Yes, not all fish can swim. This almost non swimming fish is called brachionichthyidae. It belongs to the order gobioidea and is related to the deep-sea goblet. Similar to minnows, they also hunt with baits on their mouths. Their favorite food is crustaceans and mollusks. < p > < p > in March this year, sympterichthys unipennis was declared extinct by the International Union for the conservation of nature (IUCN). However, there is only one specimen of smooth hand fish in human hands, which was fished up more than 200 years ago, and has never been seen again. Coincidentally, the smooth hand fish is also the first species recorded in Australia. It was discovered by French naturalist Fran ó OIS P é RON in the 19th century. This is the first time that IUCN has declared the extinction of modern marine fish. Among the remaining 13 species, 7 are endangered, and 3 species (spotted, red and Chi’s) are critically endangered. < p > < p > < p > hand fish, it can be said that it is the most homespun fish in the world. All the hand fish in the world live in the line meters deep near Tasmania, Australia. Although the hand fish family generally looks a bit like the defeated Saiwen Altman, but the vitality is very poor. < / P > < p > the big and small fishes in the family of hand fishes have no swim bladder. They lie down wherever they are born. This is very different from most marine fish, many of which swim deeper into the middle water zone (200-1000 meters) after hatching. Australia’s national environmental science program has found that they can only walk 4 meters a day on average, and only move 10-460 meters in a few months. They only live in one sea area in their lifetime. < / P > < p > the frogfish belonging to the same order, anennariidae, also use pectoral fins to flutter on the sea floor. But they can swim better than hand fish, and one of their unique skills is a frog jet – sucks water with its mouth and then sprays it out with its gills. Do you ever swim back to the bottom of the ocean? (FOG) < / P > < p > because of the nature of house fish, hand fish can’t spread their offspring. If the sea is a bit windy, they will be easily destroyed. Graham Edgar, a marine biologist at the University of Tasmania, says these characteristics make the fish sensitive to environmental changes and vulnerable. No wonder half of the family is on the IUCN Red List of endangered species. < / P > < p > the reproduction rate of the hand fish is still very low. What’s worse, they like to lay their eggs on the exposed and protruding things like mallets. The mother of the hand fish is also very responsible for the North nose, and will never leave before they hatch. Therefore, as long as divers accidentally kick a foot, the global hand fish may face a fish mouth crisis. < / P > < p > because the hand fish like the protruding mallet, scientists from CSIRO designed this plastic ovipositor that looks like pole dancing props for the hand fish. It seems that the hand fish like to dance the spawning pole dance around. < / P > < p > take the critically endangered red handed fish (brachionichthys polytus) as an example. At present, there are only two populations of red handed fish, each of which has less than 50 adult fish, and the total number is less than 100. They all live in a 50 meter long coral reef in Southeast Tasmania. < / P > < p > and another critically endangered hand fish, brachiopsilus ziebelli, has not been seen since 2007. Human activities also directly caused the destruction of the family of hand fish. In fact, 50 years ago, spotted hand fish had a large number of mouths, so the University of Tasmania often collected them for specimens. But by 1996, their numbers were pitifully small. IUCN pointed out that before 1967, trawling scallop fishing boats once operated in the waters near Tasmania, which directly led to the accidental capture of a large number of hand fish. Trawling is a notorious form of fishing, which can be described as “kill out”. The trawler is being dragged across the sea floor in a carpet way, and not only the seafood to be caught but also the seafood that is not needed will be entered. Although the hand fish is not only house dwelling but also self-contained, it may be a kind of long-lived fish. Although they grow slowly, growing only 2 mm a year, scientists have found spotted hand fish as long as 140 mm, which means that they may live as long as humans. However, if the family of hand fish disappears, the secret of their longevity will remain silent forever. Before being aware of the dangers of trawling, humans once thought that the threat to the hand fish was a kind of pie star, Asterias amurensis, because it was often photographed hanging around the handfish nursery. Moreover, the period when the number of paida star increased sharply was also the period of sharp decrease in the number of hand fish. It was later known that Pai Daxing was wronged. In fact, Pai Da Xing did not eat baby hand fish. They ate this kind of seaweed that looked like bean sprouts. It happened that the eggs of hand fish were laid on them. < p > < p > < p > because of their houses, hand fish are especially easy to be found and extinct once they are not online. But many of the marine fish have a wide range of activities, so it’s hard to know whether they’re extinct or have gone elsewhere. So maybe the rarest fish in the world is something we don’t know yet.