For those interested in keeping these fascinating fish, Aquatic Community has an excellent overview of the captive care for the Saxatilis group.

From the Zootaxa paper:

Habitat and ecological notes: Crenicichla ploegi has been collected in a variety of aquatic habitats, but mostly in streams and mid-sized rivers. The type locality is actually an exception, being a large river pool, more than 100 meters wide. Streams and rivers inhabited by C. ploegi possess clear water, a moderate to fast water flow, and rocky bottoms, usually with well-developed riparian forest, although the species has also been collected in rivers with highly disturbed or suppressed riparian forest