Cultivation success and fatty acid composition of the tropical copepods Apocyclops royi and Pseudodiaptomus annandalei fed on monospecific diets with varying PUFA profiles

Large-scale copepod production is limited by high-complexity production of microalgae with high contents of polyunsaturated fatty acids (PUFA). However, the tropical A. royi and P. annandalei show great promise of being cultivable on diets with less PUFA content while maintaining both population density and adequate fatty acid (FA) profiles. This ability was investigated through analysis of population density, development stage composition and FA compositions when fed diets of varying FA profiles: the microalgae Dunaliella tertiolecta and Rhodomonas salina, and baker's yeast, Saccharomyces cerevisiae. For A. royi, the population density (>1,600 L−1) did not differ significantly when fed these food items, nor did the relative content of the essential FA, docosahexaenoic acid (C22:6n-3, DHA), >28% of total FA (p < .05). P. annandalei did not reproduce when fed S. cerevisiae, but population density (>300 L−1) and DHA content (30%–60% DHA of total FA) did not differ significantly when fed D. tertiolecta and R. salina (p < .05). Eicosapentaenoic acid (C20:5n-3, EPA) content of both copepods differed dependent on the diet, but the resulting DHA:EPA ratio were >2, the optimal for live feed for fish larvae. These findings demonstrate possibilities of utilizing A. royi and P. annandalei in intensive aquaculture, exploiting cheaper diet alternatives, and possibly reducing total production cost and complexity.