Thai Culture, Siamese fighting fish, Breating and Diet

Breathing

Like anabantids and all members of the genus Betta, Siamese fighting fish have a labyrinth organ in their heads that allows them to take oxygen directly from the atmosphere in addition to the oxygen taken from water via their gills. Bettas that cannot reach the surface may drown.

Diet
Bettas have upturned mouths and are primarily carnivorous surface feeders. In the wild, bettas feed on zooplankton and the larvae of mosquitoes and other insects, such as flies, crickets, or grasshoppers.^{[citation needed]} Bettas which feed on wide range of foods live longer, have richer colors, and heal fin damage more quickly. Typically, Betta pellets are a combination of mashed shrimp meal, fish meal, brine shrimp, bloodworms, and vitamins. Bettas will also eat live or frozen bloodworms, brine shrimp or daphnia. For variety and fiber, bettas are fed finely-chopped, high-protein vegetables, such as soybeans, green beans, broccoli, corn, and carrots. Some bettas subsist on dried flaked food suitable for tropical fish, because although this feed reduces their coloring, the bettas are able to digest this better than pellets. However, bettas are carnivorous and therefore require meat products as well. Bettas can get constipated, exhibiting a swollen stomach, when their diet lacks variety.

by: http://en.wikipedia.org