The two Tilapia aquaculture farms I know about both use (virtually) male-only Tilapia for food fish production. Assuming this is an industry-wide practice, there would be a huge, periodic but year round market for male-only Tilapia fry.

"Live like you'll die tomorrow, but manage your grass like you'll live forever."
-S. M. Stirling
[Linked Image from i.pinimg.com]