Hi jaefei,
In my observations, P. dam, like many SPS can easily assimilate Artemia. And from the experiment, it is fairly conclusive. Your question about the effectiveness between artemia adn rotifers is a good one, and something that needs to be conducted. We know that corals can consume a variety of food items. The level of understanding needs to be raised a bar where we can qualify particular items as being 'better' than another. And when I say better, it is not just in producing better or faster groth rates, but economical as well. Although I did not spend a lot of time talknig about the economics, it was a very important part of the reasons behind the experiment. Rotifers, like artemia incur high production costs. We have a full-time nutritionist at the hatchery whose specific job is to culture phytoplankton, artemia and rotifers for the shrimp. His salary must be taken into account when calculating the total rearing costs for the shrimp. This is similar for corals. Therefore, a reduction in those types of costs are significant. If rotifers are able to produce significantly higher growth rates for corals than artemia, but cost the same to culture, then we have a winner. If, for example, they are comparable to artemia, but cost less to culture, then we have a winner. If they cannot match artemia in their ability to promote faster growth rates, but cost less, then the survival rates of the corals and the amount of time invested into growing them to marketable sizes must be taken into consideration. See, it can be complicated when dealing with this issue on a commercial scale. But, with proper scientific studies, this question, and others can be answered so that informed decisions to be made.