Naturalist Notes: Fish Nests

Written by: Cathy Molitor, naturalist at JNC

What looks like a collection of mysterious craters along the edge of our pond this time of year is actually something pretty amazing: fish nests!

Our nature center pond has an interesting history. Long ago, this area was a swamp before it was dug into a pond and stocked with several kinds of fish. Today, it has become a thriving habitat, and each spring one of the pond’s residents gets quite busy.

Bluegill and pumpkinseed sunfish are now in spawning season. The round, shallow depressions you see in the sandy or muddy bottom near the shoreline are nests carefully made by male fish. Using their fins, they fan away debris to create a clean spot where females can lay eggs. Often the nests appear in groups, creating what looks like an underwater honeycomb or a tiny fish city!

Once the eggs are laid, the males stay behind to guard the nests from hungry predators. They patrol fiercely, chasing away anything that gets too close. If you stand quietly along the shore, you may even spot the brightly colored pumpkinseed sunfish flashing their orange and blue markings as they defend their territory.

So next time you walk around the pond and notice all those circular spots in the shallows, take a closer look. You are getting a front-row seat to one of spring’s underwater wildlife events!

(Pictures from www.anglersbooking.com)