soft-finned

from WordNet (r) 3.0 (2006)

soft-finned
    adj 1: of or relating to fish with soft fins

from The Collaborative International Dictionary of English v.0.48

Soft-finned \Soft"-finned`\, a. (Zool.)
   Having the fin rays cartilaginous or flexible; without
   spines; -- said of certain fishes.
   [1913 Webster]