Small Bit Missing From Plecos Fin

[TaurineLittle]

Hey guys, I noticed a day or so ago that my Pterygoplichthys Parnaibae has a small chuck missing from his dorsal fin and tail, I've checked all my water parameters, Ammonia and nitrite is 0ppm but my ph might be a little low moving between 6.6 and 6.8. I have him in a community 10 gallon tank with 5 guppies, 5 neon tetra and 3 red cherry shrimp. I doubt any of the other fish would harass him but when I put an algae disc in for him the guppies like to nip at the disc and may accidentally poke the pleco, but as for the missing bits of his tail I have no idea whats going on... He is the only fish in my thank that this is happening to, the rest are lively and healthy. I'll try to take a photo of him and post before and after pics.
All help is greatly appreciated

 

[TaurineLittle]

Before
 

After
 
I hope you can see the bits that I'm talking about, will they grow back?

 

[techen]

Its not a common is it? It's possible he's been fin nipped at somepoint but if he's eating he'll be fine. 10 gallons sounds quite small for him though

 

[TaurineLittle]

Nah he isn't a common, done as much research on him that I could find and have come to the conclusion that his scientific name is Pterygoplichthys Parnaibae, no common name found. Planet Catfish have said it grows to a total of 12 inches, and after more research apparently it will take roughly 2 years to get him there. At the moment he is still quite small maybe about 7cm? he was 6cm when I got him and that was roughly 6-7 weeks ago. I'm moving him to my new 15 gallon long tank once i get the sump and overflow built and cycled. I have big plans for a lot larger tanks by the end of the year so he will definitely be in a larger aquarium before he gets too big for his current one.
He is my pride and joy, feed him well and constant eye on the tank levels. Main concern is if his fins will grow back and repair themselves?