Asian sheepshead wrasse  (Semicossyphus reticulatus)

Classified as Data Deficient (DD) on the IUCN Red List 2006 (1).

One of the largest wrasses, the Asian sheepshead wrasse is an extraordinary pinkish-grey fish with large, swelling-like protrusions on the ‘forehead’ and ‘chin’. Like its close relative, the California sheepshead wrasse (Semicossyphus pulcher), the juvenile is starkly different from the adult, being a vivid yellowish-orange with a white stripe from the eye to the tail, black patches on the fins and tail, and lacking the bulbous face protrusions of the adults, for which the species earns its common name (2).

Recorded in the Western Pacific from the main islands of Japan, the Korean Peninsula and the South China Sea (1) (2).

This is a cold-water to subtropical species that inhabits rocky reefs (1) (2).

Almost nothing is known of the biology and ecology of the Asian sheepshead wrasse, other than that it feeds on shellfish and crustaceans. Additionally, spawning behaviour has been observed in large aquaria, in which the strongest male drove away all other males before rising rapidly to the surface with a single female, where spawning occurred (1).

Wrasses, especially the larger species, generally live long lives, are slow to reach sexual maturation and produce millions of tiny eggs in reproduction (3). Many species, including the related California sheepshead wrasse (Semicossyphus pulcher), change sex from female to male several years after female maturation, a phenomenon known as sequential hermaphroditism, or protogyny (1) (3).

Although very little is known about the Asian sheepshead wrasse’s population status or the threats facing it, it is thought to be intrinsically vulnerable to overfishing due to its biology (1). The life history characteristics of many wrasses make them particularly vulnerable to fishing because, being long-lived with late onset of maturity and low rates of population growth, they are typically slow to recover from exploitation. Furthermore, sex-changing fish are at risk where fishing targets the largest fish (mostly males), as this can lead to strongly female-biased sex ratios, potentially compromising reproduction through too few males (3).

There are no known fishing restrictions within the range of this species, nor marine reserves where fishing is prohibited. However, at some regions in the Japan Sea, spawning adult fish are protected by local divers who wish to attract tourist divers. Crucial research and information is required on the population size and biology of this species before it can be properly assessed by the IUCN (1).

View information on this species at the UNEP World Conservation Monitoring Centre.

For more information on the Asian sheepshead wrasse see:

• IUCN Red List:
  http://www.iucnredlist.org

For more information on wrasses see:

• IUCN/SSC Groupers and Wrasses Specialist Group:
  http://www.hku.hk/ecology/GroupersWrasses/iucnsg/