Rotifer resting eggs: An alternative for rotifer mass cultures in fish farms – Lessons from a comprehensive study on production, storage and hatching of resting eggs

Rotifers of the Brachionus plicatilis complex species serve as the first live food for marine fish larvae. The essential daily supply of rotifers depends on a successful culture of billions of rotifers, as there are no current alternatives for this live food in the large scale production of farmed fish. This problem is not faced with Artemia, the second source of live food, as they are supplied as cysts and hatched according to demand. Rotifers produce resting eggs (RE) that can be stored for long periods of time and hatched when needed, but their use in aquaculture is limited, despite great advantages. Unlike Artemia cysts which are harvested from natural sources or salt works, rotifer RE originate from cultures. A systematic and comprehensive study was carried out to identify the main factors affecting RE production, storage and hatching, with the aim of increasing the efficiency and reducing the costs of production, thus facilitating their wider use in hatcheries.