If you look up “kyfe” on OneLook, you’re directed to the Hobson Jobson Dictionary of Anglo-Indian terms, available at Bibliomania. (Sorry, Bibliomania uses frames and I couldn’t link to the actual page. You’ll have to search for it yourself, or go through OneLook)
The quote he cites spells “kyfe” yet another way, “keif,” and defines it as the “first degree of intoxication.”
Still nothing to do with fish, unless you’re licking the backs of them to reach kyfe. Or is that toads?
Many thanks, folks! I was worried about being stuck without a definition for a while there. It seems like the most reasonable explanation (because it’s the only one that has the word dealing with fish) is the writer using kyfe as spelled here and in the site jcgmoi mentioned with the definition of a vessel used to catch fish that tomndebb mentioned. Then my own addlepated wits get in the way and I somehow misunderstood it as the behavior or attitude of the fish. Thanks again!
Deimos isn’t remembering wrong either, although it’s not the context the OP saw it in - “keifing” or “kyfing” stuff was a common slang term when I was a kid, used approximately like “swipe”. I’m not sure how it would be spelled, since I never saw it written, and I have no idea of the etymology.