Good Morning All, I noticed one of my Scarlet Plecos currently in my 180 Gallon stomach looks a bit weird and also his anus area has a small protrusion. I tested the water and ph was 7.2, ammonia 0, Nitrite 0, and Nitrate < 30 PPM. I am strict about water changes and Filter maintenance and have been in the hobby for over 15 years and I never seen this on my any of my fish. My Water changes are 40% each week to ensure optimal water quality since I am still putting funds aside for a tank set up around 500-1000 gallons. Filters are Fluval FX6 paired with 2 XL Hydro Sponge Filters. The scarlet has been with me now for 3 years and was doing excellent. Currently the 2 scarlets are housed with a Silver Arowana (15 inch) and 4 Geophagus. I feed the 2 Scarlets in the 180 Gallon a mix of Repashy Soilent Green, Repashy Morning Wood, and Repashy Bottom Scratcher for a balanced diet. He swims and is reactive to stimuli (light and movement) but is anus area looks to be "throbbing" and his stomach area looks sunken (Let me know if I am mistaken or if this is how a normal Scarlets stomach looks as they get older). Any advice MFK community?