Cardinal Tetra Lost His Tail

[Squid]

As the title says, i have a new cardinal tetra that has lost his tail (bought thursday). The end where the tail used to be is a pale stump, but he seems to be swimming around happily in the tank.. The rest of his colours are fine.. Any advice on what to do , or what caused it.

Addtional info:

Fish in tank - cardinal tetras, pentazona barbs (peaceful, not to be confused with tigers), panda corys, male dwarf gourami and otos. so i cant see how it would be another fish..

Meds - none added

Stats - PH - 7.5, ammonia 0, nitrite 0, nitrate 5-10 (in between colours ).

180 litre tank.

If ive missed other important information, let me know what you need.

Thanks

Squid

 

[Tokis-Phoenix]

Sounds like finrot, can come about suprisingly fast and feice in fragile or small fish like cardinal tetras- use an anti finrot med like pimafix or "anti finrot & fungus" by Interpet etc to treat the 'lil fishy plus lots small regular water changes and good foods like frozen/fresh daphinia and bloodworms to give it strength and energy .

 

[Squid]

Tokis. Thanks for the information. I do not have a hospital tank, and i am wary about putting meds in with the other fish present. Is there one that you would recommend that will have the least impact on the other fish.

I try to feed my fish bloodworm every other day anyway, so i will continue to do so.. It helpful for the gouramis colour anyway.

Many thanks
Squid