Cyclops are free living forms found everywhere there is water, in damp leaf litter on the ground, ponds, ditches of stagnant water, streams and rivers. They feed on plankton and other small aquatic organisms. The life cycle is adapted to their natural habitat in ponds and other accumulations of stagnant water. Fresh water copepods may act as a biological control for malaria by consuming mosquito larvae.2 They also serve as intermediate hosts of many animal parasites and parasites of humans. Copepods are worldwide distributed. In Africa, freshwater copepods have been described in Mali by 14. In the life cycle of Spirometra species copepod of the genus Cyclops is the first intermediate host. For experimental work in the laboratory, Cyclops can be cultured by using different methods. 3 cultured copepod Eucyclopsserrulatus using Chilomonas paramecium, wheat infusion and pre-boiled wheat grain as food. The adult female egg sacked Cyclops was used. In order Cyclops to survive under laboratory conditions the adult Cyclops and nauplius have to be fed Paramecium 1970; 5611. In Tanzania there is no records showing a study on culture of Cyclops. In the present study, culture of Cyclops started with an adult female single egg sac bearing which was fed Paramecium as food. Therefore, this paper reports how Cyclops were cultured in the Tanzanian laboratory from an adult female egg sacked Cyclops fed with live Paramecium and stock of Cyclops used in the experiment of life cycle of Spirometra species.

After 7 days of culture there was a swarm of Paramecium around pre-boiled wheat grains in Petri dish.

Growth of Cyclops cultured in Petri dishes had an average time of, egg sac to nauplius I was 1.2 days, while from nauplius I to copepodite I was 6.9 days. The time taken from nauplius I to adult female egg sac bearing was 26.3 days. The average measurements of nauplius I were 120.2 µm in nlength and 80.0 µm in width while the adult female measurements were 846.3 µm in length and 284.6 µm in width.The number of broods produced by an adult female was 1 to 8 (mean, 4.3) and the life span of Cyclops in this experiment was 43.1 days.

In the present study, the results shows that Cyclops were successfully cultured in the laboratory using Paramecium as food. Paramecium alone. Paramecium supported the whole life cycle of Cyclops. In previous studies copepods were maintained in the laboratory by using different methods. 7 cultured copepods in the laboratory which were used in the experiment of life-cycle of Spirometramansonoides. Cyclops were fed microorganisms (molds, bacteria, euglenoid and small ciliates) that developed in hay infusion. 9 cultured copepod by feeding Chlorella to nauplii and early copepodite stages, zooplankton containing rotifers and paramecia were fed to copepodite and adults. 4 cultured Cyclops abyssorum by feeding Euglena gracilis and Artemia.10 cultured Cyclops visinus by feeding pure algal diet (Chlamydomonas reinhardti or Cryptomonas sp.). 1 reported that Cyclops require not only green algae but also large organisms such as ciliates and rotifers as food to complete the whole life cycle. The present study agrees with previous studies that Paramecium acan be used as a source of food for Cyclops. In this study, the optimal temperature of the culture of the Cyclops was 26° to 29ºC. Many studies have been done in temperate regions where the temperature range was 10° to 20°C. The difference in temperature has not affected the development of Cyclops. In the present study, the time for development was shorter than the time in lower temperatures. This agrees with the study done by 5 who reported that the time for development of Cyclops at lower temperature is longer than at higher temperature. 813 reported the average period from egg to egg bearing adult female was 29.4 and 30.7 days respectively. These results could be due to the effect of temperature.

Laboratory maintenance of Cyclops can be achieved by using Paramecium as the source of food. The method is simple because the food organism Paramecium proliferates in the Cyclops culture and supports a rapid growth and reproduction of the Cyclops. Cyclops is maintained with minimum care because a stable and equilibrium state of micro-ecosystem is established in the Petri dish. This culture method can be used in the study of Spirometra life-cycle in which Cyclops serve as the first intermediate host. However, another study is needed for the identification of Cyclops which exist in Tanzania.