I have tried everything I can see to generate an image of a fish, nose to tail. Regardless of the prompts the final result is just a section of the fish.
Thank you for your message. I am sorry you are having a problem.
You can try using the "wide angle" camera angle or using prompts like "zoomed-out" or "distant view". But, you might get the best results by sketching the outline of the fish and using that as a structure reference.