To succeed you need to understand the fish well. Below is a list of all fish, their game size, as well as some useful tips.
1) Do not wait until the fish itself swims to you in your mouth, rush to her from all fins!
2) Prefer to catch the largest fish that you have in your teeth. In general, eat everyone in a row!
3) Try to stick to the center of the screen, so you will have more time and place to maneuver to shy away from the fish that you plan to snack.
4) The fish-hedgehog does not try to eat anything. This means that you can not be afraid of fish-hedgehog if your size is less than 5 in the absence of large teeth or less than 4 if they are available.