LACTATE DEHYDROGENASE ACTIVITY AND ANAEROBIC METABOLISM DURING EMBRYONIC DEVELOPMENT IN ARTEMIA SALINA

1. 1. When incubated aerobically, encysted gastrulae of the brine shrimp, Artemia salina, utilize trehalose and synthesize glycogen and glycerol during pre-emergence development; anaerobiosis prevents those changes and does not result in the accumulation of lactic acid. 2. 2. Under aerobic conditions newly hatched nauplii (larvae) appear to conserve glycogen by utilizing glycerol. When made anaerobic they utilize glycogen, not glycerol, and accumulate large concentrations of lactic acid. 3. 3. Under anaerobic conditions the nauplii lose motility within the first 2 hr and die in less than 12 hr. In contrast, encysted embryos are not killed by prolonged anaerobiosis. 4. 4. Lactic acid dehydrogenase (LDH) activity remains constant at a low level during pre-emergence development but increases markedly during emergence and hatching. 5. 5. This increase in LDH activity is correlated with the onset of lactic acid production in response to anaerobiosis and with the emergence of the embryos and their subsequent transformation into nauplii. © 1969.