That's made from cod, and it appears they chemically modified it so that it can be patented https://www.kerecis.com/kerecis-receives-u-s-patent-for-fish-skin-ba

That's made from cod, and it appears they chemically modified it so that it can be patented https://www.kerecis.com/kerecis-receives-u-s-patent-for-fish-skin-based-tissue-regeneration-technology/ https://www.kerecis.com/kerecis-receives-u-s-patent-for-fish...