Lab IV: Biology and Adaptations of Amphibians and Reptiles Flashcards
1
Q
Feeding Adaptations in Amphibians
Specialization of oral region
A
- Tongue - highly developed in terrestrial forms (e.g., ranids)
- Tongue attached to anterior of mouth and points backwards at rest
- Catch living prey that adhere to sticky tip
- Teeth - small and degenerate; do not chew their food
- Oral glands important in terrestrial forms for capturing prey and for swallowing
2
Q
Feeding Adaptations in Amphibians
Swallowing in frogs
A
- Assisted by tongue and eyeballs
- Jaws close, tongue returns, eyeballs are pulled inward against roof of mouth beneath them
- Eyes press down on tongue, helping to crush food
3
Q
Feeding Adaptations in Amphibians
Feeding
A
- Amphibians are carnivorous as adults
- Live prey - dependence on sense of vision and tendency to react to moving objects
- Seek prey, or wait for prey to come to them
- Terrestrial amphibians feed on prey of appropriate size; type of food is variable
- aquatic amphibians feed by snapping motion
- Size is limiting factor
- Forelimbs create current that brings food closer or to push food into mouth
- Most tadpoles are herbivorous
- Larvae of some species may be cannibalistic
4
Q
Auditory communication
A
- Organs that create sound by passing streams of air over structures that vibrate
- Air sacs or chambers are used as resonators in some frogs and toads
5
Q
Auditory Communication
Advantages
A
- Sound passes through vegetation
- Provides greater specificity and complexity than chemical communication
- Precisely timed
- Used at night and in dark environments
- Travels over long distances
- Sound is better than visual signals in getting attention of receiver because sensors do not have to be focused on signaler for message to be received
6
Q
Auditory Communication
Disadvantages
A
- Cannot convey complex information as rapidly as visual signals
- May alert predators to location of sender
- May be energetically expensive to produce
7
Q
Auditory Communication and Reproduction in Anurans
A
-
Calls convey info regarding species, sex, size, and condition of caller and location of breeding sites
- Calls distinctive to each species, vary in length and pitch
- Male call is stronger and more distinctive
- Females have weaker voices
- Males and females have laryngeal apparatus for sound production; males have vocal sac, ventral extension of mouth cavity that acts as resonating chamber
- Produce sound by passing air back and forth over laryngeal apparatus between lungs and vocal sacs at floor of mouth
- Arrival of “voice” is signal of sexual maturity in anurans
8
Q
Auditory Communication in Other Amphibians (not anurans)
A
- Caecilians are voiceless
- Salamander lack vocal cords but can emit faint squeaking sound
- Newts possess lunge and larynx and can emit sound
- Frogs and toads have second type of call described as a distress call. Produced with an open mouth and is usually high pitched and loud
9
Q
Locomotion in Amphibians
Salamanders
A
- Swimming motion of fish
- Uses limbs for paddling and walking, but when frightened, it will tuck them away and swim like a fish (undulations of body)
- Movements of walking salamander are such that vertebral column moves back and forth laterally
- Body is raised up off the ground and propulsion is via a lever action of limbs
10
Q
Locomotion in Amphibians
Saltatory locomotion in frogs
A
- Adaptations seen in saltators:
- Hindlimbs are greatly lengthened
- Forelimbs are not long, generally used for grasping or slow locomotion
- Neck is short and solid, may even have fused vertebrae
11
Q
Locomotion in Snakes
Serpentine or lateral undulation
A
- Body is thrown into serpentine or S-shaped loops, right and left
- Locates with coils projections, like pebbles and plant stems
- Body presses sideways against objects in direction that is obliquely backward relative to direction snake is to move
12
Q
Locomotion in Snakes
Concertina
A
- Draws itself into one of more S-shaped coils
- Posterior coils press downward and backward against substrate, relying on friction to prevent slippage
- Thrust is used to advance head and anterior part of body forward
13
Q
Locomotion in Snakes
Sidewinding
A
- Sidewinding for fast and efficient travel over loose or sandy soil
- Makes series of undulations at about a 60-degree angle with movement in tracks that are more or less in a straight line
- Desert snakes
14
Q
Locomotion in Snakes
Rectilinear
A
- Enables snake to advance in straight line
- Snake pulls together two sets of scutes and fixes them against ground (creates friction, snake propels itself forward)
- Tenses bands of muscles running from scutes back towards ribs
15
Q
Feeding Adaptations in Reptiles
Oral Cavity
A
- Well-developed lips, but non-muscular and non-moveable
- Some specialized forms (e.g., turtles beak)
- Tongue - composed of various muscles with skeletal support from first or second visceral arches
- Non-protrusible tongue in turtles
- Protrusible tongue in everything else
- Teeth
- Lacking in adult turtles and tortoises (found in embryos of soft-shelled turtles)
- Other reptiles have well developed teeth along margins of upper and lower jaws
- Snakes have backwardly recurved or slanted uniform, attached to jaw by fibers or roots
- Three divisions of snake teeth: solid, grooved, and hollow (latter two are for passage of venom into prey)
*
