Usually very much like male fish.
it looks like they have a big bubble in their side
ugly
There are so many species of fish and they all differ. There are some in which there appear to be no differences and others that are so different they look like different species. If you define the species then I may be able to tell you how to sex them.
Usually, they won't have big beautiful tails. They have smaller bodies in general also.
fish are fish
Fish
Dolphins look like dolphins and why would they look like a fish when they are a mammal?
There are thousands of species of fish and they all look different from one another in some way. Seawater fish look like fish as do freshwater fish.
Male and female fish have not been designated like other animals are, into things like cows and bulls, so they are simply called male and female.
yes quite a few. look at a tropical reef!
look between their legs
While the fish is swimming, look at the fin on the top of their body. If it's tall then it's male if it is short , it's a female.