Pictures of actual betta habitats...
http://www.ibanorum.netfirms.com/habitat-bb.jpg
http://www.ibc-smp.org/images/simplex/simplex_habitat_Krabi4.jpg
http://www.ikanpemburu.com/Picture/kota_tinggi_crypt1_habitat.jpg
http://www.ibc-smp.org/images/splendens/splendens_Habitat.jpg
The wild species of
B. splendens is all over Southeas Asia. Not only in the main rivers, but also in swampy marshy areas, drainage ditches, rice paddies, and anywhere there's a suitable, long-standing puddle or pond habitat after the rainy season.
Bettas can live in anything from 4 feet to 4 inches of water in their natural environment according to location and season. Monsoon rains flood entire basins, covering miles of souteast asia in a shallow freshwater marsh. Many species, including bettas, travel all over these areas and as the waters recede, they become trapped. This is part of why they developed labrynth organs. As those shallow pools heat up, oxygen is lost and so they adapted to breathe and survive in areas where other fish and predators could not. This provided them protection AND their own special environmental niche where other gill-only fish couldn't muscle in.
Bettas are hardy because of this extreme environment. When a puddle grew too shallow, too mucky, had too many predators, or ran out of food its nothing for bettas to jump out of their puddle and flop about until they find a new one. It is survival for them to do so (this is also why bettas in poor water conditions or whom feel threatened will jump out of their tanks).
This is also why they can adapt to so many water temperatures and perameters. The water quality of a slow-moving river full of deep shaded water is going to be very different from a shallow rice paddy in the full sunlight, which will differ even more from an evaporating drainage ditch on the side of a busy roadway.
Granted, our fancy bettas aren't as tough as nails as their wild cousins and need a little more pampering to thrive... but they come from strong roots and to say that they must have this or can't live without that is truly hard to say.
Hence my rule that 1/2 gallon, 6 inches deep is a good MINIMUM as long as you maintain water quality and keep a lid on it. Bigger and deeper is nice, but anything more than 3-5 gallons for a single betta seems far too extreme to me, considering the nature and origins of this fish.
EDIT: Here's information from a Thai breeder (anyone know of PlakatThai from AquaBid?) telling about where and how he catches wild Betta smaradgina and splendens in the areas surrounding his home.
http://siamesecyber.tripod.com/smarag.html
It focuses a lot on betta smarg. but splendens is known to crossbreed with this close cousin both in the wild and in captivity and both share the same environs in most of Thailand.
Exerpt taken from the International Betta Conference's own FAQ page on their website:
I've heard that Bettas like to live in jars, is this true?
No, although Bettas will survive in small containers if good water quality is
maintained. Bettas evolved in areas of very slow moving water where rice
and aquatic plants were common. Dissolved oxygen is often very poor under
these conditions and the Betta and other similar fishes evolved the ability to
use surface air. They still have gills like other fish and will not “drown” if they
cannot get to the surface. Because of this ability, Bettas can be kept in small
jars and aquaria. When keeping Bettas in smaller containers their water
needs to be changed weekly to reduce and eliminate the wastes that build up.
If you don't have an aquarium, a plastic or glass 1 gallon goldfish bowl will
suffice as a container for a Betta. Those are fairly cheap, allow the Betta plenty
of room to move around it, and are easy to clean. Even a 1/2 gal bowl is fine
for most Bettas as long as the water changes are kept up with. Remember,
male Bettas will fight with other Bettas and as such, must be kept separate.
So my perspective does hold water... pardon the pun.
;;
