David Hall / Sandperch (Parapercis sp) with two Isopod (Cymothoidae) ectoparasites on body. Pantar, Alor Archipelago, Indonesia.

Alex Mustard / Portrait of a Blackbar soldierfish (Myripristis jacobus) infected with Cymothoid isopod parasites. The large parasite between the eyes is a female, the smaller individuals are males. Seven Mile Beach,...

Franco Banfi / Fish with with isopod parasites (Nerocila sp.) Raja Ampat, Irian Jaya, West Papua, Indonesia, Pacific Ocean

Gary Bell/ Oceanwide / Leafy Sea Dragon (Phycodurus eques) with parasitic Isopod (Creniola laticauda), Yorke Peninsula, South Australia, Australia

Gary Bell/ Oceanwide / Leafy Sea Dragon (Phycodurus eques) with parasitic Isopod (Creniola laticauda), Yorke Peninsula, South Australia, Australia

Gary Bell/ Oceanwide / Leafy Sea Dragon (Phycodurus eques) with parasitic Isopod (Creniola laticauda), Yorke Peninsula, South Australia, Australia

Gary Bell/ Oceanwide / Leafy Sea Dragon (Phycodurus eques) with parasitic Isopod (Creniola laticauda), Yorke Peninsula, South Australia, Australia

Franco Banfi / Ringneck blenny (Parablennius pilicornis) with isopod parasite (Cymothoidae) sitting on its head, Marine Protected area Punta Campanella, Costa Amalfitana, Italy, Tyrrhenian Sea, Mediterranean.

Franco Banfi / Ringneck blenny (Parablennius pilicornis) with isopod parasite (Cymothoidae) sitting on its head, Marine Protected area Punta Campanella, Costa Amalfitana, Italy, Tyrrhenian Sea, Mediterranean.

Pascal Kobeh / Blue chromis (Chromis cyanea) with attached parasitic Isopod (Anilocra sp) female feeding on blood, in reef. Bahamas.

Pascal Kobeh / Blue chromis (Chromis cyanea) with parasitic Isopod (Anilocra sp) female feeding on blood. Male isopods invisible to naked eye, female excretes a chemical substance to maintain masculinity of small ma...