Zooplankton Production in the Presence of Different Manures in Culture System

Abstract

Feeding of fish with artemia involves a lot of financial investment and it is therefore essential to source for a cheap and yet adequate source of production of life food for fish. This research compares the effects of different organic manures on zooplankton production in culture systems. The manures used were Poultry droppings, Cow dung, Cassava peels and a Control (without manure) and were added into the culture systems at the rate of 57 mg dm-3 of water. The research was carried out for a period of twelve weeks after then identification and counting of species of zooplankton was done by taking 1ml/day from culture systems and water quality parameters in each culture system was also determined once daily. Zooplankton observed were Filinia sp. and Brachionus sp. belonging to Rotifera, Moina sp. and Daphnia sp. belonging to Cladocera and Cyclopods belonging to Copepoda. Moina sp. accounted for 11751 out of the total abundance of zooplankton irrespective of culture system while Daphnia sp. accounted for 11683, Cyclopods 7332, Filinia sp. 5594 and the least was Brachionus sp. accounting for 5230 total zooplankton. Poultry droppings stimulated the highest production having a total of 18908 zooplankton, followed by Cow dung (11845), Cassava peels (9505) and the least was from the Control (1332). The mean values for temperature were 27.4°C for poultry droppings, 27.1°C for Cow dung, 27°C for Cassava peels and 27.3°C for the Control. pH recorded 7.5 for Poultry droppings, 7.0 for Cow dung, Cassava peels 6.9 and 7.1 for the Control. Dissolved oxygen was 5.0 mg dm-3 throughout the culture systems. Ammonia recorded 0.9 mg dm-3 for Poultry droppings, 0.4 mg dm-3 for Cow dung, 0.0 mg dm-3 was recorded for Cassava peels and Control. Nitrite was 3.5 mg dm-3 for Poultry droppings, 0.25 mg dm-3 in Cow dung, 0.5 mg dm-3 in Cassava peels and 0.1 mg dm-3 in Control. Nitrate was 80 mg dm-3 for Poultry droppings, Cow dung was 22.5 mg dm-3, 25.0 mg dm-3 was Cassava peels while 12.5 mg dm-3 was the Control. ANOVA results showed significant relationship (P<0.05) between the number of zooplankton produced in relation to the various types of Manures applied. In conclusion, Poultry droppings gave the best result and Cassava peels can also serve as an option in areas where poultry droppings are in short supply. The Control gave the poorest result and this clearly indicates that fertilization is essential in culture systems.