Meeting Abstract

12.3  Tuesday, Jan. 4  Plasticity in the Design and Attachment Strength of Egg Mass Tethers in Response to Variation in Water Motion CASTRO, D.A.*; PODOLSKY, R.D.; College of Charleston; College of Charleston dacastro1@edisto.cofc.edu

Marine organisms reproduce in a variety of ways, including the deposition of clutches of fertilized eggs. Deposited clutches are potentially at risk of being displaced from their original deposition site by waves or currents. To counter this risk, most species that deposit egg masses have evolved some form of attachment to the substrate, which presents a special challenge in soft sediment habitats. We measured the strength of attachment in egg masses of the black bubble snail Melanochlamys diomedea in response to variation in water motion. To test the hypothesis that egg masses deposited under conditions of higher flow would have more robust tethers and firmer attachments, egg masses and their tethers were measured and attachment strength was recorded with a force gauge at several field sites around San Juan Island, Washington, as well as in a lab experiment that manipulated flow. In general, egg masses laid at sites with relatively higher water motion were attached with greater forces. Similarly, egg masses laid in the lab under higher water motion had higher attachment strengths. ANCOVA revealed a significant effect of site both in the field and when adults were placed under common conditions in the lab, suggesting that adults from different sites produce tethers with different properties. This study demonstrates that adults can manipulate the properties of egg mass attachment structures in relation to the risk of detachment.