Paper Title
Impact of Fertilizers on Mass Production of Zooplankton To Use as a Substitute of Artimia For Larvae Rearing of Prawn and Shrimp

Abstract
Zooplankton specially Rotifers and Moina are valuable live food for prawn, shrimp and fish larvae culture. Generally Artimianaupli are used as live food for larvae culture but it is very much expensive. So Rotifer and Moina can use as low cost food for larvae culture. Mass zooplankton production by using different fertilizers in pond can provide sufficient amount of low cost live food for larvae culture. Impact of fertilizer on mass production of zooplankton in pond was studied for three months in Patuakhali Science and Technology University campus, Patuakhali, Bangladesh. Twelve ponds were selected for four treatments with three replications. Different combinations of fertilizers were used for mass zooplankton production under different treatments. In Treatment-1 decomposed cow manure2000 kg, urea 150 kg, and Triple Supper Phosphate (TSP) 75kg/ha, in Treatment-2, decomposed cow manure2000 kg, urea 150 kg, TSP 75 kg and Mustard Oil Cake 250 kg/ha, Treatment-3,decomposed cow manure 2000 kg, urea 150 kg, TSP 75 kg, Mustard Oil Cake 250 kg/ha and poultry manure1000 kg/ha were used to produce zooplankton and Treatment-4 (T4) was control treatment without any fertilizer. Table: Plankton concentrationof different treatments in 1 ml of water Plankton T1 T2 T3 T4 Cyclops 50�07 b 87�12 a nil 05�0.5 c Rotifer 143�25 c 190�28 b 250�34 a 23�04 d Moina 187�11 c 256�21 b 325�43 a 46�03 d Other Zooplankton 45�06 c 98�07 b 124�10 a 08�.03 d Phytoplankton 456�56 c 570�72 b 980�86 a 89�12 d The experiment showed that significantly higher(P<0.05) amount of Rotifer and Moina are produced in T3which are most suitable as larval food. Higher amount (P<0.05) of Cyclops are produce T1and T2but in T3all cyclops were died due toeutrophication which are harmful predator of larvae.InT3,the great amount of nutrients stimulates algae growth and lead to green algae blooms. Under these conditions, copepods cannot survive longer and are ultimately eliminated from the waters. But rotifers and Moina has higher ability to tolerate eutrophication than copepods. This research revealed that high amount of fertilizers (T3) produced higher amounts of Rotifera and Moina which can be used as an alternative food of Artemia in shrimp and prawn hatchery. Keywords - Fertilizer, Zooplankton, Mass production