I got this Info over at the asian arowana website. Credit goes to Tom32 for writing this up. I just thought I would post this since breeding is becoming more popular. 1. Usual cause of pup casualty - Sudden change of environment o Water temperature o Water parameter ph/condition - Attack by bigger fishes o Usually due to over-crowding tank o Just birth when pups are struggling to stable down - Not eating o Usually cause by shock/stress o Moving out the pup to early / rush o Wrong feeding o Premature birth / pup too small - Bacterial attack o Usually due to poor water condition o Stagnant water location in tank/pond o From live feeders 2. Care of pups - Transfer of pups from birth place to new tank. a. During the first 30 minutes after birth, pups are usually unstable. Initially they may be up side down and struggling to balance and swim. For me, I will usually remove my pups from birth place only after 4 hours. b. Try not to expose pups to air during catching and transferring. Move them into a small bucket of plastic bag in the water. Try not to scoop them out of the water and exposing them to the air. c. Before transferring them to new tank, it is best if the same water can be used. If this is not possible, water in the new tank should be aged and not just fresh tap water. 50% / 50% mixed of existing and new aged water also can. I prefer 50/50 to using 100% pond water or a ready set long aside tank with prepared clean water. Best is water ph is closed to birth water. d. Introducing the pups into the new environment must be slow and steady. Some brothers are using dripping method. For me, I would use shallow bucket with 100% birth water and a tiny air stone one bucket 1 pup. Then I use a tea cup to add new water into the bucket at every 30 minutes for 4 hours. Every per adding is 2 cups. After this, I tilt the bucket and allow the pup to slowly get out of the bucket and happily swim toward the new home. e. Observe the pup, they will stay still for a short while and then after it starts to move. - The initial 3 days a. Water condition Ensure that there is enough aeration in the tank Water volume must be large enough i suggest at least a 3 ft tank with a over kill filtering system over kill does not mean a huge pump hor big filter tank with many good filtering mediums and plant if possible. Too strong current is no good. WC must be not more than 20% but with WC every day. Best is age water, if not possible than use tap water but filling must be slow with adding of anti stress coat. b. Feed I would suggest soft and tiny food like tubiflex or frozen blood worm. I prefer frozen blood worm because it is clean and less chance of bacteria contamination. Observe they intake, start with 1 to 2 cubes first. Do not over feed more than they can take in. Left over feed in water will only foul the water and cause harm to the pups. Usually pups will not eat for the first 2 days. But I do see some of my pups start eating on the 2nd day. c. Protection You should cover your tank to avoid bird [especially kingfisher] to disturb or attack the pup when it is surfacing. This is more so if your tank is housed outside your house. If you are mixing the pups with other bigger fishes, try to put some drift wood for them to hide when they are stressed. Try to avoid having sands/gravels in your tank. It will make cleaning difficult. Also disturbing of sand beds will cause bacteria attack to pups. Sharp objects in tank are strongly not recommended. Gaps and dead corners are dangerous make sure that the gap of the overflow chamber in your tank will not trap your pups especially those that are smaller than 3. Water level should not be filled right to the top, keep at least 3 below. Never try to throw in big amount of live feeders or tubiflex worms. Unconsumed feeders will tend to bite the skin surface of the pups. Leftover tubiflex will foul the water. - The next 21 days. It is easily to convert pups to eating mp if it is captive breed with parents eating MP. The next 21 days. Feeding It is easily to convert pups to eating mp if it is captive breed with parents eating MP. Once pups are eating, it is good time to convert them. I usually feed my pups 4 times a day at 4 hours interval. 1st feed 08.00, 2nd feed 12.00, 3rd - feed 16.00 and 4th feed 20.00. Best timing to introduce them MP is during the first feed in the morning. As you can observe that the last feeding timing is 20.00 hrs, pups have to wait for another 12 hrs before the 1st feed starts again. So, usually at this time, they are at the most hungry condition. Observe which pup is eating and which is not. It may take 2 to 3 weeks to get them all eating mp. The starting sign of them accepting mp is when they start chewing them. Once they are eating, start feeding them with only MP for every meal for at least a month before you start to treat them with live feeds once in a while. You will be surprised to note that pups on only mp can grow very well and fast. Try to throw in a little more mp at the last feeds. Unconsumed mp will be usually cleaned up by them during the night. Pups/rays tend to look for food during the dark. If your pups are not eating, try to switch off the lightings. Hikari sinking pellet is another good source of food. Water WC frequency can now be reduced to once or twice a week. Amount can now be increased to 30% to 50% but filling rate should remain slow with anti stress coat for direct tap water. Of course, you can continue to do 7 days a week if you have the time. Once pups are eating and stay pass through 21 days, they should be stable already. The killing part after this period is usually due to poor water or bacteria from live feeders. Good filtering system , regular WC and feeding clean foods are key factors to keep your ray alive. If you are feeding live feeders, try to quarantine the feeders or at least get them from reliable source. For me, I would avoid gold fish or baby koi. Protection Try to install a DC/AC air pump and keep a spare filter pump at home. A sudden failure with your filter and air pump can cause a great damage to your rays in tank and your pocket. Introducing of new fishes into the tank is another possible cause of casualty. Wild caught rays and other fishes can be dangerous if they carried with them some harmful parasites. Avoid wrongful use of medication. Using of Melafix and a little dissolved salt is alright for treatment. Remove the loose sting dropped by the ray in the tank whenever possible. And to the rays owners, beware not to be stung by the stinger ..it is very painful you must respect the STINGY thing on the rays tail. The thorough explainations in the attachments by TOM32 are informations that can't be found easily. Most raykeepers used to overlook on the 2 points as below; 1. During the first 30 minutes after birth, pups are usually unstable. Initially they may be up side down and struggling to balance and swim. For me, I will usually remove my pups from birth place only after 4 hours. 2. Try not to expose pups to air during catching and transferring. Move them into a small bucket of plastic bag in the water. Try not to scoop them out of the water and exposing them to the air I guess if anybody else has anything else to add feel free. Thanks!!!!!