The Gemoro (Chulin 66 a+b) says “Akunas, is a type of fish that loses its scales when
it is taken out of the water, and it is kosher.
The Aruch (Akunas) writes that you need Dayanei Yisroel to identify that it is the Akunas
Fish, only then may you eat it. ( it has no scales, you have to verify that it is indeed
Akunas Fish and not a non kosher fish)
The Gemoro (Chulin 63b) says that a hunter is trustworthy to say that his Rebbe
told him that a particular bird is a kosher species. The Gomoro says his Rebbe refers
to his hunting teacher. (not Rabbi)
Why for identifying kosher birds we don’t need a Rov, and to identify kosher fish
(according to the Aruch) we need a Rov?
The loshon (terminology) of the Aruch “Dayanei Yisroel doesn’t sound right.
Why mention that the Dayan is a Yisroel and not a Goyishe Dayan?
In the times of the Aruch, The term Dayan was used strictly for monetary
or punishment. For Issur Voheter ,the term was Chacham.
There must be that it is a printing mistake and the Gimmel got mixed
Up with a Nun. Instead of דייני it should read “ דייגי ” Jewish fishermen.
The same way you can rely on a Jewish hunter, so can you rely on a
Jewish fisherman, to identify it as a kosher species.