A Juvenile Channa Barca is very obvious when you see it. It looks like a longer version of a channa aurantimaculata, but with the colors of a barca. I also want to mention that juvenile colors are almost prismatic in appearance(almost like a rainbow), and the black spotting is very small and consistent throughout the body. The body is generally smooth and elongated, but they still have that "barca face" with the eyes positioned more forward on a big round head.
It's hard to describe, and i fear words alone are not enough. Here are some pictures...
These are not my photos, credit to whoever they belong
Tabby's young channa
[video=youtube;qtNfZM2QQac]https://www.youtube.com/watch?v=qtNfZM2QQac[/video]
edit: by the way, your posted picture is a channa true blue, a variant in the stewartii complex.