There are around 5000 different species, no-one knows the exact amount of fish
1,000
The answer to this question depends on what species of fish you are specifically asking about. The record for swordtails is 300, but whilst this seems like a large amount, keep in consideration that...
The answer is 4-6
Depends on what kind of fish you have, betta fish can have up to 150 eggs and only 90% are born.