It can take up to two years for bullfrog tadpoles to change into frogs, but once front legs appear, change happens very quickly. It takes less than 10 days for a bullfrog tadpole to change into a frog once it sprouts front legs !
Rear legs first appeared 6/22/13
Five days later rear legs much larger and bent at the knee 6/27/13
Rear legs well-developed 7/14/13
Well-developed arms. Head starting to change shape 7/16/13
See how shape of head has changed, with eyes raised 7/17/13
Time Table for
~ 10 months old before began metamorphosis.
Began metamorphosis 6-22-13: Rear legs appeared.
22 days: Rear legs continued to grow.
24 days: Front legs appear. Heed begins to change shape.
26 days: Tadpole's head is changing shape, eyes raised, mouth enlarging.
29 days: Tail reabsorbing
31 days: Metamorphosis complete. Lumpy is a frog with only a tiny stub of tail remaining.
Tiny tad finally sprouted legs 8-9-13, then metamorphosis stalled. This tadpole stayed the same... tadpole body with tiny rear legs...until he mysteriously disappeared in March 2014. Perhaps Lumpy ate him?
~ 4 months old with footage of swimming and feeding behavior. Narration by young children with kids' music.
This page is devoted to bullfrog tadpole metamorphosis with photos of our bullfrogs at different stages of their development, featuring the three bullfrog tadpoles that we followed through metamorphosis.