Thanks! Yeah, I have two guppies with slightly frayed tails. One has been in tank about a month, the other about 4 days. I did see a plattie nipping at the guppy this morning... perhaps that's the issue.sfsamm said:Fish especially those with longer fins can snag their fins, they can also bite their own fins or others fins causing a jagged appearance. Fins are, although completely different, somewhat like finger nails... Just because it's damaged doesn't necessarily mean something is wrong but can also be a good indicator of diet and environmental quality.