Chemical cues hold considerable promise for manipulating behavior in vertebrates, provided we understand an animal's natural history, biology, and behavior well. However, the development of chemical attractants, stimulants, inhibitors, and repellents for vertebrates has progressed rather slowly for several reasons. First, chemical stimulus and behavior are not connected as rigidly as in insects, for example. Second, the same stimulus may elicit different behaviors, depending on the state of the recipient and the context. Third, chemical cues often are rather complex mixtures of compounds. Fourth, learning, especially early experience plays a major role in vertebrate, notably mammalian behavior. Finally, many behaviors are modulated by several sensory modalities so that chemical stimuli alone trigger only incomplete responses at best.

Fish

The desire for improved techniques in fishing, aquaculture, and limnological management motivates much of the current basic work in the chemical ecology of fish.

Chemical imprinting

Hatcheries raise fish and release them in lakes and rivers on a large scale. Some species such as salmon imprint early in life on the odor of their home stream. Cohosalmon imprint when just over a year old (smolt stage), and sockeye salmon even earlier, right after hatching. Coho salmon prepare to migrate from rivers to the ocean as smolt. Proper imprinting ensures their return as adults to the home stream in order to spawn.