What are the differences in chemoreception in invertebrates and in vertebrates?
Vertebrates detect chemicals using general receptors and two types of specialized receptors, gustatory and olfactory. Many aquatic vertebrates have generalized chemical receptors scattered over their body surface. Vertebrates usually accomplish chemoreception by moving chemically rich air or water into a canal or sac that contains the chemical receptors. Chemoreception is much different in invertebrates than in vertebrates. For example, planarians find food by following chemical gradients in their surroundings. Their simple chemoreceptors are found in pits on their bodies, over which they move water with cilia. Insects have chemoreceptors in their body surface, mouthparts, antennae, forelegs, and, in some cases, the ovipositor. Moths, for example, smell with thousands of sensory hairs on their antennae. About 70 percent of the adult male receptors are made to respond to one molecule called bombkyol, a sex attractant released by females of the species. The molecules enter the tiny pores
