Scientists say they have discovered the world's smallest known fish in threatened(1) swampland(2) in Indonesia.

The fish, a member of the carp(3) family, has a translucent(4) body and a head unprotected by a skeleton(5).

Mature females grow to less than a third of an inch long. The males have enlarged pelvic fins(6) and muscles that may be used in reproduction, researchers wrote in a report published Wednesday by the Royal Society in London.

"This is one of the strangest fish that I've seen in my whole career,' said Ralf Britz, a zoologist(7) at the Natural History Museum in London. "It's tiny, it lives in acid(8) and it has these bizarre(9) fins. I hope we'll have time to find out more about them before their habitat(10) disappears completely."

The fish are found in an acidic(11) peat(12) swamp on the Indonesian island of Sumatra. Indonesian peat swamps are under threat from fires lit by plantation owners and farmers as well as unchecked(13) development and farming. Researchers say several populations(14) of the tiny fish have already been lost.

The previous record for world's smallest fish, according to the Natural History Museum, was held by a species of Indo-Pacific goby(15) one-tenth of a millimeter(16) longer.

According to researchers, the little fish live in dark, tea-colored water at least 100 times more acidic than rainwater. Such acidic swamps was once thought to harbor few animals, but recent research has revealed that they are highly diverse and home to many unique species.

科學家稱他們在印度尼西亞瀕臨消失的沼澤中發現了世界上最小的魚。

這種魚屬于鯉科，通體透明，頭部幾乎沒有頭骨保護。

周三，倫敦皇家協會發表報告說，成年雌魚體長不足三分之一英寸，雄性的腹鰭和腹肌比較大，可能用于求偶繁殖。

倫敦自然歷史博物館的動物學家拉夫·布利茲說：“這是我從事動物學研究以來見過的最奇特的魚之一。它們很小，生活在酸性水域中，還有這樣奇特的鰭。我希望在它們賴以生存的環境還沒有完全消失之前，可以對它們了解得更多。”

科學家們在印尼蘇門答臘島的一個煤炭沼澤中發現了這種魚。印尼煤炭沼澤在農場主和農民大肆焚燒和無限制開發、農田開墾的威脅下，面臨消失的危險。研究人員說這種小魚的部分種群已經滅亡了。

自然歷史博物館說之前世界上最小的魚是印度太平洋蝦虎魚的一種，體長十分之一毫米。

研究人員說這種小魚生活在黑暗、茶色的水中，水的酸性比雨水強至少100倍。 此種酸性沼澤曾經被認為是極少數生物的棲息地，但是最近的研究表明它們孕育著各種獨一無二的珍奇物種。