The bala shark (Balantiocheilus melanopterus) isn’t a shark at all, but a bony fish related to minnows. Sexing these fish as juveniles isn’t possible, and telling adult boys from girls is on the iffy side unless somebody’s in a family way.
It Takes a Village
Unless you have a burning desire to breed bala sharks, gender isn’t important -- they all look and behave exactly alike. Because mature balas can reach lengths of 12 to 14 inches, you’ll need an immense aquarium for breeding them. The pet trade typically offers very young specimens that require several years to reach puberty at about 6 to 8 inches long. The only way to be sure of gender is to purchase proven breeder bala sharks, which isn’t practical for most hobbyists. The next best thing is to start with a shoal of five or six youngsters and grow them up, which virtually guarantees a boy-girl mix.
All Grown Up
Adult male bala sharks grow slightly larger than females of the same age. Females in spawning condition become a little fuller and rounder in the abdominal region.
Given enough room and correct environmental conditions, mature balas may spawn, revealing their genders. Females are egg scatterers who broadcast their future offspring all over the tank. The male follows behind, releasing sperm to fertilize the eggs wherever they lie. Parents don’t care any further for the eggs and should be removed from the tank, as they may indulge themselves with caviar.