Sharks are worth as much as the beetles.
Incorrect. The golden stag and horned Hercules are 12K bells each. Catch the normal "shark" and you get 15K. Also, you get 13K if you catch a whale shark. And don't cut all the trees in the middle. You get a rainbow stag (yellowish) and giant stag (purpleish) that can only be found on the island and not on palm trees. Worth 10K each. Also, these prices can be higher with the bell ordinance.