Epibionts on parasitic copepods infesting fish: unique substrates

Abstract

Ecto- and meso-parasitic copepod basibionts harbor a wide variety of epibionts. The basibionts belong to the families Caligidae, Pandaridae, Trebiidae, Pennellidae, Sphyriidae, Bomolochidae, Ergasilidae, and Lernaeidae. Epibionts consist of bacteria, suctorian and peritrich ciliates, hydrozoan polyps, udonellid monogeneans, stalked barnacles, and algae. Udonellids and hydrozoan polyps seem to correspond to hyperparasitism, while attachment of some algae is regarded as accidental phoresy. These fish parasites provide unique substrates for epibionts, due to (1) no molting in the adults, (2) provision of relatively long-live and stable attachment sites, and (3) protection from fish immune responses, in addition to advantages of high mobility and dispersal of primary host fish.