Diseases of Echinodermata. Ill Agents metazoans (Annelida to Pisces)

Abstract

Parasitic myzostomids mostly infest crinoids but a few are known from asteroids and ophiuroids; they are either galhcole, cysticole or endoparasitic. Although many copepods have been said to be ectoparasitic on echinoderms, this has been proven for only a few species. Some copepods are known to induce gall formation in the spines of echinoids or in the body wall of ophiuroids; others have been found to infest either the bursae or gonads of ophiuroids. Ascothoracid cirripeds were reported either as ectoparasites on cnnoids and ophiuroids or as endoparasites In the body cavlty of asteroids and spatangoid echinoids. Echinoderm castration by copepods and ascothoracids was reported several times in the literature. Parasitic crabs nlostly occur on or in echino~ds. Ectoparasitic crabs often exert major effects and may kill their host; gut-inhabiting species may produce conspicuous host deformation. Some species of carapid fishes are known to live either temporarily or permanently in the body cavity of holothuroids and asteroids Carapid infestations do not seem to seriously affect the echlnoderms except for species permanently inhabihng the host's coelom. Parasitic associations between echinoderms and polychaetes, tardigrads, barnacles, amphipods, tanaidaceans, acarians, pycnogonids and insects have been casually reported in the literature.