wildlife biology lecture 4

herpetofauna

what clade do reptiles belong to

amniota clade

how are amniotes characterized

presence of 3 extra embrionic membranes in theri development

what are some characteristics of reptiles

tough dry scaly skin

shelled amniotic egg

copulatory organs - internal fertilization

atria seperated from eachother

respiration via gastralia - vental ribs

metanephros kidney - capable of excreting uric acid

salt glands

ectothermic

what are the three membranes of the amniotic egg and their function

the amnion - for protection

chorion - for respiration

allantois - nitrogen exchange

what reptiles does australia have

order squamata - snakes and lizards

• 13 families, 155 genera, 1033 species

Rhyncocerphalia- tuatara

Crocodilia - crocodiles

• 1 family, 1 genus, 2 species

testudines - turtles and tortoises

• 5 families, 15 genera, 32 species

what percentage of reptiles are lizards and snakles

95% it has a high proportion of lizard species

what are pygopodidae

flap footed lizard - 46 species

how are pygopodidae lizards differentiated

they lack forelimbs

hindlimbs are often reduced to scaly flap size

they have lidless eyes

difference to snakes - fleshy tongue, external ear opening, and their tail is longer than their body

what are the 3 families of geckos

 Gekkonidae, Carphodactylidae and Diplodactylidae

• represented by small nocturnal lizards

• large lidless eyes

  • terrestrial or arboreal

what are the characteristics of gekkonidae

pupil dilate in narrow slit

voice is squeak

oviparious

• 1 - 2 eggs

• hard, brittle, non permeable shell

digits can be angular

• microscopic adhesive setae

what are the characteristics of carphodactylidae

endemic to aus

voice is squeak or rasping bark

oviparious with clutch of 2 eggs

box shaped heads and large ornate tails

angular digits

most lack enlarged toe pads

typically larger than other gecko families

diplodactylidae

native group to australia and western pacific

most have enlarged toe pads

non angular digits

scales on dorsal surface of the tips of the digits more or less equal in size

scincidae

long cylindical bodies

many have 5 digits

smooth overlapping body scales

eyelids are present and may be movable or immovable

pupil is not a narrow vertical slit

varanidae

lizards with long snouts

loose skin with no overlapping scales

forked tongues

oviparious

diurnal

well developed limbs

moveable eyes

agamidae (dragons)

loose rough textured skin

broad, flat, fleshy tongues slightly notched at the front

very active and alert

incredibly agile

lay 2 -20 eggs

acrochordidae (file snakes)

strictly aquatic

small finely keeled scales

prehensile tails

live bearing

pythonidae

non venemous constrictors

birds, mammals, sometimes reptiles

small body scales

lay eggs and female protects them until they hatch

have cloacal spurs

colubridae

has both solid toothed non venomous snakes and rear-fanged venomous snakes

symmetrical head shield

enlarged ventral scales

loreal scale not present in elapids

homalospidae

venomous rear fanged water snakes

quatic to semi-aquatic

valvular nostrils on top of their snout

round tails

broad ventral scales

elapidae

terrestrial and marine snakes

immovable fangs at the front

Terrestrial elapids have symmetrically arranged scales on top of head

pointed tails

29 species of true sea-snake

• have vertically flattened paddle-shaped tail

• valvular nostrils

• reduced ventral scales

all venemous

typhlopidae

non-venomous

burrowing snakes

smooth shiny scales

uniform body thickness

blunt heads

cryptic

characteristics of frogs

thin semipermeable glandular skin

external fertilization

typically lay eggs in water or moist substrates

life cycle typically includes metamorphosis from gilled larval stage

what are the 5 frog families

hylidae

myobatrachidae

limnodynastidae

ranidae

microhylidae

which families had gondwanan origins

hyalidae

myobatrachidae

limnodynastidae

hylidae - tree frogs

horizontal pupil

large finger and toe pads (usually)

myobatrachidae (toadlets/froglets)

never arboreal

terrestrial or aquatic

endemic to Aus

limnodynastidae

lay eggs in foamy floating mass

never arboreal

ranidae

wood frog

maxillary teeth

fully webbed toes

microhylidae

confined to wet forests of queensland

lay eggs on land

hatch as full formed frogs

bufonidae

cane toad

invasive

enlarged pair of parotoid glands

what are the only reptile families that derive from gondwana

the two gecko families, Carphodactylidae and Diplodactylidae and the turtle family Chelidae,

what lineages are from southeast asia

Carettochelyidae, Varanidae, Gekkonidae and Elapidae

what species arrived 25 mya

scincidae, agamidae, boide

what are some of the threats to herpetofauna conservation

habitat loss and fragmentation

changes to fire regimes

cane toads

chytrid fungus

habitat loss and fragmentation

clearing land for agriculture and the suppression of fire regimes and private land