In appearance, the Brazilian luminous shark ( Isistius Brasiliensis ) is very nice and, it seems, is the most harmless, but the appearance is deceptive. This one of the most numerous sharks in the world is pretty awful when viewed.
The Brazilian luminous shark is a very formidable predator, dwelling in warm ocean waters at a depth of 3.7 km. Despite its small size (it reaches no more than 52 cm in length), a shark can inflict serious wounds to an animal that is several times larger than it, or even kill it.
So, the Brazilian shone shark hunts for small prey, but also gnaws pieces of flesh from larger marine mammals and fish, leaving characteristic crater-like wounds on them. From the bites of this shark, whales, pinnipeds, bony fish, dolphins and other sharks suffer. For example, it is known that attacks of these sharks often occur off the coast of the Hawaiian Islands, where almost every adult specimen of a long-nosed dolphin has traces from the bites of these predators. And individuals of animals that are sick or depleted, often die after the attack of the Brazilian sharks.
Look at her teeth:
To bite off the victim a piece, the Brazilian shark first sucked to the body of the prey with its lips, and then bumps into it with small and narrow teeth located on the upper jaw. Thus, the shark is fixed on the victim, not allowing that to throw off. Subsequently, while remaining attached to the body of the prey, the shark will thrust its wide and sharp lower teeth into it and begin to turn its body. Due to these actions, the predator will cut a round piece in the victim’s body, suck it in his mouth and eat it. On average, the marks from the bites of the Brazilian luminous shark are 5 cm in diameter and have a depth of about 7 cm.
It is worth noting that the Brazilian sharks have a strong bite, but weak muscles and small fins that do not allow it to pursue potential prey. Instead, the fish waits for the victim, staying in one place for a long time. And to be unnoticed by it allows a bright green glow (bioluminescence), which is provided by special organs, photophores, on the lower part of her body. This glow makes the silhouette of the predator less clear when viewed from below, so the victim notices only a dark, non-luminous “collar” in the gill area of the fish, but not herself. “Collar” in turn serves as a bait, because it reminds the victim of a small fish. Moreover, this bait works especially effectively if the Brazilian shark shark hunts in a group with other individuals of its kind, after all, so the victim sees not only one fish, but the whole flock.
Interestingly, despite the fact that the Brazilian luminous shark attacks quite often large animals, it rarely attacks people.
Researchers from the University of Florida (USA) have discovered who else should be afraid of the attacks of Brazilian shark sharks. Traces of her bites are found near the mouth of white sharks, the most famous and most terrible (according to the press) predators of the sea. That is, dolphins, whales and tuna – this is not far off, but the white sharks – that’s too much. Nevertheless, the authors of the article in the journal Pacific Science are confident in their data. Although the luminous shark lives at great depths, it constantly runs up and down, and the depth to which it rises overlaps with the level at which a white shark can descend. Their discovery was made near the island of Guadalupe.
It should be emphasized that this is not about parasitism, but about hunting one predator for another. Although it is unusual in itself that a white shark is hunted by someone who is several times smaller than her. White sharks have long occupied the top of the food pyramid in marine ecosystems. Now, obviously, they have to squeeze, making room for a small glowing shark next to each other
Once the divers managed to photograph a large white shark with a characteristic scar from a bite on its side – when small glowing sharks bite the victim, the special structure of their jaws allows them to tear out a hemispherical flesh slice from the victim’s body. In shape, the hole left in the side of the victim, like an ice cream ball.
As you know, Brazilian shark sharks hunt for a variety of marine life – their diet includes swordfish, whales, killer whales, and even humans. They do not care who is in front of them – a dangerous sea predator or their own kindred.
The maximum of such sharks grow to 50 centimeters in length. They dwell in tropical and subtropical waters around the world. The day they spend at depth, and closer to the night can swim closer to the surface of the water. One specimen of this species was caught at a depth of 3000 meters.
However, do not think that these small predators are invulnerable. Once the researchers found such a shark in the stomach of a large tuna – apparently, the tactics at that time did not justify itself.
An interesting fact: the Brazilian shark shark, unlike most of its relatives, does not fold, but swallows the teeth that have been removed. According to the scientists, this may be due to the need of her body for calcium.
A Brazilian shone shark hunts, hiding among the luminous squid. When someone attacks squid, they are attacked by this shark. Here is such an unusual sea predator!
Researchers from the University of Florida in the US told Pacific Science that the shark shark inhabits, as a rule, at great depths, but the predator constantly runs up and down, and the depth to which it rises overlaps with the level at which a white shark can descend . Scientists observed this behavior of sharks during their research near the island of Guadalupe.
In the dark, this shark is shining, as shown in the picture below.
Although the Brazilian shark shark is considered not dangerous to humans, as it rises to the surface only at night, it is still documented several of its attacks on humans. In one case, a flock of these fish attacked an underwater photographer who sank in the open sea. In other cases, she attacked a swimmer crossing the strait between the islands in Hawaii, and also bitten one of the balloons of the catamaran of the Russian traveler Anatoly Kulik, during the Pacific voyage.
According to the latest data, Brazilian shark sharks attack one person per year. Fortunately, the death case was recorded only once.NOAA PERMIT # 932-1905 1106240107
This specimen of a cookiecutter shark, Isistius brasiliensis, is housed in the Florida Museum of Natural History collections on the University of Florida campus. Cookiecutter sharks are small and adults reach about 2 feet, but their unique jaws specialize in scooping out a piece of flesh, leaving victims with a crater-like wound. George Burgess, director of the International Shark Attack File housed at the Florida Museum of Natural History on the UF campus, co-authored a study in the July print edition of Pacific Science documenting the first cookiecutter attack on a live human.
Florida Museum of Natural History photo by Kristen Grace Numerous scars from the bites of the glowing Brazilian sharks on the body of the Greybones: