Evaluation of agro-industrial wastes as diets for culture of the fairy shrimpStreptocephalus proboscideus (Frauenfeld, 1873) (Crustacea:Branchiopoda:Anostraca)

Abstract

Two micronized waste products were evaluated in a closed recirculation system for their suitability to replace a costly die of live algae in the culture of the Sudanese fairy shrimp,Streptocephalus proboscideus. The test population was kept at a density of 50 individuals 1⁻¹ (sex ratio:1/1). An agricultural waste product (YM20; mixture of pea and corn), and an industrial waste product (POME; Palm Oil Mill Effluent) were fed at two regimes: 0.1 and 0.2mg DW animal⁻¹ h⁻¹. The microalgaSelenastrum capricornutum, used as a reference diet at a density of 2.0±0.82 × 10⁵ 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 weekly observations and measurements. Results in terms of growth (=increase in length), cyst production, and mortality were more successful when animals were supplied high densities of YM20 than in all other treatments: mean brood size was 155±6 cysts with a maximum of 266. Length after 6 weeks about 2 cm while this ranged between1.4–1.7 cm for the other treatments. Weekly mortality rate was comparable under high food conditions. Mortality rate gradually increased from 5% in the first week to 15% in the last week. Water quality, especially nitriate concentration (measured as NO₂-N), was slightly better in the dry food fed than in the algae fed cultures. Present results are promising for large-scale culturing ofS. proboscideus in a cost-effective way by making use of agro-industrial waste products.