Is This A Boy Or Girl Baby Betta?

[Wildbetta]

It may not be "stress" exactly that is making your little one have stripes.  It looks like it is just now really getting into the colors and the stripes are often a form of camouflage for young bettas.  It is very possible that it is not fully comfortable enough in the new home to let go of all of its camo yet.  I wouldn't concern yourself too much about it unless you start to see other indicators of stress -- clamped fins or major paling of color.
 
Now that it has grown a bit, I am leaning toward male.  The growth of the fins - especially the anal fin and ventral fins. and shape/length of body highly suggest male to me.  It is still a bit early to be completely sure though. 

 

[GuppyGirl20]

I hope he get's comfortable. It's just him and a snail in there so he's king of the tank (even if he doesn't know it). If it's a boy as the general consensus seems to be telling me now I think I'mma have to do a name change. Now that the blue is coming in Gara just doesn't fit (I picked it because the character has bright red hair). Hmmmm if he keeps the red and the blue I'm thinking about Spiderman ('cause of the costume, ya know). I'll mull it over and we'll see what happens
 
(snapped a super good picture today) (but see how the blue outlines the fins)

 

[brittgs]

Very cool to see his growth and color change over the past 10 days. He is a lucky guy that you picked him out at Petco and have made such a nice home for him.

 

[GuppyGirl20]

Tomorrow will be two weeks since I bought my betta. Any definite answers yet?

 

[372xp]

Male