Dataset: Sterols and Acartia egg production

Phytosterols were synthesized by J. Giner. Rhodomonas cultures were labeled by dissolving sterols in 100% ethanol at a concentration of 2 mg/ml, and then adding the sterol solution at a concentration of 20 µl sterol solution per 100 ml stock culture (at stock density 1x106 cells/liter). The cultures were mixed on a LabGenius orbital shaker for 2 hr at 100 rpm to allow the sterols to bind to the algal surfaces. In vivo chlorophyll a was monitored with a Turner handheld fluorometer to ensure that all food was consumed before the subsequent feeding. This avoided the problem of algal growth diluting the phytosterol concentration over time.

Acartia tonsa were supplied by AlgaGen Inc, Florida. A. tonsa were acclimated for 5 d to a diet of Rhodomonas supplemented with phytosterols. After the acclimation period females were removed and placed in 50 ml Petri dishes. After 24 h females were again removed by pipet, eggs were counted, and the eggs were left for 48h and the number of nauplii counted to determine egg viability. Two experiments were conducted, with the first experiment at low food (≈12,000 cells/ml) and the second at high food (≈25,000 cells/ml). 3 phytosterols were used in both experiments.