A larval Eastern Tiger Salamander grows a new foot

Some salamanders can regrow missing body parts like organs and limbs. In this Nature North video, an Eastern Tiger Salamander with a missing foot, likely bitten off by a fellow tankmate, is observed over the course of 5 weeks. Watch as its leg extends into small toes that grow and separate into a fully functional foot.

Eastern Tiger Salamanders mate and lay their eggs in deep ponds from late March into April. The female lays about 100 eggs. She lays them one at a time or in small groups on rocks, plants or sticks on the bottom of the pond. It takes 20 days for the eggs to hatch. The young can change to adult shape and leave the pond in late August or early September, about 60 days after hatching. They are about 10 to 15 cm long when they change to adult shape.

Sometimes the young salamanders take more than one summer to grow big enough to change to adult shape. They can stay in the pond over winter and keep growing through the next summer. It can take nearly 400 days to go from being an egg to changing to adult shape.

And yet look at how fast one can regenerate a missing foot.

Get additional insight into what’s going on inside the salamander’s limb with this classroom-ready HHMI Biointeractive animation: Salamander Limb Regeneration. What happens as the wound heals?

“Cells are streaming out of the surrounding tissues into the area of the wound and forming what we call a blastema, which is a group of undifferentiated cells that are in fact really just like stem cells. And they’re multicolored because they come from skin, from muscle, and even from cartilage. And these have a miraculous memory of what they used to be and are able to form a perfectly functional limb.”

Note for sensitive viewers: The animated salamander’s leg is snipped off by animated scissors, much to the surprise of the video’s live audience. Please don’t try this at home.

Watch these related amphibian videos next:
• From zygote to hatched larva, a cell division time lapse
• Cell division in a frog egg, a microscopic time-lapse video
• Save the salamanders, unsung heroes of the forest

And previously from Nature North: Raising wood frogs, from eggs to tadpoles to adults in 7 weeks.