Predatory fish are unusually gluttonous, especially if they eat occasionally. The problem of nutrition is most acute in deep-sea fish, since the living resource in such conditions is significantly limited. An example of extraordinary gluttony is the black live-eater. This is a small fish that can swallow prey larger than itself.
Short description
The black livethroat belongs to the chiasmodont, or livethroat, fish from the ray-finned family. It is classified as a member of the common perch order. This is a deep-sea predator, the size of which ranges from 15 to 25 cm. True, individuals 25 cm in size are extremely rare. Like many unusual deep-sea fish species, live-throats have an elongated body, laterally compressed. Their dorsal fin is small, and the scales are completely absent. The color of the live-throat can be either black, as the name suggests, or brown. The walls of the stomach of a predator are able to stretch very strongly. This creates an elastic muscle reservoir in which large portions of food can be digested. The muscles of the predator are poorly developed, but its jaws are worthy of a separate chapter.
Teeth as a tool and a natural barrier
The structure of the mouth of live-throated fish is verypeculiarly. The black living throat has a disproportionately large mouth for its small body. The predator's jaw bones are elastic, and the mouth itself has articulated joints, which allows the jaws to strongly move forward and down when opened. Since the prey of the live-throat often exceeds its size, it was not possible to cope with it without such a device.
The teeth in the mouth are arranged in two rows and have different lengths. All of them are fang-shaped. Teeth grow not quite straight, but at a slight inclination towards the oral cavity. This feature in the structure of the jaw gave the Latin version of the name - Chiasmodon. The term is formed from two ancient Greek words - "crossed" and "teeth". A slight internal slope of the growth of the teeth does not allow the prey of a predator to break free, creating an insurmountable barrier.
How a stinger finds prey
As you know, sunlight does not penetrate into the deep layers of the ocean. How does a black live-throat fish hunt if there is total darkness around it? Especially for this, nature has provided its creation with a system of organs of the lateral line. By the way, this system is present in many deep-sea inhabitants. Thanks to it, predators are able to pick up low-frequency vibrations in the water and determine where the prey is located.
How the meal is done
Because it is almost impossible to observe this process, scientists have put forward two opposing theories.
The black cutthroat swallows fish from its tail, swimming up from behind. Booty can't break out of the crossedteeth and gradually gives up.
The predator starts the meal by grabbing the prey by the protruding part of the muzzle. Gradually, he pushes the enemy inside the stomach. At the same time, each movement of the prey helps to push through. Once the head and respiratory organs are in the stomach, the prey suffocates and ceases to resist.
Which of these theories is more like the truth, it has not yet been possible to reasonably prove. The fact is that the scientists failed to get a single living and capable live-eater.
How dangerous it is to be "greedy"
As already noted, the urge to swallow any prey is by no means out of greed. The desire to eat for the future is associated with a small number of deep-sea inhabitants. Unusual fish living under the water often pay for their "thriftiness" with their lives. The thing is that swallowing large prey is easier than digesting it. The elastic stomach simply does not have time to secrete the right amount of enzymes to complete digestion. In this case, the decomposition process begins right inside the stomach. There is a release and accumulation of gases that raise the black throat to the surface and lead to its death.
This is how the most famous specimen of the gluttonous livemouth was obtained. It happened off the coast of the Cayman Islands in 2007. The black live-eater, whose body was about 19 cm long, was found dead because it could not digest a huge mackerel. The length of the prey extracted from the stomach was86 cm. According to the state of the predator, it was not entirely clear whether the mackerel pierced the thin wall of the stomach with a sharp nose or began to decompose in it. This isn't the only time that gluttons have died because of their appetite.
Black live-throats, or chiasmodons, are the most common species among living-throated fish. Previously, they were considered rare inhabitants of the deep ocean, but today they are inclined to believe that this opinion was erroneous. Black throats are part of the food chain for tuna and marlin. Their remains are often found in the stomachs of these fish. Scientists suggest that the number of black livemouths is quite high, since 52% of the studied tunas and marlins had parts of these deep-sea predators in the stomach contents.
