CATDOLL : CATDOLL: What are the commonly used hormones for fish?

What are the commonly used hormones for fish?

Like other vertebrates, fish also contain a variety of hormone substances. These substances are secreted by the endocrine glands in the fish body. According to their chemical nature, they can be divided into three categories: nitrogen-containing hormones, steroid hormones and fatty acid hormones.

Under normal conditions, the effects of various hormones are balanced with each other. However, if there is an abnormality in the endocrine glands, the balance of hormones will be disrupted, and the normal metabolism and physiological functions will be disturbed, thus affecting the normal development of fish. Therefore, hormones are extremely important for the growth and development of fish.

The effects of hormones on fish are mainly manifested in three aspects. ① Hormones promote the growth of fish. Studies have shown that selective oral administration of hormones to fish can not only significantly increase the weight and length of fish, but also increase the protein content in fish cells. ② Hormones promote the development, maturation and ovulation of fish gonads. Aquatic workers make synthetic luteinizing hormone-releasing hormone analogs into aqueous or oily solutions, and inject them into grass carp and black carp with poor maturity in advance, which has a significant ripening effect, and the effect is particularly good with oily solutions. At present, people have widely used carp pituitary homogenate or other hormones to induce labor in grass carp, black carp and fish. Aquaculture technicians have also successfully used intraperitoneal or intramuscular injections of carp pituitary homogenate or other hormones to promote spawning or spermatogenesis in catfish and eels, and accelerate the reproduction and growth of fish.

③ Hormones can induce the sex change of fish and increase the yield. Except for a few fish, most fish are females larger than males, and some fish can be several to ten times larger. Therefore, by using hormones, a large number of single-sex fish can be cultivated, which is of great significance to increasing the yield of fish farming.

Commonly used hormones for fish:

1. Luteinizing hormone-releasing hormone analogs

Also known as LRH-A. This product is a white crystalline powder. It is easily soluble in water, and the aqueous solution is stable. It is easy to become ineffective under direct sunlight. This product has the function of stimulating the pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH), thereby promoting the maturation and ovulation of egg cells and promoting the formation of sperm.

2. Pituitary PC

It is a product of the pituitary gland of fish fixed with acetone. The pituitary gland mainly contains two types of hormones: follicle-stimulating hormone and luteinizing hormone. Injecting the pituitary suspension into the fish body can promote the further maturation of the fish gonads and cause the parent fish to ovulate and ejaculate. This product is used to induce spawning in parent fish. Dilute with fish saline and inject into the chest cavity, abdomen or muscle. Dosage: 4-6 mg per kilogram of body weight, half for male fish. It should be kept in a cool, dry place and shaded.

Fish hormones:

1. Pituitary PC

This product is white, nearly round particles, and is a product of the pituitary gland of fish fixed with acetone. The pituitary gland mainly contains two types of hormones: follicle-stimulating hormone and luteinizing hormone. Injecting the pituitary suspension into the fish body can promote the further maturation of the fish gonads and cause ovulation and ejaculation of the parent fish. This product is used to induce spawning of parent fish. Dilute with fish saline and inject into the chest cavity, abdomen or muscle. Dosage: 4-6 mg per kilogram of body weight, half for male fish. It should be kept in a cool, dry place and shaded.

2. Human chorionic gonadotropin

Also known as HCG. This product is white, off-white or light yellow powder, which is easily ineffective when exposed to heat. It is easily soluble in water, but the aqueous solution is not easy to preserve. The solution is colorless or slightly yellow. This product is extracted from the urine of pregnant women. Its main component is luteinizing hormone (LH), which can promote the continued development and maturation of female fish follicles, induce ovulation, and after ovulation, transform the theca and granulosa cells into corpus luteum cells. For male fish, it promotes the secretion of male hormones. It can be used to induce labor in various farmed fish. Dilute with fish saline and inject into the chest cavity, abdomen or muscle. Dosage: 1000-1500 units per kilogram of fish body weight, half for male fish. It should be kept in a cool and dry place away from light.

