Behold the frogfish. This bizarre creature really is a fish, despite its bullfrog face, pectoral fins that look like webbed feet, and a froglike mouth that snaps up unsuspecting prey.
But the way it lures its prey is even weirder. Frogfish belong to the anglerfish family known as Antennariidae. Like their anglerfish cousins who lurk in the ocean’s depths, these ambush predators attract their next meal via an appendage on their heads that they use like a fishing lure. This appendage is known as the illicium and thought to have once been a dorsal fin. It has a specialized skin flap, the esca at the end. It tantalizes small fish and crustaceans into thinking it’s a worm until they come too close.
How frogfish controlled the illicium was previously unknown. Led by biologist Naoyuki Yamamoto of Nagoya University, a team of researchers have now discovered that a specialized population of motor neurons have evolved to allow it to shake the illicium around like a wriggling worm. Yamamoto thinks they were originally dorsal fin motor neurons that became more specialized.
