פירוש על עבודה זרה 79:7

According to R. Papi, R. Huna allowed only the brine. He did not allow the eating of the fish itself. But R. Papa said that R. Huna was more lenient—even the fish could be eaten. R. Ashi is torn. On the one hand, he respects what R. Papa says, so he cannot rule strictly. Only the other hand, he has a tradition attributed to Ulla according to which the fish itself cannot be eaten unless the head and backbone of each fish is recognizable. So R. Ashi is left paralyzed, and cannot issue a directive one way or the other.