Ecological Complexity of Sponge-Microbe Interactions
Dr. Robert Thacker
Stony Brook University
Marine sponges have successfully expanded across diverse ecological niches around the globe. Pioneering work attributed this success to both a well-developed aquiferous system that allowed for efficient filter feeding on suspended organic matter and the presence of microbial symbionts that can supplement host heterotrophic feeding with photosynthate or dissolved organic carbon. We now know that sponge-microbe interactions are host-specific, highly nuanced, and provide diverse nutritional benefits to the host sponge. Despite these advances in the field, many current hypotheses pertaining to the evolution of these interactions are overly generalized; these over-simplifications limit our understanding of the evolutionary processes shaping these symbioses and how they contribute to the ecological success of sponges on modern coral reefs. This talk will examine how contemporary work has challenged early hypotheses about the nature of sponge-microbe interactions, focusing on the diversity and specificity of sponge microbiomes and their contributions to host fitness. The evolutionary pressures shaping these interactions are more complex than originally expected, with influences from both external (nutrient limitation and competition) and internal (fitness trade-offs and evolutionary constraints) factors.