betta fighting fishes

Question
Hi my son got a red beta, for his birthday and I'm no expert on fishes, i recently bought 4 more for him and was told that the males are bigger and more colorful, so i got plain blue ones and they are all fighting.

The one i had before has something rising under his mouth when he goes near the others and three of the new ones have the same. What does this mean?

Answer
Hi Ackleema,
 You cannot put more than one male betta in the same tank, unless the tank is large (e.g., greater than 50 gallons or so). They will fight until one kills all the others.  

 You can't tell a female betta just because it is plainer.  Only buy a female betta from someone who clearly knows the difference.  Many "females" are actually just young males.  

 Males flare some of the skin around their mouth when they attack other males -- it makes them look more ferocious.

-- Ron
  rcoleman@cichlidresearch.com
  Cichlid Research Home Page <http://cichlidresearch.com>