Tadpole metamorphosis

Columbia spotted frog tadpole (Photo July 27, 2012 by Larry Halverson)

For the last couple of weeks Columbia spotted frog tadpoles are changing (metamorphosis) into frogs. You can see the fully developed hind legs in this photo. The front legs develop inside the tadpole’s body and do not become visible until they pop out fully formed. This tadpole had also lost it’s gills and was seen swimming to the surface to suck in air. The tail is the last to disappear as it is reabsorbed into the body.

Metamorphosis is a particularly hazardous time for amphibians as they do not function well in either water or on land. At this stage they are less efficient at avoiding predation than either tadpoles or frogs.