Lab IV (amphibians): Survey of the Amphibians Flashcards
1
Q
Characteristics of the Amphibians
Skull
Jaw articulation and mouth type
A
- Jaw articulation is between articular (lower jaw) and quadrate bones (on skull)
- Large mouth with small (pedicellate) teeth in upper/both jaws
- Two internal nares open into anterior part of mouth cavity
2
Q
Characteristics of Amphibians
Skeleton
A
- Mostly bony; varying number of vertebrae with zygapophyses (extensions that join one vertebrae to the next)
- Varied body forms
- Usually four limbs (tetrapod), some legless
3
Q
Characteristics of Amphibians
Integument
A
- Smooth, moist skin with many glands (mostly mucous)
- Some poisonous
- Pigment cells (chromatophores) common and variable
- Thin outer layer of skin (epidermis) with keratinized (water-proof) outer surface
4
Q
Characteristics of Amphibians
Circulation and Respiration
A
- 3-chambered heart (2 atria, 1 ventricle), double circulation through heart, skin abundant with blood vessels
- Respiration by lungs, skin, and gills in some; larva with external gills (may persist)
5
Q
Characteristics of Amphibians
Heat regulation
A
- Ectothermy (cold-blooded)
6
Q
Characteristics of Amphibians
Excretion
A
- Done by paired kidneys
- Urea is main nitrogenous waste
7
Q
Characteristics of Amphibians
Reproduction
A
- Sexes are separate
- Internal fertilization in salamanders and caecilians
- External fertilization in frogs and toads
- Mostly oviparous, some oviviparous (eggs develop without maternal investment and hatch internally) or viviparous (bear live young)
- Metamorphosis (immature animal to adult; change in body form and way of life) usually present
8
Q
Characteristics of Amphibians
Nervous and Sensory
Special sensory area in ear?
A
- Papilla amphiborium
9
Q
Integumentary Adaptations of Amphibians
Integumentary features?
A
- Highly vascularized dermis - supports respiratory function
- Estivation - successive molts retained to prevent water loss
- Water uptake through pelvic patches in anurans
- Very vascularized skin folds in hellbenders
10
Q
Integumentary Adaptations of Amphibians
Other adaptations of epidermis?
A
- Warts on anurans
- Horny epidermal claws on spadefoot toad
- Specialized glands - produce protective mucous and poisons
- Usually milky in texture
- Glands concentrated in strategic area - e.g., paratoid glands behind head in some toads and frogs, along backs of salamanders
- Dorsolateral ridges on some frogs
- Accessory breeding structures - nuptial pads on one digit per forelimb
- Expanded fingertips of tree frogs produce sticky secretion that “glues” them to trees etc.
-
Adaptive colouration
-
Anti-predation colouration
- Cryptic/concealment - resembles background
-
Warning colouration
- **Aposematic **- noxious animals
- Mimicry
-
Anti-predation colouration
11
Q
Metamorphosis
Process and changes that occur
A
- Eggs deposited in water, gill bearing larvae (salamanders) or tadpoles (anurans), metamorphosis at end of larval stage
- Morphological and physiological changes during metamorphosis are under hormonal control
- Regression of gills, formation of lungs
- Degeneration of tails
- Develop limbs
- Form dermal glands
- Reorganize digestive tract (herbivore to carnivore)
- Modify excretory system (ammonia waste to urea)
- Loss of tail “fins” in some salamanders
12
Q
What is paedomorphosis?
What are the two different processes involved in thsi?
A
-
Paedomorphosis = Possessing juvenile characteristics in later, older development. Most extreme form involves attainment of sexual maturity in animal that retains larval form for entire life. Accomplished via two different processes:
- Neoteny: Retention of one or more larval/embryonic traits in otherwise adult body. Involves slowing down/stopping development of affected traits
- Progenesis: Early development of gonads in morphologically juvenile stage. Involves speeding up development of reproductive system
13
Q
Order Caudata
A
- Subclass “Amphibia”
- Order Caudata (“tailed”, salamanders)
- Elongate
- Mostly four limbs
- Northern hemisphere
- Two important trends:
- Paedomorphosis
- Reduction of lungs
14
Q
Family Cryptobranchidae
A
- Order Caudata
- No external gills (adults)
- Lungs present
- Progenic and permanently aquatic
- Very flat head; lots of wrinkles on side of body (increases surface area for cutaneous respiration)
15
Q
Family Ambystomatidae
A
- Order Caudata
- Mole salamanders
- Tiger salamander and long-toed salamanders in Alberta
- Lungs in adults
- Gills in neotenic forms (neotony occurs)
- Lots of stripes, long toes
16
Q
Family Salamandridae
A
- Order Caudata
- Newts
- Stout-bodied
- Lungs only in adults
- Two metamorphic stages in some - aquatic larvae to terrestrial efts to aquatic adults
- Conical, tapering tail (long and thin)
17
Q
Family Proteidae
A
- Order Caudata
- Mudpuppies
- Lungs and external gills as adults
- Neotony = rule
- All aquatic
- No folds on side (unlike hellbender); tail fin fold; big head
18
Q
Family Plethodontidae
A
- Order Caudata
- Lungless salamders
- Lack lungs and gills as adults (respire entirely through skin)
- Lower jaw immovable; tongue protrudes for prey capture
- Highly terrestrial; live in caves
- Snake-like but with four limbs
19
Q
Family Amphipiumidae
A
- Order Caudata
- Amphiumas
- Elongate, possess lungs, lack functional gills
- Limbs reduced in size (but still present)
- Snake-like
20
Q
Family Sirenidae
A
- Order Caudata
- Siren
- Elongate, gills and lungs at maturity
- Hind limbs absent, front limbs reduced
- Progenic and aquatic
22
Q
Family Pipidae
A
- Tongueless, aquatic frogs
- Dorsoventrally flattened
- Thickwaists, heavy legs, large webbed hind feet
- Forefeet for feeding
- In lab, looks like it has black toenails
24
Q
Rana luteiventris
A
- Columbia spotted frog
- Family Ranidae
25
Q
Rana pipiens
A
- Northern leopard frog
- Family Ranidae
26
Q
Rana sylvatica
A
- Wood frog
- Family Ranidae
28
Q
Anaxyrus boreas
A
- Western toad
- Family Bufonidae
29
Q
Anaxyrus hemiophrys
A
- Canadian toad
- Family Bufonidae
30
Q
Family Pelobatidae
A
- Order Anura
- Spadefoot toads
- Crescent-shaped, horny projections on side of foot (for digging)
- Plains spadefoot toad in Alberta
- Bar on heel to dig with
31
Q
Family Hylidae
A
- Order Anura
- Tree frogs
- Slender, long legs, blunt head
- Arboreal
- Toes tipped with expanded discs
- No webbed feet; long toes
- Boreal chorus frog in Alberta
33
Q
Family Discoglossidae
A
- Order Anura
- Disc-like tongue; can’t protrude
- Wide mouth
- Eggs on back
- Firebelly and midwife toads
34
Q
Order Gymnophiona
A
- Legless amphibians, caecilians
- Legless, burrowing or aquatic
- Very reduced eyes
- Small scales within dermis
- Black
- “Tentacles” in grooves near maxilla
