I have successfully kept a 3" endlicheri with a similar sized spotted gar for quite some time now. But yesterday night, the endlicheri died abruptly. He was behaving normally prior to death, lounging around the bottom of the tank and surfacing once in awhile when all of a sudden he began dashing about the tank, and floated to the surface upside down. He had not been eating several days before this. What are the possible causes?!?!
