These steps will guide you towards the preparation of artificial culture water (ACW) for your rotifer culture.

• Prepare enough DI water in recipient tank with a lid

• Add the sea salt (i.e. Instant Ocean®) to the DI water to reach the desired salinity.

RQ : B. plicatilis can maintain reproduction at salinities from about 3–50 ppt (parts per thousand; seawater is ≈35 ppt). Optima for various strains have been reported from 10–20 ppt. For use with zebrafish, it is advantageous to culture the rotifers at lower salinity (≈10–15 ppt); this pre-acclimation reduces the osmotic stress when rotifers are transferred to zebrafish cultures, so their swimming and feeding are not impaired. 824 g of Instant Ocean®_ sea salts, or 682 g NaCl (equivalent osmolarity), and 34 g sodium bicarbonate are needed to reach a 15 ppt salinity

• Setup an aquarium heater (i.e. Eheim®) in the tank to adjust the temperature as desired.

• Stir vigorously overnight with an air pump (i.e. Eheim®) and/or a water pump (i.e. Eheim®).

• If necessary, readjust the temperature and the salinity with DI water or salts. Check the salinity with a refractometer (i.e. Toledo®) or whatever accurate instrument.

• The ACW is ready to use !

Sources and references

• C.Lawrence et al., Zebrafish, vol 9 (3), 2012. Methods for Culturing Saltwater Rotifers (Brachionus plicatilis) for Rearing Larval Zebrafish

• http://reedmariculture.com/index.php