Personally, I think slate is better. Slate gelatin has high nutritional value and medicinal value. Slate gelatin is the best for stomach nourishment, followed by important effects and functions such as nourishing face and moisturizing skin, relieving aging, maintaining ovaries, treating constipation and improving sleep. The bigger the fish is, the more valuable it is. The reason for the value is the slate fish stomach made into slate fish glue, high quality slate fish glue is worth tens of thousands or even hundreds of thousands of dollars a catty. "One or two glue ten catty fish", that is, 10 pounds of fish to produce one or two fish glue, which more than 35 pounds of large slate fish can produce 3-4 two fish glue.

Redfish mainly from Iceland, Greenland, the Faroe Islands and Newfoundland near the 500-1200 meters deep sea, redfish growth is slow generally 16-18 years old redfish to reach maturity.