Well, it's coming up on 1 year since I brought home my first rays- 2 retics. I figured I'd update with some new pics and give a little background on them. The original group of two I got did extremely well for about 5 months in a breeder tank, with twice weekly 30-40% water changes. Filtration was a cascade canister rated for 100 gallons and a hang on tank magnum with biowheel attachment. They ate blackworms (when I could get them) chopped troutworms and occasional feeders. On the recommendation of several members, I tried letting krill, clam, and prawn soak with the chopped worms to entice the rays to eat, but they showed no interest for the first 3 months or so. Eventually they both began eating clam enthusiastically but were hesitant about anything else. Temps were kept at 84-86 the first few months and I added a 1/2 dose of aquarium salt with every water change. Sometime around March (?) I upgraded to a 90 gallon tank for the rays with the same filtration plus and AC110. The move went very smoothly and they seemed happier with more room to move around in.
With the larger tank, I began to experiment with less frequent water changes (to no ill effect on the rays) and found my nitrates rarely rose above 15-20ppm with one 50% change done every week or 10 days. Sometime in March or early April I purchased what turned out to be a humerosa/orbignyi brown ray just a little larger than the larger of the retics, and this turned out to be a disaster (see my other thread about retics and tankmates for details). The presence of a larger, more aggressive and active ray stressed out the smaller of the two retics and he stopped eating and died of complications of a massive fungal infection soon after.
At this point, I realized I had to separate the two rays, so I set up a 125 and transfered the surviving retic into it. For several days it did not look good, but he pulled through and is now thriving. The 125 has a sand bottom (estes special #0) and I think the ability to bury himself has really helped this ray de-stress (for lack of a better term) during the transfer. Once I was sure he was in good shape, I picked up another male retic in trade and the presence of another retic has definitely made the first one more active and considerably less shy in the big tank. After 1 year, he has grown significantly, but nowhere near the rate at which a motoro would put on size. His claspers are still tiny, so I wonder at what size and how long it will take for him to mature.
Sorry for the long post, I just though a year long summary of keeping retics may be helpful for some. I would like to ask again about whether the first ray I have is some strange morph of retic. I had posted pics of him when I first got him, but the flash made him seem a lot lighter than he is, and everyone assured me he was just a normal retic. Now he has become even darker, and much bulkier, and I wonder if anyone has ever seen any retic like him before. His underside looks more like a black ray and his tail lacks the small spines all the other retics I have seen have had. Anyways, thanks for any info and feel free to post any questions.