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| − | == MALE ==
| + | <big><center>[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]</center></big> |
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| − | === Scrotum and Testes ===
| + | <big><center>[[Reproductive_System#Small_Domestic_Mammals|'''BACK TO SMALL DOMESTIC MAMMALS''']]</center></big> |
| − | * Only a very slight scrotal region is visible externally (no true scrotum).
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| − | * Thin-walled '''scrotal diverticula''' extend cranially on either side of the base of the penis.
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| − | * Each diverticulum is occupied by the tail of the '''epididymis'''.
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| − | * On either side of the anus are two '''postanal sacs'''.
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| − | ** Caudal epididymis can lie in the postanal sacs.
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| − | * '''Testes''' and head of the '''epididymis''' is in the region of the '''inguinal ring'''.
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| − | * Large fat body extends cranially into the abdominal cavity from the cranial pole of each testis.
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| − | === Accessory Sex Glands=== | + | == Male == |
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| − | | + | == Female == |
| − | ==== Vesicular Glands ==== | |
| − | * Very long and tubular.
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| − | ==== Prostate Gland ====
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| − | * Paired large ventral lobes and paired small dorsal lobes.
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| − | ==== Bulbourethral Glands ====
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| − | * Dorsolateral to '''ischiocavernosus muscles'''.
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| − | ** Ischiocavernosus muscles are enormous, swelling on either side of the rectum and meeting over its top.
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| − | === Penis ===
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| − | * Penis points caudally when relaxed and cranially when [[Erection - Anatomy & Physiology|erect]].
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| − | * 1.5cm in length
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| − | * '''Sigmoid flexure'''
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| − | * '''Os penis''' in the distal portion.
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| − | ** The small supporting bone is known as the '''baculum'''.
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| − | === Copulation ===
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| − | * [[Spermatogenesis_and_Spermiation_- Anatomy & Physiology|Spermatogenesis]] occurs at about 2-3 months.
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| − | * Copulatory maturity is not until about 8 months.
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| − | * Breeds all year round.
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| − | * '''Copulatory plug''' at mating.
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| − | == FEMALE ==
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| − | === Reproductive Tract ===
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| − | * [[Ovary - Anatomy & Physiology|Ovaries]] are just caudolateral to the [[Renal Anatomy - Anatomy & Physiology#Common Anatomy|kidneys]].
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| − | * [[Uterus - Anatomy & Physiology#Anatomical_Types_of_Uteri|Bicornuate duplex uterus]].
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| − | * [[Uterus - Anatomy & Physiology|Uterine lumena]] do not fuse.
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| − | ** The two uterine horns continue into seperate [[Cervix - Anatomy & Physiology|cervices]]
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| − | ** Open separately into a single [[Vagina and Vestibule - Anatomy & Physiology|vagina]].
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| − | * Membrane covers [[Vagina and Vestibule - Anatomy & Physiology|vaginal]] opening except at oestrus and during [[Normal Parturition - Anatomy & Physiology|parturition]].
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| − | === Puberty and Sexual Maturity ===
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| − | * '''Puberty''' at ~8 months
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| − | ** 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.
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| − | === Oestrous Cyclicity ===
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| − | * In the Northern Hemisphere the breeding season is November-May.
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| − | * Seasonally polyoestrus with a mean cycle of ~40 days.
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| − | * Post-partum oestrus.
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| − | ** Often two litters per year, three are possible.
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| − | * Breeding life is ~10 years.
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| − | === Gestation and Offspring===
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| − | ==== Gestation ====
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| − | * Long gestation period: 111 days.
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| − | ==== Litter ====
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| − | * Litter size 1-6
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| − | * Precocious offspring
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| − | ** Weaning age is 6 weeks.
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| − | === Mammary Gland ===
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| − | * Three pairs
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| − | ** One inguinal pair
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| − | ** Two lateral thoracic
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| − | * Teats protrude sideways, allowing the young to sit beside the dam and suckle.
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| − | [[Category:Small Mammal Reproduction]]
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| − | [[Category:Bullet Points]]
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