Amazon Sword stalk broken and detached

Phyroath

Senior knowledge seeker
Jan 30, 2008
351
0
0
56
Phnom Penh
My amazon sword is growing fast. Yesterday, i noticed the stalk of the newest leave is broken then detached from the plant. I took it out and the leave all look healthy. Neither me nor the fish disturbed it (I have only a pairs of swordtails). Can anyone help what caused this?
 
Thanks Stereo - I removed that nice leave. Have not yet seen any new leave coming and that why I was so worrying.
 
AquariaCentral.com