Temperature and larval development of Carcinus maenas (Decapoda) in the laboratory; predictions of larval dynamics in the sea

Larvae of Carcinus maenas (L.) (Decapoda, Brachyura, Portunidae) were reared in the laboratory from hatching to metamorphosis.Developmental times of subsequent stages at d~fferent constant temperatures (6, 12, 12.5.18. 25°C) were recorded.Temperature-dependent development of each larval stage can be expressed by a power function.A model is presented which combines these results with the long-term mean temperature curve of Helgoland waters (North Sea).Hence prediction is possible of occurrence and presence of C. maenas larvae in the natural environment relative to their hatching date.On the basis of main hatching activities in nature, qualitative larval dynamics in Helgoland waters are discussed.To test the usefulness of the model, C. maenas larvae were reared in the laboratory from hatching to metamorphosis under simulated varying in situ temperatures.Results of this experiment correspond very well with model predictions.