Reptile Species Considerations Flashcards
What are the 2 orders of Chelonia? What are the differences between these?
Pleurodira - 3 flexion points of head, can’t fully withdraw
Cryptodira - 2 flexion points, can withdraw
Auscultation is hard with Chelonia due to the shell. What can we do to make this easier?
Wrap in a damp towel
What type of poikilothermic ectotherms are Chelonia? What is a problem associated with this?
Heliotherms - heat from basking
Difficulty cooling
What type of skulls do chelonians have? Do they have teeth?
Analysis
No teeth - use sharp beak for prehension. Egg tooth to open shell
What is the shell of Chelonia composed of?
Keratinised scutes
What is the upper shell of Chelonia called?
Carapace
What is the lower shell (ventral) of Chelonians called?
Plastron
In Chelonia, the not well developed rib cage is fused to the spine. What structures are within the rib cage? What effect does this have?
Pectoral and pelvic girdle
Limits locomotion
What are the names of the scutes found in the central of the carapace? What about the ones next to these? What are the outside scutes called?
Vertebral
Pleural
Marginal
What are the scutes found below the neck called?
Nuchal
Where are the lungs found in Chelonia? How are they separated from the abdomen?
Below the carapace
Pleura
What type of breathers are Chelonia? How is their respiratory system adapted for their anatomy?
nasal breathers. Respiratory breathing = distress
Short trachea - can breathe with neck fully drawn in
Do any reptiles have a diaphragm?
No
Why are chelonians susceptible to pneumonia?
No cough reflex
Describe the kidneys in Chelonia. Where are they found?
Paired, Lobulated
Beneath the dorsal carapace
In what form do chelonians excrete waste?
Urea/uric acid
Under what temperature does no digestion occur?
<7 degrees C
How can you sex chelonia?
Tail length and thickness
Males have concave plastron
What are 2 of the suborders of lizard?
Iguinia
Gekkata
Skincomoprha
Varinoidea
Explain how lizards scales are adapted for light absorption
Change in colour in the day
What type of skulls do lizards and snakes have?
Diapsid (2 temporal fenestrae)
What is unique about the vertebrae in lizards and snakes?
All have ribs (except cervical)
What type of kidneys do lizards have?
Lobulated
What 2 problems are common with female repro in lizards?
Follicular stasis
Egg binding tooviduct
What type of offspring do lizards produce? (In terms of live birth, egg etc)
All!
Viviparous
Oviparous
Parthogenesis (asexual reproduction, no male)
Where are testes found in male lizards?
Abdomen
Which species have hemipenes? Where are they? What do they do?
Squamata only - snakes and lizards
Stored in tail, can be exerted
One is used during copulation (NOT for urination)
How are hemipenes everted? What is a common problem with hemipenes?
Erectile tissue contraction
Prolapse
What are 2 external differences between male and female lizards?
Males larger and more colourful
Males have femoral pores
What are the 2 main groups of snake? What is the difference between these?
Boidae - 2 lungs, 2 carotid arteries, caecum
Colubridae - 1 lung, 1 carotid artery, no caecum
Give examples of 2 boidae snakes
Boa
Anaconda
Give 2 examples of colubridae snakes
Corn snake
King snake
How can snakes use their shape to alter thermoregulation?
Coil up to retain heat
Uncoil to lose heat
Do snakes shed fully? What is a common problem that owners worry about before this happens?
Yes - including spectacle
Eyes turn milky
Only primitive snakes have vestigial limbs. What are these called? How do snakes move?
Pelvic spurs
Axial skeletal muscles
What organs are found in each 1/3 of the snake
Cranial - heart, left lung, trachea, oesophagus, thyroid
Middle - stomach, liver, lung, spleen, pancreas
Caudal - intestines, kidney, gonads
What are the modifications that allow snakes to eat large prey?
Kinetic skull with no mandibular symphysis = large gape
Rostral glottis allows breathing whilst swallowing
Skin between scales allow stretch
What is the function of the tongue in snakes?
Touch
Taste
Olfaction (brings particles onto chemoreceptors on roof of mouth - vomeronasal organ)
Why do snakes easily regurgitate? Which snakes are more likely to regurgitate?
Poor cardiac sphincter
Young, stressed
What type of teeth do snakes have?
Pleurodont (attached to medial bone)
Do snakes have eyelids? How are the eyes protected? Do they have sclerotic rings?
No
Protected by the spectacle
No
Why do snakes have poor vision?
No ciliary body
Reduced eye movement
Describe the lungs in a snake?
Smaller vestigial left lung (if present)
Lungs are unicameral - one compartment
Have faveoli
Describe the kidneys in snakes
Paired
Lobulated
Elongated
Males have sexual part to kidney
Do snakes have a bladder?
No - ureters run straight into urodeum
Which types of snakes have pelvic spurs? Where are they found?
Primitive - pythons, boas
Either side of the vent
Describe olfaction in snakes
Very good due to Jacobson’s organ as well as normal olfactory cells
Describe snakes ears. What bone picks up sound vibrations?
No external ear
Internal ear only
Quadrate bone
How do snakes find prey in the dark?
Infrared sensor pits between mouth and eyes
At what age do snakes mature? What is this based on?
1-5 years
Based on size not age!
How can you sex a snake?
Males have thicker tail due to hemipenes
Evert hemipenes
Probe (most accurate)
Where are testes found in snakes? What happens to hemipenes during the breeding season?
Above kidneys
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