Exo - Reptiles Flashcards
turtles and tortoises fall under what category?
Chelonia
snakes and lizards fall under what category?
Squamata
how much slower is the reptiles’ metabolism compared to a mammal of similar size?
~1/5 - 1/7 the MR
ambushers are what type of feeder?
sit and wait
foragers are what type of feeder?
seek and hunt
how do ambushers conserve energy?
by shutting down their GI tract in the months between feeds (MR increases after feeding to aid in digestion)
when does a reptile switch to anaerobic metabolism?
diving
sprinting
chasing prey
escaping predation
what happens to stored glycogen during anaerobic exercise?
it is quickly broken down into lactate
what is significant about lactate for reptiles?
it is slow to be eliminated which is why they quickly become fatigued
how do reptiles thermoregulate?
they are ectothermic
- need external heat sources
- they have poor insulation due to lack of fat and fur
what is one advantage and one disadvantage of being ectothermic?
advantage: don’t waste resources maintaining body temperature
disadvantage: limited by environment
what are two ways reptiles derive heat?
heliothermy - basking in the sun (radiant heat)
thigmothermy - conduction with hot surfaces (stand on toes to reduce heat conduction, common in nocturnal or forest dwelling species)
what does the chelonians’ large shell help do?
maximize heat retention
how can desert species lose heat when they can’t find shade?
- hypersalivation
- urinating on their legs and plastron
how do most reptiles dissipate heat?
gular fluttering
what is the general preferred temperature range for reptiles?
20 - 38° C
what are some factors that play a role in hibernation?
major one: environmental temperature
also: photoperiod, reproduction, food supply, species
what are two reasons reptiles need ultraviolet light?
- behaviour
- vitamin D3 metabolism
what does UVA do?
- affects behaviour and well-being
- helps trigger reproduction
what is UVB necessary for?
-calcium metabolism
what 2 diseases can inadequate light lead to?
- metabolic bone disease
- nutritional osteodystrophies
reptile skin is aglandular… what does this mean?
not slimy
what is the normal shedding process called?
Ecdysis
retaining shed is an example of an abnormal shedding process… what would this be called?
Dysecdysis
how long does a shedding take?
approx 14 days
what are 3 characteristics of reptile skin?
- multiple layers of keratin and a lipid layer for prevention of water loss
- healing takes a long time!
- susceptible to thermal burns because skin has decreased sensitivity
why is a snake’s dorsum always flattened?
to aid in locomotion
what are single, central scales called?
gastropeges
what are the scales caudal to the vent called?
subcaudal scales
what is cool about arboreal snakes?
they have a prehensile tail (can grab things)
what are 2 characteristics of the reptile skull?
- kinetic, lack of ossification and elastic cartilage allows more movement
- heavily ossified brain case
what species of reptile does not have teeth?
Chelonidae spp
which species have acrodont teeth formation?
some lizards, chameleons and water dragons
which species have pleurodont teeth formation?
snakes and some lizards, iguanas
what species have thecodont teeth formation?
crocodiles
how many presacral vertebrae are in lizards? chelonia? snakes?
- 24 in lizards
- 18 in chelonia
- 200-400 in snakes
what 3 parts make up the chelonian shell?
- carapace (dorsal)
- bridge
- plastron (ventral)
what are osteoderms and what are they covered in?
- bony deposits that make up the shell
- covered in horny scutes on the outer layer
where are the scutes formed from and what are they equivalent to?
- from the epidermis
- equivalent to the scales of reptilian skin
what makes up the reptile heart? even better… what are the subchambers?
3 chambered heart
2 atria
1 ventricle
-which is divided into cavum venosum, cavum arteriosum, and cavum pumonale
what is the result of the reptiles’ rapid right to left cardiac shunt? why is it problematic?
- avoids cooling, conserves oxygen during times of depletion
- problematic when trying to mask for anesthesia
what is unique about the reptiles’ lymphatic system?
- more highly developed than the venous system but don’t actually have lymph nodes
- have vast plexiform lymphatic networks and large dilated resevoirs
what is lymphdilution and why do we need to be aware of it?
- common contaminant of lymph fluid in blood samples
- will affect the PCV and WCC
what are 4 characteristics of a reptile’s respiratory tract?
- lining has mucociliary apparatus (hard to clear exudates from lungs)
- large lung capacity, are chambered
- no air sacs
- no diaphragm
what are the three steps of triphasic breathing?
