NUTRITIONAL REQUIREMENTS OF THE WATER FLEA MOINA MACROCOPA

¹ Bodega Marine Laboratory, University of California, P.O. Box 247, Bodega Bay, California 94923
² Haskins Labs, Biology Department, Yale University, New Haven, Connecticut 06520

1. Moina macrocopa was cultured aseptically for more than 200 parthogenetic generations in a nearly-defined medium without losing fertility.

2. A biphasic medium was used. The liquid phase supplied minerals, B-vitamins, amino acids, liver infusion and nucleic acids. The fine particulate phase consisted of egg albumin, albumin fraction V, starch and lipid factors.

3. The particulate phase was essential for rapid growth, taking advantage of the food gathering efficiency of filter feeders.

4. Developmental time, brood size and sustained fertility depended on calciferol, tocopherol and saturated and unsaturated fatty acids; B carotene or retinol favored fertility but might not be essential.

5. Moina was found to require cholesterol, nucleic caids, thiamine, nicotinamide, pyridoxine, Ca pantothenate and probably riboflavin and folic acid in the presence of liver infusion, the only undefined and required component of the medium.

6. Ratios and quantities of the nutrients were important for media efficiency: excess vitamins could be inhibitory and the best starch/protein ratio was in the range of 1.5:1 to 0.5:1.

7. The requirements of Moina were compared with the range of requirements of arthropods and found to be similar to the nutritional patterns of phytophagous insects.