Betta splendens is the most popular variety of betta. They are known as the Siamese Fighting Fish, Siam being moden day Thailand. The reason a fish such as the betta exists is due to the ecological niche of stagnant slow moving water. The native water of the betta is slow moving rivers and rice paddies in southeast Asia. The large fins and labyrinth organ are nearly useless in faster moving water, which can drag the fish around due to fin size, as well as being better areated, making the labyrinth useless. In Thailand they are still raised to be fought, these fish being more similar to the wild variety. The short finned wild variety of betta is known as plakat thai. Among fighters shorter fins are preferable, as the fins are the target of attacks. Many breeders of the fancy strains of bettas object strongly to their being fought. The science of betta genealogy is growing rapidly as it is useful in selectively breeding of the more unusual modern strains. Bettas are egg layers. The male betta splendens builds a bubblenest which he tends to and keeps the eggs in. The eggs will not develop properly if they are not near the surface of the water. There is a great deal of information to be found on breeding bettas available from breeders all over the world. There are many other varieties of bettas, the better known of which may be Betta pugnax and Betta imbellis. Some species are mouth brooders, mostly in varieties that exist in faster moving water that would break up a bubblenest quickly. The betta is a good fish for beginners, as well as experienced fishkeepers who can breed them and raise the young (a daunting task, as it requires changing a large number of bowls, glasses, jars, tanks, et cetera on a constant basis). When adding a betta to a community tank one must be careful of several factors. Bettas will instinctively attack any fish with long fins, often wounding the fish mortally. Keep in mind as well, that as a long finned fish, other aggressive species will also nip at a betta's fins. While not using a significant amount of oxygen in the tank, bettas add as much pollution as any other fish to the tank. To keeps bettas at bay in a community tank, a current in the water, such as that from a power filter, will keep the fish tired and prevent it from harrassing other fish.