Are deep-sea fish red grouper, crucian carp, peacock fish and sharks viviparous or oviparous?

People used to think that fish are oviparous, so the new species on the market, red fish, sea carp, guppy and the traditional sea king shark are oviparous or viviparous? According to relevant ichthyological data, the first three species of small fish are oviparous, but the shark's imperial edict has viviparous, oviparous and oviparous three cases.

1, viviparous (placental viviparous): the outer shell of the fertilized egg in the uterus development, growth of nutrients required by the yolk sac placenta, until the young shark almost completely formed before the production, each time dozens of tail. Most pelagic sharks are viviparous. Most sharks breed seasonally each year, and some large sharks breed every other year. most sharks are pregnant for 8-9 months, and the gestation period of white-spotted dogfish is as long as 24 months. in general, large sharks produce more young at one time, while small sharks produce the opposite. Sharks also grow unusually slowly, reaching sexual maturity at ages 5-10.

2, egg vivipary (non-placental vivipary): fertilized eggs develop in the uterus, yolk sac or eggs discharged into the uterus by the ovary as a source of nutrition, in the uterus does not form a placenta. In addition to whale sharks, which can produce more than 300 fish at a time, the rest can produce dozens of fish at most at a time, and the least is fox shark (thresher shark), which produces only two fish at a time.

3. Egg production: usually adopted by large sharks. Shark eggs are large, and the nutrient supply is not lacking. The eggs are enclosed in a flat, cushion-shaped sheath, which is attached to the periphery of the egg as it passes through the oviduct. The sheath's outer skin hardens when it enters the water, and each corner of the sheath has a short, hollow horn through which seawater can enter and allow the egg to obtain oxygen. There are a limited number of ovulations at a time. The eggs are bag-shaped or spiral-shaped, and are fixed in coral reefs, benthic plants, or rock crevices. Empty oocysts washed ashore are nicknamed mermaid purses.

Attachment: Red spot fish is a deep-sea fish, also known as stone dog male, because of the red spot on the body, so get Ming. Hotels in Hong Kong and Guangdong often use it to make high-end dishes. Body long, flat side, color variation, usually brown or red, with stripes and spots, it is Shengsi Haizhen famous specialty, element for Chinese and foreign gourmets respected. Erythrocystis is rich in protein, which is the most important nutrient required for growth and development. Protein contains various essential amino acids. It is a high-quality protein food for human beings. It also contains linolenic acid, arachidonic acid, linoleic acid and other essential fatty acids for human body, eicosapentaenoic acid and docosahexaenoic acid. It is not only a high-quality food and health care nutrient, but also can resist thrombosis, reduce blood viscosity and reduce blood pressure. It can be used for preventing and treating myocardial infarction, coronary heart disease, vasculitis, cerebral arteriosclerosis and other diseases. At the same time, fish can activate brain nerve cells and improve brain function.

Sea carp is distributed in the western North Pacific Ocean. China is found in the northern Yellow Sea and Bohai Sea. It belongs to the family of sea crucian carp (99 fish, sea turtle).

Guppies are omnivorous small fish species. Due to its strong adaptability to the environment, guppy breeds and distributes in the lower reaches of rivers and lakes and ditches in some tropical regions. Its wild habitat is diversified, mainly inhabiting freshwater basins and lakes. It is resistant to polluted waters and is clustered. Widely distributed. Native to Venezuela, Guyana, West Indies, northern Brazil and other places in South America.