Read more “New Ranger” Pleco (Pterygoplichthys sp.) One of the smallest species of pleco known, the “new ranger” is an as-yet undescribed species originating from the Nanay River in Peru. They are an excellent algae eater, feeding on many species of nuisance algae in the aquarium (including diatoms). Although small for a pleco, they are still substantial fish and should be given ample space and cover in the aquarium. Supplement their diet regularly with algae-based sinking foods, gel foods, and fresh vegetables.