The Humphead Wrasse, Cheilinus Undulatus

The Humphead Wrasse, Cheilinus undulatus

The Humphead wrasse, Cheilinus undulatus, is the largest member of the family Labridae and widely distributed across the reefs of the Indo-Pacific. It is found from the Red Sea and African coast, across the Indian Ocean and much of the Pacific, north to southern Japan and the coast of southern China, and south to New Caledonia. In English it is mostly commonly referred to as the Humphead, Maori or Napoleon wrasse.

Fishery management

The species has a high economic value and is a special favorite of both the live reef food fish trade and with recreational divers.The Humphead wrasse is vulnerable to fishing due to its long life and late sexual maturation (which occurs at approximately 50 cm total length and 5 years of age). This means that its life history is one that involves slow replacement (and hence slow recovery from fishing) rates. Because of its high value as food, it is heavily sought by fishers and traders. As part of the live food fish market, its value is likely to increase with rarity, so fishers will continue to fish this species even as its numbers decline. Humphead wrasse fisheries are mostly unmanaged and, even if managed 'on paper', there is usually little management or monitoring of Humphead wrasse in local fisheries. Monitoring is needed, both of local capture and of exports. Without proper management and monitoring, it is impossible to know whether current capture rates are sustainable or to establish safe quotas capture. On the other hand, its value to diving tourism will remain high if it is protected and remains alive in the wild.

Live Reef Food Fish Trade

While there is some capture for local use, particularly in the western and central Pacific, the Humphead wrasse is primarily taken for export as part of the valuable live reef food fish trade which is centred in SE Asia. All fish in this trade are wild-caught since commercial level hatchery propagation of this species is not yet possible. The major importing countries are China (especially Hong Kong), Taiwan and Singapore. Fish are exported especially from Indonesia, Malaysia, the Philippines and from some western Pacific Islands. Hong Kong is the biggest consumer/transshipment centre for the live seafood market, including for the Humphead wrasse. Hong Kong re-exports significant but undocumented volumes of Humphead wrasse into mainland, particularly southern, China, according to traders and to market surveys. The live reef fish industry in Hong Kong is worth over US$500 million, with Hong Kong consumers willing to pay up to US$175 / kg for the smaller individuals. The most preferred trade, or market, size for this fish in the export trade as food is 'plate-sized' - between about 30-60 cm (mainly 30-45 cm) total length. Plate-sized fish are typically sexually immature since sexual maturity occurs at about 50 cm. This means that large numbers of sexually immature fish are removed from the wild for the live reef food fish trade. The relatively large sizes of these juvenile fish mean that they would very likely survive to reproduce in the wild, if not removed.

Capture Methods

The Humphead wrasse is caught in different ways according to its size, whether it is needed alive or dead and depending on local traditions. Smaller individuals may be attracted by bait of cut or living fish and crabs on hook and line or fish traps. Adult Humphead wrasse are very vulnerable to night-fishing, especially if SCUBA is used, since they are easily taken from their caves while they sleep. The Humphead wrasse spawns in aggregations that can easily be targeted

by fishers and hence are particularly vulnerable to overfishing at the times and places at which reproduction occurs. It has been well-documented that spawning aggregations in several other reef fish species are particularly vulnerable to being overfished. Recently, cyanide has been used to extract the fish from among corals if fish are to be maintained alive. Cyanide seems to be particularly widely used where this species was not formerly part of a traditional fishery and the poison is often introduced or supplied by foreign traders in live reef fish. Cyanide is a poison and is known to kill living coral. The Humphead wrasse, as with many