There are 3 different kinds of pearls in Insaniquarium.
Beetlemunchers
Beetlemuncher pearl
In Tank 3, the Beetlemunchers drop a $500 pearl every 11 seconds.
Niko
Niko's Pearl
You can also get pearls from Niko. His pearls are worth only $250 and he only opens his mouth every 40 seconds
Brinkley
Brinkley Sometimes drops pearls like beetlemunchers is $500.
Trivia
- This is odd why Niko's pearl is cheaper than Beetlemuncher's and Brinkley's pearl.