Effect Of Octylphenol (OP) Water Exposure To Sexually Mature Female Mosquitofish,Gambusia Affinis Reproductive Variables

The energy allocation to growth and reproduction,in relation to OP water exposure with different concentrations,was investigated in laboratory experiments with the sexually mature female mosquitofish,Gambusia affinis.4-tert-octylphenol(OP)is an environmental pollutant that has been shown to influence reproduction parameters as well as sexual development and growth.The effects of OP on the life history variables in mature female fish are unknown.Thus,my study investigated the energy allocation between reproduction and somatic growth in sexually mature female mosquitofish exposed to octylphenol(OP)in water for 28 days with 0(control),50 and 100 μg/l concentrations.The results showed that the exposed females devoted less energy in reproduction(reduction in reproduction allocation and embryo fat content as concentration increases)and increased body energy storage(increase in somatic lean weight).Additionally,the results revealed a high number of well-developed fish with undeveloped or regressed ovaries,and the Chi-square test has shown a highly significant association between this condition and OP concentrations,and a condition which might be related to the highest energy devotion in somatic growth compared to reproduction.But still,the mechanism of OP reducing the ovarian development in sexually mature exposed fish is unclear.In conclusion,this study showed that OP increased the energy in body building which may result in obese individuals and the reduction in energy devoted to reproduction,and the elevated number of undeveloped ovary may affect the population with low number of offspring.This study results enforce the point that any stage of life cycle can be affected significantly by EDCs.In a continuous exposure,these results may rise a prediction of the species extinction and the protection of unexposed aquatic environment is needed as well as reducing the use of EDCs and reduce the release of waste water into aquatic environment.Further research is needed to explain the way in which OP exposure regress the ovarian development in sexually mature exposed individuals.