amphibian larva - frog tadpoles. Photo by Donna L. Long.

How to Tell Tadpoles from Salamander Larva

amphibian larva - frog tadpoles. Photo by Donna L. Long.
amphibian larva – frog tadpoles. Photo by Donna L. Long.

Amphibians go through metamorphosis. Little fish like creatures hatch from eggs in moist or water environments. Amphibians are born as larvae and change into adult form. WIth big heads and long wavy tails, baby frogs can look like salamanders and salamanders and look like toads.  How can we tell who we are looking at?

I gathered some general guidelines on identifying tadpoles and baby salamanders.

With the numerous species of animals classified as either frogs, toads, or salamanders it is not useful to say every single species behaves in the same way. Research the animal you are observing for particulars related to their species.

Northwestern Salamanders.eggs. Wikimedia:Greg Schechter from San Francisco, USA [CC BY 2.0 (https://creativecommons.org/licenses/by/2.0)]
Northwestern Salamanders.eggs. Wikimedia: Greg Schechter from San Francisco, USA [CC BY 2.0 (https://creativecommons.org/licenses/by/2.0)]

What Changes does an Amphibian go through During Metamorphosis?

  1. the legs complete their development
  2. the eyelids and mouth take their final forms
  3. the tails that the animals use to swim through the water disappear
  4. the gills the animals used to breath disappear
  5. the lungs tissues develop and become the major breathing organ
  6. the digestive system undergoes a major overhaul in preparation to digest adult food
  7. the intestine is shortened
  8. the frog larva that will have toxic skin qualities as adults, develop those toxic qualities.

 

Whose Larva is it?

When you are observing these two orders of creatures in a pond it can sometimes be confusing as to what you are watching.

I can usually tell bullfrog tadpoles from other tadpoles or larva, but that is about it. So, of course, I had to do research to figure out how to know if I am looking at a tadpole or a salamander larva. Here is a chart on how to compare the two. Frogs and toad larva we call tadpoles. Salamander larva we call, larva.

Toad tadpoles at the Schuylkill Center for Environmental Education are probably Bufo americanus (American Toad). Photo by Donna L. Long.
Toad tadpoles at the Schuylkill Center for Environmental Education are probably Bufo americanus (American Toad). Photo by Donna L. Long.

 

How to Tell a Salamander Larva from a Frog Tadpole

Salamander Larva

Tadpole (frog or toad)

3 pairs of gills

2 pairs of gills

long body, ⅔ of body length

short body, less than ½ of length

no adhesive organ on the head

adhesive organ on the head

tentacle-like balancers on the underside of the head

no balancers

largemouth

smallmouth

no covering over gills (operculum)

gills are soon covered by skin

front leg buds clearly are seen

front leg buds concealed

front leg buds clearly visible throughout the development

front leg buds are hidden until metamorphosis

Source: Reptiles for Dummies by Patricia Bartlett, 2003.

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