Thank you for your comment. I think I' ve lost my paint data. When I opened my file, the model was all black. I will try the background on another sea creature.
No, I am quite sure you haven't lost anything. Except the first material. Load your model, and change the first material. Check the others also with what you had during painting. I just mean the material, not the texture. I am quite sure you'll be back in business too