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The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

author:Zeu said
The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

Wen Zhu said

Editor丨 Zeu said

preface

Baby fish, also known as giant salamander, is one of the most precious amphibians in the world, mainly distributed in mainland Sichuan, Guizhou, Yunnan, Hunan and other provinces in China, inhabiting mountains and streams at an altitude of 1000~3000m. The main food of baby fish is animal carcasses and insect larvae, which feed on zooplankton in the water, and adults feed on organic detritus, animal and plant debris in the water.

The baby fish is a wild animal with great ornamental value, which is widely distributed in the mainland area, and because it lives in an alpine environment, it has certain requirements for the living environment.

The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

At present, due to the destruction of the living environment of baby fish due to a large number of catches, indiscriminate logging and other reasons, the state is beginning to breed them in captivity so that they can be protected to a certain extent.

Distribution and morphological characteristics

The baby fish is an amphibian with a similar juvenile size and body size, with an adult body length of 40~60 cm and a weight of 200~300 grams. The distribution area of baby fish in the mainland is not wide, mainly distributed in Sichuan, Chongqing, Hubei, Guizhou, Yunnan, Tibet and other regions. It is distributed in all provinces and cities south of the Yangtze River in the mainland.

The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

The geographical distribution of baby fish in the mainland can be divided into three regions: one is from the provinces south of the Yangtze River in Sichuan Province, extending outward to Yunnan and Guizhou with the Sichuan Basin as the center; the second is from Yunnan Province to the south to Guangxi and Guizhou; The third is from Guizhou Province to the east to Jiangsu and Zhejiang.

Although the doll fish is distributed in different areas of the mainland, its distribution range and number are generally the same, which is mainly due to the living habits and reproductive habits of the doll fish, which are not tolerant to cold and will enter hibernation when the temperature is lower than 0 °C; When the water temperature is above 30°C, it will stop eating and moving.

The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

Due to the high requirements for water temperature, when the temperature is lower than -10 ° C, death will occur. Due to the vast territory of the mainland and the complex climatic conditions, the distribution area of the doll fish is also relatively extensive, and the distribution range of the doll fish in the mainland can be seen from the provinces and cities south of the Yangtze River in the mainland.

In the southeast and southwest of the Sichuan Basin is the main distribution area of baby fish; There is a small distribution of baby fish in Guizhou; There are baby fish distribution in several prefectures and cities in Yunnan; There are also a small number of baby fish in Jiangxi.

The age of sexual maturity of doll fish is about 4~5 years, while the breeding age is 6~8 years, it can be seen that there are a large number of doll fish distribution in the southeast and southwest regions of the Sichuan Basin of the mainland and Yunnan, Guizhou and other places.

The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

The baby fish is an ancient aquatic vertebrate in the mainland, and there are many names in history, such as Chinese giant salamander, baby fish, small salamander, etc., but from the perspective of scientific research, the official name currently recognized should be giant salamander.

The baby fish is large, with a total length of more than 1 meter and a weight of more than 1 kg, generally about 40 cm in length. The body is black or brown, with irregular black markings on the side of the body, soft scales on the body surface, a large head, small, round eyes, and a pair of eardrums on the sides of the head are pronounced.

The muzzle is large, arcuate, and slightly bluntly rounded at the end of the snout; two nostrils; a pair of small warts in the middle of the upper lip; There are two nostrils on either side; There is a distinct longitudinal groove between the nostrils and the eyes. larger eyes; The distance between the eyes is less than or equal to the diameter of the eye.

The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

There is a pair of large round scales in front of the eyes, a pair of small round scales in the upper posterior area, a black longitudinal band on the left and right in front of the eye socket, slender and flat limbs, all limbs are covered with fine protrusions and ridges, fingers and toes have webbed or claw-like appendages, the tail is long and laterally flattened, the tail length can reach more than twice the body length, and the caudal fin is bifurcated.

The dorsal surface of the body is black-brown or gray-brown, and the ventral surface is white or gray-white, and the body color varies from individual to individual: adult individuals are mostly dark black-gray or dark gray; The larvae are mostly greyish-white. Adult individuals who inhabit streams are often active in shallows; Juveniles that inhabit near streams often roost in rocks, caves, under rocks, or in clear water under rocks.

The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

The body color and pattern of the doll fish vary with age and environment: the juvenile is black all over and has a black longitudinal band behind the eyes; Adults are pale in color, and there is still a black longitudinal band behind the eyes; Older individuals are grayish-white all over.

Habit characteristics

The living habits of baby fish, in addition to being related to the environment, are also affected by food, reproduction, mating and other factors, baby fish have a wide range of diet, and all kinds of animal food and plant food are fond of eating.

In general, animal food is the mainstay, such as insects, small fish, earthworms, dried earthworms, crab meat, etc., and animal food mainly includes shrimp, molluscs and crustaceans; Plant foods mainly include stems and leaves of aquatic plants, algae and fungi. Under artificial breeding conditions, it also likes to eat some animal offal, insect eggs, earthworm eggs, etc.

