My green spotted puffers are two different color shades. The darker one also looks agitated or angry if they hold facial expressions. Has anyone had the same experience? Is this normal or could one be sick?
Green puffers change color periodically, so it's noting to worry about.
However, if the coloring is too light or too dark in the span of a couple hours, then you should begin to look for a problem.
Is your puffer still eating? Is he showing signs of lethargy?
He has been chilling at the bottom the last couple days but his appetite is still the same. As far as the shrimp pellets and frozen food. The darker one prefers the shrimp pellets while the second likes the frozen food. I do pellets every day cause the sharks and crawdads. Frozen food is every other day for the carnivorous rope fish and if the crawdad can get some. Anyway. Too much info. Thanks Ed.
USUALLY the puffers I've seen that have gotten darker are stressed in some way. And I agree with the poster above, species can normally change their coloring depending on various factors. The good news is he is still eating! So if you do find out what it is, you can soak his food in medication if needed. His stomach is also nice and white from the picture above so that's good. Does he show ANY physical or behavioral signs other than the coloration and lounging at the bottom? Any signs of aggression from others?
On a side note, is the information in your profile correct? I hate to be the guy that calls people out on it, but puffers can be sensitive to certain situations. Is your tank cycled? Do you have all the fish you mentioned and all the ones in your description in the one tank? And when do you plan to give the GSPs marine conditions?
Back to the food. That's amazing that you're puffer takes pellets. However, pellets don't typically have the nutritional value that puffers need. Frozen food is great, plus you can treat it. What are you feeding them? Do you ever feed live? What crunchy food are you putting in their diet for their beaks?
Sorry for the tons of questions. We like to help here and it'll make it easier with as much info as possible. Keep us updated, and good luck with the little guy. Puffers are awesome!