Lecture #12 ~ Companion Reptiles and Amphibians

Frogs class

amphibia (includes salamanders)

#of species of amphibians

4000

#of species of amphibians which are frogs and toads

3,500

why is there a significant reduction in numbers of wild amphibian populations?

deforestation and encroaching on natural habitat

fire-bellied toads

hardy toads, approx. 2 in long, good for new owner, southern asia, bright green and black backs w/ black-orange undersides, 10-15 yrs

poison dart frogs

native to south and central american rainforests, adults are .75 in long, darts dipped in mucuous can be used to kill prey

south america horned frogs “pacman”

up to 5.5 in, can live 6 yrs, fat frogs w/ wide mouth, females weigh up to 1 pound, but males are smaller, passive hunters, from tropics of argentina, uruguay, paraguay, and brazil

african clawed frogs

4-5 in, up to 15 yrs, strictly aquatic, good for new owner, forelegs too weak for dry land

tree frogs

native to north, south, and central america and central asia and europe, over 600 species of tree frogs, slit-like pupils

bullfrogs

american bullfrog > 6 in, african bullfrog >9 in, native to central and eastern US but has been introduced to western us and southern canada, native species in most countries, may live 35+ years

leopard frogs

slender greenish to brown frogs w/ dark spots edged w/ slightly lighter color, 3.5 in, northern = native to north US and south canada

toads

found in most parts, american one found in east part of US, marine one native to texas and northern parts of south america (fattt), poisonous to dogs, cats, and other animals

exception for smooth, moist, glandular skin

toads

true or false: does the frog skin have a stratum corneum?

false → highly permeable to water (some can live on water + on land = high resp capacity)t

2 kinds of skin glands in frogs

mucous + granular

parotid glands

secrete toxins which prevent ingestion by predators; located behind eyes

which toads can eject toxins from parotid glands quite a distance?

marine toads

which frogs secrete a curare-like substance?

poison dart frogs (captive ones lose ability to secrete toxin though)

what kind of structural modifications do frogs have which allow em to jump?

fused bones and heavy muscling on legs (can jump 2-10 times body length, built to withstand shock)

bladder =

storage for water

metamorphosis

begin as tadpoles (gills, 2-chambered heart, no limbs, tail for swimming and lateral line system (series of pores in skin allowing for detection of changes in water currents) then morph into carnivorous frog (3-chambered organ, lungs not gills, limbs, no tail)

acquatic species management

water of appropirtae depth, good water condition, no chlorine

semi-aquatic species

slightly slanted floors

terrestrial

solid surface, moist, material = moss or heat-treated soil or leaves or sponge

3 class of animals and what they secrete

aves/birds: uric acid

mammals: urea

amphibians: ammonia 

(all nitrogen excretions)b

build up ammonia r other toxins in the water can…

be absorbed through the frog’s skin and can quickly become toxic

cleaning

frogs are extremely sensitive to chemicals, many cleaning agents are toxic

true or false: frogs are ectotherms

true! they’re poikilothermic (tend to prefer warm temp but are adapted to cooler environment)

at what % of relative humidity do frogs fair well

80% (too dry = desiccation)

natural light should be provided in a ____ cycle

normal day/night

what can happen if a closed aquarium is placed in direct sunlight

lethal temp/death

are tadpoles herbivorous or carnivorous?

herbivorous

are adult frogs herbivorous or carnivorous?

carnivorous

how to frogs orient their prey?

visually (must be fed live food)

what are some food items commonly offered to medium/large sized frogs?

crickets and mealworms

gut loading

feeding nutritious food with vitamins/minerals immediately before feeding them to frogsr

redleg

caused by bacterium aeromonas hydrophila (found in aquatic environments w/ poor water quality, unclean, and bad nutrition, but doesn’t cause disease unless frog is immunocompromised); can be treated by antibiotics but is best prevented by appropriate husbandry and nutrition, leads to sepsis

saprolegnia (fungi)

many fungi cause secondary infections, but are common in soil/water and usually don’t cause problems; best prevention is health and no stress

chlamydia psittaci

causative agent of psittacosis in birds but can also affect African Clawed frogs; colonizes internal organs of clawed frogs and causes depression, abdominal distension, and redness and blanching of skin; tetracycline can be effective against disease, but most frogs are euthanized because it’s zoonotic

most common zoonotic agent associatd with frogs

atypical mycobacteriosis

what bacteria can tank water for aquatic and semiaquatic frogs contain?

mycobacterium

how do mycobacterium typically enter the body

through preexisting wounds

true or false: immunosuppressed individuals are more susceptible and can develop severe systemic disease

true

how can you prevent disease when handling frogs

wear gloves, wash hands right after

does salmonellosis occur more frequently with reptiles or amphibians?

reptiles

true or false: reports of frog-to-human transmission have been currently identified

false

what class are lizards a member of?

reptilia

what are lizards and snakes referred to as?

squamates

how many species are there worldwide of squamates

5,000

What family are iguanas a member of?

iguanidae

how many species of iguanas are there?

