Just in case you haven't bought the Otos yet, the most important thing to look for when you see them in the LFS is that they are fairly plump. Ask the assistant how long they've been in stock and if they are eating yet; they can take a while to start eating after their very long journey to this country. If you can find Otos that are fairly plump and are eating, you should have much less chance of any losses. Take a little longer to acclimatise them, too, just to be extra cautious. I bought five around two years ago, but they were fat when I bought them and they're still going strong.