what are this fish for? Soryu Sekiryu Kokuryu King Perch

Hey Guys i found this new fishes : Soryu Sekiryu Kokuryu King Perch
but i dont find any information about them... so anyone knows if this fishes are tradadable to Zaldon for inside the belly? or are this only fishes to NPC them? if yes, how much i get for one of this fishes? or do i need them for any crafts? i would really be happy if someone can help me out, i know the Hakuryu is a good fish to NPC it (10,5k for each fish) but the baitrate is really low... :( so not worth it for me..any informations?

the biterate on all of them is bad.

I don't know any use for them. I'm a cook, never needed one of those.