Anglerfish

lPredation
The fish are named for their characteristic method of predation. Anglerfish typically have three long filaments sprouting from the middle of the head; these are the detached and modifiedthree first spines of the anterior dorsal fin. In most anglerfish species, the longest filament is the first (the illicium). This first spine protrudes above the fish's eyes, and terminates in anirregular growth of flesh (the esca) at the tip of the spine. The spine is movable in all directions, and the esca can be wiggled so as to resemble a prey animal, and thus to act as bait to lure otherpredators close enough for the anglerfish to devour them whole. The jaws are triggered in automatic reflex by contact with the tentacle.
Some deep sea anglerfish of the aphotic zone emit light fromtheir esca to attract prey. This bioluminescence is a result of symbiosis with bacteria.
In most species a wide mouth extends all around the anterior circumference of the head, and both jaws are armedwith bands of long pointed teeth, which are inclined inwards, and can be depressed so as to offer no impediment to an object gliding towards the stomach, but to prevent its escape from the mouth. Theanglerfish is able to distend both its jaw and its stomach (its bones are thin and flexible) to enormous size, allowing it to swallow prey up to twice as large as its entire body.
Some benthic(bottom-dwelling) forms have arm-like pectoral fins which the fish use to walk along the ocean floor. The pectoral and ventral fins are so articulated as to perform the functions of feet, enabling the fish tomove, or rather to walk, on the bottom of the sea, where it generally hides itself in the sand or amongst seaweed. All around its head and also along the body the skin bears fringed appendagesresembling short fronds of seaweed, a structure which, combined with the extraordinary faculty of assimilating the colour of the body to its surroundings, camouflage the fish in areas abundant with prey....