Chinchilla Reproduction - Anatomy & Physiology
Jump to navigation
Jump to search
BACK TO REPRODUCTIVE SYSTEM
BACK TO SMALL DOMESTIC MAMMALS
MALE
Scrotum and Testes
- Only a very slight scrotal region is visible externally (no true scrotum).
- Thin-walled scrotal diverticula extend cranially on either side of the base of the penis.
- Each diverticulum is occupied by the tail of the epididymis.
- On either side of the anus are two postanal sacs.
- Caudal epididymis can lie in the postanal sacs.
- Testes and head of the epididymis is in the region of the inguinal ring.
- Large fat body extends cranially into the abdominal cavity from the cranial pole of each testis.
Accessory Sex Glands
Vesicular Glands
- Very long and tubular.
Prostate Gland
- Paired large ventral lobes and paired small dorsal lobes.
Bulbourethral Glands
- Dorsolateral to ischiocavernosus muscles.
- Isciocavernosus muscles are enormous, swelling on either side of the rectum and meeting over its top.
Penis
- Penis points caudally when relaxed and cranially when erect.
- 1.5cm in length
- Sigmoid flexure
- Os penis in the distal portion.
- The small supporting bone is known as the baculum.
Copulation
- Spermatogenesis occurs at about 2-3 months.
- Copulatory maturity is not until about 8 months.
- Breeds all year round.
- Copulatory plug at mating.
FEMALE
Reproductive Tract
- Ovaries are just caudolateral to the kidneys.
- Bicornuate duplex uterus.
- Uterine lumena do not fuse.
- Membrane covers vaginal opening except at oestrus and during parturition.
Puberty and Sexual Maturity
- Puberty at ~8 months
- Puberty can be same year as birth, but if the chinchilla is born late in the year it will not reach puberty until the next breading season.
Oestrous Cyclicity
- In the Northern Hemisphere the breeding season is November-May.
- Seasonally polyoestrus with a mean cycle of ~40 days.
- Post-partum oestrus.
- Often two litters per year, three are possible.
- Breeding life is ~10 years.
Gestation and Offspring
- Long gestation period: 111 days
- Litter size 1-6
- Precocious offspring
- Weaning age is 6 weeks.
Mammary Gland
- Three pairs
- One inguinal pair
- Two lateral thoracic
- Teats protrude sideways, allowing the young to sit beside the dam and suckle.