Peppered Cory Not Growing

[Cazgar]

I got my peppers all at the same time & they were all quite small, not much difference in size between them.
All but one have grown a lot, the small one is roughly half the size of the others.
He/she seems healthy & feeding well.
Any ideas as to why it isn't growing as well as the others?

 

[Harlequins]

Perhaps its a male...

 

[Cazgar]

I had thought maybe it could be, but are males really so much smaller than the females, he is only half the others size

 

[chokko]

what actual lengths are we talking about here, for the small one and the 'others'?

 

[Cazgar]

He died last night.
The others are about 2 & inches, he was about 1 inch