Development of Copepod Nauplii to Copepodites—a Parameter for Chronic Toxicity Including Endocrine Disruption

Abstract

Test compounds including natural hormones, endocrine disrupters, environmentally occurring compounds, and reference compounds were tested for acute toxicity and inhibitory effect on larval development in the copepod Acartia tonsa. Three compounds, 17alpha-ethinylestradiol, p-octylphenol, and tamoxifen, known for their differing effects on the vertebrate estrogen system, were potent inhibitors of naupliar development. Other estrogens, 17beta-estradiol, estrone, and bisphenol A, had little potency. Testosterone and progesterone did not inhibit development, but the antiandrogen flutamide had inhibitory effect. Juvenile hormone III was a potent inhibitor, as was expected based on the literature, whereas 20-hydroxyecdysone had no effect. 3,4-Dichloroaniline was inhibitory on development, whereas other control compounds, potassium dichromate and 3,5-dichlorophenol, did not inhibit development. Six of the 17 test compounds had 50% lethal concentration to 50% effective concentration (EC50) ratios higher than 10. The results suggest that naupliar development, as a parameter, is able to detect hormonal disrupters in addition to other chemicals that have other specific modes of action.

Effects of 4-nonylphenol, fish predation and food availability on survival and life history traits of Daphnia magna straus

“…However, recently it was reported that estrogen receptors are lacking in crustaceans-major constituents of aquatic invertebrates (Thornton et al 2003). In parallel to this observation, estrogen signaling was not associated with steroidal estrogen-induced alterations (17 b-estradiol, diethylstilbestrol, 17a-ethinyl estradiol, estrone) in several orders of the crustacean subphylumranging from cladocerans and copepods to mysids (Baldwin et al 1995;Andersen et al 2001;Segner et al 2003;Ghekiere et al 2006). Therefore, NP is not expected to exert an estrogenic effect in Daphnia.…”

Crustacean endocrine toxicology: a review

“…Steroidal estrogens (17b-estradiol, diethylstilbestrol, 17a-ethinyl estradiol, estrone) have been reported to elicit various effects in crustaceans including altered gonadal development in Amphipoda (Segner et al 2003), decreased fecundity in Branchiopoda (Baldwin et al 1995), inhibition of naupliar development in Maxillopoda (Andersen et al 2001), and reduced vitellin levels in Mysida ). However, effects from chemical exposure in these experiments are reported with no mechanistic support for the involvement of estrogen signaling.…”

Towards an internationally harmonized test method for reproductive and developmental effects of endocrine disrupters in marine copepods

“…Modified from Wollenberger (2005) exposed to natural and synthetic estrogens. In recent years, various studies on copepods have demonstrated that larval development, tightly linked to the molting process, responds very sensitively to a range of chemicals of concern including compounds known or suspected to be endocrine disrupters (Kusk and Petersen 1997;Andersen et al 2001;Brown et al 2003;Marcial et al 2003;Wollenberger et al 2003;Chandler et al 2004;Wollenberger et al 2005). Adverse effect concentrations for development and reproduction determined in these copepod studies were, in most cases, lower than adverse effect concentrations for similar endpoints reported for other crustaceans.…”

“…The test parameter was the copepodite fraction after 6 days of exposure (Kusk and Pedersen 1997). The Acartia test method was further elaborated introducing a fully synthetic media (Kusk and Wollenberger 1999) and applied on a range of natural and synthetic hormones and other potential EDCs (Andersen et al 1999;Andersen et al 2001). The concept was also used to investigate several synthetic musk substances and brominated flame retardants Wollenberger et al 2005).…”