Expert: Walter Hintz - 12/10/2011

Question
Explain how the structure of the digestive tract in different invertebrate groups affects the size of the organisms they can eat.

Answer
This is a strange question Mac. The structure of the digestive tract does not affect the size of the prey. The size of the organism determines the ability of the predator to consume it. Invertebrates without a digestive tract like Echinoderms and Cnideria are limited by the size of the prey they can capture. Size is not a factor in filter feeders. This kind of leaves us with the worms and cephalopod mollusks. The cephalopods bite of chunks of the prey and worms take in small bits of food