Dark tips on Java Fern?

Sumpin'fishy

Humble Disciple of Jesus Christ
Oct 16, 2002
673
0
0
50
Savannah, GA
Is it normal to have very dark green tips on growing leaves of Java fern? It is so noticeable that it appears that the tips have been painted dark green and has a very distinct line where it turns the normal green color for the remaining 90% or so of the leaf. I'm just wondering if this is where nutrients are being visibly stored for current growth, or what? Full grown leaves do not retain these dark tips.
 
the dark part is the part that is still growing.

the plant is a fern and ferns have their own rules as to how they grow

you know how the long skinny balloons used for making animals with do when they are being inflated? if you can connect that mental image to the java fern leaf growing that is about as good as I can describe it
 
AquariaCentral.com