The effect of management protocols for juvenile carp (Cyprinus carpio) culture on life history responses of a zooplankton food source, Moina micrura (Kurz.)

Three systems of carp (Cyprinus carpio) culture (live food system, manured system, and control system) were used to examine environmentally dependent life history characteristics of zooplankton, Moina micrura. Twelve culture tubes with one neonate of M. micrura per tube and covered by nylon bolting cloth of 75 μm mesh size were suspended in situ in each culture system. Each culture tube was examined daily to evaluate life history patterns. Time to first reproduction ranged from 4 to 7 days in the control and manured systems and 3 to 5 days in the live food system. Mean longevity, net reproductive rate, average generation time, as well as total offspring production per female, were distinctly higher for the live food system than for the manured or control systems. Interactions between chemical oxygen demand, dissolved oxygen, phosphate levels and primary productivity resulting in optimal conditions were responsible for large variations in life history characteristics of M. micrura among the culture systems.