Name: Northern Sea Chest (Prionotus carolinus)
Where it lives: The shallow waters of the western Atlantic Ocean, from Nova Scotia to Florida
What it eats: Shrimp, crabs, squid, worms and small fish
Why it’s great: Northern sea robins are strange fish with large, spiny heads; bright blue eyes; two giant wing fins; and six crab-like legs.
It is these small legs that make sea robins so unusual. Other marine animals follow these fish because they are so good at finding and digging up buried food. But until recently, scientists didn’t understand what made robins such skilled foragers.
In two studies published in 2024, researchers revealed that the legs of northern sea robins act like tongues, allowing the fish to taste their environment for signs of food.
“This is a fish that grew legs with the same genes that contribute to the development of our limbs and then reused those legs to find prey with the same genes that our tongue uses to taste food – pretty wild,” the author said of the study. Nicholas Bellonoprofessor of molecular and cellular biology at Harvard University, said in a statement.
The scientists discovered that Northern sea robins can detect and discover crushed mussels using papillae that cover their legs. Papillae are small sensory structures found on the upper surface of the tongue in humans. The researchers found that the papillae of the Northern Seabreast have taste receptors and touch-sensitive neurons, allowing the fish to use their paws to taste the ground to find food.
In one of the studiesresearchers grew North Sea robins from embryos in a laboratory to see how their legs developed. They found that the legs grew out of the pectoral fins and separated from the rest of the fin rays during development. The legs are controlled by several walking muscles at the base of the legs and are shaped like shovels to help the fish dig.
Although all species of sea robins have legs, not all are adapted for digging and testingthe team found. “We were surprised to see how much robins differ from each other in terms of sensory structures on the legs,” study co-author David Kingsleya developmental biologist at Stanford University said in the statement. “The system thus exhibits multiple levels of evolutionary innovation, from differences between sea robins and most other fish, differences between sea robin species, and differences in everything from structure and sensory organs to behavior.”
But the sole legs of Northern Seabreasts don’t always lead to a meal. After the northern sea robins dig up their food, the fish that follow them often swoop in and steal their food, an act known as kleptoparasitism.