First steps towards mass rearing of European smelt (Osmerus eperlanus, L.) using conventional hatchery equipment

Anadromous European smelt (Osmerus eperlanus) is a keystone species in lake and river ecosystems. In the past and present, stock declines in several of its habitats have been reported. The reasons for this are unclear. Experimental research on the early life stages could help to reveal the potential causes. For this purpose, knowledge on artificial propagation and rearing of early life stages is needed. Following from previous work, we show how to scale up and mass rear European smelt using conventional hatchery equipment and present a simplified protocol for first feeding. Smelt eggs, after egg adhesiveness is removed, can be incubated in standard hatchery equipment commonly used in aquaculture. Incubation in McDonald-type jars shows even improved results when settling of floating eggs is prevented. Next to avoiding egg loss this simultaneously reduces labor for daily care. First feeding of larval smelt can be achieved with decapsulated artemia cysts, eliminating the need for the labor-intensive green water production. Using the protocol presented, larvae of different stages can be produced in large quantities allowing further experimental studies.