Synodontis petricola, known as the cuckoo catfish, or the pygmy leopard catfish, is a species of upside-down catfish endemic to Burundi, Zambia, the Democratic Republic of the Congo, and Tanzania where it is only known from Lake Tanganyika. It was first described by Belgian ichthyologist Hubert Matthes in 1959. The species name "petricola" is derived from a combination of the Latin petra, meaning stone or rock, and the Latin cola, meaning inhabitant. This refers to the rocky environment where this species is found. Description Like all members of the genus Synodontis, S. petricola has a strong, bony head capsule that extends back as far as the first spine of the dorsal fin. The head is about of the standard length of the fish. The head contains a distinct narrow, bony external protrusion called a humeral process. The shape and size of the humeral process helps to identify the species. In S. petricola, the humeral process is triangular, rough, and is covered in many small, thin papillae. The bottom edge has a poorly-defined ridge on the bottom edge, and the top edge is convex. The humeral process ends in a sharp point. It is about of the length of the head. The diameter of the eye is about of the length of the head. The fish has three pairs of barbels. The maxillary barbels are on located on the upper jaw, and two pairs of mandibular barbels are on the lower jaw. The maxillary barbel has a narrow membrane attached near the base and is straight without any branches. It extends at least as far as the base of the pectoral sping, about of the length of the head. The outer pair of mandibular barbels extends just past the start of the pectoral girdle, about of the length of the head, and contains four to seven simple branches, usually without any secondary branches. The inner pair of mandibular barbels is about to as long as the outer pair, about of the length of the head, with four to six branches, with many secondary branches present. The skin of S. petricola has a large number of tiny vertical skin folds. The exact purpose of the skin folds is not known, but is a characteristic of the species of Syndontis that are endemic to Lake Tanganyika. External granular papilla are present on the head, but not the body. The front edges of the