Coral fish in symbiotic associations: Benefits and costs
A.N. Severtsov Institute of Ecology and Evolution, RAS
119071 Moscow, Leninskii pr., 33
e-mail: vicnikmik@gmail.com
Studies on feeding, behaviour and infection rate of fish in symbiotic groups associated with corals Pocillopora sp. and Acropora sp. (Vietnam, Bay of Nha Trang) revealed serious costs of the tactics called "refuge-based aggregators" (refuging in groups). Feeding conditions and efficiency of defense behaviour worsened with increasing number of fish in groups and with fish size. Aggravated with increased parasite load, these factors forced out the largest fish from the symbiotic association. Leaving the colony of the host, fish can search for more diverse food and decrease parasite load interacting with cleaning fishes. Interaction of negative factors restricts the number of fish in groups of the refuge-based aggregators and their distribution among coral fishes. Main groups of fish symbiotic with corals, parabionts and inbionts, use different tactics of feeding and defense against predators and parasites.
