Biological and physiological characteristics 1. Gophers belong to the class Mammalia, order Rodentia, family Muridae, and subfamily Silkworm. It is an animal brought into the laboratory after being trained from wild animals.
2. Gophers are diurnal and nocturnal animals. They are generally most active between 8 and 11 o'clock at night. They land on their abdomens when moving and are not agile. They build nests with skillful hands. Their teeth are very hard and can bite through thin wires. They have a strong habit of storing food. It makes a strong metallic sound when excited. Female rats are stronger than male rats. It is difficult for female rats to live with male rats except during estrus, and male rats are easily bitten by female rats.
3. The tail is short and has cheek pouches. The hamster cheek pouch is a special immunological area lacking histocompatibility antigens and is a good area for tissue culture, human tumor transplantation and observation of microcirculatory changes. 4． The reproductive cycle is short. The gestation period is 16 (14-17) days, which is the shortest gestation period among rodents. Gophers mature quickly. Female rats are sexually mature in one month and can reproduce after that, and male rats can mate in 2.5 months. The lactation period lasts for 20 to 25 days. After weaning, male rats are 2 months old and female rats are ready for breeding at 1.5 months old. When mature, male rats weigh about 100 grams and female rats weigh about 120 grams. During the mature period, female rats are not allowed to approach male rats except during estrus.
5. It has strong production capacity and rapid growth and development. Each female rat can give birth to 7 to 8 litters per year, with 5 to 10 litters per litter, with an average of about 7 litters. The cubs grow and develop rapidly after birth and are born naked. On the 3rd to 4th day, the ear shells begin to protrude from the body, and then open up. On the 4th day, hair grows. On the 12th day, they can crawl out of the nest to look for food. On the 14th day, their eyes open. While looking for food, they are fed by the mother rat juice. They grow very fast.
6. There is a habit of drowsiness. When sleeping deeply, the muscles of the whole body are relaxed and it is difficult to wake up. Sometimes it is mistaken for death. Hibernation occurs when the room temperature is low, usually at 8 to 9°C. At this time, body temperature, heartbeat, respiratory rate, and basal metabolic rate all decrease. If the room temperature is lower than 13℃, the cubs will easily freeze to death. It is best to keep the room temperature at 20-25℃ and the relative humidity at 40-70%.
7. Aggressiveness is their behavioral characteristic and it is difficult to raise them in groups. Golden gophers have a bad habit of eating their young when they are first born.
8． Chinese hamsters are prone to true diabetes, with blood sugar levels 2 to 8 times higher than normal, pancreatic islets degenerating, and β-cells degenerating, making them easy to develop into diabetic strains.
9. Have the habit of storing food. Its cheek pouches can be fully expanded and have great storage capacity, making them easy to eat during hibernation. There are deep cheek pouches on each side of the gopher's mouth, generally 3.5 to 4.5 cm deep and 2 to 3 cm in diameter, extending to the neck behind the ears. Large amounts of food are moved into the nest through the cheek pouches.
10． The reaction of hamsters to skin transplantation is very special. Under normal circumstances, skin transplants between individuals of non-inbred closed groups of guinea pigs can survive and survive for a long time. However, skin transplants between animals from different populations can It is 100% unable to survive and will be rejected.
11. The body temperature of golden hamsters is related to the season. In summer, it is generally 38.7±0.3℃, and it also changes within a day. The body temperature is highest at 9 to 10 o'clock in the evening, and is lower from noon to evening. Its body temperature rises at 3 to 5 hours and 10 o'clock in the morning. The temperature in the cheek pouch is 37±1°C. The rectal temperature of male rats and the cheek pouch temperature are roughly the same, while the rectal temperature of female rats is 1 to 2°C lower than the cheek pouch temperature.
12. The heart rate of golden hamster is 400 beats/min, the respiratory rate is 73.6 (33~127) times/min, the respiratory volume is 60 (33.3~82.8) ml/min, the blood volume is 5% of the body weight at 20~21°C, and the life span is Below, 2.3ml of oxygen is consumed per gram of body weight per hour. Carotid artery blood pressure is 78.7~101.3mmHg at 8 to 12 weeks old, 64.3~88.3mmgHg at 12 to 17 months old, 65.5~92.5mmHg at 17 to 24 months old, 62.0~91.8mmHg at 24 months old and above, and the total number of red blood cells 5.9~8.3 million/mm3, hemoglobin 14.85~16.20g/100ml blood, total white blood cell count 7.200~8.480/mm3, adult hamster 2.5~3.0 years old.
13． The anatomical and physiological characteristics of Chinese hamsters (black-lined hamsters) and golden hamsters are basically similar, but there are also some differences. For example, Chinese hamsters have fewer and larger chromosomes, and diploid cells 2n=22. Most of them can identify each other and locate each other. It is clear, especially the Y chromosome, which is unique in morphology and easy to identify.
There is no gallbladder, and the length of the large intestine is twice as short as that of the golden hamster, but its brain weight and testicles are nearly twice as heavy as those of the golden hamster.