Fish out of water: Scientists reveal how blennies adapt to life on land after leaving oceans

They are ‘jack of all trades’ in water, ‘master of one’ on land - and this could be key to blennies’ success, study suggests

A group of Pacific leaping blennies out of the water on the foreshores of the island Guam (Dr Terry Ord)

“Like a fish out of water” is an expression that does not apply to the blenny – species of which have now given up almost entirely on oceans and continue their fishy lives on land.

New research into these fascinating animals suggests that their broad capacity for adaptability in water, including flexible diet and behaviour, could have been key to propelling them ashore. However once there, their success on land has been due to new, highly-specialised behaviour.

The researchers, from the University of New South Wales and University of Minnesota, compared the fish’s evolution in the water to being a “jack of all trades”. In contrast, their subsequent adaptations on land saw bennies become “a master of one”.