The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

There are two ways to reproduce baby fish: one is ovoviviparous, that is, the fertilized egg under natural conditions develops into a larvae after a few days; The other is ovoviviparous, that is, fertilized eggs develop into larvae in the womb, and the baby fish currently farmed in the mainland are ovoviviparous, that is, fertilized eggs develop into larvae in the womb.

The mating of baby fish is mostly carried out at night, and the male will swim around the female non-stop, waiting for the opportunity to chase the female; When the female fish swim to the surface, the male quickly jumps out of the water and pounces on the female.

Spawning usually takes place in March-April each year. The egg first forms a small gelatinous mass and then gradually grows into a large gel-like substance. After the eggs are released, the male and female fish begin mating. After mating, the fertilized egg develops into a transparent spheroid in the water after fertilization.

The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

Doll fish has a wide diet, eating both animal and plant foods; Loves both water and tranquility; Resistant to both cold and temperature; can endure both hunger and thirst;

It can withstand both drying and moisture; can live in groups or alone; There are both cluster and diaspora activities; Both daytime and nocturnal activities; There is both land life and water life. Doll fish like to live in groups, like to be quiet, like to gather in groups, and like to roost in groups.

reproduction

The baby fish has a long breeding cycle, can lay eggs 2 ~ 3 times a year, each time 20 ~ 50 eggs, under the condition of water temperature 15 °C ~ 20 °C, 1 year can lay eggs 3 times, baby fish eggs are white or milky white, the average diameter of the eggs is 0.36 mm, the egg weight is 0.06 g / grain, the incubation period is about 28 days, the incubation water temperature is 20 °C ~ 25 °C, after 4~5 days the fry develop to about 2 mm when it enters the egg-bearing period.

The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

Under natural conditions, it takes 4~5 months for baby fish to lay eggs and hatch, and some individuals can reproduce offspring under wild conditions.

Under artificial breeding conditions, artificial breeding can be carried out when the water temperature rises above 20 °C.

Artificial breeding is generally carried out by the method of male and female matching: male and female broodstock are put into a tank at a ratio of 1:3 for cultivation; Place the broodstock in a plastic basin over which hang a cloth or plastic bag consistent with the temperature of the water; Then adjust the water temperature to about 25°C;

The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

Lay a layer of pebbles or foam blocks on the bottom of the pool to increase the activity of the pool water and reduce the hydrostatic pressure of the pool water; After filling the water with a clean basin, the fertilized egg is placed in the water so that the fertilized egg sinks to the bottom.

When the water temperature rises above 25 °C, the broodstock begin to feed, in order to stimulate the broodstock to feed, you can put a little food (such as loach, small shrimp) around the broodstock.

Fertilized eggs can hatch juvenile fish after 6~7 days of development in water.

After hatching in the water, the baby fish first gently rub the head and abdomen of the baby fish with their hands to reduce the secretion of mucus on their body surface (the purpose is to prevent the larvae from sticking to the body when moving in the water); Then rinse the surface and abdomen of the juvenile fish with water for a long time.

The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

When the water temperature drops below 20 °C, gently rub the abdominal skin of the juvenile with your hands to promote its gonadal development; When the water temperature drops below 15°C, gently rub the skin on the back of the juvenile with your hands to stimulate its gonadal development.

Feeding management

Juvenile feeding: Baby fish raised in captivity, 2~3 days before the pond to feed the open feed, feed 2~3 times a day, each feeding amount accounts for about 3% of body weight, the best feeding at 20 °C water temperature, feeding once a day at about 5 pm, and make a record of baiting.

The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

Adult breeding: Baby fish raised in captivity can be stocked in the whole pond, or can be stocked in separate ponds according to the breeding density and broodstock size, and 15~20 animals can be stocked per square meter.

Stocking density: In culture, it should be determined according to the size of the breeding tank, water temperature, water quality, culture method and number of broodstock.

Generally, about 100 can be stocked in 1 acre pond. When the water temperature rises to 20°C, the feeding intake of baby fish increases; When the water temperature is higher than 30 °C, the food intake will be significantly reduced; When the water temperature reaches above 32°C, the baby fish stop feeding.

The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

Water quality requirements: baby fish do not have high requirements for water quality, but in the feeding process should often replace the pool water to keep the water quality fresh and the water temperature constant, generally change the water every 15 days, each time the water change is about 1/5 of the pool water.

Feeding method: baby fish is omnivore, in the artificial breeding process can be adjusted according to different seasons and growth stages and feeding time, in spring and summer when the temperature is high, it is advisable to feed in the morning and evening; When the water temperature drops below 15 °C, it should be fed at 7~9 pm.

Daily management: baby fish is an ovoviviparous animal, and the oocysts in the female fish can survive for more than 30 days after mating, so daily management should be strengthened during the feeding process.

The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

Doll fish do not have high requirements for water quality, and can generally drink pool water or spring water directly. If tap water is to be used, water should be added to 40~60 cm deep water before feeding; If the water quality is too lean or too fat, you need to change the water first and then use it for feeding; If the water quality is polluted, the water should be changed in time or treated with disinfection such as bleaching powder.

