Herpetology 101 Aims to Teach Students the Basics of Reptile and Amphibian Biology While Instilling an Interest in Life and Animal Sciences
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Splash Herpetology Goals: Herpetology 101 aims to teach students the basics of reptile and amphibian biology while instilling an interest in life and animal sciences. Materials Requested: We’re requesting a frog life cycle replica, a coral snake replica, and a red eared slider replica. These will cost $29.97, but it is expected to be a little over $30 with tax and shipping included (we will pay the rest if we need to). We would like to use these replicas to teach about animals we don’t have—for example, we obviously do not have a venomous, deadly coral snake, so we would like to have a replica to show people what to look for. We would also like a replica aquatic turtle to demonstrate the differences between terrestrial and aquatic chelonians, and a series of frog/tadpole replicas to demonstrate the amphibian life cycle. Class outline is below. We’ll spend our time going over the below information and observing and handling live reptiles and amphibians! ● Introduction to us and WISE ○ Who we are on campus ○ What animals we work with (herps and inverts) ● Introduction to reptiles and amphibians ○ Similarities: ectotherms, no fur or feathers, oviparous ○ Differences: amphibians have an aquatic larval stage, skin versus scales, some ovoviviparous reptiles versus all oviparous amphibs, amphibs poisonous while reptiles generally venomous, reptile eggs are leathery ● Amphibian biology ○ Study of amphibians: “Batrachology” ○ 7,000 species, 90% of which are frogs ○ Ecological indicator species ■ Skin is a secondary/primary respiratory organ ■ Aquatic larval stage ○ Similar anatomy ■ Skin is permeable to water; gas exchange through skin, so can breathe in the water ■ Mucous glands on heads, backs, and tails to keep skin moist ■ Central brain, spinal cord, nerves; similar to function of fish brains ■ Likely to have color vision ■ Short esophagous lined with cilia, push food with eyes ○ Paratoid glands: bufotoxin ■ Toads: behind ears ■ Frogs: along back ■ Salamanders: behind eyes ■ Caecilians: upper surface ○ Feeding methods ■ Ambush (tiger salamanders) ■ Search (toads) ■ Lure (horned frog: vibrates toes) ○ Vocalization ■ Cae and sals: soft squeaks or hisses ■ Male frogs have air sacs ● Encourages females to approach ● Encourages males to stay away ■ Distress peeping sounds from toads and frogs ○ Defense mechs ■ Poison ● Warning coloration and mimics: aposematic coloration vs mimicry ● Poison in captivity ■ Inflation ■ Camouflage ■ Salamander autotomization (axolotls) ■ Teeth and biting ● Large toads ● Giant/arboreal salamanders ○ Taxonomy: Anura, Urodela, Apoda ○ Anura: Frogs and Toads (“without tail”) ■ Smallest known vertebrate: Paedophryne amauensis microhylid at 7.7 mm long discovered in 2009 ■ Largest frog: African goliath frog ■ Taxonomy suborders: ● Archaeobatrachia- primitive frogs ● Mesobatrachia- more advanced, + aquatic Pipids ● Neobatrachia- most modern species + toads (Bufonidae) ■ Anatomy ● Skin has mucous glands ● Poison glands in some anurans ● No tail ● Lungs or no lungs ● Tympanum ● Toads: parotoid glands ● Tadpoles have gills ● Frogs have tympanum, which pick up high-frequency sounds ● Papilla amphibiorum, or specialized haircells, pick u pdeep sounds ■ Diet ● Tadpoles herbivores ● Adults insectivores ● Frogs triggered by sight ● Toads triggered by sight and smell ■ Life history ● Most go from egg to larvae to adult ● Some go from egg to froglet to adult ● Toads typically terrestrial ● Frogs typically semi- or fully-aquatic ○ Urodela: Salamanders (“tail”) ■ Largest amphibian: Chinese Giant Salamander, 3-5 ft long ■ Largest amphibian ever: Prionosuchus 30’ long, 270 million years ago in Permian period ■ Taxonomy suborders ● Cryptobranchoidea- giant sals and hellbenders ● Salamandroidea- includes the family Plethodontidae (no gills or lungs), Salamandridae, and the subfamily Pleurodelinae (newts) ● Sirenoidea- sirens, eel-like aquatic sals with reduced forelimbs and no hind legs ■ 20% amphib species