TT #119 · Parshas Shemini · Aliyah 6 · Passuk 9
English: These you may eat among all that live in water: anything in the water, whether in the seas or in the streams, that has fins and scales—these you may eat.
Chullin 99b.
E-Daf.com — Chullin 99b (Tsurras Hadaf)
אֹתָם תֹּאכֵלוּ. תֹּאכֵלוּ – לְרַבּוֹת אֶת הַטָּהוֹר שֶׁנִּכְבַּשׁ עִם הַטָּמֵא, יָכוֹל אַף עַל פִּי שֶׁנִּמּוֹחַ? תַּלְמוּד לוֹמַר אֹתָם.
Textual inclusion and exclusion — “You may eat these” includes a pure creature pickled together with an impure one, while excluding a case where the pure creature has dissolved.
The pure fish mixed with an impure one is permitted while it remains identifiable and intact.