This picture shows the gurnard, a fish full of peculiarities. Not only does it have fins that it can spread like wings, it also has six leg-like limbs, as can be clearly seen here. These gurnard legs are similar to those of crabs and are used by some subspecies for locomotion – they use them to “walk” across the seabed.
But some gurnard species use their legs for another purpose, as researchers led by Corey Allard from Harvard University have discovered. They investigated the question of why some gurnard species can so accurately detect prey hidden in the seabed, such as shrimps and mussels. Closer investigations revealed that the legs of the gurnards Prionotus carolinus and Prionotus scitulus are not only broadened like a shovel to make it easier to dig in the seabed: the legs are also covered with papillae that resemble human taste buds.
Thanks to these sensory organs, the fish can detect chemical stimuli and “taste” their hidden prey through the sand, as the team discovered. To develop these legs and their taste buds, the fish use genes that also play a role in the development of human limbs and those that are responsible for the development of human taste buds.
The “tasting legs” of gurnards also explain why other fish often follow them and try to contest their prey: most other fish species cannot detect the crustaceans and molluscs that gurnards find buried beneath the seabed. That’s why they simply leave the prey to them and then try to take part in the meal.