Isopods FOUND!

Yes you read that right.
I was dissecting the Indian Meckerel I bought from a local mart this morning to get rid of its innards when I discovered that I actually bought home, together with those meckerels, a pair of alien-looking lifeforms.

I was pulling the heart, liver, and the gills out of the last fish when the two lil crustacean-looking creatures dropped out from the fish's mouth.

I didn't recognized the species initially, and the first thought that came to me was that those two were the undigested prey of the fish. But the zoologist in me wasn't happy with the answer. Were they really the undigested prey of the fish? They looked nasty, with segmented body and evil little eyes. They have seven pairs of claws underneath their belly. SEVEN! What kind of animal that needs fourteen limbs?

So I searched the internet looking for information for these animals, and ta-da! They were actually the parasitic crustacean called tongue-eating louse, Cymothoa exigua.

This animal enters fish through the gills, and attaches itself to the base of the fish's tongue. It suck the blood from the tongue, causing the tongue to slowly waste away-a condition called antropy. So it's basically eating away the fish's tongue. The louse will then attach itself to the muscle of the tongue, and the fish can use the parasite just like a normal tongue.

Image: threadless.com

The female is typically larger, and attaches itself on the tongue, while the smaller male usually attaches itself behind the female. The two creatures I found inside the fish, one of them was male and the other female.

Image: themanyfacesofspaces.com

Wikipedia says that the parasite is found mostly in the North and South American seas, until one was found in the United Kingdom in 2005, which means there are these parasites in the Atlantic as well. So I don't know whether this is a ground-breaking discovery, to actually find the animal here in South East Asian seas. Unfortunately the tongue of the meckerel had been severed together with the gills, so I couldn't really check out the fish's tongue.


Malcolm
info: http://www.dnr.sc.gov/marine/sertc/Isopod%20Crustaceans.pdf