Difference between revisions of "Chinchilla Reproduction - Anatomy & Physiology"

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(New page: <big><center>'''BACK TO REPRODUCTIVE SYSTEM'''</center></big> <big><center>'''BACK TO SMALL DOMESTIC MAMMALS'''</cen...)
 
 
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<big><center>[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]</center></big>
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== MALE ==
  
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<big><center>[[Reproductive_System#Small_Domestic_Mammals|'''BACK TO SMALL DOMESTIC MAMMALS''']]</center></big>
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=== Scrotum and Testes ===
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* 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===
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 +
 
 +
==== Vesicular Glands ====
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* Very long and tubular.
 +
 
 +
==== Prostate Gland ====
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* Paired large ventral lobes and paired small dorsal lobes.
 +
 
 +
==== Bulbourethral Glands ====
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 +
* Dorsolateral to '''ischiocavernosus muscles'''.
 +
** Ischiocavernosus muscles are enormous, swelling on either side of the rectum and meeting over its top.
 +
 
 +
=== 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.
 +
 
 +
== FEMALE ==
 +
 
 +
=== Reproductive Tract ===
 +
 
 +
* [[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 ===
 +
 
 +
* 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

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.
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