Imposing giants – Global reef checks show the species have disappeared from even the best reefs over most of its range.

Imposing giants

HUMPHEAD wrasses (also known as Napoleon or Maori wrasse) are among the most beautiful, yet bizarre-looking, fish in the sea. With their bulbous lips, prominent forehead humps and a body pattern consisting of swirls, spots and lines in shadesof electric blue, grey and green, humpheads rank high on recre ational divers’ “must see” list – yet they are being eaten out of existence,
Global reef checks show the species have disappeared from even the best reefs over most of its range. In Peninsular Malaysia’s east coast, in islands such as Redang, Tioman and Tenggol, divers report that humpheads have vanished from reefs. Thefe is little information on humphead trade in the peninsula.
Humpheads occur patchily through- out the lndo-Pacific and Indian Ocean regions. Though widely distributed, they are not abundant in the wild. Late sexual maturity (they breed only in the fifth year or later), slow growth, predictable spawning sites, hermaphroditism (sex reversal) and rarity make them highly vulnerable to over-exploitation.
Humpheads can grow up to 2.3m in length and 190kg in weight, and live up to 40 to 50 years. Once a female reaches a size of 20 to 22kg, it turns into a male and thrive to be the dominant male. In Pulau Layang-Layang, Dr Steve Oakley has observed the dominant male mating with over 100 females in one day.
Adult humpheads are usually found at reef slopes while juveniles, at the reef top. Their colours change with age – from silver-grey with yellow spots in juveniles to a deep olive green with black spots in adults. The males have prominent humps on their foreheads and are greener in colour.
Humpheads are omnivores and feed on molluscs, fish and crustaceans, among others. Oakley says as humphead numbers decline, the reef ecology will change. He says spiny sea urchins and crown-of-thorns starfish have invaded many reefs simply because humpheads, which prey on them, have declined in numbers.
Unlike some species of groupers, humpheads have not been commercially bred yet. Farming efforts have failed to go beyond the larval stage.
Apart from the humphead wrasse, various species of groupers are also netted in large numbers for the live reef fish trade, triggering yet another worry.
IUCN-World Conservation Union has listed eight species of groupers as “endangered” and intends to propose some for inclusion in the Convention on Trade in Endangered Species.