Why do male anglerfish, which have never been found, appear on the body of females?

Because the male anglerfish is not only weak in size, but also has little ability to hunt in the deep sea, and if the male anglerfish does not find a female in the first time of its life, it will probably not survive.

Because of the physical disparity, the male anglerfish had no way to hunt, and began his life of eating soft rice, living on the nutrients of the female.

The difference between the appearance and size of the male and female anglerfish is very large, and the survival strategy of the male is to rely on the female, which is equivalent to what we call "eating soft rice", because of the weak size, there is no means of fishing in the deep sea, if it does not find a female to rely on when it is young, then it will not be able to survive.

Summary. Trout follow other fish because they use the swimming pressure of other fish to reduce their swimming resistance, thus conserving energy and gaining higher speed.

The trout follow the clump because they use the swimming pressure of other bondfish to reduce their swimming resistance, thus conserving energy and gaining higher speed.

I'm still a little confused, can you be more detailed?

Trout are social fish species that tend to move in large groups. In wild waters, such as rivers and lakes, trout swim behind other orange fish, not only to prevent separation, but also to adopt a strategy of pursuing predation in a chaotic manner, using the potential prey of other fish to improve their own food harvesting efficiency. In addition, this behavior may also help to reduce the resistance of the water flow, which in turn lowers one's own energy expenditure.

These are all possible reasons why trout fish swim behind other fish.

There are many species of fish, and the methods of distinguishing males and females are different, but generally speaking, in addition to the distinction between primary sexual characteristics - ovaries and sperm nests, people mainly use secondary sexual characteristics (or secondary sexual characteristics) to identify their sex. However, secondary sexual characteristics are usually more obvious during the reproductive season, and it is difficult to distinguish them accurately.

Generally speaking, females are larger than males, with enlarged abdomen and slightly convex genital pores. Male fish are mostly manifested in the variation of fins and snouts, such as fin lengthening, but it is not the same, and the male and female characteristics of some fish are not obvious.

Many fish change their color during the reproductive season, with males showing bright colors. Some fish males have beads on their bodies, especially on their snouts and pectoral fins, and some fish also have beads on many parts of their heads and anal fins. This is very common in goldfish.

Some fish males become particularly aggressive during the reproductive season, even fighting to the death. Males often "fight" when they meet males or compete for mates, as in the case of the African phoenix.

Some fish have a large difference in appearance between males and females. Like betta fish (like peacocks), males have beautiful fins, especially a wide and longer tail fin, while females have a smaller tail fin. The fork-tailed betta fish in our country has a bright body color for males, especially during the reproductive period, and a dull body color for females.

Of course there is, otherwise how to reproduce.

Male and female goldfish are mainly distinguished from the following aspects:

a) Differences in external morphology:

1) Difference in body shape: Male goldfish are generally slightly longer, while female goldfish have a shorter and round body. During the egg-bearing stage, females have larger abdomen than males.

2) Difference in caudal peduncle: males are slightly thicker than females.

3) Differences in pectoral fins: careful observation shows that males are slightly pointed and long, and the first pectoral fin spines are thicker and harder; Females are short and round, and the first fin spines of the pectoral fin are not too hard.

4) The difference between the cloacal pores: from the belly upwards, the cloacal pores of male fish are small, narrow and concave; The cloaca of females is large, slightly rounded, and convex outward.

2) The difference in color: the male and female goldfish are slightly different in body color, the male fish is generally brightly colored, while the female fish is slightly lighter, and the male fish is more vivid in the reproductive development period.

3) Feel and movement: Gently support the belly of the fish with your hands, and feel a clear hard line on the abdomen of the male and female with the middle finger and ring finger, while the female has a softer abdomen. When walking past the edge of the pond, stomp on the ground and observe, the male swims fast and agile, while the female moves slower.

4) Star chasing: As the temperature rises, goldfish will have a second characteristic during the spawning period - star chasing, which is the easiest and most accurate time to identify the sex of goldfish, and it is also the easiest way to grasp a method of identification. The star-chasing of male fish appears on the first spine of the pectoral fin and the edge of the gill cover, and often there is a star-chasing on each fin bar of the entire pectoral fin, the front end is obvious, and the back one must be carefully observed.

This kind of rough little white dot is star chasing.

Using the above identification methods, it is also necessary to rely on many years of breeding experience and careful observation to accurately distinguish the male and female of goldfish.