Meeting Abstract

P1.27  Wednesday, Jan. 4  Effect of lipophilic compounds on the early development of microcrustaceans HUTCHISON, ER*; GUNDERSON, MD; MILANOWSKI, AC; COVI, JA; UWSP; UWSP; UWSP; UWSP

Micro-crustacean embryos may be more susceptible to lipophilic toxicants than the adults that are currently used as a standard for environmental assessment of toxicity. Most invertebrate embryos possess large stores of lipids in the form of lipid granules. These granules present a location for the bioaccumulation of lipophilic compounds that could interfere with metabolic or developmental processes. Because these embryos remain metabolically and developmentally arrested for years to centuries, pollutant levels that are permissive for short-lived adults could negatively impact embryos during recruitment from dormancy. The implications of this are profound. Exposure of these genetic storehouses to lipophilic toxicants could drastically, and irreversibly, reduce genetic variation in isolated populations. Individuals and/or species with the greatest capacity for embryonic dormancy would be most affected. As a test of the bioaccumulation hypothesis, embryos of the brine shrimp, Artemia franciscana, were exposed to common toxicants found in freshwater and coastal marine habitats (rotenone and crude oil). Hatching success was monitored for intact and dechorionated embryos after acute and prolonged exposures to lipophilic toxicants. Hatching of dechorionated embryos was completely abrogated by acute and chronic exposures to rotenone. Chronic exposure of dechorionated embryos to crude oil decreased hatching success, but exposure to volatile compounds released by the burning of crude oil had no effect. The data presented here suggest that invertebrate embryos possessing only cuticular barriers are susceptible to lipophilic toxicants. Given the broad distribution of invertebrates that rely on dormant embryos for survival of adverse environmental conditions, and their essential role in diverse ecosystems, it is imperative that we understand the effects that toxicants have on embryo viability.