Their largest concern with respect to competition is for rock shelters with other species such as crayfish.
en.wikipedia.org At the aquarium he instituted experiments on the migration of smelts, the habits of the herring, whitebait, crayfish, and other topics.
en.wikipedia.org This is an indication that the behavior is mediated in the brain or the thorax of the crayfish.
en.wikipedia.org It has a diet of small vertebrates, carrion, arthropods, and freshwater crayfish, among other things.
en.wikipedia.org Sub-surface flies are designed to resemble a wide variety of prey including aquatic insect larvae, nymphs and pupae, baitfish, crayfish, leeches, worms, etc.
en.wikipedia.org