Biol. 452 - Vertebrate Natural History

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POND vs. STREAM SALAMANDER LARVAE

POND - typified by Northwestern & Tiger salamander larvae	STREAM - typified by Giant Salamander larva
Dorsal view of an Ambystomatid larva shows how the caudal (tail) fin extends onto trunk, almost to head. They can use the entire body to propel themselves in water.	Giant Salamanders have small tail fins & a more stream-lined body profile so they won't be swept away by fast water.
Ambystomatids have long, plume-like gills that increase surface area for gas exchange so these species can live in warmer water or more stagnant water (e.g. ponds). You can see a bit of its tail fin as the lighter yellow material along the back.	Giant Salamander larvae have short, bushy or thread-like gills with lower surface area for gas exchange. Oxygen demands are lower in cold water & water has a higher oxygen content.

SAMPLES OF PALATAL TEETH & TONGUE DESIGN

Tongue of a plethodontid, Common Ensatina showing the short "stalk" which extends the projection of the tongue. More derived plethodontids have projectile tongues on even longer stalks.	Tongue of the Roughskin Newt, its small & simple, attached to the floor of the mouth. They also have a row of vomerine teeth that form an inverted V.
The family Plethodontidae [pleth = many, dont = teeth] is named after the large cluster of parasphenoid teeth in the midline of the skull.	The vomerine teeth in the ambystomatid, Northwestern salamander, is in a "broken", but nearly straight line between the internal nares.
The maxillary teeth & inner, curved vomerine tooth row that passes along side the internal nares are clearly visible in the Giant Salamander.	The vomerine teeth in the ambystomatid, Tiger salamander curve & are very similar to the teeth of a Giant salamander. These families are close relatives but they were once lumped together into 1 family.

FAMILY DIVERSITY

Order Caudata Family Sirenidae Greater Siren	The specimen is a bit twisted, the Greater Siren's head is to the left. Note absence of hind limbs.	Greater S iren's head is flat, with small eyes, gills & the tiny pair of front limbs.
Order Caudata Family Cryptobranchidae Hellbender	Dorsal view showing extremely flattened head & body.	Ventral view showing some of hte folds of skin along trunk & limbs.
Order Caudata Family Amphiumidae Three-toed Amphiuma	It's front & hind limbs are extremely reduced.	Close up of its head: small eyes & gill slit just in front of leg (but no external gills).
Order Caudata Family Plethodontidae Common Ensatina	The Common Ensatina has a constriction at the base of the tail. The body coloration & markings on Ensatina are variable by region, locally they are relatively unpatterned.	Close up of the constriction at the base of it's tail.
Order Caudata Family Plethodontidae Western Redback Salamander	Dorsal & ventral views. The dorsal stripe is often obscured in preserved specimens.	Close up of it's small, relatively short, simple hind toes.
Order Caudata Family Plethodontidae Arboreal Salamander	Dorsal & ventral views; note the tiny faint light spots on the dorsal side.	Close up of its square-tipped toes & broad foot pad that aid climbing.
Order Caudata Family Rhyacotritonidae Olympic Torrent Salamander	It's plain, unpatterned body looks superficially similar to the Ensatina. However, torrent salmanders have shorter legs that don't touch when adpressed & a shorter rostrum relative to it's large eye size.	The torrent salamanders have an unusual shape to the posterior edge of their cloaca:
Order Caudata Family Proteidae Common Mudpuppy	Dorsal view shows large caudal (tail) fin, and relatively large limbs.	A close up of it's head shows its flattened head, small eyes & extremely large plume-like gills.
Order Caudata Family Salamandridae Roughskin Newt	Dorsal & ventral views show the rough, bumpy skin of the terrestrial adult.	The heavy, short toes of a Rough-skinned newt.
Order Caudata Family Salamandridae Roughskin Newt	When these newts return to water to breed, their skin gets much smoother & they reaquire a tail fin.	The breeding male Roughskin newt has a swollen cloaca.
Order Caudata Family Ambystomatidae Northwestern Salamander	This salamander has a uniform brown or dark color and large concentrations of poison glands are visible over the entire body, note swelling on dorsal side of tail, light, "spots" on the back and head.	A closeup of its head shows the large parotid gland behind the eye.
Order Caudata Family Ambystomatidae Long-toed Salamander	The long-toed salamander has that small body & delicate appearance of some of the plethodontid salamanders & has a light stripe down its back that makes it look a lot like the Western Red-backed salamander. Compare Ambystomatid palatal teeth to Plethodontid teeth & using a scope note the absent nasolabial groove (found only in plethodontids).	The 4th hind toe of this salamander is noticeably longer than any other toe on the foot & the toes in general are long & delicate compared to the toes of other salamanders seen in lab.
Order Caudata Family Ambystomatidae Barred Tiger Salamander	Tiger salamanders have either a mottled black/dark with yellow or black/dark with green pattern that varies across different populations.	The Tiger salamander has a pair of tubercles on the base of its feet, they are just barely visible here.
Order Caudata Family Ambrystomatidae Pacific Giant Salamander	These are the largest salamander found in the Pacific northwest.	Their toes have keratinized tips to help them maintain a grip when in fast, cold streams.

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