I honestly don't know anything about stingrays other than that they need a tank with a large footprint and motoro's get pretty BIG. As far as the reticula your best bet would be to ask someone in the stingray section. 
well i do happen to know myself what i did was bought a senegal bichir and raized it up in a 20 on blood worms and fish (frozen hes my favorit no feeders for him) then he was moved to a 55 at 5-6 then i added a small jag not the smallest but a small one (go to petsmart or pet co if theres one by you thay all ways have small fish at a good price toAttackFish;807426; said:I went and asked about tank sizes for jardini's in the aro section here on MFK and now have the proper dimensions to house a single jardini.
I wish there was someone out there that kept a jag and a bichir that would post here! I really want to keep an albino bichir and a jag but I dont want my jag trying to eat the bichir and the bichir putting up its spikes on its back (thats probably not the technical term) and killing the jag, then they wuld both die!