What are the characteristics of the snakehead fish's living habits
The snakehead fish is the common name for Channa argus, also known as the snakehead and wu bang, among others. It is a fierce carnivorous fish with tender, delicious flesh and high nutritional and medicinal value. It has strong adaptability, tolerates low oxygen, is easy to farm, grows quickly, reproduces prolifically, and suffers from few diseases. Therefore, it sells well in both domestic and international markets and is one of the promising high-quality freshwater aquaculture species.
The snakehead fish prefers to inhabit lakes, reservoirs, rivers, ditches, and ponds with lush aquatic plants and soft muddy bottoms. It usually lurks on the bottom and only moves to the middle and upper layers of the water when feeding or when the water is low in oxygen. The snakehead fish has strong adaptability to poor water quality, water temperature, and low oxygen. In addition to gills, the snakehead fish has an auxiliary respiratory organ (the suprabranchial organ). When the water is low in oxygen, it can stick its head out of the water to breathe oxygen directly from the air. It is good at jumping; when startled, when water is added, or when feed is thrown in, it often jumps 0.5-1.0 m above the water surface.
The survival water temperature for the snakehead fish is 0-38°C, and the optimal water temperature is 16-30°C. When the water temperature rises above 8°C in spring, the snakehead fish often moves in the middle and upper layers of the water; when the water temperature drops below 6°C in autumn, it swims slowly and often lurks in deep water; when the water temperature is too low in winter, it lies dormant on the bottom.
The snakehead fish is a carnivorous fish, and its food varies with the size of the fish. Young fish under 3 cm mainly feed on copepods, cladocerans, and chironomid larvae, among others. Small fish 3-8 cm in body length mainly feed on aquatic insect larvae, fly maggots, small fish, small shrimp, and small tadpoles. Adult fish over 20 cm mainly feed on small wild trash fish, shrimp, frogs, and other carnivorous animals. When hunting, the snakehead fish does not chase its prey, but hides near aquatic plants or other cover, closely watching the surroundings. When it sees fish, shrimp, frogs, or the like passing by, it strikes quickly and eats the prey.
The growth rate of the snakehead fish depends on the quality of the growing environment and the amount of bait and food. Under natural conditions, a 1-winter-old fish can reach 19-39 cm in body length and 100-750 g in weight; a 2-winter-old fish can reach 38-45 cm in body length and 600-1400 g in weight. Under artificial rearing conditions, it can reach 250 g in weight in the same year and 0.5-1.0 kg the following year.
The snakehead fish reaches sexual maturity at 2 winters of age, with an individual length of more than 30 cm and a weight of more than 0.5 kg. A fish with a body length of 50 cm has a brood amount of 35,000 eggs, 40 cm has 20,000 eggs, and 30 cm has about 10,000 eggs. Generally, the brood amount per kg is 10,000-20,000 eggs, and spawning occurs in multiple batches. The spawning and breeding season is April-May in southern China and May-July in northern China. The breeding water temperature for the snakehead fish is 18-30°C, and the optimal temperature is 23-28°C. Natural spawning mostly occurs on quiet, grassy shorelines. Before spawning, the male and female parent fish together carry aquatic plants or plant fragments to build a round nest. The nest is about 50 cm in diameter and floats on the water surface. After the nest is built, before dawn when the wind is calm and the water is still, the male and female fish chase each other and become aroused, and finally spawn on the nest. After spawning, the parent fish lurk at the bottom of the nest and protect the eggs until the fry grow to 4-5 cm, at which point the parent fish leave the nest and stop protecting the young.