Somewhat serious question... Not trying to body shame him. He looks like he's going to explode. Not sure how to limit his diet when he goes around picking at algae all day long.
Hahahaha. I have the same problem with my lawnmower blenny. The other day my wife wondered if he was sick. I will wait and see what others think. He is a pig and eats everything along with grazing all day long.
They're always like this. I've kept about 5 in the past 25 years and they get absolutely obese off of spirulina, pellets, algae film, and anything else they can get their hands on. Never had one live past 5, but I think that's the top end of their lifespan.
Mine is the same. Big bloated stomach. I have some other blenny that is also displays the bloated gut. They kind of scare me at times as they breath real heavy like they have ich. When they swim they breath normal but when they are just perched on top of their gigantic bellies they huff and puff.