Over 200 fish species are so specific to this area that they have the word "Taiwan" in their Chinese names, but many of them have not been seen for a long time. Hyporhamphus gernaeri, for example, a species unique to local waters, used to spawn in the estuary of the Tanshui River.
以台灣為原產地所命名的魚種不下 200 種，但絕大多數已經很久沒再出現了，原產於淡水河口的台灣特有種──「台灣下鱵」就是一例。