2 days ago I noticed a white smooth growth between the eyes of my YWG and it appears to be growing. It does not look fuzzy, but rather clearly defined. The goby is in the 29g aquarium for about 2 months now. It behaves normally (doing Goby things) and eats well all kinds of food (pellets, mysis, even dry seaweed) and the water parameters are fine (1.025; 8.0; nitrate/nitrite/ammonia at 0). No other fish (2 Ocellaris clowns and 3 pajama cardinals) is affected. Any idea is appreciated.