What are the brances of fishery?

What do stingray eat? What is a sharks scientific name? Is a great white shark a mammal? Do sharks eat otters? Where have extinct pufferfish been found? Are there laws about overfishing? What cause phosphate in aquarium water? What does it mean when goldfish stay at the bottom of tank and it's still alive? How many liters should i have in a fish tank for perch? What size are tiger sharks? Do you need a backflow preventer with a well pressure tank? How do you get the bait out of your gear? Do fish swim all day? Do tiger sharks eat people? What to do if your aquarium water level starts to go down? How do a whale shark survive? Where can one purchase Metris scales? Liquid egg white in tetra pacK? What are the body parts of a great white shark? How many sea horses live in the coral reefs?