3. Luteinizing hormone-releasing hormone analogs

Also known as LRH-A. This product is a white crystalline rubber-based powder. It is easily soluble in water, and the aqueous solution is stable. It is easy to become ineffective under direct sunlight. This product has the function of stimulating the pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH), thereby promoting the maturation and ovulation of egg cells and promoting the formation of sperm. Its products include fish ovulation hormone No. 2 and fish ovulation hormone No. 3. The former is suitable for aphrodisiac and ripening of various fish; the latter is suitable for early broodstock induced spawning, especially for broodstock with poor gonadal maturity. Dilute with fish physiological saline and inject into the chest, abdomen or muscle. The broodstock ripening is 10 to 25 days before induced spawning, and the injection dose is 0.2 to 0.5 micrograms per kilogram of body weight. Male fish are halved or not injected; the injection dose for broodstock induced spawning is 10 to 15 micrograms per kilogram of body weight. Male fish are halved. It should be kept in a dark place at a low temperature and dry place.

Why do female guppies attack fish that approach them?

It may be because the female guppy is about to give birth. She likes to be alone and will chase and bite any fish that approach her. Before giving birth, she will become restless and jump up and down, so she should be separated from the male fish.

The signs of its birth are: the abdomen is swollen, and the black spots on both sides of the anus are darker. This is because the female guppy is about to give birth two days before. The method of inducing birth is to change the water and increase the

If the water temperature is 1-2 degrees Celsius, the baby will be born within 1-2 days. But don't use this method often. If you change the water too often and the water temperature changes too much, the fish will get sick. After the female guppy gives birth, do not change the water within three days, otherwise it will get sick easily. If conditions permit, put the female guppy alone in a tank, otherwise the baby fish will be eaten by other large guppies after they are born. The more large guppies there are, the higher the probability of being eaten.

[Edit this paragraph] [Basic information]

Origin: River basins in Venezuela, Guyana, West Indies, etc.

Water temperature 22～24℃

PH 7.5～8.5

Food: earthworms, water fleas and artificial synthetic bait

It has a gentle temperament, is lively and active, and can be kept together with small fish.

[Edit this section] Introduction to Guppy

Guppies are 4 to 5 cm long and are the easiest tropical freshwater fish to keep. They are favored by tropical freshwater fish keepers for their rich colors, diverse shapes and strong reproductive capacity. In particular, the offspring produced will have many fish species with different colors and shapes from their parents. There are obvious differences between male and female fish. The size of male fish is only about half of that of female fish. Male fish have rich and colorful body colors and tail shapes of various shapes.

Also known as rainbow fish, million fish, and Kubi fish. Guppies are slender and have extremely beautiful tail fins. Adult male fish are about 3 cm long, with bright colors such as light red, light green, light yellow, red, purple, peacock blue, etc. The tail length accounts for about 2/3 of the body length, and there are 1-3 rows of neatly arranged black round spots or a large colorful round spot on the tail fin. The tail fin shapes include round tail, flag tail, triangle tail, torch tail, harp tail, tooth tail, swallow tail, skirt tail, upper sword tail, lower sword tail, etc. Adult female fish can reach 5-6 cm in length, with the tail length accounting for more than 1/2 of the body length. The body color is more monotonous than that of male fish, and the tail fin is bright blue, yellow, light green, light blue, and is dotted with black spots of varying sizes. The tail fin of this fish is very distinctive, and it looks like a small fan flapping when swimming. Guppies are highly adaptable, with the most suitable growth temperature of 22-24℃. They prefer slightly alkaline water with a pH of 7.2-7.4. They have a wide range of food habits, are mild-tempered, lively and active, and can be mixed with other tropical fish. Guppies are easy to raise, but to obtain fish with bright colors and beautiful shapes, they need a large water body, more aquatic plants, fresh bait, and suitable water quality from the fry stage. Guppies have mature gonads at 4 to 5 months of age, but their reproductive capacity is very weak. In water with a temperature of 24℃ and a hardness of about 8 degrees, they can reproduce once a month. The number of fry produced each time varies depending on the size of the fish, ranging from more than 10 to 70 to 80. When the abdomen of the female fish swells and bulges, and a clear black fetal spot appears near the anus, it is a sign of labor.

