Linked from
The 15 pages that link to Ectoparasite, each with the reason it gives.
Cleaner fishRelated: Ectoparasites are the main food that cleaners remove from client fish.
GroomingRelated: Removing ectoparasites is a direct hygienic function of grooming.
ParasitoidRelated: Ectoparasitoids develop externally while remaining attached to their hosts.
HematophagyRelated: Many familiar hematophages feed externally, though some blood feeders do not.
ArgulidaeRelated: Argulids attach to fishes rather than living inside them.
ElacatinusRelated: These organisms are among the food items removed by cleaning gobies.