Herpetology Lab 1 – Gymnophiona/Caudata
Class Amphibia
Class Reptilia
Amphibians (Class Amphibia)
– Gymnophiona (Caecilians)
– Urodela (Caudata) (Salamanders and Newts)
– Anura (Frogs and Toads)
Reptiles (Class Reptilia)
– Testudines (Turtles and Tortoises)
– Squamata (“Lizards,” Amphisbaenians, Snakes)
– Rhynchocephalia (Tuataras)
– Crocodylia (Alligators and Crocodilians)
– Aves (Birds)
• Ectotherms
• Thermoregulation
Amphibia
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Greek “amphibios”= a being with a double life.
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Caecilians, Salamanders, Frogs and Toads
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~ 230 mya
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3 orders; 57 families
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434 genera; 6,182 species
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Found on every continent except Antarctica.
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Metamorphosis (Hormonal control)
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Herpetology Lab 1 – Gymnophiona/Caudata
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Tadpoles Frogs/ Toads (herbivorous/cannibalistic)
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Salamander larvae (aquatic) Eft (land-dwelling) Adult Salamander(aquatic)
(carnivorous)
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Juvenile features:
– Larval tails
– Tadpole “teeth”
– External gills
– Lateral-line sensory organs
– Amphibia
• Paedomorphosis
– Reproductively mature individuals retain larval features.
Ex. Ambystomatids
Ambystoma mexicanum
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Family Cryptobranchidae
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Necturus
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Amphiumidae
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Sirenidae
All species are paedomorphic.
“Neotenic” forms are reproductively mature individuals that retain juvenile features
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Heterochrony - rate/timing of developmental events.
• Order Gymnophiona
- elongated bodies, limbless
- segmented (annuli)
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Herpetology Lab 1 – Gymnophiona/Caudata
- little/ no tail past cloaca
- fossorial (bony skulls)
- S. China, Ghana, C. America & radiated throughout tropics.
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Cloaca
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Snout-Vent Length (SVL)
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Total Length (TL)
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Tail Length (TL)
Gymnophiona
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Smallest – Idiocranium russeli (W. Africa) (2.8 in)
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Longest - Caecilia thompsoni (Colombia) (5.2ft)
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Diet - Opportunistic feeders
– Earthworms, termites, crickets..etc
– “sit and wait” foraging mode
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Family Typhlonectidae – Aquatic caecilians
-Typhlonectes sp.
Order Urodela (Caudata)
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“Caudate”- having a tail or tail-like appendage.
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Salamanders and Newts
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9 families, 64 genera, 556 species
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Caudata
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Aquatic, amphibious, or terrestrial
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Herpetology Lab 1 – Gymnophiona/Caudata
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Body size ~ 2-6 in.  4.6ft
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Elongated bodies
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Similar-sized limbs
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Salamander - tailed amphibian in terrestrial habitats
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Newt - refers to genera that return to water
to breed (Notopthalmus, Taricha)
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Smooth, scale-less skin
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Skin involved in gas exchange
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All carnivorous (invertebrates)
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Most have internal fertilization
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Oviparous, ovoviviparous
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Spermatophore
• Ambystomatidae
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Mole Salamanders (2 genera, 35 species)
– Found only in N. America (New World)
– Inhabit moist environments (rotten logs, animal burrows)
– Aquatic larvae  terrestrial adults
– Paedomorphic species
– Stocky body form, costal grooves
– Tail laterally compressed
– 4 “fingers”, 5 “toes”
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Rhyacotritonidae
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Torrent Salamanders
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Herpetology Lab 1 – Gymnophiona/Caudata
– 1 genus, 4 species
– N. America (Pacific Northwest)
– Inhabit cold streams/springs (aquatic, semi-aquatic)
– Greatly reduced lungs
– Small body size (9-12 cm), large eyes
– 4 short well-developed limbs
– 4 fingers, 5 toes
– Costal grooves
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Salamandridae
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Newts (20 genera, 74 species)
– N. America, Europe, Asia
– Brightly colored (noxious secretions)
– SVL (7-35 cm), slender, long tails
– Lack costal grooves
– Rough  smooth skin (environment)
– Internal fertilization (spermatophore)
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Plethodontidae
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Lungless Salamanders (24 genera, 377 species)
– New World distribution (N.,C.,S. America & Europe)
– Inhabit woodlands, caves, mountain streams
– (2.5-21 cm) SVL, cylindrical
– Costal grooves present
– Gas Exchange occurs via skin
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Herpetology Lab 1 – Gymnophiona/Caudata
– Nasolabial grooves
• Proteidae
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Olms, Mudpuppies, and Waterdogs
– 2 genera, 6 species
– Balkans (olm) / East & Central N. America
– Entirely aquatic, external feathery gills (paedomorphic)
– (11-35 cm) SVL, stout body, tail laterally compressed, small limbs
– Costal grooves
• Cryptobranchidae
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Giant Salamanders (2 genera, 3 species)
– China, Japan & E/C USA (hellbender)
– (60-160 cm) body length ~1.5 m = 5 ft
– Massive head & body, short limbs
– Nocturnal, cold mountain streams
– Long-lived (52 years in captivity)
– Lateral skin folds
• Sirenidae
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Sirens (2 genera, 4 species)
– SE USA distribution
– Shallow water, buried in mud/sand
– (10-90 cm) length “eel-like” body
– External gills, no hindlimbs, small forelimbs
– Costal grooves, horny beak (suction feeding)
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Herpetology Lab 1 – Gymnophiona/Caudata
• Amphiumidae
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Amphiumas (1 genus, 3 species)
– SE USA, Stagnant waters, swamps
– Live in burrows, nocturnal , totally aquatic
– Feed on frogs, snails & fish
– (22-76 cm) length “eel-like” (Congo Eels)
– Tiny limbs (1-3 fingers, toes)
– Costal grooves, adults possess lungs and 1 gill slit
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