Siamese Fighting Fish are kind of like a guppy with an incredibly extended tail and dorsal fins, waving like the multinational flags on the banks of the Tonle Sap. They’ve been bred over the years from a natural plain-ness to an iridescent brilliance and kept in separate containment because as their name suggests they are aggressive little blighters and so can not be trusted to leave a cell mate alone. One dull green or gray fish in a bowl does not a Feng Shui cure make so they were engineered to become little spots of much more interesting colour.
These ones are at the bottom of the escalator in Plaza Singapura in tiny rectangular tanks side by side like a fishy bookcase. There are black plastic dividers between their watery homes so they don't wear each other out stalking up and down the glass sides like hungry penned in tigers.
They’re like miniature sociopaths, males, when put together will attack each other, and if placed in a confined space with a female, will attack her if she’s not in the breeding mood.
According to Burkes Backyard they are as uptight as they are because their native habitat is usually so small; rice paddies, stagnant ponds, roadside drains even the puddle left in a dent made by a buffalo hoof after the rain, that there is not room for two dominant males. Evolution has thus, through a constant game of 'mines sharper than yours', breed a species so aggressive they are often pit against each other in a similar way to cock fighting rings here in South East Asia.
The Betta Splendens also possess, I discovered according to the same source, supplemental breathing apparatus (other than the normal gills) called the 'labyrinth.' Located in a chamber above the gills it is supplied with blood vessels which absorb the air gulped in through the mouth allowing the fish to survive in such a tiny environment even in stagnation.