different swordtail fry

[alLexX]

ive got about 8 swordtail fry right now,and recently noticed one that had a small cemicircular peice missing from its tail,is this a birth defect,evidence that its male,or something else?in case it helps they are a few days old.

 

[Fishies86]

Sounds like another fish has nipped his tail.

 

[alLexX]

i wouldnt think so,there in a tank by them selves(and snails)and ive never seen any aggression between them.its 10 gallons,so its not like there crouded.i cant see any aggression going on,there still really young.