Artificial farming

The construction of artificial breeding bases requires a quiet, cool and humid environment for the growth of baby fish. Under the condition of water temperature 10~30 °C and pH value of 7.8~8.4, the growth rate is fast, and eggs can be laid throughout the year, and the spawning time is from late March to mid-May every year. Artificial breeding sites should be selected in places with high terrain, sufficient water sources and convenient transportation, preferably rectangular or square.

The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

The construction of breeding ponds should choose areas with sufficient water sources, good water quality and no pollution to build breeding ponds, and the depth of the pool water should be 60~70 cm. The pond is built in the leeward direction of the pond, and drainage ditches are set up in the pond to maintain a water depth of more than 0.5 meters. The breeding pond should be disinfected regularly, and the pond should be disinfected with quicklime powder or bleaching powder every 10 days or so.

Feed sources: The bait of baby fish mainly includes insect-like animal food such as flies, maggots, earthworms and plant food such as bloodworms. Since baby fish are fish that live in water, they should be dominated by water earthworms;

In the artificial breeding process, artificial compound feed can be used instead of raw natural food to facilitate the rapid growth of baby fish. Bait feeding should be flexibly mastered according to the change of water temperature and the feeding power of baby fish, and feed 4~6 times a day when the water temperature is 10~30 °C; When the water temperature is 20~30 °C, feed 2~3 times a day; When the water temperature is higher than 30 °C or lower than 10 °C, the number of feeding should be reduced.

The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

Water quality managementAquaculture water should maintain a certain amount of dissolved oxygen (oxygen content in air is 2 mg/L), and the dissolved oxygen content in water should not be less than 4.5 mg/L. Too low dissolved oxygen in the water can cause baby fish to float or die. When the dissolved oxygen content in water is less than 3 mg/L, new water should be added in time or an aerator should be used to increase oxygenation.

Socio-economic value

Medicinal value of baby fish: baby fish is a precious precious medicinal fish, which has the effects of replenishing deficiency and aphrodisiac, invigorating essence qi, strengthening muscles and bones, etc., and is known as one of the "Nine Fairy Fish in China".

Edible value of baby fish: The meat of baby fish is tender and delicious, rich in nutrition, and is a high-protein, low-fat aquatic product, with the characteristics of tender meat, delicious taste and rich nutrition.

The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

Medicinal value of baby fish: baby fish oil can prevent and treat colds, sore throats and other diseases; Doll fish gallbladder can clear heat and detoxify, reduce swelling and relieve pain; Doll fish liver has the effect of treating liver cancer, stomach cancer and so on; Doll fish blood can cure vomiting blood, blood dysentery and other diseases.

Doll cod liver is rich in vitamin A and is an ideal "advanced nutrition" for children; Doll fish meat: it has the effect of replenishing qi and nourishing blood, enhancing physical fitness, and aphrodisiac; Doll fish skin: it has clear heat and detoxification, reduce swelling and relieve pain, and is used for boils and ulceration.

Reproduction in the wild is the most difficult part, first of all, there must be sufficient food sources, and secondly, there must be excellent varieties, if there is not enough food, it will affect the growth of the next generation.

The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

When raising in captivity, the temperature and humidity should be controlled, the temperature should be controlled between 25~30 degrees, the humidity can be about 50%, and the suitable growth environment should be selected, such as sufficient water sources, excellent water quality, stable water quality, no pollution and other conditions of breeding.

The aquarium should be cleaned regularly during captivity, the manure and dead bait in the aquarium should be cleaned every three months or so, and the moss and algae in the aquarium should be cleaned regularly during the breeding process.

conclusion

Doll fish belongs to the amphibian anura doll fish family, is a rare animal unique to the mainland, widely distributed in the southern mountains of the mainland, in Hubei, Hunan, Jiangxi, Anhui and other provinces, and the number is large.

The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

Due to the sparse number of wild populations and the extreme susceptibility to environmental conditions during artificial farming, the growth of baby fish is slow, or even death, so artificial breeding is more difficult.

With the deepening of scientific research and the continuous improvement of people's awareness of ecological environmental protection, the genus has been listed as a national second-class key protected animal.

In order to protect this rare animal, we should treat the conservation and research of baby fish species resources with scientific rigor.

The distribution and habit characteristics of baby fish, the influence of artificial breeding industry

bibliography

1. Wang Tao: "Experimental Research on Artificial Reproduction of Doll Fish", College of Life Sciences, Jilin University, 2013.

2. Cao Xiaosong: "Research on Gender Identification and Male and Female Identification Technology of Baby Fish Juvenile Fish", Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, 2013.

3. Du Xiaoxia: Discussion on the development trend of artificial breeding technology and large-scale production of giant salamander in China, Journal of Fisheries of China, 2011.

4. Wang Yong: Technical points and suggestions for artificial breeding of giant salamanders, Journal of Fisheries Society, 2010.

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