I usually recomend yellow rays, or bullseye rays for starters. both are easily kept and will often breed in captivity. Blue dots are extremely sensitive animals. they need a PERFECT environment to thrive. A friend & myself have gone though around 8 or so to get our trio. They must be fed constantly, and need the utmost attention. I have prob spent $2800-3000 on their setup and im just now tweaking it! For awhile Shedd Aquarium was keeping them, but they couldnt keep new ones coming fast enough from what i have been told. Im sure they went though hundreds, if that tells you anything.