My mandarin goby has been pretty thin ever since i bought him and im kinda worried.. hr never gets any fatter or thinner. But he eats frozen brine shrimp when i feed so i worry about that. I have seen little copepods on the glass, but i only ever see them for sure in one spot. Heres a picture, excuse the moss. Looking back he mightve been a tad fatter when we bought him, particularly around the back of his head. If i buy copepods and put them in multiple times (or how ever many times i need too) will that be enough to fatten him back up? Were not sure whats up with his tail, i think its because of dangerously high salinity we've had in the past (i'm fixing it). The reason im so unsure is because my family insists hes fine because he eats the frozen shrimp, but ive never seen him eat more than two in one feeding. My other fish are perfectly fine so i know its not a water issue (aside from salinity).