Step #1
First commence the tutorial by making three ovals & curve line.
Step #2
Draw outline for tail & draw line in the middle of the fish's body as shown.
Step #3
Make head & eye.
Step #4
Make outline for body.
Step #5
Make fins, gill & tail.
Step #6
Make retinas & skin texture as shown. Also draw lines over the fins and tail.
Step #7
Finally, make necessary improvements to finish.