Some years ago I worked on Malting's up in Bridlington, Grimsby and Imingham, they used to breed fish for the table in their water tanks.
I was told they were only trout but when I got the opportunity to look, they had perch and carp in there to.
Lovely clean fish no earthy taste to them, I did bag me a few on a poachers line and took em back to me digs.
Good ol days when the world was still black and white.