Abstract: Grass carp lays 1.38 million eggs at a time and loves to eat their own feces, why are wild grass carp extremely rare?
Do you like fishing? What fish are usually caught in the wild?
If you love fishing, you should have found a strange phenomenon, that is, there are many fish in the wild, and there are many types of fish that can be caught in normal times, but only grass carp is caught.
I also like to fish, and every weekend I go fishing with my friends in some reservoirs and rivers. Fish such as carp, crucian carp, and tilapia are often caught, but grass carp has never been caught.
According to my understanding, grass carp has a strong reproductive ability, they can grow up by eating grass, and they like to eat their own feces, it is reasonable to say that this fish can grow naturally in the wild environment, why rarely see wild grass carp, where are they?
Grass carp, one of the four major fish
Grass carp is now the most common freshwater fish on the mainland, it is also the most popular fish among the four major fish, in the market if you go to buy fish, most people will prefer grass carp.
When it comes to grass carp, some people will think, is it a fish that eats grass and grows up? It is also possible to say this, but it is not a fish that specializes in grazing, and this fish occasionally eats meat, especially in its juvenile stage, mainly eating larvae and algae.
When they grow up, they often eat some meat foods, such as earthworms, dragonflies, etc. are the objects that grass carp love to prey on. In particular, the bigger they are, the more vegetarian their diet becomes, and when they reach adulthood, almost all of them live by eating plants, so it is called grass carp, which is also deserved.
In addition, grass carp also has a habit of loving to eat their own feces. This is mainly because the digestive system of grass carp is not perfect, resulting in various grasses that they eat into the stomach and cannot be completely digested, that is, the absorption utilization rate is very low.
Therefore, when they are excreted, grass carp will eat these excrement again, so that after the action of saprophytic organisms such as bacteria, the utilization rate of food will be improved. Therefore, grass carp will repeatedly eat feces many times, which is also to make up for the shortcomings of their digestive system.
The conditions for grass carp breeding are harsh
After understanding some of the growth habits of grass carp, continue to get back to the truth, why are wild grass carp so rare? In fact, the reproductive ability of grass carp is still very strong, it can lay 300,000 to 1.38 million eggs at a time, generally the larger the head, the more eggs are laid.
However, grass carp is very harsh on the breeding conditions, the first is that it can only breed after the age of 4.
Grass carp is a relatively long-lived fish, they can also grow to a large size, some of them weigh forty or fifty pounds over the years is not surprising. The author has seen more than 40 pounds of large grass carp, which is also the largest grass carp I have seen with my own eyes.
And for older fish, they mature later. Grass carp, for example, generally take four or five years to reach sexual maturity, and it takes more than 10 pounds for females to start spawning. The grass carp farmed by farmers often weighs a few pounds and starts to fish and sell, and most of these grass carp have not yet grown up to be caught, so most of the grass carp has not yet reached the conditions for spawning.
The second is that grass carp are difficult to spawn in their natural environment.
Like most fish, they can spawn when they reach sexual maturity and hatch soon after. Some fish will also have the habit of protecting the nest and protecting the small fish in order to improve the survival rate of the baby fish.
However, grass carp has very strict requirements for spawning environment, that is to say, if the conditions are not met, then after reaching sexual maturity, it is impossible to hatch and spawn. Grass carp like to spawn at the confluence of the river at the main stream, the deep trough waters on the side of the bend, and the sudden tightening of the river section on both sides, that is to say, the grass carp's gonads must be stimulated by the flowing water to spawn after maturity, otherwise it is impossible to hatch and spawn.
Like many fish ponds, reservoirs of grass carp, then the number of years is relatively long, but the environment here has no flowing water, can not stimulate grass carp gonad spawning, naturally it is not difficult to naturally reproduce offspring, and this is also the reason why grass carp is called a domestic fish, that is, it requires human intervention. Carp can reproduce naturally in the wild environment, so it is not related to the four major fish.
Finally, the survival rate of hatching after spawning is low. If it is in the wild environment, some grass carp are lucky to hatch and spawn, but the survival rate of these eggs is very low, especially if they can hatch small fish, which is why grass carp fry are basically not seen in the wild.
Because there are many carnivorous fish in the water, they like to eat some fish that are smaller than them, and there are also some fish that naturally love to eat the eggs of other fish, such as tilapia, white stripe, mosquito-eating fish, etc., which are fish that love to eat fish eggs. Grass carp is a herbivorous fish and is not aggressive. In addition, most grass carp will not be guarded after spawning, so these eggs will be swallowed up by other fish in large quantities.
In addition, although grass carp is a traditional four major fish in the mainland, with a long history of culture and a wide range of culture, this fish also has many diseases in its juvenile stage, and it is very difficult to survive in the natural environment, especially in the juvenile stage. Like the grass carp farmed by fishermen, in order to improve their survival rate, they will start to receive various vaccines at the juvenile stage, in order to improve the resistance of grass carp and thus reduce various diseases and insect pests.
It is precisely for these reasons that although grass carp has super reproductive ability, it is rare to see wild grass carp in the wild environment, and even some grass carp fry are rare, let alone some large grass carp. But it is also due to this defect of grass carp, so it has evolved a super reproductive ability, if it is not able to lay as many as 1.38 million eggs at a time, it is estimated that grass carp has long been extinct, it is unlikely to become a four big fish.
Grass carp has been farmed on the mainland for thousands of years, but the real success of artificial breeding was in 1958, and before that, it was fished in natural rivers to catch fry, and then stocked in ponds to be raised and sold or eaten.
Well, I'll share it with you today, do you like grass carp? Have you ever caught wild grass carp? Welcome to leave a message to discuss!