how can you tell a boy fish from a girl fish?

Answer 1

Tiny little testis?

Answer 2

depends entirely on the species... and in some cases, the FISH are the only ones who can tell, without surgery.

many young fish are not the same color or pattern as a breeding adult - and color can also vary over the seasons. a salmon out at sea looks like NO remote relative of a salmon coming upriver to spawn! whole other critter...

a library or images on the 'Net might help U; be sure to get the LATIN or scientific species name, not a common name; many common names, like 'rockfish', are used for lots of unrelated spp.

Answer 3

Male fish usually looks more colourful and attractive than the female ones. Some fishes' sexes are determined by their fins --- pointed fins is male, roundish fins is female.

Answer 4

It depends on the species. Live bearers (such as guppies and mollies) can be identified by the presence of an anal fin on the males called a "gonopodium" and also sometimes by color.

http://freshaquarium.about.com/cs/beginnerinfo/f/fishsex.htm

Egg layers are harder, while some have differences in size and shape, many look the same for both males and females and a difinitive identification cannot be made unless you see them layer eggs or fertilizing them.

Answer 5

I think sometimes there are differences in size or coloring, but other than that, I have no clue.

Answer 6

males are brightly colored and females brown/gray... this is usually true in tropical freshwater fish.

Answer 7

Your parents never had that talk with you?.......lol

Answer 8

size of their fins.....

Answer 9

idk i think like there gills