exhibit parental care ■ Anatomy ● No claws ● Mucous glands on skin ● Flattened tails ● Lungs ● Skin folds with capillaries to breathe ● Poorly developed ears ■ Diet ● Insectivores/carnivores ● Triggered by sight and smell ■ Life history ● Terrestrial or aquatic ■ DEMO: tiger salamanders ● Example of caudal folds and capillaries ● Flattened rudder tails ● Mucous glands on skin ● Feeding demonstration ○ Apoda: Caecilians (“no legs”) ■ Generally 3-30 inches, but Thomson’s caecilian is up to 4.9 feet ■ Anatomy ● Skin is many folds ● Mineralized dermal scales embedded in dermis ● Eyes covered in skin: can only discern light ● Tentacles near the eye that can feel and smell ● Electroreceptors: locate objects around them in water ■ Diet ● Insectivores/carnivores ● May ingest some plant material ■ Life history ● Fossorial in damp soil or aquatic ● Oviparous or ovoviviparous ● Larvae undergo metamorphosis either before or after hatching ● Mostly in Africa, Asia, and Cental/South America ○ Conservation ■ Amphib extinction rates are 48-1024x higher than with birds or mammals ■ > 1/6th of all amphib species are threatened (IUCN) ■ Causes: habitat destruction, pollution, climate change, endocrine disruptors, ozone layer disruptions, chytridiomycosis, bsal ● Reptile Biology ○ 8000 species ○ Taxonomy: Crocodilia, Chelonia, Squamata, Tuatara ○ Similar anatomy ■ Lungs ■ Epidermis covering skin ○ Low metabolisms ○ Defense mechs ■ Camouflage ■ Displays ● Tiliqua and Chlamydosaurus ■ Venom & poison ■ Shells ■ Tail whipping/defensive strikes ■ Gaping, hissing ■ Aposematism and mimicry ■ Tail rattling ■ Autotomy ○ Crocodilia ■ 23 species ■ Largest is saltwater crocodile at 19’ ■ Temp-dependent sex determination ■ Parental care: mothers defend nests ■ Anatomy ● Replace teeth continuously ■ Diet ● Carnivorous: fish, mammals, invertebrates, reptiles, amphibians ● Gastroliths: swallow rocks to help with digestion in plant matter or for water stabilization ■ Life history ● Eggs to babies to adults ● Semi-aquatic w/ aquatic adaptations ○ Testudines ■ Anatomy ● Carapace, plastron, bridge ● Shell is bone with keratinous scales on top ● Cannot leave shell, most cannot go all the way into shell ● Turtles are semi-aquatic, so have aquatic adaptations ● Tortoises have claws, more domed shells ■ Diet ● Herbivores: tortoises ● Omnivores: turtles ■ Life history ● Aquatic turtles, box turtles, tortoises ● Long life span ■ DEMO: box turtle ● Shell example, terrestrial adaptations ○ Squamata ■ Serpentes: ● 3000 species ● 4” to 25’ ● Some parental care: Burmese pythons ● Anatomy ○ Legless ○ Overlapping scales ○ No external ears or eyelids ○ Flexible jaws and rostral notch ○ Modified quadrate bone to eat ○ No diaphragm so have to open and close rib cage ○ Heat pits ○ Vomeronasal organ ● Diet ○ Carnivores: rat snake ○ Insectivores: green snakes ○ Piscivores: cottonmouth ○ Constrictors, venomous, or live feeding ● Life history ○ Oviparous or ovoviviparous ■ DEMO: black rat snake ● Overlapping scales, no eyelids or ears, tongue ● Constrictors, native status ■ Sauridae: ● 3800 species ● 3” to 10’ ○ Smallest is the dwarf gecko Sphaerodactylus ariasae at 18 mm ○ Largest is Komodo dragon at 10’ ● Anatomy ○ Legs OR legless ○ Eyelids and external ears ○ Fixed jaws ○ Plated OR overlapping scales ○ No rostral notch ○ Some tail autotomy ○ Highly developed color vision ● Diet ○ Herbivores: Uromastyx ○ Omnivores: Blue-tongued skink ○ Carnivores: Komodo dragon ● Life history ● DEMO: crested gecko ○ Potential for autotomy ○ Arboreal ○ Ciliae, prehensile tail ○ Tympanum, can see color in dark ○ Rhynchocephalia ■ 1 species: tuatara ■ Anatomy ■ Diet ■ Life history ○ Intelligence ■ Most have a simple brain with simple reactions ■ Larger monitor lizards can cooperate and be trained ■ Crocs have larger brains, social structure, tools ■ Komodo dragons can play ■ Turtles can play ○ Conservation ■ Loss due to SFD, habitat loss, poaching Questions at the end of every section Sources: ● https://en.wikipedia.org/wiki/Amphibian ● http://blogs.cornell.edu/naturalistoutreach/files/2013/09/Reptile-Adaptations-I- 24vvxdw.pdf ● https://en.wikipedia.org/wiki/Reptile .