Effects of temperature on the moulting and locomotory activity of hatchery-reared juvenile lobsters (Homarus gammarus) at Helgoland (North Sea)

Abstract

Optimized release conditions of hatchery-reared juvenile lobster (Homarus gammarus) can reduce loss in the field. The effect of seasonal temperature on the behavioural and physiological activity of lobsters was examined, observing the timing of moulting and locomotory activity in juvenile lobsters maintained at increasing temperatures under standardized laboratory conditions. The juveniles of three different year and size classes mostly moulted when a threshold temperature between 12 and 14°C was reached. In addition, the locomotory activity of lobsters showed significant responses to seasonal temperatures between 12 and 15°C in the dark-phase. The knowledge about the temperature-dependent activity of lobsters may be helpful to explain behaviour in the field and in assessing the chances of a future large-scale stock enhancement programme.

Keywords:

• Homarus gammarus
• locomotory activity
• moulting activity
• temperature

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Acknowledgements

This study was supported by the Ministry of Fisheries and Agriculture of the State of Schleswig-Holstein, Germany. Thanks are due to local fishermen for capture and delivery of ovigerous females and to Michael Janke for technical support in keeping of the lobsters. We are also grateful to many hands for help to maintain juvenile lobsters, who worked as temporary voluntaries within our project, partly in fulfilment of their Voluntary Ecological Year.

Notes

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark