1. AND THERE WAS LIGHT Most deep-sea anglerfish lures glow with light that is generated by an enzyme called luciferase. Some species make the light themselves, while others harbor colonies of luminescent bacteria that do the job for them. In addition to attracting prey, the fish’s blue-green radiance may attract mates and ward off predators.
2. GONE FISHING Over millions of years of evolution, the front-most spine of the anglerfish dorsal fin developed into a fishing rod with fleshy “bait” dangling at the end. The creature floats passively and wiggles its rod until a prey fish approaches. This lie-in-wait strategy was long suspected and finally confirmed in 2005 by a remotely operated underwater vehicle that captured some of the first footage of an anglerfish in the wild.
3. THE BETTER TO EAT YOU WITH When the anglerfish’s jaw opens, it creates suction that pulls her victim inside. In some species, retractable teeth spring down, trapping the meal. An expandable stomach can hold fish larger than the anglerfish herself. High-speed cinematography from the University of Washington has revealed that anglerfish can pop open their mouths in just four milliseconds.
4. CLINGY RELATIONSHIPS The male anglerfish chomps down on the female, which may be 25 times his size, and never lets go. His circulatory system fuses with hers, and all of his own organs—except for his reproductive system—shut down. He siphons off nutrients from his mate and in return provides a permanent sperm bank. At just 6.2 millimeters long, a swamp-dwelling male anglerfish from Southeast Asia, first described in 2005, is currently regarded as the world’s smallest vertebrate.