(n) most primitive teleost fishes; all are soft-finned: salmon; trout; herring; shad; sardines; anchovies; whitefish; smelts; tarpon, Syn. order Isospondyli
The Collaborative International Dictionary of English (GCIDE) v.0.53 Collaborative International Dictionary (GCIDE)
‖n. pl. [ NL., fr. Gr. 'i`sos equal + &unr_;, &unr_;, a vertebra. ] (Zool.) An extensive order of fishes, including the salmons, herrings, and many allied forms. [ 1913 Webster ]