WA9 Ecotoxicology: Endocrine-disrupting Compounds and Their Impacts at the Population, Community, and Ecosystem Levels
Room 12A/B, Level 4
8:00 AM - 12:00 PM, Wednesday, 12 November 2003
Chair: Willingham, Emily ,
(400) Responses of mud snails to sex pheromones: comparison of responses at a low and high imposex site.
Straw, J.1, 2, Rittschof, D.1, 1 Duke University Marine Laboratory, Nicholas School of the Environment, Beaufort, NC 28516, USA2 Wittenberg University Biology Department, Springfield, OH 45501, USA
ABSTRACT- Imposex is a condition characterized by the presence of male secondary sexual characteristics in female snails and is a morphological consequence of sublethal exposure to organotin compounds. Our study quantified the behavioral responses of mud snails to both male and female sex pheromones collected from low (7.5%) and high (59%) imposex sites. Pheromones were generated by soaking individual sexually active snails in sea water and these waters were used in behavioral assays. Individual test snails were placed in the center of rings of odor comprised of sea water, male or female pheromones. Snail responses upon contact with the rings were recorded. Snails responded by moving directly through the ring, or by turning and following. Gender and imposex status were determined for each snail after the assay. Between 15 and 20% of females from the low imposex site followed rings of sea water and female pheromone while over 65% of females followed male pheromone. Between 15 and 28% of males from the low imposex site followed sea water and male pheromone while over 70% of males followed female pheromone. This strong sexual dimorphism in responses to pheromones was absent at the high imposex site. The responses to male and female pheromones by high imposex site snails were between 40 and 50% for morphological males, females and imposex snails. Thus snails collected from the high imposex site were behaviorally compromised. No reproducing snails were found at the high imposex site.
Key words: Imposex, Sex Pheromones, Endocrine Disruption, Behavior