Exam 3

Question 1

Anura

Answer 1

frogs (family ranidae) & toads (family bufonidae).

all toads are frogs, but not all frogs are toads!
most diverse group

Question 2

Urodela

Answer 2

salamanders (caudata) & newts.

Question 3

Gymnophiona

Answer 3

cecillians.

least understood

Question 4

What are some shared characteristics of Amphibians?

Answer 4

• ectothermic.
• lack true ribs (chest cavity not fully enclosed).
• mucous glands in the skin.
• metamorphosis.

Question 5

What lifeforms are endothermic?

Answer 5

birds and mammals.

all other lifeforms are ectothermic!

Question 6

Describe metamorphosis in Amphibians:

Answer 6

larval stage:
- fully aquatic
- extract O2 with gills
- herbiverous

adult stage:
- carniverous
- extract O2 w/ lungs (some w/ gills) or cutaneously

Question 7

What are some derived characteristics of Amphibians?

Answer 7

• cutaneous gas exchange.
• papilla amphibiorum (pick up low-frequencies) & columella complex.
• green rods (night vision).
• pedicellate teeth.
• levetor bulbi muscles.

Question 8

Levetor Bulbi Muscles

Answer 8

moves the eyes in/out to increase cavity volume for increase respriation.

Question 9

What are some shared derived characteristics of amphibians?

Answer 9

• cutaneous gas exchange (mucous glands keep skin moist).
• pedicellate teeth
• columella-operculum complex = bones that increase vibration/sound to the inner ear.
• green rods (night vision).

Question 10

What are different respiratory/gas exchange methods in amphibians?

Answer 10

• gills (all larval stages, adult salamanders).
• skin (how much use may depend on temperature).
• buccopharyngeal membrane = thin, highly vascular mucuous lining in the mouth (buccal pumping).
• lungs = buccal pumping to actively force air into lungs by contracting muscles.

cannot breath/eat at same time

Question 11

Describe Caudata/Urodela skeletal/locomotive strategies:

Answer 11

• most generalized body form and locomotion.
• fish-like movement, similar to early tetrapods.

related to ecological niche in rapid movement for escaping predators and capturing prey.

Question 12

Describe Gymnophiona skeletal/locomotive strategies:

Answer 12

• true leglessness (no pectoral or pelvic girdle)
• solid, dense skull for burrowing
• concertina/hydrostatic locomotion (muscle contraction).

related to ecological niche in burrowing lifestyle.

Question 13

Describe Anura skeletal/locomotive strategies:

Answer 13

• hindlegs elongated.
• attatched pelvis to spinal column for stiffness.
• posterior vertebrae fused into ridig rod: urostyle.
• extensive fusion of skeleton –> less muscle attatchement

related to ecological niche in juping lifestyle.

Question 14

Describe Plethodontid Salamander adaptations:

Answer 14

• lungless, no buccal pumping, so hyoid apperatus modified for ballistic tongue projection.

Question 15

Describe reproduction in Caudata:

Answer 15

• internal fertilization w/ spermatophores (sperm packets) - NO INTERMITTENT ORGAN.
• some sexually dimorphic.
• most lay eggs in water…..