Shells

Shells are items scattered across the ocean that activate missions.

Missions
Missions are a great alternative way to collect coins in Hungry Shark Evolution, and players can activate them by collecting sea shells from the bottom of the ocean or out of underwater caves. The shells you discover only unlock your current shark's missions. Players can see their mission list by clicking the shell icon in the top-left corner of their game screen; this list tells you how many, and what specific missions are available to you, as well as what requirements you have to meet to complete the mission and to be able to have them checked off of your list. Although, you will only able to physically complete it having unlocked it.

Once players completes a mission, the promised number of coins will be given to them. Complete all of the available missions to unlock a super mission for even more coins. As you progress through the game, missions will become harder, and the same goes for collecting shells.