ABSTRACT
In this study we report the hematological, biochemical and hormonal parameters in a juvenile male Amazonian manatee measured before transport, immediately after transport, and during adaptation to a new facility. The animal was transported from Manaus, Amazonas, Brazil, to São Paulo, São Paulo, Brazil, (2,733 km) within 6 hours. Among all blood parameters analyzed, we observed obvious neutrophilia, lymphopenia, and increases in the neutrophil/lymphocyte ratio and serum glucose and aspartate aminotransferase (AST) levels, but these parameters subsequently returned to normal. These results suggest that transport and changes in the environment are temporary stressful events for Amazonian manatees. We, therefore, recommend monitoring the hematological and biochemical parameters before and after translocation to minimize the effects of handling stressors in this species
ABSTRACT
Livers of thirty specimens of Astyanax altiparanae obtained from a commercial fish farm were subjected to light and transmission electron microscopy, in order to describe the hepatic parenchyma and the intrahepatic exocrine pancreatic tissue. Anatomically, the liver showed only three hepatic lobes. Histological analysis demonstrated that the hepatocytes were spread out as anastomotic cords, arranged in two cellular layers and surrounded by sinusoids. The intrahepatic exocrine pancreatic tissue exhibited an acinar arrangement and was diffused in the hepatic parenchyma. Ultrastructural analysis showed that the hepatocytes had a rounded nucleus and a rough endoplasmatic reticulum, with a parallel disposition to the nuclear membrane. The exocrine pancreatic cells showed secretion granules at the apical portion, and the rough endosplasmatic reticulum was concentrically distributed
Fígados de 30 exemplares de Astyanax altiparanae, obtidos de pesqueiros, foram submetidos à microscopia de luz e à microscopia eletrônica de transmissão para descrição do parênquima hepático e do tecido pancreático exócrino intra-hepático. Anatomicamente, o fígado apresenta somente três lobos hepáticos. A análise histológica demonstra que os hepatócitos se encontram arranjados na forma de cordões anastomosados, dispostos em duas camadas celulares, sendo que estes estão cercados por sinusóides. O tecido pancreático exócrino intra-hepático apresenta arranjo acinar difuso pelo parênquima hepático. A análise ultraestrutural demonstra que os hepatócitos possuem um núcleo arredondado e retículo endoplasmático rugoso, com disposição paralela à membrana nuclear. As células pancreáticas exócrinas apresentam grânulos de secreção na porção apical e retículo endoplasmático rugoso com distribuição concêntrica
ABSTRACT
The lethal concentration of 50% (LC (I) 50-96h) and the histopathologic effects of diquat herbicide on Nile tilapia (Oreochromis niloticus) fish were evaluated in three experiments. The fishes were exposed to concentrations of 0, 25, 30, 35, 40, 45, 50, 55 and 60 mg diquat L-1, and gill and liver histology were evaluated in the surviving fishes. The estimated LC (I) (50-96h) of diquat was 37.28 mg L-1, with lower limits of 33.12 mg L-1 and upper limits of 41.44 mg L-1. In the treatment with 30, 35 and 40 mg L-1, signs of apical fusion of the secondary lamellae were observed; with 45 and 50 mg L-1, congestion of the primary lamellae was observed; in the treatment with 55 mg L-1, congestion of blood vessels on secondary lamellae took place. The livers of fishes in treatments with 0, 25, 30 and 35 mg L-1 showed cordonal organization of hepatocytes. In the treatments with 40 and 45 mg L-1, hypertrophy of hepatocytes took place; with 50 and 55 mg L-1, cell fusion and the presence of vacuoles inside hepatocytes were observed. Diquat presented low risk of toxicity for Nile tilapia, as the more severe histopathologic alterations occurred only in higher concentrations
