Stranger than imagination: The fishing and mating methods of trolls are beyond description

In 1833, a spherical fish was washed ashore in Greenland and taken to Zoology professor Johannes Reinhardt in Copenhagen, Denmark.

This fish, later known as the football fish, or Hemantylphus grunlandks, was the first “fishhook” known to science, writes Theodore Beach, a biologist and evolutionary scientist, in his book Oceanic Anglerfishes (University of California Press, 2009). ). Read also These types of fish can walk on land Fishing with environmental DNA instead of electrocution Like humans, sound pollution disturbs the fish and forces them to leave Seepage of psychotropic drugs into waterways is dangerous for fish

Immense diversity

Today there are about 170 species known Angler fish, fall under the 12 families, and there is “tremendous diversity” within those families, she said McKenzie Jrnger, a professor of biology at the State University of New York in Jncio (SUNY Geneseo), and specialized in deep – sea site fish Live Science Live Science.

But despite the presence of these fish around the world, they are isolated creatures that are difficult to monitor – for fish that live at depths ranging from 300 to 5 thousand meters under the surface of the water – so we are still discovering new species, each one more strange than the previous one.

But regardless of its shape, any fhishfish is the worst nightmare of the tiny creatures that live in the deep ocean.

It has been named “tassel fish” because of the glowing bait that it uses to attract fish and crustaceans that feed on it. These fearsome fishermen quietly lurk in the depths of the ocean. They are – as Grainger said – predators that set up ambushes.

You lie and wait in the dark for the prey to approach, and then after that, they use a “hook or hook” (an appendix at the front of the head) to attract the unfortunate prey; They move the bait, hide it, and then show it to attract the prey until it gets close enough to devour it.

This strategy of hunting explains the reason behind the shape of the tricycle fish, because they do not move to hunt, they did not evolve to become fast-moving, and this is the reason that many of them are bulging and non-streamlined shapes, so that National Geographic said about the tassel fish that it is ” You may be the ugliest animal on the planet. “

Luminous taste and teeth

The glow of the troll bait can be seen in the depths of the ocean half a mile (0.8 km) away, thanks to luminescent bacteria in the bait.

The bait at its tip – also called “esca” – contains pores designed to host these bacteria, many of which cannot live anywhere else, and many of them are characteristic of species of hookfish.

However, the diversity of tassel fish is not limited only by its glowing taste. Some species such as Phyllorhinichthys balushkini have distinct growths of light that hang from their bodies like biological optical fibers.

Others, such as Cryptopsaras couesii, have glowing spots on their backs called polyps, and some, like Thaumatichthys genus, have a graft on the roof of the upper jaw.

And once a fish has attracted its prey, it will not let it slip away, according to Karlie Cowen, a PhD student who studies the biomechanics of fish teeth at the University of Washington, that most animals have teeth firmly attached to their jaws, but the hookfish is a notable exception. Some of their canine-like teeth are “folding” or able to bend when pressed.

“The tooth function might be similar to the serrations in a parking garage,” Cowen tells Life Science. “It is easy for prey to get into its mouth, but it is difficult for it to get out.” https://www.youtube.com/embed/XhsyZnVx2rQ?version=3&rel=1&showsearch=0&showinfo=1&iv_load_policy=1&fs=1&hl=ar&autohide=2&wmode=transparent

The strangest way to reproduce

Many species of troll fish have one of the strangest reproduction strategies on this planet. Males are parasites, and we don’t say this metaphorically.

In many species of tricycle fish, Granger says, males are often 10 times smaller than females, have no function other than reproduction, and they use sophisticated organs to track females, and when they find one, they cling to it with their teeth.

According to Cowen, some male hookworms grow to have hooks in front of their mouths to cling to the females; Cowen is looking for whether these teeth are real teeth or a type of primitive tooth called odontod (dermal tooth). Then the males secrete an enzyme that dissolves the skin of their mouth to merge with the female’s body, so the male becomes completely dependent on the female for nutrients. And the circulation fuses so that they share the same blood

The attachment that occurs is similar to an organ transplant, in which the male physically becomes part of the female’s body, and research published in Science in 2020 revealed how tricycle fish succeed in this extraordinary process.

They lack the genes to produce most of the substances that might attack foreign tissue, plus they contain few or no T cells and antibodies.

“This deficiency in the immune system is sure to cause the death of a human being,” said the study’s co-author, Dr. Thomas Bowim, in a press release describing the study, but this is what the tricycle fish needs to conduct this strange reproduction based on sexual parasitism.