Male and female oriental fire-bellied toads (Bombina orientalis) have equally brilliantly coloration, but they do not look identical. Enough physical and behavioral clues exist for you to determine their gender with a fair degree of accuracy. The task is not an urgent one - the fire-bellied toad is a sociable species and no combination of the sexes is likely to fight. It is also a simple matter to get rid of unwanted eggs if you have a mixed sex group.
The most definite physical difference between the sexes is found on the forearms. These are the nuptial pads - thick black pads on the male’s forefeet that allow him to get a better grip of the female. Because the toads only need the pads for a short time, they only appear during the breeding season.
Other Physical Characteristics
Outside the breeding season, several other clues hint at gender, although none is as certain as the nuptial pads. Males have slightly better developed forelimbs than the females, more webbing on the hind feet, more knobby backs and somewhat slimmer physiques -- females tend to look chubbier.
Only the males vocalize. If you notice a fire-bellied toad calling, which sounds like a croaky sort of bark, he is definitely a male. During the breeding season, another aspect of this toad’s behavior pretty quickly sorts males from females. If one of the toads clasps another, he’s a male. The toad he’s clasping may or may not be a female -- generally, if he is not shoved off rapidly, the object of his affection most likely is a female.
Fire-bellied toads are highly social and should be kept in small groups. It doesn’t particularly matter how many of each gender you have, although a roughly 50-50 split would be ideal. They will, however, breed, so only keep the eggs if you are prepared to raise the tadpoles, which would require another tank, and can find homes for all the resulting toadlets.
Note that they each female can lay up to 200 eggs at a time and they will hatch within a couple of days, so act quickly to sterilize unwanted eggs, which can be done by freezing or boiling before you throw them out. If you keep large fish elsewhere, they might appreciate the eggs as a snack.
Judith Willson has been writing since 2009, specializing in environmental and scientific topics. She has written content for school websites and worked for a Glasgow newspaper. Willson has a Master of Arts in English from the University of Aberdeen, Scotland.