how to identify male or female for a goldfish?

Answer 1

Sexing goldfish is difficult, especially when they are young.

When they are spawning, its easy - the male will develop obvious pimples (white bumps called tubercles) on his gills and fins.
http://www.bristol-aquarists.org.uk/goldfish/info/male_gill_tubercles1.jpg
Females will get chubby with eggs.
Her vent will also be more prominant than the male's
http://www.bristol-aquarists.org.uk/goldfish/info/female_vent1.jpg

While not in spawning mode, you just have to take your best guess - females will be rounder, and have a slightly more pronounced vent.

Answer 2

There is a way to tell the gender of a goldfish. There's the tubercles way mentioned above, and then there's this way: Look right in front of the anal fin, where the anal opening is. In females, it'll stick out a little bit. In males, it doesn't, and goes in, rather than out. The site I listed below has more information on it.

Answer 3

Here's a great article on sexing goldies.
http://thegab.org/Articles/SexingGoldfish.html

Their behavior is a clue. Males will pester females typically bumping the females near their vents. Males get breeding stars on their gill covers and on the leading ray of their pectoral fins. Females tend to get rounder when they're making eggs. The shape of their vent also differs when they're ready to spawn.

Answer 4

Can't tell by looking at them. For the most part it doesn't matter as they only breed if they're among lots of other goldfish.

Answer 5

Its nearly impossible to sex a goldfish

Answer 6

Female are bigger than a male.
Male have bright colour than a female.

Answer 7

i asked at petsmart they told me they only sold males because if they sold male and female everyone would be breeding fish

Answer 8

well if it is a female it will usually be darker than the male and they will be big er

Answer 9

Look between their dorsal fins with a microscope.
Seriously dude, you can't tell. It's all internal.