Meeting Abstract

P3.53  Friday, Jan. 6  Quantitative genetic analysis of acquisition of metamorphic competence in Hydroides elegans, and consequences for larval dispersal HOLM, E.R.*; ANIL, A.C.; HADFIELD, M.G.; Naval Surface Warfare Center, Carderock Division; National Institute of Oceanography, Goa, INDIA; Kewalo Marine Laboratory, University of Hawaii

Dispersal of planktonic larvae of sessile marine invertebrates is the product of physical processes acting on the larvae while they are in the water column, larval behavioral responses affecting exposure to those processes, and the length of time the physical processes and behaviors have to act. Minimum time in the plankton is set by the age at onset of metamorphic competence. We used a sib analysis to quantify genetic and maternal components of variance in the timing of acquisition of competence in larvae of the serpulid polychaete Hydroides elegans. After 4 and 5 days of development, larvae from each cross were challenged with a metamorphosis-inducing biofilm. We considered the proportion of larvae responding to the biofilm by metamorphosing as equivalent to the proportion of larvae that had attained metamorphic competence. Additive genetic and maternal environmental effects significantly influenced acquisition of competence for 4-day old larvae. In contrast, the proportion of competent larvae after 5 days of development exhibited a significant additive genetic effect, but no maternal effect. These results suggest the presence in H. elegans of substantial genetic variation in the timing of acquisition of metamorphic competence, and thus the potential for larval dispersal.