Fish with evolved legs for hunting and tasting buried food

A unique fish living in the Atlantic Ocean, the northern sea robin, has evolved legs that act as a sensory organ to locate prey hidden in the seabed. These fish have three legs on each side of their body that extend from the base of their pectoral fins. These legs were originally part of their fins, known as fin rays.

Researchers from Harvard University, led by Nicholas Bellono, discovered the remarkable hunting abilities of the sea robins during a trip to Massachusetts. The fish were able to uncover food hidden in capsules and sand with their legs. However, upon collecting a different species, the striped sea robin, they found that this species excelled at walking but struggled to locate buried prey.

The unique legs of the sea robin contain sensory papillae, which are similar to taste buds on the human tongue. These legs allow the fish to move independently and quickly, making them proficient at both walking and digging. The evolution of these specialized legs is governed by a regulatory gene called tbx3a.

According to Amy Herbert from Stanford University, the sea robin’s legs are a fascinating example of adapting old tools to create new body parts. This discovery sheds light on the extraordinary abilities of these ocean-dwelling creatures.