First, reproductive tigrina frogs wake up soon after they wake up and they are breeding. The breeding period is from May to September. Its reproduction, development and metamorphosis are all done in water. The frog did not have a mating device. Before the spawning, they first hug in paddy fields, ponds, or gutters before spawning. At the same time as the female frog spawns, the male frogs are discharged and fertilized in water (in vitro fertilization). According to their gonad development, Rana tigrina is a multiple spawning type.
(I) Seasonal changes of gonads
1. The development of the ovarian ovary of Ovarian tiger frogs varies with the seasons. In the South Central region, one-month-old ovaries are in the oocyte stage; two-month-old ovaries are in the primary follicular phase; oocytes in the ovaries three to eleven-month-old develop into small growth stages; and the ova of the 22-month-old ovary The mother cell develops at a large growth stage; the 2-year-old female frog develops sexual maturity, and the oocyte nucleus has been biased toward the animal pole. At the time of spawning, the ovary develops to the highest peak. After oviposition, the ovaries begin to shrink, but at this time there are still eggs of different developmental stages in the ovary. Black and yellow eggs can be seen with the naked eye. From the tissue section of the postpartum ovary, large oocytes can be seen. Cells and mature follicles, such ovaries may be spawned for the second time. After some frogs have produced one egg, the eggs remaining in the ovary are gradually absorbed. The ovary is mainly composed of black, which gradually changes to light yellow, and finally to light yellow. It enters the rest period of gonadal development, and the weight is lightest at this time. There are differences between individuals in this process of change. With the development of the ovary, the body of fat rapidly shrinks, indicating that the body of fat not only provides the nutrients needed by the body during winter, but also partially provides the nutrients needed for ovarian development.
2. In the first personality cycle, the testis develops faster than the ovary. The testes within 2 months of age are in the spermatogonia stage, with only a few primary spermatocytes; 3-6 months of age are the secondary spermatocytes; 10-11 months of age have matured and the sperm almost occupied the song. Half of the seminiferous tube shows that the male tiger frog can reach sexual maturity by 1 instar.
(b) The amount of egg-returning is very different among individuals, and it can be 6-7 times different. It is usually closely related to the size of the individual. Individuals have small amounts of ovulation, and individual individuals have more than the amount of eggs, but there are also many small individuals.
(3) Egg-laying amount The tiger-horse frog is a multiple spawning type, and the amount of egg production per time varies greatly. In the field observation table, the small egg group has only 580 eggs and the large egg group reaches 2,620. (Chen Huihui, 1983). In the case of artificial oxytocin production, up to 7020 tablets (Pan Yuhua, 1990).
Tiger frog eggs have a diameter of 1.9 mm or more, animals are extremely black, and plants are milky or pale yellow. For many yellow eggs, but the content of yolk less than fish, pigment concentration in the animal pole, the absorption of sunlight, egg growth is conducive to the development. As the yolk is concentrated in the hemisphere of the plant, the plant is extremely heavy and towards the bottom, the animal has very little yolk and therefore faces upwards. The resulting eggs are glued into small pieces that float on the surface of the water. Each piece has more than ten to ten tens of eggs. Eggs are produced in permanent ponds or puddles.
Second, hibernating tiger frog enters hibernation below 15 degrees Celsius. Most hibernation sites are in caves near the icy waterways, or in puddles at groundwater outlets. The temperature of the hibernation site is around 8-10 degrees Celsius. Tiger frogs are not cold-tolerant and hibernating under artificial breeding conditions. A large number of deaths have occurred. During the hibernation period, tiger frogs do not eat or move, and their metabolic activities such as respiration are very weak. However, hibernation is not necessary for tiger frogs, and the temperature or water temperature is high (above 15 degrees Celsius). Even if it does not hibernate in winter, it is possible to use hot springs and waste heat sources in the factory to warm up the tiger frogs in winter.
(I) Seasonal changes of gonads
1. The development of the ovarian ovary of Ovarian tiger frogs varies with the seasons. In the South Central region, one-month-old ovaries are in the oocyte stage; two-month-old ovaries are in the primary follicular phase; oocytes in the ovaries three to eleven-month-old develop into small growth stages; and the ova of the 22-month-old ovary The mother cell develops at a large growth stage; the 2-year-old female frog develops sexual maturity, and the oocyte nucleus has been biased toward the animal pole. At the time of spawning, the ovary develops to the highest peak. After oviposition, the ovaries begin to shrink, but at this time there are still eggs of different developmental stages in the ovary. Black and yellow eggs can be seen with the naked eye. From the tissue section of the postpartum ovary, large oocytes can be seen. Cells and mature follicles, such ovaries may be spawned for the second time. After some frogs have produced one egg, the eggs remaining in the ovary are gradually absorbed. The ovary is mainly composed of black, which gradually changes to light yellow, and finally to light yellow. It enters the rest period of gonadal development, and the weight is lightest at this time. There are differences between individuals in this process of change. With the development of the ovary, the body of fat rapidly shrinks, indicating that the body of fat not only provides the nutrients needed by the body during winter, but also partially provides the nutrients needed for ovarian development.
2. In the first personality cycle, the testis develops faster than the ovary. The testes within 2 months of age are in the spermatogonia stage, with only a few primary spermatocytes; 3-6 months of age are the secondary spermatocytes; 10-11 months of age have matured and the sperm almost occupied the song. Half of the seminiferous tube shows that the male tiger frog can reach sexual maturity by 1 instar.
(b) The amount of egg-returning is very different among individuals, and it can be 6-7 times different. It is usually closely related to the size of the individual. Individuals have small amounts of ovulation, and individual individuals have more than the amount of eggs, but there are also many small individuals.
(3) Egg-laying amount The tiger-horse frog is a multiple spawning type, and the amount of egg production per time varies greatly. In the field observation table, the small egg group has only 580 eggs and the large egg group reaches 2,620. (Chen Huihui, 1983). In the case of artificial oxytocin production, up to 7020 tablets (Pan Yuhua, 1990).
Tiger frog eggs have a diameter of 1.9 mm or more, animals are extremely black, and plants are milky or pale yellow. For many yellow eggs, but the content of yolk less than fish, pigment concentration in the animal pole, the absorption of sunlight, egg growth is conducive to the development. As the yolk is concentrated in the hemisphere of the plant, the plant is extremely heavy and towards the bottom, the animal has very little yolk and therefore faces upwards. The resulting eggs are glued into small pieces that float on the surface of the water. Each piece has more than ten to ten tens of eggs. Eggs are produced in permanent ponds or puddles.
Second, hibernating tiger frog enters hibernation below 15 degrees Celsius. Most hibernation sites are in caves near the icy waterways, or in puddles at groundwater outlets. The temperature of the hibernation site is around 8-10 degrees Celsius. Tiger frogs are not cold-tolerant and hibernating under artificial breeding conditions. A large number of deaths have occurred. During the hibernation period, tiger frogs do not eat or move, and their metabolic activities such as respiration are very weak. However, hibernation is not necessary for tiger frogs, and the temperature or water temperature is high (above 15 degrees Celsius). Even if it does not hibernate in winter, it is possible to use hot springs and waste heat sources in the factory to warm up the tiger frogs in winter.
Grape Seed Extract,Pine Bark Extract,Flaxseed Lignans
Medicine,Health Food Co., Ltd. , http://www.cn-medicines.com