So I've had a Senegal Bichir in my 65 gallon tank for probably a month now. He hasn't hurt anyone (That i've seen, but a tetra did go missing 2 weeks ago) and is probably about 4 inches. He is a nice little fellow and spends most of his time sitting up by the surface wedged between the heater and the glass. Not the part of the heater that heats up though. Today I was planning on moving him to a 20 gallon all by himself (Very very temporary mind you) but he is acting very strange. His stomach is lumpy and when he swims it looks like his back 1/3 of his body is floating upward. I feed him shrimp pellets daily and there are usually algae wafers in there for the plec that he steals. I also feed bloodworms as a treat once and a while. When he sits near the surface his back 1/3 is usually floated to the surface while the rest is underwater. Should I be worried?