2 Amphibian Basics Ectothermic vertebrates 3 Chambered heart Glandular SkinCrypticScalelessEctothermGlandular SkinDon’t drink waterCryptic behavior and secretiveMetamorphosis:-4 limbs-The gills are replaced by other respiratory organs, i.e., lungs.-The skin changes and develops glands to avoid dehydration.-The eyes develop eyelids and adapt to vision outside the water.-An eardrum is developed to lock the middle ear.-In frogs and toads, the tail disappears.Well developed olfactory senseLittle metabolic control of body temp., body temp from env’tal (air, water, substrate, sun), behavior/physiological adjustmentsSkin: absorb/lose water passively, respire; contact w/moist substrate, relatively humid air, postural adjust w/moisture gradient2
3 Metamorphosis Aquatic to land Primary Changes: -Legs -Lungs -Eyes -Tail (anurans)-SkinUnique to amphibians (separates them from reptiles and fish which they are related to evolutionarily)Larvae (tadpole0 to adult)Grows as larvae, then hindlimb 1st developsEggs are laid in water..The intestine shortens to accommodate a carnivorous dieteyes migrate rostrally and dorsally.In frogs the tail is absorbed by the body, There are many deviations from the typical amphibian lifecycle. Some species of salamander do not need to metamorphose to be sexually mature, and will only metamorphose under certain environmental stresses. Many species of frog from the tropics lay their eggs on land, where the tadpoles undergo metamorphosis within the egg. Once they hatch, they are immature copies of the adults, sometimes possessing a tail which is re-absorbed in a couple of days.
4 Metamorphosis Exceptions Environmental stress inductionTerrestrial egg metamorphosisHourglass tree frog
5 Timeline for Metamorphosis Weeks to yearsSpecies and environment dependent
6 Taxonomy-Three Orders CaudataAnuraGymnophiona3 ordersNatural hx understanding is important for good husbandry practices: habitat,temp6
7 Order Differences Limbs Tails Vision Fertilization Sirens lack hindlimbs7
8 Salamander vs. Lizard Water requirements Skin Eggs & young AMPHIBIAN VS. REPTILE
9 Size-Largest -Chinese Giant Salamander-up to 180 cm -Goliath Frog-up to 32 cm
11 Owning an amphibian Life Span: up to 55 years! Aggressive vs. Friendly Budgett’s frog, related to horned frog11
12 Owning an amphibian Research and Plan!!!!! LIBRARY!!! KNOW Natural HistoryReview literature about desired species prior to ownershipBooklets, hobbyist magazines, animal care staff at zoos/aquaria, local herp society, scientific journals, caution with websitesknow life span, adult size, handling, feeding, habitat, temperament, daily care needs, space req’ts12
13 Pet Trade Restrictions Within the U.S.:ex. African Clawed FrogCITES listings-Appendix I= 16 spp.~GiantSalamanders-Appendix II- 98 spp.~DendrobatesAppendix I includes species threatened with extinction. Trade in specimens of these species is permitted only in exceptional circumstances.Appendix II includes species not necessarily threatened with extinction, but in which trade must be controlled in order to avoid utilization incompatible with their survival.
14 Gymnophiona (caecilians) 6 families,172 speciesPantropicNot keptas petsGymnophiona-not kept as pets (or as lab animals)-caecilians, pantropic6 families, 172 species14
30 Anura 33 families, >5000 species Worldwide* Common Pets/Research: -Xenopus spp. (African clawed frog)-Rana spp. (Leopard frog)-Dendrobates spp. (Poison arrowfrog)-Hylidae family. (Tree frogs)Anura distrubition: frogs and toads, cosmopolitan, except high latitude in Artic and Antartic, & some ocean islands, xenic desertsXenopus spp. (African clawed frog et. Al) Rana spp. (leopard frogs) Dendrobates spp. (poison arrow frogs)poison arrow frogs: brighly coloration = pets req’ts of each in habitat-2700 species, 21 families30
31 Frog vs. Toad -Water -Skin -Leg length and power -Predators Leopard frog and Giant toadPopular vs. Scientific Use (2 of the families, bufonids (“true toads”) and pelobatids (spadefoot toads)Frogs:Need to live near waterHave smooth, moist skin that makes them look “slimy”.Have a narrow body Have higher, rounder, bulgier eyesHave longer hind legs Take long high jumpsHave many predatorsToads:Do not need to live near water to surviveHave rough, dry, bumpy skinHave a wider bodyHave lower, football shaped eyesHave shorter, less powerful hind legsWill run or take small hops rather than jumpDo not have many predators. Toad’s skin lets out a bitter taste and smell that burns the eyes and nostrils of its predators, much like a skunk does.-Water -Skin -Leg length and power -Predators31