The female anglerfish is equipped with a modified first-dorsal fin spine placed on the tip of the snout called an illicium.  The illicium has a single distal appendage, called an escal that has a filamentous quality that allows it to move swiftly while being pulled through the water.  The escal varies between anglerfish species but it often represents invertebrates such as worms and crustaceans. In a nonluring situation, the illicium is laid back over the head with the escal tucked next to the dorsal fin. While luring, the illicium is extended straight forward in front of the mouth (Pietsch, 1978).
Luring is achieved by a combination of bioluminescence and escal movements that simulates the motion of worms and crustaceans. The escal and distal appendages are wriggled, vibrated, swung, and swept in order to attract the angler’s choice of prey.
Female ceratioids are gape-and-suck feeders. The combination of the expansion of the mouth, creating a large increase in volume, and the rate at which it is expands results in suction pressure inside the mouth. Compared to other teleosts, the female anglerfish have a more flexible and much larger oral cavity that provides a more effective sucking function. The gape-and-suck feeding is adapted to pull large prey inside the mouth past the teeth. The prey is then transported through the pharynx, forced through the esophagus, and finds its fate in the stomach (Pietsch).
Living at great oceanic depths, it seems anglerfish cannot afford to let a meal go by, no matter how large or small. Anglerfish consume a wide variety of food sources including zooplankton, fish, crustaceans, cephalopods, and sea urchins. Occasionally, there have been reports of female anglerfish found floating with large fish caught in the mouth and throat. The teeth of the anglerfish are folded inward, which provides no mechanism for the removal of large prey once engulfed (Pietsch).
In the deep sea where very few organisms are present, consuming sizeable energy-rich food sources is a successful strategy. Anglerfish seldom feed and practice a very inactive lifestyle. The structural and behavioral adaptations involved in the energy-saving luring method played an important role in the evolutionary success of the anglerfish (Pietsch, 1978).
At an early stage, the male anglerfish depends on the female anglerfish for survival. When a male anglerfish finds a female, he attaches to her skin by releasing an enzyme that digests the skin and fuses the pair down to the blood-vessel level. The female provides protection and nutrients to the male through their shared circulatory system. In return, the male provides sperm to the female anglerfish when she is ready to spawn. The female and male anglerfish have a symbiotic relationship (Munk, 2000).
A variety of ceratioids species have been found in the stomachs of black scabbard fish, longnose lancetfish, and sperm whales. The bones of a large ceratioid anglerfish was also reportedly found in the stomach of a Deep-sea Swallower Saccopharaynx lavenbergi. The primary diet of the Saccopharynx is unknown but they are thought to feed on large fishes (Pietsch).

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