JUVENILE 3-SPINED STICKLEBACKS AVOID PARASITIZED CONSPECIFICS

Juvenile three-spined sticklebacks, Gasterosteus aculeatus, were given a series of four 'choice' tests to determine whether they avoided schools of conspecifics in which individuals were parasitized with the ectoparasite Argulus canadensis. Results from these tests indicate that juvenile sticklebacks can avoid schools of parasitized conspecifics. Furthermore, parasites alone did not elicit an avoidance response, suggesting that it is both the presence of the parasite and its effect on stickleback behavior that causes avoidance of parasitized individuals.