On Tue, 30 May 2006 18:03:13 -0500, Linzee_02us
wrote:


My betta has been perfectly healthy but in the last few days has a
developed a red spot on his tail. He is very active and doesn't show
signs of being sick. Does anyone have any suggestions of what it could
be?


The most obvious cause of damaged fins is aggression by other tankmates.
Most often, the tail is affected first, and long, clean slits appear
between the fin rays. In the case of cichlids, other fins will usually be
damaged quickly, and scales will begin to disappear as well. The biggest,
most assertive fish that is undamaged is always the most likely suspect,
but smaller "nippy" fish may also bear watching. Sometimes finding the
culprit isn't easy, as fish behave differently when they know they are
being watched. The aquarist may need to turn off the room lights one
evening and sit quite still for 10 or 20 minutes before normal behavior
resumes.
Treatment: separate the offending party.

Fins sometimes seem to deteriorate all on their own in cases of extremely
poor water quality (for example, very high nitrates and low pH) that are
the result of overcrowding, overfeeding or inadequate water changing.
Exposure to chlorinated tap water may also cause fin damage.
Treatment: get caught up on water changes and reduce feeding size and
number of fish if necessary. Properly dechlorinate water before adding to
aquarium.

Quite a few parasites and bacteria can cause fins to decay. These may gain
a foothold if the fin is already damaged from handling or aggression, or
if the fish's disease resistance is lowered by stress. Excess mucous
and/or red blotches at the wound's edge indicate the likelihood of
infection. Unfortunately, since any one of several different pathogens
might be involved, there is no one simple cure.

After the cause of "fin rot" is addressed, fish can heal quite quickly,
often regenerating almost all the lost tissue within a few weeks. Good
nutrition, especially in terms of vitamins, is essential during the
healing process.

HTH