Rapid growth of the brine shrimp, Artemia franciscana Kellogg, in xenic cultures of Chlorella sp. (Chlorophyceae)

Abstract

A simple, quick, low-maintenance means to culture brine shrimp to adults is described. Continuously illuminated, organically enriched 1.5-l bacterialized (xenic) cultures dominated by a small Chlorella sp. MWB at a density of > 1 × 10 7 cells/ml were inoculated with brine shrimp cysts and aerated for 24 h. Cyst hatching was followed by rapid growth of nauplii to preadults. Copulating adults appeared as early as 8 days. In cultures aerated for only about 1 min/day, final mixtures of preadults and adults had a mean size range of 6–8 mm, in densities of 0.26–2.18/ml ( x = 1.3 ml ) in 11–16 days. With continuous aeration, a mixture of preadults and adults with a mean size of 7.0 mm (with riders) was obtained in 9 days at a density of 0.34/ml, and a mean size of 10.4 mm in 13 days at a density of 0.55/ml. The final Chlorella densities of cultures aerated for only about 1 min/day, or continuously, were similar to or greater than initial densities and reached as high as 5 × 10 8 cells/ml. Experiments suggest that resuspension of bottom fertilizer and sediments of cultures, by aeration or by mechanical stirring, are ways in which dissolved oxygen can be rapidly lowered and the brine shrimp fatally stressed. The strategy of growing food for brine shrimp with the brine shrimp, the community culture concept, is thus demonstrated. Advantages include: no food addition during growth; no separate biological filtration; no removal of brine shrimp feces or exuviae; no additions to cultures during growth except water to make up for evaporation.