ASPECTOS REPRODUTIVOS DO PEIXE-ZEBRA, Danio rerio, EXPOSTO A DOSES SUBLETAIS DE DELTAMETRINA

The deltamethrin is listed by the Environmental Protection Agency of the United States (USEPA) as a possible endocrine disruptor, being able to interfere in the reproductive system. It is a synthetic pyrethroid, with potent insecticide action, relatively low toxicity in mammals and limited persistence in the environment, but high toxic to aquatic organisms. It is also used in the human and veterinary medicines for prophylaxis and treatment of parasitic diseases. The aim of this study was to evaluate possible endocrine alterations in the reproduction of the zebrafish (Danio rerio) following the protocol of USEPA (2002). The fish were exposed to sublethal concentrations of deltamethrin (6 µg/L and 10 µg/L of the technical deltamethrin) and acetone, used as solvent, during 14 days. Parameters as number of eggs, hatching, size and histology of the gonads were evaluated. It was not observed any significant difference of the evaluated parameters among the groups. The deltamethrin didnt alter the reproduction of the zebrafish. In the present study the progeny was not evaluated, because was not included in the used protocol. However, endocrine disruptor substances can affect the neuroendocrine reproductive system and the alterations can appear in the progenitors or in the progeny in different stages of the development.A deltametrina está listada pela Agência de Proteção Ambiental dos Estados Unidos (USEPA) como possível desregulador endócrino, podendo, portanto, interferir no sistema reprodutivo. É um piretróide sintético, com ação inseticida, toxicidade relativamente baixa para mamíferos e persistência limitada no meio ambiente, mas de alta toxicidade para organismos aquáticos. É também empregada nas medicinas humana e veterinária para profilaxia e tratamento de doenças parasitárias. O objetivo deste estudo foi avaliar possíveis alterações na reprodução do peixe zebra (Danio rerio) seguindo o protocolo da USEPA (2002). Os peixes foram expostos a concentrações subletais de deltametrina (6 µg/L e 10 µg/L) e à acetona (solvente), durante 14 dias. Parâmetros como número de ovos, eclosão, índice gônado-somático e histologia de gônadas foram avaliados. Não foi possível observar nenhuma diferença significativa dos parâmetros avaliados entre os grupos, concluindo-se que a deltametrina não alterou a reprodução da espécie estudada. Neste trabalho a progênie não foi avaliada, pois não fazia parte do protocolo proposto. Porém, as substâncias desreguladoras endócrinas podem atuar afetando o sistema neuroendócrino reprodutivo e estas alterações podem apresentar-se tanto nos progenitores como na progênie em diferentes etapas do desenvolvimento

Evidence of contamination by oil and oil products in the Santos-Sao Vicente estuary, Sao Paulo, Brazil

Different components of the mixed function oxidase (MFO) system and the levels of fluorescent aromatic compounds in bile (FACs) were measured in Cathorops spixii in order to assess the impact of polycyclic aromatic hydrocarbons (PAHs). Fish were sampled in an estuary (Santos/Sao Vicente) with a history of contamination by PAHs, mainly due to the presence of the industrial complex of Cubatao city and of another of low anthropogenic influence (Cananeia) on the Brazilian coast. FACs were higher in fish from the polluted site, and the PAH 5 and 6-ring metabolites were the most frequent - with 14% and 15%, respectively. Levels of the different components of the MFO system showed the same variation profile as the FACs for both estuaries. Therefore, the values found for somatic indexes and biomarkers with data of bile PAH metabolites indicate the presence of organic contaminants, especially in the area subject to the influence of the industrial complex on the Santos/Sao Vicente estuary.CAPES (Brazilian Agency for Science and Technology); Oceanographic Institute of Sao Paulo University; Laboratory of Ecotoxicology and Environmental Chemistry of the University of Algarve; CAPES-PDEE [BEX 2176/07-6]info:eu-repo/semantics/publishedVersio

Reproductive tactics used by the Lambari Astyanax aff. fasciatus in three water supply reservoirs in the same geographic region of the upper Iguaçu River

The species Astyanax aff. fasciatus was investigated as regards differences in reproductive tactics in three reservoirs with different ages (Iraí, Piraquara and Passaúna) located in the same geographic region. The biological material was obtained through monthly collections carried out from july/2006 to june/2007. The average value of the gonadosomatic index (GSI) in Passaúna reservoir was significantly higher in relation to the values obtained in the other reservoirs. Spawning was total in Iraí reservoir and partial in the others. Allometric growth of the species was negative in Iraí reservoir and positive in the others. The highest condition factor value was estimated in Iraí reservoir, followed by Piraquara and Passaúna reservoirs, respectively. Females predominated in all of the reservoirs during the study period. The sex ratio per length class showed, for the three reservoirs, the predominance of males in the smaller length classes. These results verified that the species uses distinct reproductive tactics in the analyzed reservoirs and that these tactics seem to reflect the degree of stabilization of each environment