Parasitos metazoários de cetáceos da costa nordeste do Brasil. / Metazoan parasites of cetaceans of the northeast coast of Brazil.

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

03/12/2009

RESUMO

Cetaceans are parasitized by a wide diversity of endo and ectoparasites in various tissues, organs and cavities. Some species are related to causes of strandings and mortality of dolphins and whales. In addition to knowledge about the pathological effects of these organisms, their importance in ecological and evolutionary studies is highlighted. The parasitic fauna of cetaceans in Brazil is still little known. Only few studies have been conducted in a systematic way using standardized methods, occurring mainly in the south and southeast regions. The present study aims to identify the metazoan parasites that occur in cetaceans in the northeast of Brazil. Parasites were collected from cetaceans rescued from the states of Ceará to Bahia, including the archipelago of Fernando de Noronha, between 1994 to 2009. Fourteen species of cetaceans were evaluated: Sotalia guianensis (n = 21), Stenella clymene (n = 16), Stenella longirostris (n = 13), Megaptera novaeangliae (n = 6), Peponocephala electra (n = 5), Steno bredanensis ( n = 4), Kogia breviceps (n = 4), Kogia sima (n = 3), Globicephala macrorhynchus (n = 3), Stenella coeruleoalba (n = 2), Stenella sp. (n = 2), Tursiops truncatus (n = 2), Physeter macrocephalus (n = 2), Lagenodelphis hosei (n = 2) and Stenella frontalis (n = 1). Samples were collected during the necropsy of 82 animals and from the feces or regurgitate of 4 living S. longirostris in their natural environment The parasites were fixed and preserved and 70% alcohol or AFA, cleared in phenol, stained with hematoxylin (flatworms and acanthocephalans) and mounted on slides for morphological identification under an optical microscope. In the evaluated animals, 11 species and 8 genera of metazoan endo and ectoparasites were identified: the nematodes Halocercus brasiliensis (lung), H. Kleineberg (lung), Stenurus globicephalae (inner ear), Halocercus sp. (lung), Anisakis sp. (stomach) and Crassicauda sp. (muscles and penis); the cestodes Phyllobothrium delphini (blubber), Monorygma grimaldii (abdominal cavity), Scolex pleuronectis (liver), Strobicephalus triangularis (intestine), Tetrabothrius forsteri (intestine), Tetrabothrius sp. (intestine), Trigonocotyle sp. (intestine) and Diphyllobothrium sp. (gut); the digenean Campula sp. (liver); the acanthocephalan Bolbosoma sp. (stomach and intestine), and crustaceans Cyamus boopis (skin, callosities), Syncyamus pseudorcae (skin, mouth and blowhole) and Xenobalanus globicipitis (caudal fin). The nematodes were the most prevalent parasite group (82.55%), followed by cestodes (34.88%), crustaceans (15.11%), acanthocephalans (4.65%) and digeneans (1.16%). Among the most prevalent species, the most common were the nematodes Anisakis sp. (61.62%) and Halocercus sp. (26.74%) and the merocercoids P. delphini (20.93%) and M. grimaldii (18.6%). Pathological effects resulting from parasitic infections were observed in some animals, mainly caused by pulmonary, gastric and inner ear nematodes. This study is the first survey of the parasitic fauna of cetaceans rescued in northeast Brazil. The results of this work are new records for the country and increased the occurrence of some parasites to new hosts. The use of standardized methodologies and evaluation of a larger number of animals are essential for studies of host-parasite relationships and their use as biological indicators in the region.

ASSUNTO(S)

cetáceos ectoparasitos endoparasitos comensais reproducao animal cetaceans ectoparasites endoparasites commensals

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