Module 12 - Reptilians Flashcards
Give two physical differences of Turtles, Terrapins and Tortoises.
- Turtle: Webbed feet, non retractable head
- Terrapin: Clawed webbed feet, head retratcs sideways
- Turtle: Clubbed clawed feet, head retracts straight
Name 4 snakes in South Africa that give birth to live young?
- Berg Adder
- Horned Adder
- Gabbon Adder
- Puff Adder
Can the Nile Crocodile move the top jaw? TRUE or FALSE. Please explain.
FALSE.
The upper jaw is an extension of the skull. Only the bottom jaw can be moved. It has to hold the head upwards, allowing the bottom jaw to fall open.
Snakes tend to ignore and do not strike at stationary objects. TRUE or FALSE?
TRUE.
Except of Boomslang and Vine Snake as they recognise stationary objects.
Reptile Characteristics
- Dry, horny skin, usually modified in scales or plates
- Ectothermic
- Jecobson’s organ
- Produce eggs
- Internal fertilisation
What are Scutes?
Tortoises:
- the layer of shields covering the body never stops growing;
- grow in warm summer month and stop growing in the cooler winter months;
- this leads to growth-rings like in trees which can be used to determine the age of a
tortoise.
Tortoise Characteristics:
- Shell (fused bones)
- Bottom is dented in Male, flat in female
- Beak with cutting edge (no teeth)
- Bursa (anal sac holding water)
Gender determination in Crocodiles and Tortoises
Tortoise: 26-30°C = M; 31-36°C = F
Crocodile: 26-30°C = F; 31-34°C = M
4 differences between Agama and Gecko
- Agama is active during day, Gecko at night (except dwarf gecko)
- Agama: short, thin tail can not be shed, Gecko: can shed tail
- Agama: Small eyes, moveable eyelids, Gecko: large eyes, covered with transparant skin, can not move eyelid
- Agama: digits have recurved claws, Gecko: digits covered in minute hairs
Serpentes characteristics
- Internal ears
- Scales
- Shed skin (sloughing): 15/yr juvenile, 3-4/yr adult
- Some shed tail; no regrowth
- Forked tongues used for smelling
- Long backbone with articulating ribs
Chameleon characteristics
- Eyes move independently
- Change color (cells operated by nerves)
- Telescopic, club-shaped tongue
- Tail = prehensile
- Digits on feet can grip around branches
- Arboreal (except when nesting)
- Escape by climbing flimsy twigs and/or by droppping down
- Head-but opponents
Snake’s senses
- Eyes: good vision
- Hearing: no external ear; auditory nerve picks up vibrations
- Smell: Jacobson’s organ and forked tongue
Snake Locomotion
- Sidewinder (desert)
- Concertina (anchor head and pull body)
- Serpentine (lateral undulation): use projections to push forward
- Caterpillar: ventral scales grip the ground
Snake’s reproduction
- oviparous (egg tooth)
2. ovoviviparous (adders)
Snake’s tooth structures
- Solid toothed (no venom)
- Back-fanged (grooved)
- Front-fanged, fixed
- Front-fanged, hinged
