Last week I was diving off the north coast of Brittany in France. Marine life is much like the UK. We did however see a few Goldsinny and a female cuckoo wrasse with these great big parasites stuck on the top of their heads. I have never seen this in the UK.
I would be fascinated if anyone can tell me anything about these creatures. I presume that I'm correct in thinking that this is a parasite?
Thanks, Trev
Just out in interest - how do I attach an image directly in to this post without it being an irritating thumbnail?
Yes, it's a parasitic isopod most likely in the family Cirolanidae or Cymothoidae. There are a couple other families it could belong to but the majority of big ones photographed by divers are in these two. They're all parasites of one type or another. Some lie in wait for a fish to swim by then climb on board to fill up on blood and drop off again. Others cling to the fish for their own fish cycle, still others burrow into the fish & pretty much eat them from the inside out. One relatively benign (but gruesome to us) species goes into the fish's mouth, eats the tongue, then settles in place of the tongue. If I remember right that particular one was originally known from the Gulf of Mexico but it was recently found off England.
A web search for parasitic isopods and tongue eating isopod will turn up a lot of information, as will the names Cirolanidae, Nerocila, Renocila, Anilocra, and Cymothoidae.
Thanks Leslie,
I searched the web and found a site with the same fish and isopod parasite from Guernsey. This is sort of close to where I was diving.
The name Anilocra frontalis came up. Quite well documented - but a new one to me!
Trev
One relatively benign (but gruesome to us) species goes into the fish's mouth, eats the tongue, then settles in place of the tongue. If I remember right that particular one was originally known from the Gulf of Mexico but it was recently found off England.
I seem to remember Alex was of the opinion we are looking at one of those in this picture.
This is from Pulau Siladen in North Sulawesi, Indonesia
timo
Could be. I would think that "tongue replacement" is such a good life style for a parasite that many different species all over the world would do it, it just hasn't been noticed that much.
I've seen the bug replacing isopods here in the gulf of mexico in the mouths of flying fish. Pretty gross.
James
I have a bad memory - the first known tongue-eating isopod (Cymothoa exigua) is from the Gulf of California. Other species are known from India (Cymothoa indica), Spain, and Indonesia. The animals James saw might be another species as well.
This first link tells a little bit about the animal's behavior-
