Amphibians

Question 1

Modern amphibians are called

What does it include
When did it appear and diversify

Answer 1

Lissamphibians
-anurans (frogs and toads)
-salamanders

Appeared Carboniferous

Diversified Permian

Question 2

Temnospondyls

What modern characterisitc do they share with modern amphibians

Answer 2

Stem amphibians or stem lissamphibains

Four digits on fire limb.

Question 3

Modern amphibians shared traits

Answer 3

-associated with freshwater, not marine
-transition from aquatic larval to terrestrial adult form within lifetime
-ectothermic
-adults (non-larval forms) are carnivorous

Question 4

Skin of amphibians

Answer 4

-cutaneous respiration (through skin) is primary mode of respiration
-smooth, thin, glandular skin makes it moist and permeable, assists respiration and prevents animal from drying out

Question 5

Structures in skin of amphibians

Answer 5

-mucous glands to keep skin moist
-poison glands or glandular glands
-pigment cells (chromatophores) : aposematic

Question 6

Reproduction of amphibians

Answer 6

-even terrestrial forms rely on cool, moist habitats for reproduction
-non-amniotic egg=anamniotic egg: keeps amphibians tied to water
-larval forms are aquatic and breathe with gills, such as tadpoles

Question 7

When do lungs (if present) appear in amphibians

Answer 7

Usually become active after metamorphosis

Question 8

Three orders of amphibians

Answer 8

Salamanders (Urodela)

Caecilians (Gymnophiona)

Frogs and Toads (Anura)

> 7000 species total

Question 9

Salamanders
-size
-habitat
-Manitoba species

Answer 9

<15cm typically
Moist, temperate regions

Blue spotted, eastern tiger, barred tiger, mudpuppy

Question 10

Salamander locomotion

Answer 10

Serpentine fish-like movement when swimming or walking

Salamanders have a more ancestral body plan than forge or caecilians

Question 11

Salamander reproduction

Answer 11

courtship and fertilization: most have no physical contact, yet have internal fertilization (90% of species have internal fertilization)
-male deposits spermatophore on substrate, female recovers spermatophore in cloaca
-some species: male mounts female during courtship but deposits spermatophore in habitat

-Oviparous: lay eggs in water, aquatic larvae hatch.
-terrestrial species deposit eggs under logs or in moist earth and some have direct development (no larval stage)

Question 12

Ancestral form of salamander life cycle

Answer 12

Metamorphosis from aquatic larval to breeding stage terrestrial adults

Question 13

Facultative metamorphosis

Answer 13

-depending on region or habitat conditions, adult tiger salamanders may live in aquatic “larval” form or in terrestrial form when sexually mature.

Question 14

Paedomorphosis

Answer 14

Retention of juvenile characteristics in sexually mature adults

-some species of salamanders retain gills, aquatic lifestyle and other larval characteristics after sexual maturity
-no metamorphosis

Ex: mudpuppy (necturus)

Question 15

Red spotted newt lifecycle

Answer 15

Two metamorphoses

• gilled larva
  Metamorphosis
• red eft: terrestrial juvenile that does not breed (1-3 years)
  Metamorphosis
• aquatic adult: breeding form (sexually mature)

Question 16

Caecilians
-characterisitcs
-habitat

Answer 16

-elongated, limbless, burrowing animals, 12cm-1m, greatly reduced eyes: dark/ light perception, dermal fold (annuli)

-tropics

Question 17

Smallest group of amphibians

Answer 17

Caecilians

Question 18

Caecilian reproduction

Answer 18

-only order of amphibians to use internal insemination and fertilization exclusively (males have copulatory organ)
-some species are oviparous: eggs usually deposited in moist ground near water
-other species are viviparous

Question 19

Some oviparous species of caecilians feed their young how?

