Difference between revisions of "Chinchilla Reproduction - Anatomy & Physiology"
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* Large fat body extends cranially into the abdominal cavity from the cranial pole of each testis. | * Large fat body extends cranially into the abdominal cavity from the cranial pole of each testis. | ||
| − | |||
== Accessory Sex Glands== | == Accessory Sex Glands== | ||
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* '''Bulbourethral glands''' are dorsolateral to '''ischiocavernosus muscles'''. | * '''Bulbourethral glands''' are dorsolateral to '''ischiocavernosus muscles'''. | ||
** Isciocavernosus muscles are enormous, swelling on either side of the rectum and meeting over its top. | ** Isciocavernosus muscles are enormous, swelling on either side of the rectum and meeting over its top. | ||
| − | + | ||
== Penis == | == Penis == | ||
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** The small supporting bone is known as the '''baculum'''. | ** The small supporting bone is known as the '''baculum'''. | ||
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== Copulation == | == Copulation == | ||
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* Breeds all year round. | * Breeds all year round. | ||
* '''Copulatory plug''' at mating. | * '''Copulatory plug''' at mating. | ||
| + | |||
| + | ---- | ||
| + | |||
| + | = FEMALE = | ||
| + | |||
| + | == Reproductive Tract == | ||
| + | |||
| + | * [[Female_Reproductive_Tract_-The_Ovary_-_Anatomy_%26_Physiology|Ovaries]] are just caudolateral to the [[Kidney_-_Comparative_Anatomy_%26_Physiology|kidneys]]. | ||
| + | * [[Female_Reproductive_Tract_-The_Uterus_-_Anatomy_%26_Physiology#Anatomical_Types_of_Uteri|Bicornuate duplex uterus]]. | ||
| + | * [[Female_Reproductive_Tract_-The_Uterus_-_Anatomy_%26_Physiology|Uterine lumena]] do not fuse. | ||
| + | ** The two uterine horns continue into seperate [[Female_Reproductive_Tract_-The_Cervix_-_Anatomy_%26_Physiology|cervices]] | ||
| + | ** Open separately into a single [[Female_Reproductive_Tract_-The_Vagina/Vestibule_-_Anatomy_%26_Physiology|vagina]]. | ||
| + | * Membrane covers [[Female_Reproductive_Tract_-The_Vagina/Vestibule_-_Anatomy_%26_Physiology|vaginal]] opening except at oestrus and during [[Reproductive_System#Parturition|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 [[Reproductive_System#Gestation|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. | ||
Revision as of 11:31, 21 July 2008
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 are very long and tubular.
- Prostate gland has paired large ventral lobes and paired small dorsal lobes.
- Bulbourethral glands are 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.