A Marbled Salamander.
These salamanders display a rather stunning silver-on-black saddle-like pattern on their backs.
One of two fall-breeding Ambystoma in MO.
A few of the 20+ A. opacum we found at our breeding sites during and after the round of storms that swept through the area that night. All individuals appeared to be male, with the exception of a couple individuals.
Male (judged by swollen cloaca observed upon closer inspection) located under a fallen branch roughly two feet from pair found in observation (http://www.inaturalist.org/observations/884766)
Possible breeding pair found underneath log following autumn rains.
Male: Individual with white markings. Cloaca clearly swollen upon closer inspection.
Female: Individual with silver markings. Possibly full of eggs.
The marbled salamander (Ambystoma opacum) is a species of mole salamander found in the eastern United States.