Guppies, the representative of ovoviviparous fish, have earned the title of "million-dollar fish" due to their periodic productivity, and are therefore often seen in the homes of those who are new to raising ornamental fish. Early guppies were mainly imported from Southeast Asia and produced in southern China. The common characteristics of the two are that they require very high water hardness and are both raised outdoors, so they are fully exposed to the sun, so their colors appear particularly bright. Although guppies were initially accepted by all walks of life, they were left with a tragic impression of being mixed with other fish species and being cheap and easy to die. Therefore, although the development of domestic ornamental fish has a history of decades, guppies have remained the same for decades without any progress. Although there have been several waves of promotion of guppies during this period, they have always ended in failure due to the lack of favorable conditions. The main reason is that the domestic ornamental fish industry has reached a bottleneck after decades of high development, so this wave of advocacy activities has finally received responses from all parties, allowing guppies to establish a new field in the ornamental fish industry. Guppies are often the first fish species raised by beginners, but they are also often the fish species that people who have been raising fish for decades pick up again. This phenomenon just illustrates the characteristics of guppies: they are easy to understand but difficult to master. No wonder people are so fascinated by them and are willing to abandon all other fish species and keep only guppies.

Guppies are ovoviviparous fish. They have strong reproductive capacity and early sexual maturity. After 3-4 months of breeding, young fish will enter the mature stage and reproduce offspring. The early or late sexual maturity is closely related to the water temperature and breeding conditions.

When breeding guppies, you should choose a larger aquarium with a water temperature of 26 degrees Celsius. The pH should be 6.8-7.4. At the same time, you should plant more aquatic plants and then add breeding fish in a ratio of 1 male to 4 females. When the fish are in estrus, the abdomen of the female fish gradually swells and black fetal spots appear. The male fish will constantly chase the female fish at this time, and the male fish's copulator will be inserted into the female fish's cloaca to discharge sperm for internal fertilization. When the female fish's fetal spots become large and black and the anus protrudes, it can be scooped into another aquarium to wait for delivery.

The temperature in the birthing box should be 1-2 degrees higher than the original water temperature. Put moss or water plants at the bottom of the box to provide a shelter for the small fish. After the female fish gives birth, it should be taken out immediately to avoid eating the fry. Alternatively, plastic sheets should be used to form a funnel-shaped isolation wall, which should be inserted into the water. The female fish that gives birth should be placed in the funnel so that the fry will fall into the water outside the funnel from the hole under the funnel after they are born, and the female fish will not be able to eat the fry.

Guppies give birth once a month, and depending on the size of the female fish, they can produce 10-120 fry each time. The annual output is quite large, so they are called "million fish". When breeding, care should be taken not to keep more than three generations of breeding fish in the same litter, so as to avoid continuous inbreeding leading to breed degeneration, making the offspring smaller and smaller, and the tail fin shorter. It is best to introduce fish of the same species for purposeful distant hybridization to prevent the degeneration of the species and achieve the goal of improving the species. However, guppies have a very short lifespan, usually only 2-3 years. The first litter generally produces fewer fish, about 10 to 80 fish; the second litter produces about 80 to 120 fish. The price ranges from a few yuan to dozens or even hundreds of yuan per fish.

Guppies will fight for territory in a narrow area, which may even lead to the death of the fish, so it is suitable to breed a single guppy when the space is small.

Other fish may eat the young when they are giving birth. The fish with a belly bigger than the round one will hide alone in a corner of the fiberglass or in the water plants of the fiberglass. There is a big black spot on the belly. It is timid and has a lot of eggs. Generally, if it is fed properly, it can produce from a few to more than 100 eggs per month.

Pay more attention to its stomach and feed it enough food every day. Otherwise, the small fish will eat it if you don't know about it. It attacks other fish. You mean the male fish? Maybe it doesn't like it. I always isolate my small fish when its stomach is getting bigger! To prevent the male fish from always teasing it.

It's time to give birth to small fish~ Take them out and raise them separately~