My Betta's tail fin literally disappeared.

[Trendkill]

I got the fish on Thursday at the LFS. I got all of my plants for my planted tank here and have seen this beautiful yellow betta everytime I've gone in there, we decided to pick him up and take him home after some lady almost bought him.

Anyway, I put him in my planted tank with about 15 guppies. Friday rolls around and we leave for the weekend. We get back on Sunday and his tail is missing. I've seen fin rot before and this isn't like fin rot. The fish looks fine, has an appetite, but his tail fin is gone.


Has anyone ever had this happen before?

[MSG]

I highly doubt it's "fin rot". A few of your guppies probably decided the NEW betta is invading their TURF. Hence the missing tail.

• What size tank do you have?
• What is the m/f ratio of guppies?

When I had guppies housed with a betta, the long finned bettas had issues with being nipped by the speedy demons. (So once I noticed, the long finned betta was removed)

Female bettas had some small issues at first, but the guppies that tried to nip them had their fins tore up & the nipper eventually learned their lesson.

The rest of the guppies left the SHORT finned female bettas alone because they knew BETTER.

[Option]

Male bettas (esp the long-finned varieties) are known to bite their own tails in times of stress. But never to the point where the entire tail fin is gone.

So I can only assume that the male guppies saw the betta as some sort of competitor and nipped at the betta. Unfortunately, long finned bettas are not especially fast swimmers and if there were multiple guppies then I'm pretty certain this was the culprit.

[wicca27]

in the past when i have got bettas from lfs or walmart/petco/pestmart, they look great and a day or 2 later the tail can be gone and the day after that the betta is dead with white fuzz by the tail(the flesh part not the fin) i would use melafix/bettafix and up the heat for him. it could be a combo of him and the guppies nippin the fins but could also be something bacterial. if he was in a cup or bag at the pet shop then it could be bacterial. they are not known for keeping them clean in those cups. if you cant find bettafix only use about 1/2 dose of melafix cause the bettafix is same med just not as strong due to the breathing organ they have.

[Suzie Q]

Don't use melafix type stuff....it coats their labyrinth organ. Clean water, 1 tsp salt per gallon. IAL, or oak leaf tea. I used to always say use it, but not any longer. At the dose you have to use for a betta, might as well not use it at all.

I have just recently lost EVERY fish I owned because of rot...no matter how clean I kept them, their fins would just fall off. I treated for fin rot, columnaris, fungas, bacteria...you name it, i treated for it. Finally sent my fish to a lab and it came back as Mycobacterium. Every fish I owned is contaminated. I've killed all my show fish, breeders went into the 75g to live until they show the rot (had 2 fish that their faces started rotting off!!!). All my Peacock Endlers that I got from Ryan have to go (had them for 12 yrs now?), my RCS, all my fish...the still contaminated ones are in my bedroom under HEAVY QT (nothing in, nothing out). I had gotten a spawning pair of Betta rubra (and 21 unrelated just spit fry), had to destroy them (rare betta).

anyway...the reason I'm posting...is be careful!!! Mycos can not be killed with bleach, and it can live "dry" for weeks. I had to get a special cleaner that kills human TB because it has the same cell structure as human TB. wicca27...what you described is what I saw...the rot ate into the belly of one female, and all the way past the peduncle in a male

[lauraleellbp]

Get him away from the guppies. Guppies are notorious tail nippers.

[Suzie Q]

Originally Posted by lauraleellbp

Get him away from the guppies. Guppies are notorious tail nippers.

I agree also (somehow missed the 15 guppies)...1.5g "heated" tank (78-82*F). Clean water and see how he does. If his tail grows back, it was the guppies

[polukoff]

Guppy are notorious for fin biting betta, I have sold many betta to clients that want them in a tank full of guppies. it always ends badly for the betta.