Unit 11

Question 1

Controlling water loss

Answer 1

Behavior - less frequent calling in warm dry nights
Pelvic patch - vascularised skin absorbing water
Permeable bladder - store dilute urine

Question 2

Respiration methods

Answer 2

Cutaneous
Buccopharyngeal - has exchange in buccal cavity/pharynx
Pulmonary
Gills - larva and neotenics

Question 3

Characteristics of amphibians (6)

Answer 3

Smooth, moist skin
-Defense mechanisms
-Water loss control
Multiple respiration methods
Pedicellate teeth (flex teeth)
Unique hearing adaptions
Retractor bulbi and lavator bulbi muscle (swallowing)
Green rods (see in dim light)

Question 4

Unique hearing of amphibians

Answer 4

Operculum-Columella complex
Inner ear: (hair Cell systems)
-basilar papillae = high frequency
-amphibian papillae = low frequency

Question 5

Caecilians characteristics

Answer 5

Gymnophiona
Long, slender body; small dermal scales
Legless; no postanal tail
Eyes covered by skin
Specialized sensory tentacles (snout)
Diet = small insects

Question 6

Caecilians history

Answer 6

Min known about courtship
Internal fertilization via phallodeum
-75% viviparous, 25% oviparous
Parental care in some species
Nutrition: yolk then uterine milk
Breathe via fetal gills

Question 7

Salamanders, newts morphology/locomotion

Answer 7

Caudata/urodela
Anguilliform locomotion (walking-trot/swim)
Paedomorphosis/neoteny
- adults retain laterally compressed tail/flattened head, internal/external gills

Question 8

Caudata/urodela respiration

Answer 8

Aquatic = primarily gills
Terrestrial = 50% lungs, 50% skin
Plethodontidae = lungless, breathes using 10% skin, 90% buccopharynx
-evolved in cold water with high O2 —> lungs disadvantageous (buoyancy)

Question 9

Anura mating systems

Answer 9

Explosive breeder (season = a few days)
-temporary aquatic habitat
-large aggressions; limited mate choice
Prolonged breeders (season = months)
- males defend territories
-males outnumber females; strong mate choice

Question 10

Anura external fertilization

Answer 10

Amplexus

Question 11

Tadpole metamorphosis

Answer 11

Triggered by thyroid hormone
Premetamorphosis (grow)
Prometamorphosis (hind legs)
Metamorphic climax (fore legs + short tail)

Question 12

Threats to amphibians

Answer 12

Habitat change
-Habitat fragmentation
-Habitat destruction
-Habitat alteration
Introduced species
UV radiation
Chemical contamination
Disease (Batrachochytrium dentrobatides)

Question 13

Neotenics

Answer 13

Adults that retain juvenile characteristics

Question 14

Lungless caecilians

Answer 14

Plethodontidae
10% cutaneous
90% buccopharynx
Projective tongue (hyoid bone)
Acute vision

Question 15

Caecilian nose

Answer 15

Olfactory epithelium
Vomeronasal organ
Nasolabial grooves

Question 16

Chemical contamination

Answer 16

Atrazine (no steroidogenesis = hermaphroditism)
Acidification (less hatching)
Nitrogen pollution (lazy)

Question 17

Amphibian fungi

Answer 17

Batrachochytrium dendrobatides