At present there are something over 4,000 species of crab known to science worldwide. But the seas around Ilan County's Kuishan Island are home to a remarkable abundance of crabs-over 400 species have been discovered there, accounting for a far higher proportion of the world total than for any other group of animals in Taiwan.
目前世界已知螃蟹有四千多種，宜蘭龜山島海域得天獨厚，在這裡發現的螃蟹已超過四百多種，比台灣其他物種在全球的佔有率高出許多。