Summary

Olfaction is a chemical sense present not only in mammals, insects, and other terrestrial animals, but also in crustaceans, most of which are aquatic. Crustaceans use olfaction for detecting and responding in appropriate ways to chemicals relevant to most ecological contexts, including: environmental cues indicating quality of food, habitat, and location; interspecies cues indicating presence of predators and competitors; and intraspecific signals indicating social status of conspecifics and presence of possible mating partners. Olfaction is only one of the chemical senses of crustaceans, being distinguished based on anatomical and functional features of the sensory neurons detecting the chemicals and the pathways within the central nervous system that processes this information.