The kuhli loach is an eel-shaped fish with slightly compressed sides, four pairs of barbels around the mouth, and very small fins. The dorsal fin starts behind the middle of the body, and the anal fin well behind this. The eyes are covered with a transparent skin. The body has 10 to 15 dark brown to black vertical bars, and the gaps between them are salmon pink to yellow with a light underside. When the fish is not actively breeding, distinctions between males and females are not readily apparent. However, close observation will reveal that males have more a muscular upper/dorsal cross-section and their pectoral fins tend to be larger, more paddle-shaped, and often have some pigment in them.