Update(April 2026):
Added files that bake actions and split them into separate animations(AyuBlenderSizeHighPolyaAnimBakeSplitAnim.zip, Blender4.5.1).
This makes NLA editing easier.
https://eizouasobi.blogspot.com/2024/04/efficient-use-of-blender-assets.html
This is a 3d model and animation of a Ayu.
https://www.youtube.com/watch?v=UdLK1_uGYrE
https://www.youtube.com/watch?v=jBElkFjTZpo
Blender(2.79) file of 3D model and animations of a Ayu.
I stuck with the structure and animation around the mouth and gill.
Two size models are included.
AyuBigSize assumes use with UE4.
See below for how to use AyuBigSize with UE4.