Mainly balance and locomotion. Some use them to attract a mate.
Steering and propulsion in water
Propulsion
The main function would be for fish to be able to see. Providing them the ability to sense food, predators, mates...etc.
It is to balance the fish in the water.
They do
yes
Mermaids have the upper bodies of women and fish tails.
fish hit the ground with there tails
no fish don't have legs they have tails and gills.
they both have tails
fish tails
No. Sharks, being fish, have vertical tails, while whales, being mammals, have horizontal tails.
Its quite simple to breed cold water fish: The main thing you need for breeding is a moss plant they are dark green and quite smelly, moss plants contain small worms in them that swim around in the tank. Its always important for the tank to be the right temperature but its not a main priority they can still breed if the temperatures not completely right. To tell the sex of the fish all you have to do is look at there tails. males have smaller tails than females. To get a simple breed of fish try mixing together a fintail fish with a common goldfish.
Don't now