What is a parasitic isopod?

Qing Lin's colourful clownfish image, The insiders, features more creatures than it may seem at first glance.

Three extra sets of tiny eyes can be seen peeking out of the mouths of the anemone-dwelling clownfish. These eyes belong to three tenacious parasitic isopods.

While diving in the Lembeh Strait in Indonesia, Qing managed to photograph the three cohabitants with patience and a pinch of luck. Lined up in a row with mouths agape, the fish appear to be showing off their parasitic inhabitants.

Likely entering through the gills of the fish as larvae, these distant relatives of the woodlouse stretch out their clawed legs to attach themselves to the base of the fish's tongue.

The insiders © Qing Lin

The insiders © Qing Lin
 

Remaining there for several years, the isopods suck blood out of the tongue, which eventually withers - at which point the parasite becomes its permanent replacement.

Watch curator Lauren Hughes explain what hosting a tongue-eating louse can mean for a clownfish.  

Visitors to the Museum can view Qing's image alongside 99 other finalist and winning shots at the Wildlife Photographer of the Year exhibition, now open.

Dive in

Discover more about life in the ocean and explore marine science at the Museum.