Meeting Abstract
P2.37 Tuesday, Jan. 5 Zoochorous dispersal of Symbiodinium by the stoplight Parrotfish Sparisoma viride CASTRO, C.*; SANCHEZ, J.A.; Univ. de los Andes, Bogotá; Univ. de los Andes, Bogotá c.castro55@uniandes.edu.co
Many terrestrial vertebrates have been identified as important zoochorous dispersers of seeds, contributing to the population dynamics and regeneration of plant populations. In the tropical oceans most of coral species reproduce through asymbiotic larvae hence depending on free-living pools of Symbiodinium to their post-larval survival and resilience after disturbances such as bleaching. Then, where do these new symbionts come from? It has been recently found that parrotfish feces, carry viable Symbiodinium cells. The aim of this study was to estimate the extent of the zoochorous dispersal of zooxanthellae (Symbiodinium spp.) by Sparisoma viride in Caribbean reefs. They feed at a rate of 6,95 ± 0,49 bites min-1 in a combined diet of scleractinian corals (12,9%), sponges (7%), macroalgae (23,6%) and filamentous algae on sediments (56,5%). Feces are dispersed in the water column and substrates at a rate of 18 ± 1,69 feces h. Viable symbionts were observed from most feces collected (80 samples) with densities ranging between 22 and 3481 cells ml-1 (2354 ± 1309 cell ml-1) and cultured at the laboratory reaching densities between 8.2 and 24.6 x 103 cells ml-1 suggesting viability after ingestion from fishes. The preliminary results of this study suggest an ecological important role of parrotfishes as a marine zoochorous system for zooxanthellae in coral reef ecosystems, that could facilitate larvae infection and uptake by bleached corals. Although these results help us to understand free-living Symbiodinium populations, questions remain on the life span and survival of symbionts in the environment. Likewise, the dynamics of coral-zooxanthellae symbiosis re-establishment awaits further studies.
