cleaner fish Fish (e.g. the cleaner wrasse Labroides dimidiatus) that remove ectoparasites (see PARASITISM) from other fish (which usually are much larger in size). Cleaner fish have conspicuous colour markings which make them easily recognizable to their temporary ‘host’, allowing them to come close with little risk of being eaten. About 45 species of cleaner fish are known.

cleaner fish A fish (e.g. the cleaner wrasse Labroides dimidiatus) that removes ectoparasites (see parasitism) from other fish (which are usually much larger in size). Cleaner fish have conspicuous colour markings which make them easily recognizable to their temporary ‘host’, allowing them to come close with little risk of being eaten. About 45 species of cleaner fish are known.