Shark

Sharks are available in every world in the game, considering they're the central focus. They become available for purchase once you have at least 5 fish. Their description is "Recruit a shark to help catch more fish."

Career Path
Sharks have the option of becoming Science Sharks once you have at least 1 shark and 20 crystals, or Diver Sharks once you have at least 1 shark in Shrouded worlds. In most cases Science Sharks are the first method available for obtaining science and unlocking the laboratory.

Laboratory Research
There are 4 generic upgrades that can be researched that are specific to only sharks, 2 generic upgrades that affect shark income, and 5 upgrades that affect shark technology. The research listed below is available in every world and has an effect on sharks and their jobs: {| class="article-table" ! scope="col" |Upgrade ! scope="col" |Description ! scope="col" |Result ! scope="col" |Cost

Crystal Containers
Make weird bottle things from the crystals we have. Maybe useful?? Scientists are twice as effective at making with the science. Science shark power x2

Unlocks Underwater Chemistry 100 Science

50 Crystals

Exploration
Swim beyond the home seas to see what can be found! Sharks and rays are twice as effective. Did you know oceans are big? Fascinating! Shark power x2 5K Science

5K Fish

Crystal Bite-Gear
Bite the crystals we have into something to help biting! Sharks are twice as effective with their new biting gear. Turns out they work better outside the mouth! Shark power x2 50 Science

10 Fish

Underwater Chemistry
With the weird bottles, we can now put things and other things into them and see what happens. Scientists are twice as effective with their new chemical insights. Science shark power x2

Unlocks 200 Science
 * Transmutation (also requires Thermal Vents)
 * Biology (also requires Agriculture)

50 Crystals

Automation
Using sharkonium, we can make things to do things so we don't have to do the things! Machines can be built to supplement population duties. This is efficient. Unlocks 1K Science
 * Build crystal miner
 * Build sand digger
 * Build fish machine
 * Engineering

100 Sharkonium

Engineering
The machines sort of suck. Let's make them better by learning how! Machines are twice as effective. Skimmers and auto-transmuters are now possible to create. Crystal miner power x2

Fish machine power x2

Sand digger power x2

Unlocks 2K Science
 * Build auto-transmuter
 * Build skimmer (also requires Recycler)

2K Sharkonium

Biology
What is a shark? What is inside a shark, except for large amounts of fish? Sharks are twice as effective. Did you know shark eggs don't actually form just because a shark wills them to exist? Shark power x2

Unlocks Train nurse shark 400 Science

Transmutation
By heating things up and doing science things to them, maybe new things can be made! Enables transmutation of some random junk we have lying around into sharkonium, material of the future. 1K Science
 * Unlocks Transmute stuff to sharkonium

4K Sand

2K Crystals

Ancestral Recall
The sharks and rays know we share some features among ourselves. Using the vague glimpses of dreams, let's piece together the puzzle. Sharks, rays and chimaeras, and their roles, are all four times as effective. We have had a glorious past. Now, on to a glorious future. Shark power x4

Diver shark power x4

Nurse shark power x4 10B Science The following research is available only in worlds with eels, Frigid worlds and Abandoned worlds respectively: {| class="article-table" ! scope="col" |Upgrade ! scope="col" |Description ! scope="col" |Result ! scope="col" |Cost
 * }

Bioelectricity
There has to be a way to harness the powers of some of the eels. We all know they have powers. Painful ones. Eel technicians are twice as effective. So are our machines. Convenient! Fish machine power x2

Sand digger power x2

Auto-transmuter power x2

Skimmer power x2

Purifier power x2

Heater power x2 1.6K Science

400 Clams

Environmentalism
So the machines might be destroying the ocean. We need to fix this. Purifiers can be made to combat the harmful effects of the other machines. Anti-machine machines? Unlocks Build purifier 500 Science

Thermal Conditioning
We're freezing to death! Machines make heat, right? We need to work on this!! Heaters can be made to fight the freezing process. We don't want to become giant novelty ice cubes! Unlocks Build heater 500 Science
 * }

Story
Warning: This section includes speculation, as canon answers don't yet exist.

To hunt. To catch. To win. Sharks are not the smartest creatures, but they have plenty of determination and can be found in every world with a gate. They turn out scientists early on but advancements come slowly mostly because, as the log notes, the majority of their research is done with their mouths. Science sharks have seemingly endless curiosity though, considering the lengths they go to investigating even the hated dolphins.

The feud between the sharks and the dolphins begins with the realization that they are essentially the same, but dolphins have bigger brains. The dolphins don’t help the matter with their superior attitude, but the basis of their dislike for each other is that jealousy. The sharks manage to get along well if every other species they meet.

Trivia
Sharks have multiple rows of teeth that continue to grow constantly throughout their lives. These teeth move forward over time until they eventually fall out and are replaced by a corresponding tooth from the previous row. These rotating teeth work like a conveyor belt, ensuring the shark always has at least one full set of teeth to use.