On coral reefs across the Maldives, few fish are as instantly recognizable as the Moorish Idol (Zanclus cornutus). Known locally as Dhidha mas, its bold black bands, flowing dorsal filament, and sharply contrasting colours give it a presence that feels almost ceremonial. Moving calmly among corals, it appears less like a reef fish and more like a symbol—one that has captured human imagination for centuries. Growing to a maximum length of about 22 centimeters, it is neither large nor imposing, yet its elongated form and trailing fin make it seem larger than life as it glides deliberately through the reef.
The Moorish Idol’s body is strongly compressed and deep, allowing it to turn with ease among branching corals. Its slender, projecting snout is perfectly suited for picking sponges and invertebrates from narrow gaps where other fish cannot reach. The dorsal fin is its defining feature: with seven spines and over forty soft rays, it culminates in a long, white filamentous streamer. This flowing streamer demands refined control and balance, especially in the surge of the outer reef.
Its coloration is among the most striking in the ocean. The body transitions from a bright white at the front to a vivid yellow toward the rear, interrupted by two broad black vertical bands. A black-edged orange saddle marks the snout, and a solid black caudal fin anchors the design. These colours remain highly visible even in complex reef environments where light and shadow constantly shift.
Occupying an unusually wide range, the Moorish Idol can be found from shallow reef flats to depths of at least 180 meters. This versatility is mirrored in its unique biology; it is the sole living member of its family, Zanclidae, standing apart from all other reef fishes. While it is a familiar sight to divers, its complexity is hidden in its diet—it feeds primarily on benthic sponges—and its dramatic transformation from a transparent larva into the living emblem of the coral reef.
Species Snapshot
| Scientific Name | Carangoides orthogrammus |
| Local Name | Thumba handhi |
| Identifying Mark | Yellow/Gold spots |
| Breast Pattern | Naked (Unscaled) |
References
- M.R.S. (1997). Fishes of the Maldives. Marine Research Section, Ministry of Fisheries and Agriculture, Republic of Maldives.
- Froese, R. and D. Pauly. (2025). FishBase. Zanclus cornutus. www.fishbase.org.
- Pyle, R. (2001). Zanclidae. Moorish idol. In FAO species identification guide.
