My common pleco "squeaky" is approx. 7 years old and i havent had any problems until recently. A couple months ago, I decided to add a few more fish into the tank. The store I went to said tiger barbs and green barbs were ok for the tank, so thats what I purchased. I will say that I regret my purchase because since then, we ha e had nothing but problems with them. We've had a few die from others nipping them to death im assuming, and a little over a month ago I noticed a few of the barbs were nipping at my plecos tail occasionally. We have noticed now that when he comes out of his cave to eat and raises his dorsal fin, there is a small hole towards the end of it, and the edges now seem like they're more jagged. Also, ive noticed lately that he has several lighter patches on the sides and top of his body...they don't look fuzzy, just like his skin is lighter colored. I took pictures close up of the ones on his side. I couldn't get a good picture of his fin though other than the ones on his side...which seen jagged looking in the pictures as well. Im not sure if they're normal or not. He has been behind the plant stuck to the glass in the same spot as in the picture, for about 3 hours now..which isn't normal for him. I am somewhat attached to this fella, and would be devastated if something happened to him! I've checked water and ammonia isn't present and everything else seemed to be ok as well. Any suggestions would be appreciated!