lizardfish vs soft-finned fish

lizardfish and soft-finned fish both are nouns.

Word	Noun	Adjective	Verb	Adverb
lizardfish	Yes	No	No	No
soft-finned fish	Yes	No	No	No

As nouns, soft-finned fish is a hypernym of lizardfish; that is, soft-finned fish is a word with a broader meaning than lizardfish:

lizardfish: tropical fishes with large mouths in lizard-like heads; found worldwide
soft-finned fish: any fish of the superorder Malacopterygii

Other hypernyms of lizardfish include malacopterygian.

lizardfish (noun)	soft-finned fish (noun)
tropical fishes with large mouths in lizard-like heads; found worldwide	any fish of the superorder Malacopterygii