Answer:
The amino acid profile of collagen derived from tropical freshwater fish compared to ocean-caught fish is more compatible with the collagen needs of humans. The closer a particular collagen peptide is to human skin, the more desirable it is. This molecular similarity is heavily influenced by the temperature in which the source animal lives. Ocean fish are adapted to cold saltwater. By contrast, our farm-raised pangasius (pangasius hypophthalmus) spend their entire lives in fresh, room temperature water. The result is collagen that more closely resembles that of terrestrial animals, including humans.