What are the main differences of the rabbit skeleton
- Suprahamate bone (scapular process)
- Distal 2/3rds of tibia and fibula are fused
- Completely fused radius and ulna
- Large pinnae. Very vascular and mobile.
- Large lateral orbits
- Powerful hindlimbs; short forelimbs for digging
- Herbivore teeth
Describe the digestive system of the rabbit
Monogastric with well-developed sphincters - rabbits cannot vomit.
Hind-gut fermenters/ non-ruminant herbivores
Coprophagy
Liver has 4 lobes
Small intestine is long and terminates at caecum (where fermentation of plant material takes place) at the sacculus rotundus (swelling of gut between ileum and caecum). Then onto colon.
State the dental formula of rabbits
I 2/1 C 0/0 PM 3/2 M 3/3
Describe rabbit teeth
Open-rooted
Continuously growing
Elongated Jaw
PM and M often referred to as ‘cheek teeth’
Diastema is the gap between the incisors and molars
2nd pair of incisors are vestigial and lie behind 1st pair
Describe rabbit respiration
Diaphragm is the primary mechanism for respiration
Don’t really use chest muscles
Obligate nose breathers - due to position of the epiglottis
Lungs have 3 lobes in each - cranial lobes are small.
Left lung is smaller than right.
Describe the urinary system of rabbits
Calcium is excreted in urine (in other animals, its excreted in bile) Turbidity/ cloudiness of urine is dependent on calcium deposits Produce a lot of urine Huge colour range
Describe the reproductive system of rabbits
Bicornuate uterus - 2 uterine hones No uterine body Double cervix Induced ovulators. Altricial young. Don't have distinct heat cycles 4 or 5 pairs of mammary glands Each side can function independently
2 testes in 2 scrotal sacs, cranial to penis.
No os penis
open inguinal ring allows retraction of testes into abdomen.
What group of animals do guinea pigs fall into?
Hystricomorphs
Describe the digestive system of guinea pigs?
Very similar to rabbits. Also exhibit coprophagy - 2nd pellet is not as dry as rabbits. Herbivores Hind-gut fermenters Monogastric Large caecum Relatively long small intestine 6-lobed liver
What is unique about guinea pigs?
They cant produce their own vitamin C
What are myomorphs?
Rats, gerbils, mice and hamsters
Describe the teeth of myomorphs
Open rooted incisors and rooted molars
I 1/1 C 0/0 PM 0/0 M 3/3 = 16
Diastema between incisors and molars.
Describe the digestive systems of myomorphs
Designed to breakdown a varied diet
Caecum doesn’t ferment so have a longer gut
Herbivorous material moves slowly through the small intestine to accommodate the breakdown of this
May or may not produce caecotrophs
Rats lack a gall bladder
Hamsters have a distinct fore-stomach
Describe the reproductive system of myomorphs
Bicornuate uterus. Little or no uterine body.
Spontaneous ovulators.
Female rats have 5 pairs of teats.
Female hamsters have 6 pairs of teats
2 testes in external scrotum - can return to abdomen via open inguinal canal in some species.
Have os penis
What is unique about hamsters?
Have flexible pouches to store food
Little tail stump - no tail
Very small, shallow eye sockets
What is unique about gerbils?
Prehensile tail used to balance
Can shed their tail as a defence mechanism
Describe the feet of rabbits
No footpads
5 toes on forefoot; 4 on hindfoot
Entire foot lies flat on ground from toe to hock.
How many vertebrae do rabbits have?
C7 T12-13 L7 S4 C16
Describe the lips of the rabbit?
Have split upper lip - philtrum
Describe guinea pig teeth?
I 1/1 C 0/0 PM 1/1 M 3/3 = 20.
Incisors and cheek teeth are open rooted and continuously growing.
Describe the skeletal anatomy of guinea pigs?
No tail, 4-6 vestigial coccygeal vertebrae. C7 T13-14 L6 S2-3 C4-6 Short, stocky legs 4 toes on forefeet; 3 on hindfeet. Small ears
Describe the feet on hamsters, rats and mice?
4 toes on front feet and 5 toes on hind feet
Describe the reproductive system of guinea pigs?
Both male and female have a pair of long inguinal nipples
Bicornuate uterus and 1 cervix
Have an os penis.
