Difference between revisions of "Chinchilla Reproduction - Anatomy & Physiology"
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− | + | == MALE == | |
− | + | === Scrotum and Testes === | |
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− | = | ||
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− | == Scrotum and Testes == | ||
* Only a very slight scrotal region is visible externally (no true scrotum). | * 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. | * Thin-walled '''scrotal diverticula''' extend cranially on either side of the base of the penis. | ||
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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. | ||
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− | == Accessory Sex Glands== | + | === Accessory Sex Glands=== |
+ | |||
− | * | + | ==== Vesicular Glands ==== |
− | + | * Very long and tubular. | |
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− | == | + | ==== Prostate Gland ==== |
− | * Penis points caudally when relaxed and cranially when [[ | + | * Paired large ventral lobes and paired small dorsal lobes. |
+ | |||
+ | ==== Bulbourethral Glands ==== | ||
+ | |||
+ | * Dorsolateral to '''ischiocavernosus muscles'''. | ||
+ | ** Ischiocavernosus muscles are enormous, swelling on either side of the rectum and meeting over its top. | ||
+ | |||
+ | === Penis === | ||
+ | |||
+ | * Penis points caudally when relaxed and cranially when [[Erection - Anatomy & Physiology|erect]]. | ||
* 1.5cm in length | * 1.5cm in length | ||
* '''Sigmoid flexure''' | * '''Sigmoid flexure''' | ||
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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 === |
− | * [[ | + | * [[Spermatogenesis_and_Spermiation_- Anatomy & Physiology|Spermatogenesis]] occurs at about 2-3 months. |
* Copulatory maturity is not until about 8 months. | * Copulatory maturity is not until about 8 months. | ||
* Breeds all year round. | * Breeds all year round. | ||
* '''Copulatory plug''' at mating. | * '''Copulatory plug''' at mating. | ||
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+ | == FEMALE == | ||
+ | |||
+ | === Reproductive Tract === | ||
+ | |||
+ | * [[Ovary - Anatomy & Physiology|Ovaries]] are just caudolateral to the [[Renal Anatomy - Anatomy & Physiology#Common Anatomy|kidneys]]. | ||
+ | * [[Uterus - Anatomy & Physiology#Anatomical_Types_of_Uteri|Bicornuate duplex uterus]]. | ||
+ | * [[Uterus - Anatomy & Physiology|Uterine lumena]] do not fuse. | ||
+ | ** The two uterine horns continue into seperate [[Cervix - Anatomy & Physiology|cervices]] | ||
+ | ** Open separately into a single [[Vagina and Vestibule - Anatomy & Physiology|vagina]]. | ||
+ | * Membrane covers [[Vagina and Vestibule - Anatomy & Physiology|vaginal]] opening except at oestrus and during [[Normal Parturition - Anatomy & Physiology|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=== | ||
+ | |||
+ | ==== Gestation ==== | ||
+ | |||
+ | * Long gestation period: 111 days. | ||
+ | |||
+ | ==== Litter ==== | ||
+ | |||
+ | * 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. | ||
+ | |||
+ | |||
+ | [[Category:Small Mammal Reproduction]] | ||
+ | [[Category:Bullet Points]] |
Latest revision as of 13:50, 5 July 2012
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.
- Ischiocavernosus 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
Gestation
- Long gestation period: 111 days.
Litter
- 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.