Hey guys! About 2 hours ago, My betta was perfectly fine! However I just went and checked on him and he has this little mark on his head — I got him on Monday, he is still however his same chirpy self, eating straight away and being friendly and coming up to the glass when he sees us!! Please help!!

Around 10am I fed my betta Rufus 3 freeze dried bloodworms and it's about 10pm now, he looks a little full? Is he going to be okay? The grey area underneath, a little behind his head, looks bigger than it did yesterday... Here are some pics: he has a heater and 10 gallons he's still pretty...