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University of Connecticut Mark Urban
Eco-Evolution in Space


In early spring male spotted salamanders (Ambystoma maculatum) place several spermatophores on a branch or leaf at the bottom of temporary ponds.

Female A. maculatum head to the pond to pick up one or more spermatophores to fertilize her eggs.

Females then lay a baseball-sized egg mass attached to vegetation in the pond. Egg masses can be either clear or white.

If all goes well, A. maculatum larvae will hatch in several weeks. The newly hatched larvae are quite small (less than 20 mg), especially when compared to their main predator, larval marbled salamanders (Ambystomata opacum).

In some years, however, ponds dry too quickly for A. maculatum eggs to hatch and develop.

In successful ponds, the A. maculatum larvae develop over several months, before losing their gills and metamorphosing into terrestrial juveniles. The juveniles will return to the pond to mate after 2-3 years.

Larvae differ substantially in size within and among ponds.
The larva on the bottom is almost ready to transform into a juvenile.
We are researching the ecological and evolutionary reasons underlying these differences.