my 14inch male mm is doing great for years eating fine and all is very active and never have problems with him. but i just finished feeding the tank (tilapia filet) and after he ate a bunch and was all stuffed he was swimming around and i was looking at his bottom side and notices the anus area is red.... i dnt think that is good but yet again idk, i do weekly to twice a week 25% water changes have had fish for years and rays, i havent tested my water in quite some time and no longer own a test kit. every fish in the tank is fine and the ray seems to b fine and hasent been acting funny at all. wondering whats up with the redness, any one ? thnx