Before that question can be answered one would need to know what kind of catfish you are asking about. There are so many different species that are called "catfish" that it is impossible to make a generalisation.
You can find it easily by checking the fins of and tails of catfish. Female catfish have large tale and fins so you can check it by comparing two. The second thing is that you should check is to find out fins of catfish in female catfish there is a mark on her fin which distinguish her as female.
They are simply called "male" and "female".
The adult female Corydoras tend to be more triangular when viewed from above than the more elongated male.
A male catfish
If you want to sex a catfish, look at the dorsal fin. The male's fins are brighter in color and larger.
A person can find pictures that show the difference between the genders of catfish in a book about catfish. It can also be found in a book about aquatic animals.
Catfish eggs are fertilized by the male after being They must be goldfish eggs. It is nearly impossible to have catfish breed on their own in a tank or pond. Any fish female can have eggs, the eggs are fertilized after the female lays the eggs. So if the eggs hatch then most likely they be goldfish.
I have three bristlenose catfish, one old male that has been alone all his life, and two young females. when I moved the females in, I moved in three other catfish, a bit bigger than fry. The large male killed the three young ones, and later I had to move one of the females because of the male. I recently moved the other one too, and the loner female didn't like it much. now they live happily together though. I think they bristlenose become more hostile the longer they live by themselves, but it depends on what sort of catfish you have
That all depends on if you had both a male and female involved in the spawning and what species of catfish it is.
Yes.
Yes
If the fish has a "GONOPODIUM" it is definitely a male.