The Legend of Zelda: Tears of the Kingdom has a very high degree of freedom, so you can use a lot of techniques to reduce the difficulty of the game during the game. Please take a look at the editor's The Legend of Zelda: Tears of the Kingdom: Bone Toothfish Here is a list of scale locations. If you are interested, please take a look. I hope it can help you.
Osteoglossus Location #1
It can be found southwest of the initial sky island, at the base of the waterfall. This location can be visited during or after the main quest "The Closed Door". In addition, this kind of fish will also appear on the northern Tabangta Sky Islands marked in the illustrated book, but it is more difficult to find.
The second location is on the surface of [Laniel Region>Thunder Beast Mountain>Mifa Park (east side of Zora territory)]. You can visit this area during the main quest [Hido in Zora's Territory]. From the top of the mountain where the temple is located, take the stairs to reach the fountain. Jump into the fountain to find the ancient Osteognathus.
