Unneeded replacement name for Cyprinodon umbra Cuvier, 1829; junior homonym of Umbra krameri Walbaum, 1792. See also Eschmeyer (CofF ver. Feb. 2010: Ref. 83763).
Etymology of Generic name :
Latin, umbra, -ae = shadow, in the sense of phantom; due to its quick movements (Ref. 45335).