Swallowers and Gulpers: Saccopharyngiformes
SWALLOWERS AND GULPERS: Saccopharyngiformes
Swallowers and gulpers are among the most unusual fishes. They have no scales, or the thin, hard plates that cover the skin of many fishes. They also have no pelvic fins, the rear pair, corresponding to the rear legs of four-footed animals, and they have very long dorsal (DOOR-suhl) and anal (AY-nuhl) fins, the single fins that run along the top and the bottom of the body. Swallowers and gulpers are flabby to the touch and probably are poor swimmers. The mouth is quite large to enormous, and the throat and stomach can stretch to allow for the capture of large prey, or animals hunted and caught for food.
Except for a huge head and mouth, the bodies of these fishes are very long and thin. The body color varies from patchy light brown to solid black. Some of these fishes have thin white lines of unknown function that extend from the head to the tail, along the upper body. Some swallowers and gulpers have glowing bulbs at the very tip of a stringy tail, which can be half or more of the overall length of the fish. The rest of the body is no longer than 20 inches (50 centimeters).
Swallowers and gulpers live in the Atlantic, Pacific, and Indian Oceans.
Swallowers and gulpers live in very deep, open water at depths greater than 3,281 feet (1,000 meters). Larvae (LAR-vee), a form of these fishes in the early stage of growth before becoming adults, and the young live in shallower waters.
Swallowers and gulpers are poor swimmers. It is thought that they draw prey close to them by means of glowing lures on their tails and then quickly open their mouths to suck in food. Some swallowers and gulpers eat only other fishes, but others eat fish and invertebrates (in-VER-teh-brehts), or animals without backbones. One type lures shrimps with a scent (SENT) released from glands around its mouth. When the shrimp comes close enough, the swallower bites it with a hollow fang that injects venom, or poison. The fish then swallows the dead or dying shrimp whole.
BEHAVIOR AND REPRODUCTION
Because of the extreme depths at which swallowers and gulpers live, little is known about their behavior. They have thin, ribbonlike larvae that are transparent, or see-through. In some species, or types, males and females look the same; in others they look different. It is widely believed that male gulpers locate their mates by following scent trails released by the females and that both males and females die after mating.
SWALLOWERS, GULPERS, AND PEOPLE
Swallowers and gulpers are objects of curiosity because of their strange appearance.
Swallowers and gulpers are not threatened or endangered.
Physical characteristics: Gulper eels have a short, flabby body, with a long stomach region. They have tiny eyes that function as light detectors. They also have a huge mouth with many slightly curved teeth. The tail is extremely long, about three fourths of the total body length, and ends in a long string with a glowing bulb at the end. The body has no scales. The largest gulper eel found was 5.2 feet (1.6 meters) long, although most of that length was the long whiplike tail.
Geographic range: Gulper eels live in the northern part of the Atlantic Ocean.
Habitat: Gulper eels live in the deep, open water of the ocean. Only young gulper eels have been captured at depths of less than 2,625 feet (800 meters). It is believed that adults typically live deeper than 6,562 feet (2,000 meters).
Diet: Gulper eels eat other fishes. The stomach can stretch quite far, allowing the eel to eat very large prey.
Behavior and reproduction: Because gulper eels live in such deep water, scientists can only guess at their behavior. Because of the weak skeleton and body muscles, gulper eels probably are very poor swimmers. They are believed to lure prey within range by means of the glowing bulb on the end of the tail. The eel may hang the bulb in the water near its mouth. The jaw muscles are the only well-developed muscles and probably allow the gulper eel to suck its prey into the large mouth by quickly opening the jaws. Males may locate females by tracking scent trails released by the females. Like other eels, gulpers are believed to die after reproducing. And like those of other eels, gulper eel larvae are ribbonlike and clear.
Gulper eels and people: The bizarre appearance of gulper eels fascinates people.
Conservation status: Gulper eels are not threatened or endangered. ∎
FOR MORE INFORMATION
Hoyt, Erich. Creatures of the Deep. Richmond Hill, Ontario, Canada: Firefly Books, 2001.
Nelson, Joseph S. Fishes of the World. 3rd ed. New York: Wiley, 1994.
"Gulper Eel." Enhanced Learning. http://www.enchantedlearning.com/subjects/fish/printouts/Gulpereelprintout.shtml (accessed on September 7, 2004).
"Gulper Eel: Eurypharynx pelecanoides Vaillant, 1882." Australian Museum Fish Site. http://www.amonline.net.au/fishes/fishfacts/fish/epelecan.htm (accessed on September 7, 2004).
"Monsters of the Deep: Gulper Eel." Sea and Sky. http://www.seasky.org/monsters/sea7a1j.html (accessed on September 7, 2004).