These live marine Brachionus plicatilis rotifers are approx. 1/3rd of the size of newly hatched brineshrimp and have been reared on live phytoplankton for maximum nutritional value. These rotifers are harvested prior to shipping and may be stored in the fridge and then decanted to feed to your fry; use within 1 week. The rotifers are being cultured at a salinity of 20-22ppt. Already in use by customers rearing seahorses, clownfish, and corals. May also be used for freshwater fish species and amphibians requiring small live feed.