Well, betta arn't the smartest fish. It probably spreds its fins out because it "thknks" there is another male fish in their so it wants the female to pick him... Also I advise you don't put 2 male betta fish together because they will REALLY TEAR EACH OTHER APART!
usually a male has longer tail fins but they are about the same for side fins
you can tell if its a boy or girl by the fins the male Betta has long fins and the female Betta has small fins
Your betta fish is a female if she has smaller fins than an average male.
Male betas are colorful and have large fins. Females have virtually no fins and have no color
A female betta has very small fins with a long body while the male betta have lots of nice flowing fins.
Male betta's are larger, more colorful, and have much longer fins. Female betta's are small, less colorful, and have short stubby fins.
Male Betta's have much longer fins and normally have brighter colors and are bigger than the females.
Yes but never as large or fancy as a male.
It probably means that your female (girl) Betta is a male that has not yet fully matured.
The male Plakat is still a male Betta splendens (although its fins are not as showy) so it will display when shown itself in a mirror. A female Betta will not display.
Male Betta fish will attract a female by flaring and showing off their long flowing fins.
Male Bettas have more colour, are larger fish and have much larger fins than the females.