This huge tiny fish is a famed predator, capable of swallowing fish up to ten times its own size because to its massive jaws and balloon-like stomach.
The black swallower (Chiasmodon niger) is a deep-sea fish of the Chiasmodontidae family. It is distributed all across the world’s tropical and subtropical waters, usually at depths of 2297–9006 feet (700–2745 meters). They average 6 to 8 inches (15 cm to 20 centimeters) in length, however specimens as long as 9.8 inches have been discovered (25 centimeters).
The scaleless body of the black swallower appears elongated and brownish-black in appearance. Its blunt skull is adorned with tiny black eyes and a gruesome mouth that it employs to choke and consume animals. Its lower jaw is longer than its upper jaw, and both are equipped with a row of sharp teeth that interlock when the mouth is closed. It may use its long fangs to drive its prey through the jaw, securing it. The prey finally finishes up in a distensible intestine that normally hangs below the body of the black swallower.
These remarkable characteristics enable the black swallower to swallow bony fish twice its length and ten times its bulk. All of this without even attempting to gnaw on the hapless fish. It is said to hunt by biting on its prey’s tail and then walking its jaws over its body until it is entirely coiled within the swallower’s stomach.
Because the species dwells in the twilight zone, it is rarely observed in its native environment. Dead specimens, on the other hand, are frequently brought to the surface because these deep-sea predators occasionally bite off more than they can chew. Sometimes they swallow fish so large that decomposition occurs before they can digest it, and the released gases drive the swallowers to the surface, killing them.
In reality, this is how James Yate Johnson found the species in 1864, off the coast of Bermuda. Another example was reported in 2007, when a 7.5-inch (19-centimeter) long swallower was discovered dead off the shore of Grand Cayman. That specimen’s stomach included a 33,9-inch-long (86-centimeter-long) dead snake mackerel (Gempylus serpens), which was four and a half times its own length.
We know relatively little about the species because of its remote living environment, save that it reproduces by oviparous means. This suggests that the eggs are laid by female black swallowers, with little or no embryonic development within the mother.
While it is hard to know how many members of the species reside in the waters, its wide habitat range implies that black swallowers are common all over the planet. As a result, they are classed as Least Concern on the IUCN Redlist.