Marine Mammal Theriogenology & Neonatology

Question 1

What hormone is used for estrus synchronization and how long until ovulation when withdrawn in cetaceans?

Answer 1

Progestin (usually altrenogest), ovulation 20-30 days after withdrawn (F8)

Question 2

At what point during the cetacean cycle is it recommended to perform AI?

Answer 2

After LH surge; detection of LH survia is via urinary hormone monitoring TID (F8)

Question 3

Gestation period, bottlenose dolphins

Answer 3

376 days

Question 4

Pregnancy confirmation, bottlenose dolphins

Answer 4

Progesterone in weekly blood samples, peaks wks 9-12 after conception, confirmation based on persistence in progesterone rise, not increase (F8)

Question 5

Most common presentation of fetus during birth

Answer 5

Fluke-first (F8)

Question 6

Where are cetacean mammary glands located?

Describe the anatomy of the vagina and penus of cetaceans.

What accessory sex glands do cetaceans have? What about pinnipeds?

Where are the testes located?

Answer 6

• Urogenital/Mammary
  
  • Cetacean mammary glands within mammary slits; males sometimes have slits
  • Reproductive tract: easily accessible upon entry to the caudal abdominal cavity during necropsy or surgery
  • Vagina: contains single or multiple transverse folds/valves
  • Penis: fibroelastic, sigmoid flexure (similar to ruminants) in cetaceans
    
    • Pinnipeds, sea otters, polar bears: baculum
  • Prostate: only accessory sex gland in pinnipeds and cetaceans
  • Testicles: testicond (intra-abdominal) in cetaceans and sirenians
    
    • Testes and epididymides have countercurrent exchange surrounding them that is delivering cooled venous blood

Question 7

What type of placentation do pinnipeds have?

What is unique about its color?

Where are the mammae located?

Describe the uterine anatomy of the california sea lion.

Where are the testicles located in otarrid and phocid seals?

Answer 7

• Urogenital
  
  • Pinniped placenta: zonary, endotheliochorial with a deep orange because of marginal hematoma w/ iron stores
  • Prostate: only accessory sex gland in pinnipeds and cetaceans
• Otarrids
  
  • Urogenital/Mammary
    
    • 2 mammary slits lateral to urogenital opening
    • California sea lion – no true uterine body, horns exit into cervix through independent cervical os
    • Testicles: shallow scrotum that testes ascend and descend based on temperature
• Phocids
  
  • Urogenital/Mammary
    
    • Testicles: inguinal canal

Question 8

Describe the reproductive anatomy of sirenians.

Where are the mammary glands?

Where are the testicles?

Answer 8

• Urogenital/Mammary
  
  • Axillary mammary glands (unlike other marine mammals)
  • Reproductive tract: found after removal of GIT on necropsy (compared to first thing you see on necropsy of a cetacean)
  • Testicles: testicond (intra-abdominal) in cetaceans and sirenians
  • Testes and epididymides have countercurrent exchange surrounding them that is delivering cooled venous blood