Meeting Abstract
What affects a sponge, what does it perceive and how does it detect and respond to these stimuli? Sponges are generally thought of as simple, but the array of stimuli they perceive and range of mechanisms of response are probably as diverse as the types of sponges that are known. Sponge larvae respond to light but opsins are not used, nor is there a common photoreceptor molecule or mechanism used across sponge groups. Other better-known cues are gravity and chemicals (e.g. molecules in algae or in other sponges or invertebrate symbionts). Adult sponges appear static but are in fact quite twitchy in their own time frame and one less studied stimulus may be change in pressure. The sensors for these cues as far as we know are individual cells, and these most likely act as independent effectors, and generate a whole body reaction by the global reach of the stimulus to all parts of the animal, except in the case of electrical signalling in Hexactinellida. Most surprising so far is that the molecular basis of all these systems appears to be as varied as the cell types and coordination mechanisms seen in sensory systems. This talk will examine examples of form, function, and their molecular basis across Calcarea, Demospongiae and Hexactinellida.
