population health, by highlighting factors such as diseases and anthropogenic threats. However, not all stranded specimens are suitable for analysis, as the availability of some types of data depends on the level of decomposition of the carcasses. One of these types of data is the nutritional status, which depends on structural and chemical integrity of the body. Highly decomposed carcasses lose a large part of their tissue and biochemical properties, making it difficult to assess the individual's nutritional level. Still, some of these properties may be sufficiently intact for analysis, such as cellular structure. In these cases, methodologies based on histological examination, such as the adiposity index, can be used for pre-death nutritional diagnosis of individuals. This study aimed to test the applicability of the adiposity index methodology for different levels of decomposition (CODE2, CODE3 and CODE4) of blubber from carcasses of humpback whales, Megaptera novaeangliae, (Borowski, 1781). Samples collected from stranded carcasses were analyzed histologically to test cellular integrity. Different levels of preservation were observed, from structurally intact adipocytes to slightly to highly deformed cells. Samples with good levels of cellular preservation could be observed for all CODEs, including two CODE4 samples. Well-preserved tissues from necropsy samples are viable for assessing the adiposity index. The need for a standardized method of blubber collection during necropsy was also proposed, as factors such as how the material was preserved were decisive for sample quality. This study should contribute to marine fauna monitoring and research institutions, optimizing the use of collected materials by refining sample collection techniques during necropsies.
Descrição
Citação
MADUREIRA, Lara Bennati. Aplicabilidade do Índice de Adiposidade para material de necropsia de baleias-jubarte (Megaptera novaeangliae)(Borowski, 1781). 2024. 95 f. Dissertação (Mestrado em Biodiversidade Marinha e Costeira) - Universidade Federal de São Paulo, Instituto do Mar, Santos, 2024.