It is not very clear what you want to achieve. Do you want a 3d fish like shape covered with the triangles shown in the image? In that case:
I would create the fish in a 3d modeling program such as Blender (free), Autodesk 3ds Max or Autodesk Maya (and probably many other which I’m not that familiar with). You also might be able to find ready to use fish models on the web.
You will have to make the image yourself, unless you have some good quality, ready to use image file already. Use this image to put a texture on the fish model. The 3d modeling program will allow you to shift/rotate/scale the texture on the model in such a way that it will look good.
Now you have the fish in a 3d modeling program and you will be able to render still images, or movies. If you want the fish in your own OpenGL program, you should create an OpenGL program (many ready to use 3d engines do exist which you can use for that) and make sure the program can read the file created by the 3d modeling program (that file will probably contain lots of triangles which make up the 3d model, and also information about coordinates that specify how to put the image on the model). With OpenGL you should render each individual triangle that makes up the model (depending on the complexity of your fish, it can range from about 100 to thousands of triangles).
Mind you… if this is the first time you’re doing such a thing (creating a 3d model, writing an opengl program) you will probably have months of work on this alone as you have to learn a lot of new things.