Specimens of Serrapinnus piaba were collected monthly from April 2001 to April 2002 in the rio Ceará Mirim, Rio Grande do Norte State, Brazil. The reproductive period, determined through the monthly variation of the gonadosomatic index (GSI) and maturation stages, occurred from January to April. Non-parametric Spearman test was performed in order to test correlation of monthly GSI variation in males and females with water temperature, rainfall and day length. Rainfall and Temperature were correlated with GSI variation in females only and day length showed a negative correlation with GSI variation of males only. It was verified the presence of hooks on the anal fin of mature and maturing males along all the period of study. The absolute fecundity mean was 441 (±178.08) oocytes, determined by the number of yolky oocytes counted in 27 mature female gonads. The relative fecundity, estimated by the number of yolky oocytes divided by milligram of total body weight was 0.74 (± 0.19). Espécimes de Serrapinnus piaba foram coletados mensalmente de abril de 2001 a abril de 2002, no rio Ceará Mirim, Rio Grande do Norte, Brasil. O período reprodutivo, determinado através da variação mensal do índice gonadossomático (IGS) e estádios de maturação gonadal, ocorreu de janeiro a abril. Utilizou-se o teste não paramétrico de Spearman para testar a correlação entre a variação mensal do IGS de machos e fêmeas com temperatura da água, pluviosidade e fotoperíodo. A correlação entre IGS e pluviosidade e IGS e temperatura foi significativa para as fêmeas somente. A correlação entre o fotoperíodo e IGS foi significativa e negativa somente para os machos. Verificou-se a presença de ganchos na nadadeira anal de machos em maturação e maduros durante todo o período de estudo. A fecundidade absoluta média, estimada através da contagem dos ovócitos vitelinados de 27 fêmeas maduras, foi de 441 (±178.08) ovócitos. A fecundidade relativa, estimada através do número de ovócitos vitelinados produzidos por mg de peso, foi de 0.74 (± 0.19) ovócitos por miligrama de peso total
The coal industry may generate acid mine drainage (AMD) and mining wastes, which may adversely affect the quality of the environment. In this study we propose the use of this waste in the removal of acidity and metal ions, as well as in the reduction of the toxicity of AMD. A physico-chemical analysis of the waste shows the presence of mainly SiO2, Al2O3 and Fe2O3 and a superficial area of 4.316 m2 g(-1). The treatment of AMD with the waste resulted in an increase in pH from 2.6 to 7.8 and removed 100% of the Al (III), 100% of the Fe (III) and 89% of the Mn (II). We also observed that the high toxicity of the AMD towards Daphnia magna (LC50 = 3.68%) and Artemia sp. (LC50 = 4.97%) was completely eliminated after treatment with the waste. The data obtained allow us to propose that the waste can be used in the treatment of AMD, providing an economic use for the waste.
The objective of this research is to verify the genotoxicity caused by pesticides used in irrigated rice cultures in Araranguá city in the southern Brazilian state of Santa Catarina through the alkaline comet assay in peripheral blood of Geophagus brasiliensis and to analyze the toxicity of the water using Daphnia magna as sentinel organism. Three collections of water and fish were made in the main rice ditch, and one collection for the control group was taken in the Araranguá River. The toxicity test with D. magna and the comet assay followed protocols previously described. The toxicity factor for the control group and collections 1, 2, and 3 were, respectively, 0, 1, 0, and 2. The comet assay demonstrated significant differences just in collection 2, in comparison to the control group and collections 1 and 3. These results, despite significant statistical data, are not a biological problem, because the values were not so large but serve to warn of a possible disruption of the balance in this environment system.
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