Was out fishing at the local reservoir the day... which to state off the water is low and the moss is thick.... I did manage to catch 2 bluegill... decent sized for this part of Montana and I noticed that their gills and throat were "blue're" than usual... I also caught a small Largemouth bass... It too also was "blue" colored under it's throat...?? Blue as in what I can best describe as pool table chalk blue.... I've fished this reservoir before and never encountered this with fish I've caught... anyone else experience this in a small reservoir..??? Any thoughts or comments would be appreciated... Sorry I don't have pictures...

Perhaps what you saw was a bloom of blue-green algae. This happens often in hot weather especially after a veggitation die off. I would advise against consuming any fish from that water.

An Algae bloom had crossed my mind... the reservoir is spring fed, I have asked other locals and advised them that I wouldn't be eaten anything outta there... However there are other small reservoirs containing the same fish species and even though the waters getting low and the moss is getting thicker... None of the fish in there look like someone rubbed their underside with a piece of blue pool stick chalk... thanks for your response...