splittail

[ split-teyl ]
/ ˈsplɪtˌteɪl /

noun

a minnow, Pogonichthys macrolepidotus, of the Sacramento River, having the upper lobe of the tail much longer than the lower lobe: habitat changes have greatly reduced its numbers.

Origin of splittail

An Americanism dating back to 1880–85; split + tail1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019