ryukin - missing gills and discoloration

[abfab]

I've noticed a couple of things lately and am not sure whether to be concerned or not...

Two weeks ago I noticed that my two fish have a patch of gills missing on one side... both in the same area. I suspected it was due them squeezing behind a log that had moved closer to the back glass when I cleaned the tank. One of them seems to have torn his lower caudal lobe, just below the fork. It on the same side as the missing gills, so I suspect that they are related. I removed the log, but there's still another one.

This morning, I noticed that above the tear, the edge of the lobe is dark brown. I can't really describe the length, but it goes a bit above the fork. It seems a little more noticable on the outside, but can't say for sure. Maybe he just rubbed up against the log?

This fish did have an issue with constipation, but I switched to lower protein fish pellet a few weeks ago and he seems to be swimming happily. I also increased feeding from once a day to 3 times a day as I learned from this forum that they were being underfed.

The water parameters are fine and they are in a 20 gallon tank. They are over a year old. Aside from these appearance issues, both seem to be very happy.

What can cause the discoloration? Could it be the new food?
Will the gills grow back? How long does that take?

thanks!

 

[jsoong]

Missing gills?? Perhaps you meant missing fin? or may be missing scales?

The gills are inside the fish, under the gill cover (operculum to be technical). It is pretty unlikely to have the gills ripped off from injury. You have to stick something under the gill cover to injure the gills. You have to do that deliberately (say doing a gill biopsy). Otherwise, you would see major damage to the covers before the gills are involved. Small amount of injury to the gills are not serious and they do grow back, but major gill injuries are usually fatal.

As for the tail fin, small tears are common & they will grow back in time. The edges normally turn black as it heals, so turning black is a normal sign of healing. <Turing white & ragged looking is a sign of infection.>

 

[abfab]

Sorry about that. I meant to say missing scales.
Thanks for the info about the fins. The black-brown colour is disappearing.

 

[jsoong]

Scales will usually grow back too, unless there had been extensive damage to the underlying tissue. If you have a fancy scale breed (ie pearl scales), the scale may not grow back to "normal" state. This is just cosmetic. the fish will still be healthy & happy.