ENG-1979 — Page 287

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NATURAL HISTORY

death from snake bite is rare. Apart from back-fanged snakes – the local species are not dangerous to man -- the venomous land snakes are: the Banded Krait, with black and yellow bands; the Many-banded Krait, with black and white bands; Macclelland's Coral Snake, which is coral red with narrow, black transverse bars; the Chinese Cobra and the Hamadryad or King Cobra, both of which are hooded; the rare Mountain Pit Viper; and the White-lipped Pit Viper or Bamboo Snake. The Bamboo Snake is bright green and less venomous than others, but it is not easily seen and strikes readily if closely approached. The Hamadryad, Kraits and Corals prey almost exclusively on other snakes. Several species of sea snakes all venomous are found in Hong Kong waters, but they have never been known to attack bathers. An amphibian of special interest is the Hong Kong Newt, which has not been recorded elsewhere in the region.

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Of more than 200 recorded species and forms of colourful butterflies, several in their larval forms cause considerable damage to farmers' crops. These include the two commonly- found species of Cabbage Whites, the Swallowtails, and the beautiful but less common Small Blue. Among the many local moths are the giant silk worm moths. These include the Cynthia, the Fawn, Golden Emperor, the Atlas and Moon moths. The Atlas has an average wing span of 23 centimetres and the Moon, 18 centimetres. Two local plant bugs are noted for their colour and shape. They are the rare and beautifully-spotted Tea Bug, which has only been recorded on hill-tops, and the Lantern Fly, which has delicately-coloured wings and a remarkably long forehead. Dragon and damsel flies are common, as are wasps and metallic-coloured beetles. Of particular interest is the Large Spotted Batocera Long-horn Beetle, which feeds on mountain tallow trees.

Since it was introduced to Hong Kong in 1938, the African Giant Snail has become a major pest in vegetable crops and gardens. Farmers are also troubled by several slugs. One of these - Veronicella – is a large, black slug sufficiently different from the other slugs to be placed in a separate family.

Aquatic Life

Marine life forms in Hong Kong are diverse and mainly tropical in character. They include a large number of commercially-important species of fish, crustacea and molluscs. The types and quantities of fish prevalent fluctuate according to seasonal influences and also vary according to the area. The waters of Hong Kong can be broadly divided into a western sector, influenced by the Zhu Jiang (Pearl) River and predominately brackish, and an eastern sector, subject to the influences of the open sea. Various locations provide natural propagation and nursery grounds for many species of fish, crustacea and molluscs, and provide seasonal feeding for large transient predators, such as the Little Tuna, Dolphinfish, Sailfish and sharks.

The presence of sharks in local waters was highlighted in 1979 when a number of swimmers were attacked and many sightings were made. Over the years, more than 20 species of shark have been recorded in Hong Kong waters, mainly in the eastern and south-eastern areas. Sharks have been sighted in Mirs Bay in the New Territories and as far south as Stanley and Deep Water Bay on Hong Kong Island. Their presence in Hong Kong is a result of the influence of warm ocean currents off the South China Sea during the summer months, in particular, July to September.

Sharks, which are common in Hong Kong and are potentially dangerous, are the Hammerhead Shark species and the True Shark family species, which can grow to more than three metres. Other commonly-found sharks which do not normally attack humans include the Cat Shark and the Leopard Shark.