Potential use of the astaxanthin-producing microalga, <Emphasis Type="Italic">Monoraphidium</Emphasis> sp. GK12, as a functional aquafeed for prawns

We determined the nutritional profile of Monoraphidium sp. GK12, a newly isolated astaxanthin (AXA)-producing microalga, and investigated its potential use as a functional aquafeed by evaluating its effect on prawn pigmentation. GK12 contained high levels of pantothenic acid. The β-carotene content of GK12 was higher than that of Haematococcus, a well-studied AXA producer, and was similar to that of Spirulina. GK12 also had a high content of unsaturated fatty acids, of which linolenic acid (C18:3 n−3) was the most plentiful. A GK12-containing feed resulted in significant pigmentation of the prawns, comparable to that of prawns fed on synthetic AXA or Haematococcus. A GK12-containing feed also increased the survival rate of the prawns. Therefore, in addition to improving cultivation methods for Haematococcus, further research is needed into the use of GK12 as an alternative AXA source and as an ingredient of functional aquafeed for farmed fish.