You could add a JD if you got rid of the jag. In fact the jag needs to go regardless. You can keep everything else though. You need atleast double that size tank for a jag.
yeah like previously said, the jag would need to go anyways no matter what so you could get rid of him add the jd and call it a day will be a tad overstocked but as long as you got a lot of biomedia and they arent fighting then you should be fine, are the bichirs senegals or something that gets bigger?