Answer 19

Mother grow new layer of skin every 3 days for young to feed on when they emerge from egg

Question 20

Frogs and Toads
-Habitat
-size

Answer 20

Worldwide distribution
Every continent except Antarctica

Frogs come in all sized, from tiny to giant lap size

Question 21

Largest group of amphibians

Answer 21

Anurans

Frogs and toads

Question 22

Typical Anuran life cycle

Answer 22

Young to be born as an aquatic tadpole, then metamorphose into adult, air breathing form

Question 23

Frog and Toad diet

Answer 23

-invertebrates and even small vertebrates or even other frogs

Question 24

How anurans eat

Answer 24

-large mouths
-projectile sticky tongues
-contraction of eye muscles helps push prey into throat

Question 25

Frogs and toads jumping specialization

Answer 25

-Hind limbs form lever system that catapults animal into air (elongated hind limb)
-powerful pelvic fastened to vertebral column (pelvis and urostyle: rod of fused vertebrae make posterior half of trunk rigid)
-short rigid vertebral column

Strong, flexible pectoral girdle absorbs shock of landing

Question 26

Body shape, limb length and webbed feet indications of locator motion of anurans

Answer 26

1. Short forelimbs and short hind limbs are associated with burrowing
2. Long fire limbs and long hind limbs are found in species that climb and leap
3. Hind limbs that are distinctly longer than the fire limbs usually indicate that a species is a hopper if the webbing on the hind feet is limited
4. If the animal has longer hind limbs and webbing, it indicates it is a swimmer

Question 27

Three common families of frogs in North America

Answer 27

Ranidae- true forge (bullfrog)

Hylidae-tree frogs

Bufonidae-true toads: short legs, stout bodies, thick skin with warts that produce milt fluid to protect from predators

Question 28

How do anurans survive the winter

Answer 28

1. Rest on bottom of water body, lower metabolism and absorb oxygen through skin (green, mink and leopard frogs)
2. Manitoba toads tunnel into loose soil or burrows to remain in micro habitat with temperature above their freezing point
3. Some terrestrial species tolerate freezing: body tissues flood with glucose to act as antifreeze allowing them to survive about -10

Question 29

Frogs and toad courtship

Answer 29

-males call loudly and frequently to attract females during spring
-males have vocal sacs that amplify their courtship or advertisement calls

Question 30

Do frogs and toads have internal or external fertilization?

Answer 30

External: female lays eggs, and male deposits seminal fluid over eggs during amplexus (mating posture). Eggs expands with water into jelly-like mass, often attached to vegetation.

Question 31

Do frogs take care of young?

Answer 31

-most forge abandon their eggs, but some species guard or carry them
-tropical fiefs more likely to lay eggs on leaves or carry eggs/tadpoles

Ex:
-South American marsupial frog females have dorsal pouch for tadpoles
-female Surinam frog Carrie’s eggs in dorsal pouches until froglets emerge
-make poison arrow frog Carries tadpoles on his back
-male Darwin frog Carries tadpoles in vocal pouch

Question 32

How can frog embryos develop quicker?

Question 33

Amphibian populations have declined worldwide due to….

Answer 33

-habitat loss and fragmentation: deforestation, loss of wetlands, separation of forest and water, roads
-climate change
-chemical contaminants
-disease

Question 34

Chytridiomycosis

Answer 34

-infectious disease caused by a chytrid fungus, an aquatic pathogen that affects anurans (Bd) and salamanders (Bsal), which is even more deadly
-chytrid fungus contributed to decline of 501 species worldwide, 90 of those went extinct
-fungus originated in Asia, global pet trade and testing of pregnancy tests led to spread

Question 35

How does Bd affect amphibians

Answer 35

-fungal spores that live in water penetrate skin of amphibians
-infect keratin-containing tissues, which mostly affect froglets or adult amphibians
-spores mature and form reproductive body, which branches through animals skin
-skin gets thicker and tougher and interferes with respiration and water and electrolyte balance, eventually causing death and heart failure

Question 36

When can affected amphibians of Bd be allowed back into environment

Answer 36

When fungus is gone…

Panamanian golden toad are only found in captive breeding programs rn

Question 37

Characteristics of amphibian biology that make them especially vulnerable to factors like climate change, habitat loss and disease…

Answer 37

Permeable skin (susceptible to drying out)
Dependency on aquatic habitats