Influência da qualidade ambiental na biologia reprodutiva de Hoplias malabaricus (BLOCH, 1794) (Characiformes, Erythrinidae)

Abstract

The expansion of industrial and urban activities have changed the quality of rivers and negatively affected the reproductive biology of fish. The objective of this study is to investigate how changes in environmental quality can influence the reproduction of Hoplias malabaricus in Capibaribe river, Pernambuco. The samples were collected from september 2013 to august 2014, in three different parts of the Capibaribe river (CAP 1, CAP 2 and CAP 3, in the city Paudalho, São Lourenço da Mata and Recife, respectively), totaling 67 females and 51 males. Were realized analysis of maturational stages, sex ratio, reproductive activity index (IAR), gonadosomatic index (IGS) and hepatosomatic (IHS). To determine the environmental quality we used a rapid assessment protocol (PAR). Furthermore, were evaluated the water temperature, pH, conductivity, dissolved oxygen, biochemical oxygen demand, total solids, total suspended solids, color and fecal coliforms. It was made a spearman correlation matrix to correlate reproduction of biological data (IGS, IHS) with environmental factors (water quality). The PAR indicated that CAP 3 is classified as a "preseverd" environment, however, CAP 1 e CAP 2 were classified as "altered" environments. The frequency of the reproductive cycle stage of H. malabaricus females indicated mature stages for almost every quarter in the evaluated sample points. The sex ratio did not indicate significant differences in the evaluated points. The IAR indicated that there was a higher reproductive activity in CAP 3, followed by CAP 1 and CAP 2. Correlation analysis of environmental and reproductive parameters for the CAP 1 point indicated correlation of IHS with the conductivity and turbidity. In CAP 2 the IGS showed negative correlation with rainfall and turbidity. The IHS analysis for this point was obtained high correlation with temperature. For CAP 3, correlations were obtained between the IHS and Total Coliform. Therefore, it is concluded that H. malabaricus can reproduce against different levels of environmental quality, which can probably be related to its high resistance to anthropogenic environments.