Crenicichla ploegi, a male (left) and a female (right) photographed alive in the Rio Verde, tributary of the Rio Papagaio, Mato Grosso, Brazil. Photo by Marcelo Krause.
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