You can tell by the shape of the roof. The trusses of the roof will run perpendicular to load bearing walls. A wall that separates one apartment from another for example would most likely be a load bearing wall (if it runs perpendicular to the trusses).
That is what I figured, and is where my 55 is currently located.
Don't worry friends the research will be done before any moves are made. I will consult a professional. I plan on examining my lease. If aquariums are not covered I will purchase appropriate renters insurance just to be sure. Also, the aquarium I have likely won't be ready untill this summer.