First commence the tutorial by making a circle & an oval.
Draw an oval & a line in the middle of the body. Also draw outline for fins.
Make head, mouth & eye.
Make tail, fins & outline for the body.
Make left fin & lines over the face as shown.
Make tail and draw three horizontal lines over the lower body as shown.
Draw retinas & lines over the tail and body as shown.
Finally, make necessary improvements to finish.