The Collaborative International Dictionary
Atherine \Ath"er*ine\, n. [NL. atherina, fr. Gr. ? a kind of smelt.] (Zo["o]l.) A small marine fish of the family Atherinid[ae], having a silvery stripe along the sides. The European species ( Atherina presbyter) is used as food. The American species ( Menidia notata) is called silversides and sand smelt. See Silversides.
Silversides \Sil"ver*sides`\, n. (Zo["o]l.) Any one of several species of small fishes of the family Atherinid[ae], having a silvery stripe along each side of the body. The common species of the American coast ( Menidia notata) is very abundant. Called also silverside, sand smelt, friar, tailor, and tinker.
Brook silversides (Zo["o]l.), a small fresh-water North American fish ( Labadesthes sicculus) related to the marine silversides.
Wikipedia
The sand smelt (Atherina presbyter) is a species of marine fish of the Atherinidae family, common in the north-eastern Atlantic from the Danish straits to the Canary Islands and the western Mediterranean Sea. They live in shoals near the water surface, but go deep in winter.