【明報專訊】◆What are seahorses?
Despite their peculiar body shape, seahorses are fish named for the shape of their head. Instead of scales, they have hard bony plates covering their body like a suit of armour. They do not have a tail fin (尾鰭), so they use their pectoral fins (胸鰭) to swim. Seahorses are just as big as teacups. Some are even shorter than your fingernails!
How do yellow seahorses adapt to the environment?
Yellow seahorses may look fragile, but they have their unique way of life. As poor swimmers, they have a curly tail to anchor (固定) themselves among sea grass or corals. They can also change their body colour to blend in with the surroundings to fool their enemies.
◆Why do yellow seahorses dance?
For love! Yellow seahorses have life mates, which means they find a new partner only when they lose the old one. Before breeding, the couples would "dress up" by adjusting their body colour. Then they hold each other's tail, swim side by side, or wheel around as if they are dancing in a ballroom. This romantic waltz helps enhance their relationship.
Unlike most other animals, seahorse males, but not the females, are the ones that get pregnant. The wife deposits eggs into the husband's brooding pouch (孵化囊), which is used to carry and protect the eggs until they develop into baby seahorses.
◆Why are yellow seahorses declining?
Yellow seahorses are threatened by overfishing . They are caught and used as traditional medicine, though their benefits for human health have not been scientifically tested. They are also captured incidentally by unsustainable fishing methods such as trawling (拖網捕魚). Their habitat is destroyed by pollution and coastal development. Yellow seahorse used to be common in Hong Kong a few decades ago, but have now become rare.
◆Conservation of seahorses
Ocean Park Conservation Foundation, Hong Kong (OPCFHK) has conducted a survey and tagging project on seahorses in Hong Kong. The survey recorded the number, species, size, sex and distribution of seahorses, while the tagging enabled researchers to monitor the survival, growth and home range of seahorses. The ultimate goal is to generate useful data and help formulate effective conservation management plans for conserving these animals and their habitats.
Text & photos: Ocean Park Hong Kong
■Glossary
peculiar(adj) 奇怪的
armour (n) 盔甲
fragile(adj) 脆弱的
incidentally(adv) 偶然地
[Smarties' Power English 第204期]
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