- inspiration
- expiration
- rest
T/F aquatic species can take a breath under water
False - they can only take a breath when their head is above water
T/F chelonians can not actively take a respiration when retracted into their shell
True
T/F snakes use the same muscle groups for respiration and locomotion so they can do both at the same time
False - they do use the same muscle group for both but can only do one at a time
reptiles have a larger ______ and ______ than herbivores
colon, cecum
reptiles digestive tract is much ______ than that of birds and mammals
shorter
what 2 things do oral secretory glands do?
- lubricate prey
- modified into venom glands in certain species
what affect can low temperatures have on the GI tract?
putrefaction and maldigestion
what 3 things does hydrochloric acid help with?
- prevent putrefaction
- kills live prey
- aids digestion (by decalcifying bone)
what is the main bile pigment called?
biliverdin
what are 5 methods of water conservation in reptiles?
- produce uric acid
- cloacal resorption
- decrease in GFR
- salt glands
- renal portal system
what do reptiles lack that means they can’t concentrate urine very well?
Loop of Henle
what is gout, what causes it, and where will you generally see it?
- disease of uric acid systemically circulating in system - VERY PAINFUL
- improper hydration status and sub optimal husbandry
- looks like white, opaque deposits in visceral organs and joints
what do the salt glands do?
-excrete potassium and sodium to conserve water
what are the 3 chambers of the cloaca?
- coprodeum (first chamber)
- urodeum (second)
- proctodeum (third)
what do the spurs on squamata reptiles do and where are they located?
- used during courtship and mating, also combat between males in some species
- on either side of the vent (snakes lack a pelvic girdle)
T/F some lizards self amputate their own tail and it can regrow
True - it is a defense mechanism against predators and it will regenerate but not look the same
what are 4 ways to differentiate males and females?
- males have longer tails than females
- males tend to have a broader tail base (due to hemipenes)
- probe extends 6-10 subcaudal scales on males, 2-3 on females
- gently squeeze the tail to see if you can evert hemipenes
what are 4 ways to differentiate male and female lizards?
- males are more brightly coloured and possess crests, throat fans, etc.
- male iguanas have taller dorsal spines and larger dewlaps
- male chameleons have elaborate horns, crests, and plates on their heads
- femoral or pre-cloacal pores are more prominent in male chameleons and bearded dragons
what is unique about female snakes reproductively?
they have sperm storage - can use years later
what does it mean to be oviparous?
egg producing species, eggs hatch into young, most reptiles
what does it mean to be viviparous?
mother produces love young, ~1/5 reptiles
how do most reptiles hear?
tympanic membrane
how do snakes hear?
picking up sensitive vibrations via the quadrate bone
what is the most developed sense in many reptiles?
olfaction
what is the vomeronasal organ also called and what is it? and what does all of that mean?
- aka Jacobson’s organ
- located in the roof of the mouth, highly sensitive, innervated by a branch of olfactory nerve
- the tongue is used for both taste and smell
what are 8 common presenting complaints for reptile emergencies?
- adr/lethargy
- limited mobility
- skin disease
- trauma
- tremors
- dyspnea
- ocular disease
- constipation/obstipation
what is the most common underlying cause of illness for reptiles?
poor husbandry
where should you place a doppler on a tortoise? a snake? lizards?
tortoise - between head/neck and forelimb, listen for over 2 minutes
snakes - over the heart (near the end of the cranial 1/3 of the body)
lizards - axilla (esp. large lizards) or between forelimbs on ventrum
*more developed lizards ie. monitors, heart might be more caudally located
what are 4 steps to take in a reptile emergency?
- place in warm incubator if possible
- place entire cage in oxygen short term if in resp. distrss
- give midazolam 1mg/kg intranasally or IM if seizing
- check for HR with doppler if obtunded
why is it easy to intubate a reptile?
they lack an epiglottis
remember how birds present with dyspnea? what about snakes?
🐦 tail bobbing
🐍 neck stretched up
what are the 4 biotypes in reptiles?
- tropical
- desert
- temperate
- aquatic
what is the preferred optimum temperature range for the cool area for most species is? what about the hot area?
❄ 20-25°C
🔥 35-40°C
what are two factors important to the air for reptiles?
humidity and ventilation (hard in Canada!)
what key vitamin from UVB helps reptiles absorb calcium?
vitamin D3
