How do sea robin pectoral rays help the fish find food on the seafloor?

Sea robins (family Triglidae) utilize the lower two or three rays of their pectoral fins as specialized sensory organs to locate food on the seafloor. These rays are detached from the rest of the fin, thickened, and highly mobile.123

As the fish moves along the bottom, these rays continuously explore the ground ahead and to either side, acting as organs of touch and taste. This allows the sea robin to detect mollusks, crustaceans, and other prey, including those that burrow into the seabed. In addition to their sensory function, these rays support the fish during locomotion, enabling it to move slowly across the bottom.21