Any of numerous types of fish. (See Wikipedia for a list.)
A white variety of the goldfish.
Lepisma saccharina, a small wingless insect with silvery scales, a type of bristletail.
Ctenolepisma lineata (four-lined silverfish).
Ctenolepisma longicaudata (grey silverfish).
Raiamas senegalensis (silver fish).
Leptatherina presbyteroides (hardyhead, prettyfish)
Steindachnerina argentea (toothless characin)
Elops saurus (ladyfish)
Trachinotus ovatus (pompano)
Antarctic silverfish, Pleuragramma antarcticum.
Argentina sphyraena (herring smelt)
Enteromius mattozi (papermouth])
Argyrozona argyrozona (carpenter sea bream)
Callorhinchus milii (elephant shark)
Pseudocaranx dentex (white trevally)
Ulaema lefroyi (mottled mojarra)
Trichiurus lepturus (largehead hairtail)
Megalops atlanticus (Atlantic tarpon, tarpum.
Aphareus rutilans (rusty jobfish)
Labeobarbus bynni (Niger barb, barbel, Nile barb)