Salamander Key



Dichotomous Key to Salamanders



A dichotomous key is constructed of a series of couplets, each consisting of two separate statements. For example: couplet 1. Seeds round soybeans
1. Seeds oblong 2 (this statement indicates that you go to couplet “2”)

couplet 2. Seeds white northern beans
2. Seeds black black beans

By reading the two statements of each couplet, you progress through the key from typically broad characteristics to narrower characteristics until only a single choice remains. As long as the correct statement of each couplet is chosen, and the unknown organism is included in the key, a confident identification is usually achieved. Many types of organisms can be identified using a dichotomous key. In this lab, you will identify salamanders.


pictures of various salamanders, dichotomous key, metric ruler, pencil


  1. Use the dichotomous key provided to identify the salamanders in Figure 1.
  2. Write the pathway you took to get to the name of the salamander next to the drawing.
  3. Write the correct name for the salamander on the line below each picture.

Figure 1 – Types of salamanders

Key to the Salamanders:


1Hind limbs absentSiren
Hind limbs presentGo to 2
2External gills present in adultsMud puppy
External gills absent in adultsGo to 3
3Large size (over 7 cm long)Go to 4
Small size (under 7 cm long)Go to 5
4Body background black, large white spots irregular in shape and size completely covering body & tailTiger salamander
Body background black, small, round, white spots in a row along each side fro eye to tip of tailSpotted Salamander
5Body background black with white spotsGo to 6
Body background light color with dark spots and or lines on bodyGo to 7
6Small white spots on a black background in a row along each side from head to tip of tailJefferson salamander
Small white spots on a scattered throughout a black background from head to tip of tailSlimy salamander
7Large irregular black spots on a light background extending from head to tip of tailMarbled salamander
bNo large irregular black spots on a light backgroundGo to 8
8aRound spots scattered along back and sides of body, tail flattened like a tadpoleNewt
bWithout round spots and tail not flattened like a tadpoleGo to 9
9aTwo dark lines bordering a broad, light mid-dorsal stripe with a narrow median dark line extending from the head onto the tailTwo-lined salamander
bWithout two dark lines running the length of the bodyGo to 10
10aA light stripe running the length of the body and bordered by dark pigment extending downward on the sidesRed-backed salamander
bA light stripe extending the length of the body, a marked constriction at the base of the tailFour-toed salamander