a24f8ac4_uxent_Wildlife_Research_Center__Reference_on_Site
[Did You Know...] that tadpoles typically are in specific aquatic habitats for longer periods than their adults, they sometimes are more difficult to find and nearly always more difficult to identify? [Reference on Site] 
A key for the tadpoles of the United States and Canada features a different format and approach to identifying frog larvae. More details of ontogenetic variation are included than in many keys, and more attention is paid to using characteristics of living tadpoles. A tutorial examines morphological traits, and color photographs are included to simplify the identification process. More information...
Did you know? - Patuxent Wildlife Research Center
Reference on Site