Reproductive aspects of zebrafish, Danio rerio, exposed to sublethal doses of deltamethrin

Abstract

The deltamethrin is listed by the
Environmental Protection Agency of the United States
(USEPA) as a possible endocrine disruptor, being able
to interfere in the reproductive system. It is a synthetic
pyrethroid, with potent insecticide action, relatively low
toxicity in mammals and limited persistence in the
environment, but high toxic to aquatic organisms. It is
also used in the human and veterinary medicines for
prophylaxis and treatment of parasitic diseases. The aim
of this study was to evaluate possible endocrine
alterations in the reproduction of the zebrafish (Danio
rerio) following the protocol of USEPA (2002). The fish
were exposed to sublethal concentrations of deltamethrin
(6 µg/L and 10 µg/L of the technical deltamethrin) and
acetone, used as solvent, during 14 days. Parameters
as number of eggs, hatching, size and histology of the
gonads were evaluated. It was not observed any
significant difference of the evaluated parameters among
the groups. The deltamethrin didnt alter the reproduction
of the zebrafish. In the present study the progeny was
not evaluated, because was not included in the used
protocol. However, endocrine disruptor substances can
affect the neuroendocrine reproductive system and the
alterations can appear in the progenitors or in the
progeny in different stages of the development.