Meeting Abstract

S5.2  Tuesday, Jan. 5  Sponge regeneration in ecological context WULFF, Janie; Florida State University wulff@bio.fsu.edu

Creative application of new imaging and molecular techniques to sponge larval development and a variety of sub-organismal levels in adult sponges has recently demonstrated greater potential for integration and co-ordination of developmental and physiological responses within individuals than had previously been imagined (e.g., Leys, et al., 2009. ICB 49:167-177, and references therein). Nevertheless, by comparison with other metazoans, adult sponges are structurally simple and homogeneous. Rather than being a liability, simple homogeneous design may allow sponges to regenerate, reorganize and reorient, and propagate asexually to a greater extent than other animals; and the resulting morphological flexibility may contribute significantly to the continued success of sponges. Comparisons among sponge species in how effectively they recovered after damage by a hurricane revealed an inverse relationship between resistance to damage and recovery from damage, suggesting the possibility of trade-offs between traits that promote regeneration and traits that prevent the need for regeneration. Data accumulated from experiments and long-term monitoring of Caribbean sponges typical of coral reefs, seagrass meadows, and mangrove prop roots evaluate sponge regeneration in the contexts of partial mortality due to consumption by predators (fish, starfish, nudibranchs), physical disturbance, disease, and smothering by neighbors (colonial ascidians, other sponges). Fragment generation and reorientation experiments demonstrate differences in regeneration capacities of different portions of a sponge individual under some circumstances. As frequencies of different sources of partial mortality change (e.g., fewer predators), and the contexts for evaluating the adaptive significance of regeneration change (e.g., increasingly obstructed recruitment surfaces), variation in regeneration capabilities may play a key role in shifting the balance for and against particular sponge species.