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 chlorinese

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 toxi

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