Herpetology (Amphibians and Reptiles Part 1) Flashcards
What class of animals are warm-blooded?
Mammals
How do mammals keep warm?
- Body warmth is generated by metabolism
- Endothermic: Obtain heat internally
What class of animals are cold-blooded?
- Amphibians
- Fish
- Reptiles
- Invertebrates
How do cold-blooded animals stay warm?
- Body warmth is obtained from the environment
- Ectothermic: Obtain heat externally
Are Herptiles cold-blooded?
Not truly cold-blooded
- They need to warm their bodies since many of their physiological processes are temperature dependent.
- They maintain body temperature (Tb) within a preferred range
Each species has a preferred ____________ ? What does it affect?
Has a preferred optimal temperature range or zone (POTR or POTZ)
- Affects their ecology, behaviour, morphology, and physiology
What other factors are considered in Ectothermy?
- Source of body heat is external and not metabolic
- Require 10-14% of the energy used by similar sized birds/mammals
- Lower metabolic rate (slower healing)
- Can exploit environments of low biological productivity
Where does the efficient use of food energy go?
Goes to growth/reproduction and not Tb maintenance
What is behavioural thermoregulation?
Use behaviour to change heat gain or loss to maintain Tb in a range that optimizes physiology
How is infrared radiation (solar) is absorbed?
- Posture
- Body shape and colour (Change absorptivity)
- Blood flow
Behavioural Thermoregulation
Convection: Fluid (Air/water)
Conduction: Surface area
Metabolic heat
- Brooding pythons (6-8 C)
- Sea turtles (18-20 C)
Thermal gradients are the most important aspect of a ___________ environment?
- Reptile’s
- Allows an animal to select a thermal environment that meets its needs
What 3 Orders of Class Amphibia?
1) Salientia or Anura - Frogs and toads
2) Caudata - Salamanders and Newts
3) Apoda - Caecilians
Amphibian Physiology
- Dependence on water
- Moist skin
- Absorb water
- Respiration - Plethodon (Lungless salamanders)
- Skin shedding
- Require high humidity
What are Amphibians?
- Passive ectotherms: Body temperature is dependent on and approximates that of the environment
- Limited behavioural thermoregulation due to risk of desiccation if they are too warm.
Thin permeable skin. Confined to a life close to water
Do Amphibian’s lay eggs?
Majority lay eggs in water which are not guarded
What are the 2 life cycle stages for Amphibians?
1) Larval (Tadpole)
2) Metamorphose to adult form
Are Amphibians carnivores?
Adult amphibians are carnivorous but some of the young are herbivores or omnivores
How to care for amphibians?
- Use aged/de-chlorinated water at same temperature for tadpoles and aquatic species
- Chlorinated water at same temperature can be used for adults
- If in doubt, mix aged water with tap water
- All spray bottles disinfected monthly - Bottles should be emptied and air dried overnight
- Water (Dishes; freestanding; wet substrate) Always available - Save a life
What is involved in handling amphibians?
- Wash hands before and after handling
- Skin toxins are irritating to you and frog
- Latex gloves can be used (Not for tadpoles)
- Vinyl or Nitrile gloves
How do you feed Amphibians?
- Supplements and gut loading
- Feed small amount 3 x per week
- Tong feed supplemented items
- Do not leave live food with sick animals
Common food items for amphibians include:
- Crickets
- Mealworms
- Fruit flies
What are some nutritional diseases for Amphibians?
- Spindly leg
- Paralysis (Calcium, thiamine)
- Gout
- Overfeeding; weight regularly - Liver and kidney disease
What is involved in sexing?
Sexual Dimorphism
- Size
- Colour
- Behaviour:
* Male release call
* Throat punch
* Nuptial pads
* Cloacal swelling
Amphibian respiration, cutaneous, buccal, and lung factors are?
- RESPIRATION: Most breathe with gills when young and with lungs when an adult.
- Cutaneous: Blood capillaries within the skin; particularly good at CO2 removal in all species
- Buccal- High dependence on gas exchange in the mouth/oral cavity
- Lung - Variable dependence on this mode - Amphibians possess a 3-chambered heart; most have lungs
Significant factors in Amphibian skin:
- Absence of scales - No bony or keratinized scales
- Mucous glands: Keep skin moist, fairly permeable (High water losses possible)
- Amphibian Chemical Defenses:
- Poison glands - Chemistry variable
- Parotid glands
- Skin swellings/bumps
- Sticky, noxious to be very poisonous
- Most alkaloids are acquired from insects
- Water-soluble alkaloids - Tetrodotoxins lipophilic alkaloids - batrachotoxin
- Aposematic colouration (Warning colours)
Anesthesia requirements:
- MS 222: Tricaine methanesulphonate
- 1-2 g/L dechlorinated water
- 3 g/L for toads
- Induction: 20 minutes (Loss of righting reflex)
- Benzocaine - 0.2 - .03 mg/L
- Isoflurane: 2-3% - Use induction chamber
- EMLA cream: 2.5% each of lidocaine and prilocaine - Topical (Max 5 minutes)
What does Red-legged disease cause?
Red underside of the legs due to hemorrhages, resulting in septicemia
Common diseases in Amphibians:
- Viral:
Iridoviruses (Ranavirus spp.) - Bacterial:
Red-legged disease (Aeromonas hydrophilia - Fungal:
Chytridiomycosis (Batrachochytrium dendrobatidis)
What does Iridoviruses (Ranavirus) cause?
- Cause systemic infection generalized swelling
- Hemorrhage
- Limb swelling
- Swollen friable liver
What does Chytridiomycosis cause?
- Causes thickening of the skin
- Skin shedding
- Death
What are the four Orders from Class Reptilia?
1) Crocodilia (Crocodiles & Alligators)
2) Squamata (Snakes & Lizards)
3) Chelonia (Turtles)
4) Rhynchocephalia (Tuatara)
What are Rhynchocephalia (Tuatara)?
- This is the only surviving species in the order Rhynchocephalia
- Looks like a squat lizard with a large head
- Internal structures very different from modern reptiles (i.e. lacks copulatory organs)
- More closely related to extinct forms
- Tuataras are strictly protected by law (CITES 1)
Describe Chelonia turtles.
- Water and ocean-going turtles
- Flattened shells and paddle-like feet
- Terrapins refer to fresh water turtles
Describe Chelonia tortoises.
- Land turtles
- High shells and ‘club-like’ feet
Chelonia (Turtles and tortoises) characteristics:
- Their body is covered by a plastron below and a carapace above.
- Thoracic, lumbar, and sacral vertebra are fused
- Pelvic and pectoral girdles are inside the rib cage (shell)