My small one's about 4", big one's about 5". The small one seems to have some problems eating floating stuffs, it's light-butt floats up all the time when it tries to eat from the surface, that makes it very difficult. Now I am feeding it raw fish I bought from the market. That's its favorite food now.

The bigger one, on the other hand, was traumatised when he got choked once while eating raw fish. Now, his favorite food is dried anchovies.