Blue-spotted Salamander and leadback Redback Salamander
Redback Salamander: leadback phase (photo Ron Merrick and John Gilhen; drawing Fred Scott)
Juvenile Blue-spotted Salamander (photo Mary Macaulay)
Generally, the blue spots on a Blue-spotted Salamander are a dead giveaway. However, the triploid female Blue-spotted Salmander has very few spots or none at all. Small Blue-spotted Salamanders might be confused with the all-dark or leadback phase of the Redback Salamander. Leadback-phase animals are finely sprinkled with whitish dots that can only be seen up close, but they never have pale blue patches or blotches. The two species can also be distinguished by counting their costal grooves (the indentations between the animal's ribs). Blue-spotted salamanders have 13-15 costal grooves whereas Redback salamanders have 18-20. The easiest way to tell these two species apart, regardless of color and costal grooves, is to look at their proportions. Blue-spotted Salamanders are at least twice as thick through the body as Redback Salamanders of the same length (see silhouettes).