Poecilia reticulata as a valuable biological indicator of endocrine disruption

Natural and man-made compounds that interfere with the endocrine system activity are termed endocrine disruptors (ED). Endocrine disruptors may induce either hormone agonist or hormone antagonist effects in human and wildlife by interference with the biosynthesis and biological action of endogenous hormones. The biological response of an organism exposed to an ED which is able to determine quantifiable alterations at the molecular, cellular or physiological level, represents a potential biomarker of exposure to ED. In vertebrates, the mechanisms and metabolic pathways modulated by hormones are genetically conserved. Therefore, endocrine disruption induced by a chemical compound in a taxon will, presumably, result in similar effects in other species. In view of the easy breeding and keeping facilities, their rapid reproduction rate, the short time interval between generations and their ecological relevance, a series of fish species are studied as biological indicators. Several toxicological tests are elaborated in these species, testing for endocrine-disrupting effects of chemical compounds. Some of these fish are members of the family Poeciliidae and particularly important is Poecilia reticulata.