Freshwater fish nursery habits

Many fish have the habit of protecting their young after spawning. Any fish that has the habit of protecting its young will probably build a nest to lay eggs. Because the number of eggs these fish lay each year is relatively small, ranging from a few eggs to a few thousand at most. The behavior of parents protecting their young has positive significance for the development and survival of eggs and young fish and for avoiding predators. The broodstock that protect the young near the eggs and fry not only have to guard the eggs or seedlings and drive away invading enemies, but some also have to constantly clear the nest of debris or stir up water flow to maintain a good environment in the nest. After the stickleback lays eggs, the female fish leaves the nest, but the male fish always guards the fish nest, driving away other fish approaching the fish nest, clearing the nest from time to time, and even moving the eggs out of the nest. Carry out nest cleaning and repairs.

After snakeheads lay eggs, their eggs float on a floating nest surrounded by aquatic plants. Male and female fish, or only male fish, lurk at or near the bottom of the nest to drive away other enemies that come to devour their eggs. When the larvae (11-13 mm in total length) leave the nest and swim in groups about 3-4 days after hatching to look for food, the larvae are limited to swimming near the nest. At this time, the defensive activities of the parent fish are intensified. If there are other When fish or frogs attack the seedlings, they will go all out to drive away the enemy. When the larvae have grown to a body length of 1-3 cm, are active and active, and their range of activities has also expanded, then the parent fish will swarm with them. When the young fish grow to 5-8 centimeters, the young fish that have passed the 20-day guarding have the ability to live independently and begin to disperse, and the parent fish stop guarding the young.

After the betta fish lays eggs, the female fish leaves immediately, and the male fish takes care of the young alone. He is constantly active near the bubble nest, driving away the female fish who want to swallow the eggs. If the eggs sink due to vibration or being blown away by the wind, the male fish will Pick up the eggs at any time and put them back in the bubble nest. After the larvae hatch, they temporarily attach to the nest bubble. If any larvae sinks, the male fish will drag it back to the floating nest. This kind of conservation work is maintained until the larvae can find food on their own, and then they are released from the floating nest to live on their own.

Yellow catfish is also a male fish that guards the nest. After the female fish lays eggs, she leaves the nest to look for food. Only the male fish floats in the nest or swims near the nest to protect the eggs and larvae. If other fish swim close, they will leave the nest and expel them. If there are any fish that endanger their own safety, they will leave the nest. situation, that is, leave the nest for a while, and then return to the original nest to guard it after calming down. It is not until 7-8 days later, when the larvae can leave the nest to swim freely and look for food, that the male stops guarding. During this period, the male fish eats almost no food. There is a kind of spear-tailed goby whose larvae-nurturing habits are similar to those of yellow catfish. After laying eggs, the female fish leaves, leaving the male fish to protect the eggs. When the larvae hatch, the parent fish becomes emaciated and dies.

Tilapia all dig nests to reproduce. After the eggs are laid and fertilized, they are guarded by female or male fish. Some species hold their eggs in their mouths for hatching, such as tilapia. During reproduction, the male fish digs mud in shallow water to build a nest. The female fish lays eggs and the male fish discharges sperm into the nest, and then the female fish will Eggs and sperm are sucked into the mouth one after another for fertilization and hatching. The newly hatched juveniles remain in the mother's mouth until the yolk sac disappears before leaving the mother's mouth to make a living on their own. However, if it encounters predators within a few days of leaving the mother's mouth, the mother will suck the young back into her mouth for protection. During the spawning and incubation period, the male fish keeps guard to prevent enemy invasion and interference. After the young fish live independently, the parent fish no longer recognizes their "children", and sometimes even swallows their "children" as food. As for another type of big-headed tilapia, the male fish holds the eggs and hatches them, and the method of protecting the young is the same as that of Mo Sanbi for tilapia.

In eel-tailed catfish that live in South American rivers, during the reproductive period, the female's abdominal skin becomes swollen and soft. After the eggs are laid and fertilized, the female lies on the eggs, so that the eggs are embedded in the soft abdominal skin. The eggs are connected to the mother by a small stalk with small arteries and veins. After the larvae hatch, the abdomen of the female parent fish returns to its original shape.

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