Alterations on growth and gill morphology of Danio rerio (Pisces, Ciprinidae) exposed to the toxic sediments

Renata Fracácio, Nelsy Fenerich Verani, Evaldo Luiz Gaeta Espíndola, Odete Rocha, Odila Rigolin-Sá, Cássio Arilson Andrade
2003 Brazilian Archives of Biology and Technology  
The objective of this work was to assess the toxicity of sediment samples from six cascade reservoirs in Tietê river system, in São Paulo State, Brazil, through chronic-partial toxicity bioassays with Danio rerio larvae as test-organisms. Histology of gills and biometric measurements were used to determine the existence of toxicity problems. The alterations on gill morphology here detected were considered of first stage (hyperplasia, lamellar junction and excess of mucous cells) in the first
more » ... ls) in the first reservoirs and very slight in the last ones. The biometric analysis pointed to inadequate conditions for the growth of the test-organisms when exposed to the sediment of the rivers and upstream reservoirs and also indicated an improvement of environmental conditions along the system.
doi:10.1590/s1516-89132003000400023 fatcat:t3ouc4ykkvez5atvzqy7wg6bjq