On April 12, 2019, my sister-in-law was hiking on a mountain close to our home in Central Massachusetts, USA.
There was a pond at the end of an established trail. Near the water's edge were jelly-like clumps of what looked like eggs, with lots of black dots. In the water were twigs and leaves. The egg masses were either on or wrapped around those twigs or both. Some were below the surface of the water, some just above.
Nobody in her party saw or heard any aquatic animals on the pond or nearby. They didn't touch the eggs or the water, for fear of upsetting the delicate eco-system.
The pond has recently completed a spring thaw. The multi-colored leaves were almost definitely from last fall when they fell into the water before it froze for the winter.
What aquatic animal laid these eggs?