650

Most commonly kept pet iguaana

common green iguana (native to central/south america, 6.5 ft)

where is the desert iguana native to?

southwestern US

what family are chuckwallas a member of?

iguanidae

describe chuckwallas

flattened body shape, hide in cracks and crevices of boulders, can inflate lungs to wedge body in rocks, 2nd-largest lizard in US, up to 18 in, natural habitats in west/southwest US

what animal is this:

flattened body shape, 

hide in cracks and crevices of boulders, can inflate lungs to wedge body in rocks, 2nd-largest lizard in US, up to 18 in, natural habitats in west/southwest US

chuckwalla

describe dragons

mid-sized stocky lizards, have dark beards, can puff out jaws when frightened, easily tamed as pets

what animal is this:

mid-sized stocky lizards, have dark beards, can puff out jaws when frightened, easily tamed as pets

dragon

describe the Australian bearded dragon

native to central Australia, basic colors can be brown/grey/red-brown/orange, and can change body color to help regulate body temp

what family are anoles a member of

igunidae

describe the green anole

found in southern US

lives in trees, shrubs, around houses

8-5 in long as adults

can change color depending on environment

describe the cuban brown anole

found in southern Florida

brown in color with light brown/grey markings

describe knight anoles

native to cuba

adults are 18 inches long and green w/ white markings

eyes are surrounded by a circle of blue

what family are skinks a member of

scinidae (1275 species)

where do skinks usually live

among trees and underbrush of forest floors

name three skinks

five-lined, Australian blue-tongued, Solomon islands giant

what family are geckos a member of

gekkonidae (800 species)

where are geckos found

tropical and subtropical habitatwhat

what do the feet of geckos have for climbing

adhesive pds (lamellae)

describe leopard geckos

found in dry regions (india, iraq)

grey-brown in color w/ dark patches and spots and small wart-like projections on epidermis

nocturnal

ground-dwelling

can’t climb well

other geckos:

giant day

gold dust day

lined day

frog eyed

describe monitors

large lizards w/ powerful jaws, tails, and claws

some places ban ownership

fork-shaped tongue

savannah monitors may be 5 ft in adults and live 10-12 years

describe tegus

fairly large lizards

maybe aggressive

terrestrial lizards

good swimmers

active in day

4 ft in length, 20 lbs, 15 yrs

true or false: most lizards have eyelids

true, except geckos

how many chambers in a lizard heart

3

what lies just inside the abdominal wall

a large midventral abdominal vein

how does an iguana’s tongue look

fleshy

how does a snake tongue look?

forked

true or false: all lizards have teeth

true

which species of lizards are venomous

Gila monsters and beaded lizards

what happens sometimes if many male lizards are houses together

display aggressive behaviors (territorial)

what do some lizard species have to avoid predators?

autonomy

what happens when special lizards are restrained by the tail?

tail will break off and the lizard can escape (when tail regrows, it’ll be off-color)

what enables autonomy in lizards

special zones of weakness at regular intervals in vertebrae below the vent

what does the lizard do to fracture the vertebra?

contract a muscle

what contracts around the caudal artery to minimize bleeding?

sphincter muscles in the tail

where can desert lizards species be kept

on sand

lizards tend to be ____ by nature, so animals should be provided with a retreat

secretive

where do lizards soak?

water dishes

which animals require frequent misting of the vegetation in their cages in addition to having a water bowl

certain lizards which lap dew in the wild

how often should you clean water bowls?

daily (because lizards defecate in their bowl)

true or false: lizards are ectotherms

true (poikilothermic)

in general, do lizards prefer warm or cold climates?

warm

lizards engage in behavioral ____

thermoregulation

what kind of heat source should be provided in cages so animals can move from warmer to cooler areas?

focal

what kind of bulb should be focused on a rock or other basking. site

low-wattage incandescent

why are “hot rocks” hazardous

if they malfunction, it can create an intense hot spot in the rock, causing thermal burns

whats the range for relative humidity

30-70%

which species require 100% humditity

tropical

which species 30-40% relative humidity

desert