Which heavily armored fish is often found in freshwater systems?

The heavily armored fish often found in freshwater systems is indeed catfish. They possess a unique adaptation of having bony plates or scales, known as scutes, which provide protection against predators. This distinctive feature makes them sturdy and resilient in various environments.

Catfish are a diverse group of fish that inhabit numerous freshwater ecosystems, such as rivers, lakes, and ponds. Their ability to thrive in a range of aquatic habitats, combined with their defensive armor, gives them an ecological advantage and allows them to be prevalent in many freshwater systems. This is a key characteristic that differentiates them from other fishes such as trout, goldfish, or salmon, which do not have the same level of armor and protective adaptations.