not sure if fin rot or a bite, has got no worse in a wk have medicated once, re-homed 2 nippy 5 lined barbs wen we noticed this, we did have a guppy die this am tho n he had a split tail
Hmm from the picture it's hard to tell. Normally fin rot is very uneven and often caused the blood vessels in the fins to become more prominent, leaving red streaks around the decaying area. That looks pretty smooth, it may be a bite mark. What other fish do you have though?
HIYA, YEAH IT SMOOTH, I HAVE MEDICATED THIS PM THO JUST 2B SURE, WE HAVE 1 RTBS, 2 SERPAE TETRA, 2 ODESSA BARBS, 3 GUPPYS, 2 BLACK PLATY, 2 SUNSET PLATY, 1 5 LINED BARB, LOTS OF OTHER PLATY!?
Ok, well if it's smooth, and the immediate are around the missing fin isn't reddened, or doesn't have a lot of milky white cloudy looking bacterial growths, then it likely is just a bite mark.