By the time they arrive, they've grown approximately 45 mm, and transformed into semi-transparent glass eels.

它们到达的时候，已经长到大约 45 毫米长，变成了半透明的玻璃鳗鱼。

Eels arrive in British Waters as tiny transparent glass eels having drifted across the Atlantic for months.

鳗鱼在抵达英国水域前，会以透明的小玻璃鳗鱼的形态在大西洋漂流数月。

But when glass eels reach the coast, their kidneys shift to retain more salt and maintain their blood's salinity levels.

但是当玻璃鳗鱼到达海岸时，它们的肾脏转而会保留更多盐分，并保持血液中的盐分水平。

Researchers were aware of leptocephali and glass eels, but no one guessed they were related to the elvers and yellow eels living hundreds of kilometers upstream.

研究人员知道细叶鳗和玻璃鳗，但没有人猜到它们与白叶鳗和黄鳗有关，后者生活在上游数百公里处。