Combination of agriculture fertilizer for intermediate cultivation of isolate Nannochloropsis sp. of the waters of Lampung Mangrove Center as live feed

The availability of microalgae(phytoplankton) has an important role in aquaculture.Nannochloropsissp.is amicroalgaethatcanbeusedasthelivefeedfor larvaecultivation ofshrimp, fish and shellfish. In this study,a Nannochloropsissp.isolate obtained fromLampung Mangrove Center waters was cultured by using combination of agriculturalfertilizerasasubstitute forproanalyze fertilizer(Conway). The aimsofthisresearchweretoinvestigatethecelldensity (cell/L),thegrowth rateofcell,and doubling timeofisolatesNannochloropsissp.from thewaters ofLampungMangroveCenter,whichwereculturedintermediately withthe volumeof100L. Thisresearchwasdesigned using completely randomized design (CRD),with 5 treatmentsof agriculturalfertilizer consisted of A:Urea 40,ZA 20,TSP5 ppm,B:Urea40,ZA20,TSP10ppm,C: Urea40,ZA20,TSP15 ppm, D: Urea40,ZA20,TSP20ppm,andE:Conway andvitaminB121ppm (control),with4replications. Theresultsshowedthatt h e treatment of A producedthe highestcell density andthefastestgrowthrate(p<0.050)comparedwiththeothers. Inaddition,thetreatmentofAshowedthefastest doublingtimesignificantly (p<0.050)toB,D,andEtreatments,butitisnot in significantdifferencewiththe treatmentof C(p=0.065).It was concluded that the combinationof the agriculturalfertilizertreatmentAwasthe bestforgrowthrateof Nannochloropsissp.in intermediateculture.