Tilapia are freshwater fish. These fish are significant in aquaculture and are found globally beyond their native African and Middle Eastern regions. This article describes the general body characteristics of tilapia, and their distinctive physical features.
General Body Shape and Size
Tilapia typically exhibit a deep, laterally compressed body, giving them an oblong or oval silhouette. Their flattened sides contribute to streamlined appearance, aiding efficient movement through water. This body shape is often compared to sunfish or crappie.
The size of tilapia varies by the species and environmental conditions. Mature individuals commonly range from 6 to 16 inches (15 to 40 cm) in length. Some species, like the Nile tilapia, can reach up to 24 inches (60 cm) and over 9 pounds (4.3 kg).
Distinctive Physical Features
Tilapia have prominent fins. A long dorsal fin runs along their back, with a spiny, rigid anterior portion followed by a softer, rayed posterior section. This dorsal fin often appears as a single continuous structure, though some species may show a slight notch separating the spiny and soft-rayed parts.
Their caudal fin is typically rounded, truncated, or fan-shaped. Many tilapia species, particularly the Nile tilapia, display distinct vertical stripes on their caudal fin, aiding in identification. The anal fin, located on the underside, also contains spines and soft rays, while the pectoral fins are positioned behind the gills, and the pelvic fins are found in a thoracic position, beneath the pectoral fins.
The body of a tilapia is covered with cycloid scales, which are smooth, rounded, and overlap each other, similar to roof shingles. These scales are generally moderately large, providing a protective covering. The mouth of a tilapia is typically terminal, meaning it is located at the forward end of the head and points straight ahead. Their jaws are protrusible, meaning they can extend outwards, and are often bordered with thick, sometimes swollen, lips. Tilapia possess conical teeth on their jaws, and also have pharyngeal teeth located in their throat, which assist in processing food.
Their prominent eyes are positioned laterally on the head, providing a wide field of vision and adapted for underwater sight. Coloration in tilapia is variable, influenced by genetics, environment, and diet. Common hues include silvery, olive, or gray-brown. Many species may exhibit dark vertical bars, particularly when young or stressed, and some have a distinct dark “tilapia spot” on the dorsal fin or operculum. Breeding males can also display more vibrant colors, such as reddish or bluish tints on their bodies and fins.