NUTRITIONAL REQUIREMENTS OF THE WATER FLEAMOINA MACROCOPA

Abstract

M. macrocopa was cultured aseptically for > 200 parthenogenetic generations in a nearly defined biphasic medium without losing fertility. 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; the particulate phase was essential for rapid growth. Developmental time, brood size and sustained fertility depended on calciferol, tocopherol and saturated and unsaturated fatty acids; .beta.-carotene or retinol favored fertility but might not be essential. Moina required cholesterol, nucleic acids, thiamine, nicotinamide, pyridoxine, Ca pantothenate and probably riboflavin and folic acid in the presence of liver infusion, the only undefined but required component of the medium. Ratios and quantities of the nutrients were important; excess vitamins could be inhibitory, and the best starch/protein ratio was 1.5:1-0.5:1. The requirements of Moina were similar to the nutritional patterns of phytophagous insects.