Just posting an update here that the Pleco has died.
Unfortunately, there is almost no information available on the Web that pertains to Pleco illness symptoms and the correct procedures for treating a sick Pleco. I did call the local PetSmart yesterday and spoke with someone who told me that if there are no visible exterior signs of injury, etc. then it is most likely an interior infection or something on the inside (nothing obvious exterior then must be interior makes sense). The person recommended Maracyn, which is an antibiotic for treating a variety of illnessess, including secondary and internal infectons. Unfortunately, that recommendation came too late for the Pleco. He was a beautiful 9" Snow-King Pleco. What surprises and disappoints me is that of all the web sites that I visited and posted help inquiries, no one on the Web gave any recommendations for treating the Pleco. The only person that gave a recommendation was someone from PetSmart - - but it was too late - - since I assumed (wrongly) that I would get some solid help from aquarium/fish sources on the web.
Losing a 9" Snow-king Pleco because of lack of info is not the greatest feeling. Especially since I have not seen a Snow-King Pleco for sale in any of the Pet Stores that I have visited. I have purchased some smaller replacement common Pleco's, but they are not as beautiful as the Snow-King. I will have to continue to look for another one and hopefully will find one sometime. I also plan on purchasing the Maracyn
antibiotic - - since I now feel it is a good idea to have such basic medication on hand just in case it is needed in the future.