I am growing increasing alarmed at my HM disappearing caudal fin and now anal fin. He first blew a bunch of his caudal fin 2 days after arriving in this country from thailand which I attributed to ammonia burn and travel stress.
That is the first pic (sorry don't know how to imbed pics). Then after I left for a 1 1/2 day vacation where he fasted for only one full day and did not get his light turned on, I returned to half of his moon being missing. The next pic of the tank shows it after a week or so of growing in. Then just a few days ago things began getting worse again, with now a large chunk out of his anal fin (2 close up pics - sorry they are blurry I just can't get a good one because he is fast).
Is it even possible for a betta to bite one's anal fin? Or is this something else. He lives alone and his tank is heated, filtered 6.6 gallon parameters are:
nitrates 0-5 ppm
The current appears failry gentle, nothing in the tank is sharp... the sharpest things are the roots of anubias really. I never see him get sucked in a filter or bothered by it.
The changes I made near the time of the last finniage missing is adding Betta Spa - an Indian Almond leaf extract that does have low levels of salt, changing his food from hikari to New life spectrum betta, and letting him flare for 30 seconds a day.
I thought all my changes were improvements... I am so confused. I see no black edging or any symptoms of fin rot. Other than the clear areas of new growth on the caudal fin, the edges are always crisp with no discoloration and ragged and torn looking. He eats very well and is very active.