I stumbled across a bunch of vids the other night that I had no idea I had uploaded to you tube. 3 pages of Characin vids, before I really got into rays. I'm ALaake over there. There's some with Cynopotomus, Armatus, Odoe, and Dorado..... Even one of my big old Rhaphiodon doing backflips in the pond.
Growthrate on the Dorados vary a bunch. Seem to go in spurts. Groups grow much quicker. Dorado in ray tanks that get fed pounds of food a day might grow quicker then they do with normal feedings..... They're also supposed to slow down a bunch when bigger.... I'm not sure how long I've had mine, but I think they've only picked up like 3, maybe 4 inches. They've gotten way thicker though....
The 2 I have hate eachother, but have had no issues whatsoever with any ot the other fish I've ever tried mixing them with.