EVALUATION OF AGROINDUSTRIAL WASTES AS DIETS FOR CULTURE OF THE FAIRYSHRIMP STREPTOCEPHALUS-PROBOSCIDEUS (FRAUENFELD, 1873) (CRUSTACEA, BRANCHIOPODA, ANOSTRACA)

Two micronized waste products were evaluated in a closed recirculation system for their suitability to replace a costly diet of live algae i n the culture of the Sudanese fairy shrimp, Streptocephalus proboscide us. The test population was kept at a density of 50 individuals l(-1) (sex ratio: 1/1). An agricultural waste product (YM20; mixture of pea and corn), and an industrial waste product (POME; Palm Oil Mill Efflue nt) were fed at two regimes: 0.1 and 0.2 mg DW animal(-1) h(-1). The m icroalga Selenastrum capricornutum, used as a reference diet at a dens ity of 2.0+/-0.82 x 10(5) cells ml(-1), proved adequate in preliminary screening experiments. The effect of the diets and feeding regimes on selected biological variables and water quality were followed by week ly observations and measurements. Results in terms of growth (= increa se in length), cyst production, and mortality were more successful whe n animals were supplied high densities of YM20 than in all other treat ments: mean brood size was 155+/-6 cysts with a maximum of 266. Length after 6 weeks was about 2 cm while this ranged between 1.4-1.7 cm for the other treatments. Weekly mortality rate was comparable under high food conditions. Mortality rate gradually increased from 5% in the fi rst week to 15% in the last week. Water quality, especially nitrite co ncentration (measured as NO2-N), was slightly better in the dry food f ed than in the algae fed cultures. Present results are promising for l arge-scale culturing of S. proboscideus in a cost-effective way by mak ing use of agro-industrial waste products.