A concentração letal 50% e os efeitos histopatológicos do herbicida diquat para a tilápia nilótica (Oreochromis niloticus) foram avaliados em três experimentos. Os peixes foram expostos às concentrações de 0; 25; 30; 35; 40; 45; 50; 55; e 60 mg de diquat L-1 e a histologia da brânquia e do fígado foi avaliada nos peixes sobreviventes. A CL (I) 50-96h do diquat estimada foi de 37,28 mg L-1, com limite inferior de 33,12 mg L-1 e superior de 41,44 mg L-1. No tratamento com 30, 35 e 40 mg L-1, ocorreram início de fusão apical das lamelas secundárias; com 45 e 50 mg L-1 ocorreram congestão nas lamelas primárias e no tratamento com 55 mg L-1, ocorreu congestão sangüínea nas lamelas secundárias. O fígado dos peixes dos tratamentos controle, 30 e 35 mg L-1 estavam com organização cordonal dos hepatócitos. Nos tratamentos com 40 e 45 mg L-1, ocorreram hipertrofia dos hepatócitos; com 50 e 55 mg L-1 ocorreram fusão celular e presença de vacúolos. O diquat apresentou baixo risco de intoxicação à tilápia nilótica e as alterações histopatológicas mais severas ocorreram somente nas concentrações mais elevadas
ABSTRACT
The aim of this study was to analyze the salinity tolerance of pacamã Lophiosilurus alexandri larvae at different ages. The test was conducted in post-hatching-larvae and larvae with 8 and 12 days old post-hatching. Larvae were acclimatized to experimental conditions for 24h, kept in 18 plastic tanks with 1 L at a density of 15 larvae L-1. After this period, larvae were subjected to the salinities: freshwater, 2, 4, 6, 8 and 10 g salt L-1, and observed over a period of 96h. Post-hatching larvae exhibited complete mortality in 6, 8 and 10 g salt L-1. Survival was 100% in freshwater, 2 and 4 g salt L-1 although with the decrease in weight and length values to the salinities of 2 and 4 g salt L-1. The CL(I)50-96h of larvae 8 days old post-hatching was 8.9 g salt L-1. The weight was diminished with the increase in salinity, but no difference was registered in length between the different treatments. Larvae 12 days old post-hatching did not show differences in length and weight. The survival was lower in 8 and 10 g of salt L-1. Larvae 8 and 12 days old post-hatching changed their swimming activity behavior to saline water up to 6 g of salt L-1. Pacamã larvae showed higher tolerance to the different salinities with larval development.
O objetivo deste trabalho foi avaliar a tolerância de larvas de pacamã Lophiosilurus alexandri ao teste agudo de salinidade da água em diferentes idades. Os testes foram realizados em larvas recém-eclodidas, com oito e 12 dias pós-eclosão. As larvas foram aclimatadas às condições experimentais por 24h, sendo estocadas em 18 tanques plásticos de 1 L na densidade de 15 larvas L-1. Após esse período, as larvas foram transferidas para as salinidades: água doce, 2, 4, 6, 8 e 10 g de sal L-1 e observadas durante 96h. Larvas recém- eclodidas apresentaram mortalidade total em 6, 8 e 10 g de sal L-1 e 100% de sobrevivência para água doce, 2 e 4 g de sal L-1; porém, com redução dos valores de peso e comprimento mediante as duas salinidades. Larvas com oito dias pós-eclosão apresentaram CL(I)50-96hde 8,9 g de sal L-1. Para o peso, verificou-se redução gradativa a partir da salinidade de 2 g de sal L-1, mas sem diferenças para o comprimento das larvas entre os tratamentos. Para as larvas com 12 dias pós-eclosão, não se registraram diferenças no comprimento e peso e a sobrevivência foi menor a 8 e 10 g de sal L-1. Larvas com oito e 12 dias pós-eclosão tiveram alterações no comportamento natatório em salinidades superiores a 6 g de sal L-1. Larvas de pacamã apresentaram maior tolerância às diferentes salinidades da água com o desenvolvimento ontogenético.