Eeltail catfishesPlotosidae

Eeltail catfishes (Plotosidae) possess elongated, tapering bodies, distinctly eel-like in form, a characteristic reflected in their common name. The dorsal, caudal, and anal fins are fused into a single, continuous structure that extends to a pointed tail. Four pairs of sensory barbels encircle the mouth. Most species in the family reach lengths up to 32 cm (12.5 in). All members also bear strong, venomous spines in their dorsal and pectoral fins, capable of inflicting painful wounds. Body coloration typically ranges from dark brown to black, often with pale yellow or white longitudinal stripes, especially prominent in juveniles.

These catfishes inhabit shallow reef environments, lagoons, and sandy areas, frequently found near rubble or rocky outcrops, from the intertidal zone down to depths of 25 m (80 ft). Juveniles form dense, often ball-shaped schools conspicuous over sand flats and shallow reef slopes. Adults are usually solitary or occur in smaller aggregations. Eeltail catfishes are benthic feeders, primarily foraging at night on crustaceans, molluscs, and worms found in the substrate.