Ecdysteroid Responses of Estuarine Crustaceans Exposed Through Complete Larval Development to Juvenile Hormone Agonist Insecticides

Fenoxycarb and pyriproxyfen are insecticides that gain their toxicity by specifically acting as insect juvenile hormone agonists (JHA), and so are endocrine disruptors by design and effectively prevent larvae from maturing into adults. Efforts to assess the environmental effects of JHAs on nontarget populations of invertebrates have resulted in the utilization of several established estuarine crustacean models. This work was conducted to test the hypothesis that the mortality, inhibition of development and decreased fecundity reported previously in these animals from JHA exposure coincides with abnormal circulating titers of ecdysteroids. Gravid female grass shrimp (Palaemonetes pugio) and mud crabs (Rhithropanopeus harrisii), species with different developmental plasticity and JHA tolerances, were collected and held at wet lab conditions (20 ppt salinity, 25°C) until larval release. Larvae were collected