PLANET EARTH Shallow Seas

Coral reefs（珊瑚礁） are oases（绿洲） in a watery desert. Most tropical shallows are barren but these coral havens contain one quarter of all the marine life on our planet. Reefs are the work of polyps（珊瑚虫，用在医学上表示息肉） tiny colonial animals like minute sea anemones（海葵） yet the great barrier reef is so big it can be seen from the Moon. It's actually two thousand separate reefs that together form a barrier stretching for over a thousand miles along Australia's northeastern coast.



Despite its vast size this reef does not contain the greatest variety of marine life on the planet. For that one must travel north to Indonesia. There are individual reefs in Indonesia that contain almost as many kinds of fish as live in the whole of the Caribbean（加勒比海）. There are also ten times the number of coral species. Corals thrive（蓬勃生长） in these waters with the help of microscopic plants, algae（水藻） that grow within the tissues of the polyps and the polyps feed by snaring passing morsels（碎屑） with their tentacles（触须）.