Even-spotted Squeaker

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 3⁄10 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 1⁄2 of the length of the head. The diameter of the eye is about 1⁄9 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 spine, about 3⁄4 of the length of the head. The outer pair of mandibular barbels extends just past the start of the pectoral girdle, about 1⁄2 of the length of the head, and contains four to seven simple branches, usually without any secondary branches. …

In the wild, the species is endemic to Lake Tanganyika, which has a temperature range of 23 to 26 °C (73 to 79 °F), and an approximate pH of 8.5 – 9, and dH range of 4–15. It inhabits rocky shorelines in the littoral zone, to a maximum depth of 30 metres (98 ft). Juveniles appear to be carnivorous, feeding on water mites, seed shrimp, and insect larvae. Adults are generalists, feeding on algae scraped from rocks as well as small invertebrates; a 2026 study found that their dietary proportion, in descending order, consists of sponges, algae, plant detritus, and small aquatic arthropods such as crustaceans. The reproductive habits of most of the species of Synodontis are not known, beyond some instances of obtaining egg counts from gravid females. Spawning likely occurs during the flooding season between July and October, and pairs swim in unison during spawning. The growth rate is rapid in the first year, then slows down as the fish age.