Mysid crustaceans as standard models for the screening and testing of endocrine-disrupting chemicals

Abstract

Investigative efforts into the potential endocrine-disrupting effects of chemicals have mainly concentrated on vertebrates, with significantly less attention paid to understanding potential endocrine disruption in the invertebrates. Given that invertebrates account for at least 95% of all known animal species and are critical to ecosystem structure and function, it remains essential to close this gap in knowledge and research. The lack of progress regarding endocrine disruption in invertebrates is still largely due to: (1) our ignorance of mode-of-action, physiological control, and hormone structure and function in invertebrates; (2) lack of a standardized invertebrate assay; (3) the irrelevance to most invertebrates of the proposed activity-based biological indicators for endocrine disruptor exposure (androgen, estrogen and thyroid); (4) limited field studies. Past and ongoing research efforts using the standard invertebrate toxicity test model, the mysid shrimp, have aimed at addressing some of these issues. The present review serves as an update to a previous publication on the use of mysid shrimp for the evaluation of endocrine disruptors (Verslycke et al., 2004a). It summarizes recent investigative efforts that have significantly advanced our understanding of invertebrate-specific endocrine toxicity, population modeling, field studies, and transgeneration standard test development using the mysid model.

Ovarian cycle and embryonic development in Gammarus fossarum: Application for reproductive toxicity assessment

“…Finally, in the amphipod Melita plumulosa, Chung et al [15] have recently shown that a significant difference in two life-history traits (female length and fertility) could be observed between organisms from polluted and unpolluted waterways. To date, no specific ED biomolecular markers are available in the crustaceans currently used in aquatic ecotoxicology [17,[33][34][35]. This can be attributed for the most part to the shortage of fundamental knowledge of their endocrine systems.…”

“…Moreover, given the phylogenetic distance between species and the molecular divergence through bilaterian animal evolution, ED biomarkers available in aquatic vertebrates cannot be easily and/or should not directly be applied to the majority of invertebrates, because these two groups belong to two distinct ancient lineages of animals (deuterostomes vs protostomes). Consequently, as recommended by Verslycke et al [34], bioassays should be developed to measure the impact of physicochemical stressors on various physiological process under endocrine regulation, such as growth, molting, embryonic development, vitellogenesis, and fertility.…”

Mysid population responses to resource limitation differ from those predicted by cohort studies

“…Americamysis bahia (formerly Mysidopsis bahia) is commonly used as a test organism in ecotoxicology (reviewed in Verslycke et al 2007), so substantial effort has been devoted to the standardization of laboratory culturing methods and production of uniformly conditioned individuals (Lussier et al 1988. Individuals are 5 to 10 mm in length (rostrum to telson).…”

Effects of elevated ambient histamine level on survival, growth, sexual maturity and tissue histamine accumulation of the mysis Neomysis awatschensis and Neomysis japonica Nakazawa

“…Estuarine regions are known to be often subjected to intensive discharges of aquaculture effluent water from aquaculture ponds and they are also the sites for aquaculture cage culture. In addition, there has been an increasing interest in using the brackish water mysis as model species for environmental toxicological test Verslycke et al 2007). …”