When will a fin NOT grow back?

[howmanyds]

A month ago I stocked my tank and within a day my little Mastacembelus spiny eel had nipped four caudal fins. By now, three of the fish's fins have grown back beautifully, but not for the julidochromis marlieri. This guy is about 1.25" long and the nip seems to go all the way to the flesh, poor guy. He swims fine and shows no unhealthy behavior, but after this much time I thought the fin would have at least started growing back. Thoughts?

 

[howmanyds]

This might be a better shot.

 

[Perryuk]

Is the whole tail gone ? Previous threads read shredded fins , scales missing = plenty water Changes clean clean water

 

[howmanyds]

I think the whole tail is gone, yes.

Is there a particular medical treatment I should be putting in the water or is it too late at this point since it has been a month?

 

[mikem691]

That looks to me beyond the tail fin and into the flesh. If it healed after being bitten off he may never get the fin part of the tail back. But he should be fine as long as he can get around and eat.

 

[Rivers2k]

If the base is gone then it wont grow back. I have been told add some melafix if it is a new wound to prevent infection.

 

[Oohitsae]

If the base is gone then it wont grow back. I have been told add some melafix if it is a new wound to prevent infection.

+1!
It won't grow back if it's into the actual peduncle rather than just the caudal, but if he moves around without a problem, or much of one, he'll be fine without it. Just keep an eye on him and maybe give him some special care.