I just noticed that my green spotted puffer has some sort of green streaks on both sides of his jaw. Is this a cause for concern? Can anyone tell me what this is?
What are water conditions (ammonia, nitrites, nitrates, specific gravity, pH)? Last water change? Temperature?
Generally, color changes in puffers indicate stress. Could be from water conditions, could be from nutritional quality, tankmates, parasites, disease...Lots of things.