Working on the basis of a tutorial I have followed in the past (it was for an elephant, I made a camel to accessorise a game map, have a horse WIP, and now a fish, handy technique!) I laid out the basic shape and have started pulling verts. Once I have the basic shape I shall start more splitting to improve the shape and add details.

The smaller picture at the bottom is a quick smooth of my basic mesh with a little texture I knocked up in PS, definitely not final (took a few minutes and is dreadful) but I wanted to see how it looked striped as I rather like those clown fish thingies.