Small fishes of the family Jiangke that are found in fresh water.
Fish discussion:
The giant fish is a common small ornamental fish, also known as big-eyed fish and big-eyed thief. In biological classification, it belongs to the animal kingdom, chordates, teleost, whitebait and CYPRINIDAE. There are 8 subfamilies, 90 genera and more than 550 species in the world, which are widely distributed in brackish water, fresh water and fresh water all over the world. It not only has a petite posture and bright colors, but also has a unique way of reproduction.
Morphological characteristics:
The giant fish is spindle-shaped with a wide and vertical head; The mouth is bigger, the mandible is elongated and tilted upward; The pectoral fin is very high; Underdeveloped ventral fins; The dorsal fin is small with 6 fins; The gluteal fin is developed, 17~ 19 fin; Tail fin was truncated; Body length is 25 ~ 40 mm.
Distribution range:
Giant salamanders are widely distributed in semi-arid water, salt water and fresh water all over the world, including hot springs in desert areas. Most of them are distributed in tropical and subtropical swamps and streams in South America, North America and Africa, with a few in Asia and Europe.
Living habits:
1. Environment: The giant salamander is a warm-water fish, and the optimum water temperature is 18~26℃, generally not exceeding 30℃. A few species can tolerate the high temperature of 40℃, and most species prefer weakly acidic water with pH value of 5~7.5.
2. Feeding habit: The giant salamander is an omnivorous fish, which mainly feeds on plankton, aquatic insects and higher plant debris. Under the condition of artificial feeding, it can be fed with fish and worms or mixed with granular feed.
3. Reproduction: The giant salamander is an oviparous fish, and it is sexually mature when its body length is more than 25cm. The female fish has 1500 ~ 2500 eggs, which are fertilized in vitro, and the fertilized eggs hatch into young fish in about 5~8 days.
Male and female identification:
Generally, the female fish is large, with pale yellow transparent pelvic fins, and the abdomen is swollen and soft during pregnancy; The ventral fin and anal fin of male fish have dense pigment cells, which are black and opaque.
Oviposition habits:
The total length is more than 25 mm, indicating sexual maturity and strong reproduction. The spawning period is from late May to August. Oviposition occurs in the morning, but it can be carried out all day when the environment is quiet.
There are two situations of spawning:
(1) The male fish waits at the spawning ground-there are aquatic plants such as Ceratophyllum, and when the female fish swims, the male fish swims out to meet them;
(2) Male and female fish swim to the spawning ground in pairs, and the movement is slow, and the male fish is mostly below the female fish.
When laying eggs, the female fish turns around in the grass and rubs her abdomen, then stops in the grass and begins to lay eggs. At this time, the male fish came up from the downstream of the female fish's abdomen, parallel to the female fish, bent sideways, near the reproductive hole, and began to discharge sperm. The eggs laid by the female fish are piled up around the reproductive hole in blocks. When female fish swim in aquatic plants, they will lay eggs on aquatic plants alone or in blocks with the help of filamentous protrusions on eggs.
Ornamental value:
The spawning giant fish is very attractive in body color, and it is one of the few species of freshwater ornamental fish that can compete with marine coral fish. Coupled with its small size and lively personality, it is a natural collocation of aquatic plants in the aquarium.
In addition, most spawning giant fish have wide adaptability to water quality and are easy to raise, so they are popular ornamental fish species at home and abroad. The well-known varieties are salamander, salamander, salamander and black pearl salamander.