Maria José de Arruda Campos Rocha Passos

EROD activity and genotoxicity in the seabob shrimp Xiphopenaeus kroyeri exposed to benzo[a]pyrene (BaP) concentrations

Seabob shrimp Xiphopenaeus kroyeri is a marine species that lives in shallow waters of coastal environments, often impacted by polycyclic aromatic hydrocarbons (PAH) pollution. In the present study, seabob shrimp were exposed for 96 h to benzo[a]pyrene (BaP) at the nominal concentrations of 100, 200, 400 and 800 microg-L(-1). Animals of the control groups were exposed either to clean water or to the BaP-carrier (DMSO). At the end of the exposures, muscle tissues were sampled for BaP uptake assessment and hepatopancreas and hemolymph for EROD enzyme activity and hemocytes DNA damage, respectively. EROD activity and DNA damage increased significantly as a function of BaP exposure concentrations. Significant correlations between BaP uptake and both EROD activity and DNA damage suggest that they can be used as suitable tools for integrated levels of study on the biomarkers of PAH exposure.

Karyotypes of three species of marine catfishes from Brazil

Os cromossomos de 3 especies de peixes da familia Ariidae - Netuma barba, Genidens genidens e Arius parkeri - foram estudados apos coloracao convencional com Giemsa. As tres especies apresentaram numero modal diploide de 2n = 56. O cariotipo de N. barba compreende 18 pares de cromossomos metacentricos (m), 18 submetacentricos (sm), 18 subtelocentricos (st) e 2 telocentricos (t); o de G. genidens compreende 12 pares m, 20 sm, 20 st e 41; o de A.parkeri compreende 16 m, 16 sm, 22 st e 2 t. Os resultados obtidos sao comparados entre si e com os de outros ariideos encontrados na literatura.

Preliminary study on chromosomes of Antarctic krill, Euphausia superba Dana

SummaryMeiotic chromosomes of antarctic krill, Euphausia superba Dana, collected at Admiralty Bay, are described and the method used to obtain this genetic material is reported. Forty seven dividing meiotic nuclei at diakinesis and metaphase I from seminal glands of four males were examined, all with n= 17 bivalents. The results were compared with those obtained by other workers using krill specimens from the opposite side of the Antarctic continent and apparent differences in chromosome numbers were observed. Possible reasons for these differences and the potential for using cytogenetic techniques to study populations of krill are discussed.

The karyotype of cathorops sp, a marine catfish from brazil

Foram realizados estudos cromossomicos em 25 especimens de Cathorops sp pelo metodo de air-drying. O numero modal diploide encontrado foi de 54 cromossomos sendo 1 par m + sm, 6 pares m, 6 pares sm e 14 pares st. Os resultados sao comparados com dados da literatura referentes a cromossomos de outros ariideos, principalmente de Ariopsis felis e Arius dussumieri.

Assessment of trophic transfer of benzo(a)pyrene genotoxicity from the post-larval pink shrimp F. brasiliensis to the juvenile Florida pompano T. carolinus.

In the present study, the polycyclic aromatic hydrocarbon (PAH) genotoxicity was investigated in a one-step predator-prey relationship with the trophic-related marine species. Florida pompanos were fed for 5 and 10 days with pink shrimp post larvae previously exposed to benzo(a)pyrene (BaP) concentrations. Parent BaP body burden was measured in samples of Farfantepenaeus brasiliensis. BaP metabolites were determined in bile samples of Trachinotus carolinus and DNA damage was assessed through the comet and erythrocyte nuclear abnormalities (ENAs) assays in fish erythrocytes. BaP body burden increased significantly with the PAH concentration in pink shrimp PLs as well as the fish bile BaP metabolites. Both, comet and ENAs assays indicated significant increase on erythrocyte DNA damage of Florida pompanos fed with BaP-exposed pink shrimp on both feeding periods. The trophic route of BaP genotoxicity is discussed as well as the PAH biotransformation as the inducing mechanism for the DNA damages observed.

Karyotypes of Two Antarctic Fishes, Notothenia gibberifrons and Notothenia coriiceps neglecta

The chromosomes of two species of Antarctic fishes,Notothenia (Gobionotothen) gibberifrons andNotothenia (Notothenia) coriiceps neglecta, were prepared by the air-drying method at the Polish Antarctic Station “Henryk Arctowski” during the austral summer 1984–1985. ForN. (G.) gibberifrons the diploid number is2n = 46 consisting of 2 metacentric (m) pairs, 1 submetacentric (sm) pair and 20 telocentric (t) or subtelocentric (st) pairs. ForN. (N.) coriiceps neglecta the diploid number is 2n = 22 consisting of 9 m pairs, 1 sm pair and 1st pair. Some aspects of karyological evolution of these fishes are discussed.

Estudo eletroforético sobre a estrutura populacional do krill, Euphausia superba Dana, na região da Passagem Drake-Estreito de Bransfield - oeste da Península Antártica

Foram analisadas amostras de krill, Euphausia superba, coletadas em 18 estacoes na regiao da Passagem Drake-Estreito de Bransfield-oeste da Peninsula Antartica para estudar as variacoes geneticas atraves de eletroforese de enzimas em gel de poliacrilamida. Dezenove loci enzimaticos foram analisados, dos quais quatorze (73,6%) apresentam variacoes alelicas. Cinco dos loci polimorficos apresentam alelos nulos. A heterozigosidade media varia de 0,129-0,157 dependendo da localidade. Nao foram observadas, no entanto, diferencas relacionadas ao sexo e ao tamanho do animal A conformidade de distribuicao de fenotipos em relacao ao equilibrio de Hardy-Weinberg foi encontrada em todos os loci em todas as estacoes, exceto Aph-1 das estacoes 8 e 18, Est-1 das estacoes 9 e 11 e Mdh-1 da estacao 18. As analises de distribuicao de alelos indicam a homogeneidade entre todas as amostras coletadas em localidades diferentes. A distância genetica entre as amostras varia de 0,000 - 0,002. Os resultados sugerem que os individuos de todas as amostras coletadas em todas as estacoes, pertencem a uma unica populacao com acasalamento ao acaso. A contribuicao de fatores fisicos e biologicos na homogeneidade do krill na regiao e a necessidade de um estudo mais detalhado, utilizando nao somente a eletroforese mas tambem outros metodos, foram discutidas.

Nota sobre o transporte de krill (Euphausia superba Dana) vivo da Antártica para o Brasil

E apresentado nesta nota experimento sobre o transporte do krill vivo da Antartica para o Brasil, realizado durante a V Expedicao Brasileira a Antartica, verao 1986-1987. O sistema de aquario utilizado e a mortalidade do krill em funcao do tempo e de outros eventos durante o experimento sao descritos. A importância deste experimento para o desenvolvimento do estudo experimental do krill e discutida.