In their wild form, the Siamese Fighting Fish is dull green and brown in color and it has a stout elongated body with short rounded fins. The name "fighting fish" comes from the fact that males will most often fight each other until either one or both of them are dead. Short-finned males have long been bred in Thailand for fighting purposes, though in this sport the combatants are usually separated before a fatal outcome. They are ferocious fighters, yet interesting behaviors occur during combat. If one of them goes to the surface for air they will pause the conflict, and the other will not take advantage of its rival during this temporary helplessness. Also if there is a third male, it will wait its turn to fight the victor rather than joining in the fray between the other two.
Siamese Fighting Fish - Copper/Red Rose Tail Betta Splendens
It has been found in many species, including Betta splendens (Siamese fighting fish) and Hirundo rustica (barn swallows), that red pigmentation indicates good immunity and health in an individual, which is indicative of their genes and reproductive success (Saino et al, 2000). In addition to this, previous research has shown that female bettas tend to prefer dark red-pigmented males over light red-pigmented males (Clotfelter et al., 2007), as well as preferring red males over blue males (Clotfelter et al. 2007). In some species of fish, such as Poecilia reticulata, color may indicate a severe parasite infestation and thus, bright flashy colors might indicate immunocompetence (Houde et al. 1992). However, severe parasite infestations result in lethargy, which might make a male less willing to expend the energy required to court a female.
Red Veil-Tail Betta (Siamese Fighting Fish, Betta Splendens)
The Betta or Siamese Fighting Fish will swim in all parts of the tank. This fish is quite hardy and will adapt to most aquarium conditions. Like all other anabantoids their special 'labyrinth organ' enables them to survive in oxygen-depleted waters. Because of this they can survive in smaller spaces. A minimum sized aquarium for a single specimen would be 3 gallons if kept in a warm room, and with regular maintenance. They will do best however in a larger aquarium, with adequate filtration and a heater, along with regular maintenance. A 10 gallon aquarium is recommended. Provide gentle water circulation and some sturdy aquarium plants. The aquarium should be covered to prevent jumps.
Red Siamese Fighting Fish, Betta Splendens by bluehand