This strange creature found in a tin of tuna could be a parasitic crustacean with an astonishing life cycle. Cymothoa exigua is known for its habit of taking up residence in the mouths of fish where it gets rid of their tongue in order to take the place of the organ.
When opening a tin of tuna for the evening meal, Zoe Butler came face to face with a strange little creature. ‘I opened the tin and saw a purple thing, then I turned it around, pushed it with a fork and saw it look back at me,’ she told the Nottingham Post. ‘It had a thorny tail, it was pretty sinister.’
‘I dropped my fork, jumped and shouted a little, calling my grandmother to come see,’ she continued. Frightened as much as driven by curiosity, this British mother left her dinner preparations for a few minutes to document the unwelcome guest with photos and relayed her discovery on Twitter.
The photos taken by her were inspected by biologists including Stuart Hine, a researcher at the Museum of Natural History in London. His findings indicate that it may be a parasite known as Cymothoa exigua. A crustacean that is distinguished by its formidable methods, which has even earned it the nickname of ‘tongue-eating louse’ in Britain.
Tongue taken over by the crustacean
‘From what I can see, I will support the hypothesis that it is the tongue-eating louse, Cymothoa exigua. I think they are associated with fish smaller than tuna, but fish that tuna do eat. We could certainly say more if the specimen was presented to us,’ said the specialist to The Telegraph.
Generally, the parasite preys on pink snapper, a species of fish in Pacific waters. Less than an inch long, it enters its host through the gills and attaches itself at the base of its tongue. From there, it begins to extract the blood from the fish using its claws.
As time passes, Cymothoa grows and changes completely. The tongue becomes fed less and less by blood and ends up atrophying and dying. At this point, the parasite usually stops its blood intake and starts feeding on the fish’s mucus.
The host now devoid of its own tongue, it replaces it by using the body of the parasite attached to what remains of the organ. This substitution allows the fish to stay alive and continue a ‘normal’ existence. Thus, fishermen sometimes have a big surprise when examining their catch, discovering a squatter in the mouth of the fish.
A unique case of parasitism
According to the scientific community, this case of parasitism is without equal. No parasitic organism discovered so far has shown such abilities as replacing an organ successfully. Of course, the creature found by Zoe Butler was dead at the time of its discovery. It may have been in the mouth of a fish swallowed by a tuna.
An in-depth review should confirm its identity. Other hypotheses put forward by the experts indicate that it could also be a young crab or a tadpole.