Definition that contains pelvic fin
- catfish large ferocious northern deep-sea food fishes with strong teeth and no pelvic fins
- suborder mugiloidea fishes distinguished by abdominal pelvic fins: families Mugilidae; Atherinidae; Sphyraenidae
- anguilliformes elongate fishes with pelvic fins and girdle absent or reduced
- batfish bottom-dweller of warm western Atlantic coastal waters having a flattened scaleless body that crawls about on fleshy pectoral and pelvic fins
- order anguilliformes elongate fishes with pelvic fins and girdle absent or reduced
- four-wing flying fish having both pectoral and pelvic fins enlarged
- seasnail small tadpole-shaped cold-water fishes with pelvic fins forming a sucker; related to lumpfish
- superclass agnatha superclass of eel-shaped chordates lacking jaws and pelvic fins: lampreys; hagfishes; some extinct forms
- biplane flying fish having both pectoral and pelvic fins enlarged
- blennioid elongated mostly scaleless marine fishes with large pectoral fins and reduced pelvic fins