jackknife fish
plural of jackknife-fish
/ˈdʒækˌnaɪf ˌfɪʃ/
noun
- A tropical fish with a tall, thin body and a long dorsal fin, often kept in aquariums.
- The jackknife-fish has a striking black and white pattern.
- Jackknife-fish are peaceful but need plenty of swimming space.
- We added a jackknife-fish to our saltwater tank last week.