Exam 4

Question 1

Anura (frogs & toads) Habitat

Answer 1

Temperate climates; safer location for breeding (less predation risk)

Tropical climates; higher predation risk

Question 2

Amplexus

Answer 2

Male grasps onto female with front legs (most Anurans do this)

Question 3

Anuran Reproduction

Answer 3

Ritualized calling

Oviparous

Fertilized egg masses

Tadpoles in aquatic stage

Question 4

Schreckstoff

Answer 4

Fear hormone in Gray Tree Frog tadpoles

When predation risk is high, stimulatesincreased coloration and features to make it look larger to reduce predation risk.

Metamorph into an adult frog.

(No predation risks = no chantes in tadpole)

Question 5

Wood Frogs vs Environmental Differences

Answer 5

Wetter = longer growth period and larger adult size

Dry = limited growth and smaller adult size

Based on concentrations of ions in the waters

Question 6

Plethodontidae

Answer 6

Lungless, skin respiration, high surface rea ratio of skin

Question 7

Ambystomatidae

Answer 7

Spotted newts

Question 8

Salamandridae

Answer 8

Red spotted newt, rough skin, crested

Question 9

Latin Name for Tiger Salamander

Answer 9

Ambystoma tigimum

Question 10

Salamander Response to Environment

Answer 10

Decreased reliance on terrestrial environments

Paedo in permanent water (high oxygen, stable temp)

Metamorph to terrestrial stage in temporary habitats (warm, low O2)

e.g. northwestern salamander, axolotl

Question 11

Salamander Response to Increased predator and desiccation risk & abiotic/radiation factors

Answer 11

Paedomorphosis/neoteny

Retain external gills

Remain in water

Question 12

Ambystomatidae & Paedomorphosis

Answer 12

(mole salamanders)

Obligate and facultative paedomorphosis

Depends on environment

Question 13

Alpine Salamander (elevation fluctuations)

Answer 13

Gestation Periods 38 months in high elevation, 24 months in low elevation

Only 2 eggs develop

Question 14

Olfaction and Breeding

Answer 14

Critical for breeding

Pheromones transferred by physical contact

Question 15

Physical Contact & Mating

Answer 15

amplexus, breeding balls,& sex glands

tooth on snout to inject females

Question 16

Sex Glands

Answer 16

Mental glands on chin

Hedonic gland on base of tail

Question 17

Aquatic vs Terrestrial Parenting

Answer 17

Aquatic: spermatophore taken up by female, internal fertilization, no parental care, larvae have gills

Terrestrial: brooding, parental care, protect eggs from desiccation and predation

Question 18

When to Breed (Salamanders)

Answer 18

Photoperiod (day length), seasonal rains, temperature abot 50’s

Question 19

How Long to Breed (Salamanders)

Answer 19

Explosive breeders: Few nights per season, chorus callers, little variability between calls, no parental care.

Prolonged breeders: Several months, antiphonal callers, choosey mating, guard eggs, have sneaker males

Question 20

Where to Breed (Salamanders)

Answer 20

In natural pools (aquatic)

Use stars as navigation

Pollution is a problem

Question 21

Feeding Habits

Answer 21

Ambush predators

Use vision and olfaction

Blend in with cryptic colorization

Pedicellate teeth, protrusible tongues, some suction feeders

ALL are carnivores

Question 22

Amniotic Egg Physiology

Answer 22

Yolk Sac: nutrients

Amnion: fluid filled, surrounds embryo to protect from desiccation and concussion

Allantois: waste collection

Chorion: outer most layer for gas exchange

Albumen: ‘egg whites’, provides water and proteins

Shell: protective layer; hard and calcified or leathery (increases diversity into new habitats)

Question 23

Selective Pressures on Land

Answer 23

Gravity, temperature, gas exchange, navigation, egg care, locomotion, etc.

New skin: thicker, more adipose, more lipids, and resistant to desiccation and radiation. Not as much need for cutaneous respiration (but still used)

Question 24

Splayed Gait

Answer 24

Limbs out to the side of the body

Question 25

Upright Body

Answer 25

Narrow track gait, saved energy, faster, better endurance

Question 26

Reptile Types

Answer 26

Turtles and Crocodylia

Question 27

Oviparous Reptiles

Answer 27

Most common Size of organisms determines # of eggs produced per event Egg clutch volume directly correlated with female size (abdominal cavity)

Question 28

Why not maximize egg volume?

Answer 28

Save E for 2nd clutch Fewer eggs relates to longer life due to strain on body Increased size = increased predation risk Egg size increases with fewer eggs (more yolk, larger offspring, increased survival)

Question 29

Viviparous Reptiles

Answer 29

Some Squamates (lizards, snakes) Low temp, high altitudes, more stable Better chances to put on fat before winter Increase energy requires Fewer young = lower fitness ~140 origins of viviparity Sceloporus : grass lizards; 30-70 are viviparous

Question 30

Parthenogenesis

Answer 30

Virgin birth Originates from hybridization of 2 closely related species Clonal inheritance (female produces diploid eggs) Pseudocopulation required (other females or sneaker males stimulates ovulation)

Question 31

Sex Determination in Reptiles

Answer 31

Most verst use genotypic sex determination Many reptiles use environmental or temperature based determination (ESD, TSD; temperature of nest determines sex, not genotype)

Question 32

Temperature and Sex Determination for Turtles

Answer 32

Cold temperatures = all male Warm temperatures = all female Certain range where clutch can be both sexes

Question 33

Temperature and Sex Determination for Lizards and Alligators

Answer 33

cold temps = all female warm temps = all male small range where clutch can have both sexes

Question 34

Temperature and Sex Determination for Crocodiles, Snapping Turtles, and Leopard Geckos

Answer 34

extreme cold and warm = all male middle temps = all female

Question 35

Why temps related to sex?

Answer 35

Reduce inbreeding Decreased fitness when males and females are present Environmental selection Gonads are indifferent when eggs are first laid

Question 36

Oviparous vs viviparous vs ovoviviparous

Answer 36

oviparous - egg laying viviparous - giving birth to live young ovoviviparous - giving birth to live young that hatch from eggs within the body