To be sure, there is no more bleak animal than the deep-sea trout. In the endless black waters of up to 3 kilometers deep, the trout dragged a fragile body to the bottom of the sea motionless, muscle atrophy, only the paper-thin black skin with some luminous bacteria accompanying. They will constantly turn on and off the light source on their bodies, hoping to tempt other creatures in the darkness to get as close to their huge mouths as possible. In his lifetime, the trout seems to have nothing but to wait, and each time the waiting is often as long as several months.
There are about 300 species of squid, including toadfish, frogfish, batfish and so on. A notable common feature is the growth of a long, soft fishing rod-like structure in the center of the head, which is used to attract prey. The top of the "fishing rod" is a protrusion where the bait is placed, and when it swings, it is like a live bait. It grows with bacteria that, through a chemical reaction, can control the bait of the deep sea to emit light. In return, the trout provides food for bacteria. Different species of squid have different shapes of bait, which were originally thought to attract different prey, but now indicate that they attract the same kind of prey. This difference may be a show-off to the opposite sex: the larger, softer, brighter the bait on the head, and the stronger the attraction to the opposite sex.
The trout in the deep sea is one of the ugliest and most peculiar creatures on Earth. Their stomachs are very elastic and they are able to swallow prey that is twice as large as their own body. It has a layer of light-proof inner membrane in its body, so that it will not cause confusion of light when swallowing a glowing fish. They have a row of upside-down teeth in their mouths, and the same teeth have a row in the pharynx, which prevents prey swallowed in their mouths from escaping. The female treetail looks like a vegetable root that emits light, its body is black and salmon-like, and the two flickering baits on the top of her head emit a series of lights like psychedelic leaves, and its Latin name means "tree-shaped toad that can fish with a net".
Males in the deep sea are much smaller than females and have no bait. Male trouts are only keen on mating and have no interest in predation. It searches for suitable females with its large eyes and sniffs the female's pheromones with its huge nostrils. Once it finds the target, it will use its teeth to firmly adhere to the female's body, but its own body begins to slowly disappear: the salmon pieces, bone iliacs, blood vessels, etc. are all fused into the female's body. After a few weeks, all that remains on the male's body is the seminal vesicles hanging on the side of the female's body to supply the female with sperm. Female trouts with 8 seminal vesicles hanging from the side of the body have been found.
In some species, if the male does not absorb into the female's body, it will eventually turn itself into a female squid and become very large. As people usually say when commenting on the trout: There is only one thing that is scarier for the trout than being a trout, and that is to be a male trout.