Rotifer Resting Eggs (Cysts) Startup Guide

To initiate rotifer cultures from diapausing egg inocula start a 1–100 l culture of live microalgae  grown to a density of about 105–106 cells/ml.

Many algae species are suitable, including Tetraselmis, Nannochloropsis, Chlorella, Isochrysis, and Dunaliella, grown at temperatures of 15–32C and salinities of 15–35 psu.

Place Approximately 100 rotifer diapausing eggs/l into the algae culture and expect hatching in about 24 h.

Note:  B. rotundiformis cysts take at least 48 h to hatch at 25°C. Longer if incubated at lower temperatures. Also, salinities higher than 15 ppt can slow hatching. Keep checking the hatching dish for several days until hatching is observed.

Light is important, so hatching should occur under fluorescent or LED lights.

Diapausing egg hatchlings initiate rapid asexual reproduction and soon enter into log phase population growth.

After about 1 week, depending on temperature, the culture will contain a dense population of rotifers, free of contaminants, that is suitable for inoculating mass culture production tanks.