Definition of "keepworthy"

The nation of beggars on horseback which first colonized California has left behind it many traditions unworthy of conservation, and multitudinous fleas not at all traditional, but even less keepworthy […]

1871, Fitz Hugh Ludlow, The Heart of the Continent, page 414

Data, collected by one field man who interviewed and counted anglers daily, indicated that the rate of harvest was 0.29 fish per man hour, and that the average catch (keepworthy fish only) amounted to 1.5 fish per fishing trip.

1960, Sport Fishery Abstracts, volumes 5-6, page 144