From March till October 1979 the food consumption of the shrimp (Crangon crangon L.) in the Dutch Wadden Sea has been investigated. The relationship between daily ration (DR) and weight (W) was determined: DR=O,13580W0,5941; DR=mg ashfree dryweight (AVD) , W=weight of the shrimp in mg AVD. From data on respiration (R), excretion and faeces (U+F) and consumption (C),delta B was estimated according to delta B=C-R-(U+F). The mean growth of juvenile shrimp (7,5mm -32,5mm) amounted 0,14mm/day (T=15 °C). During 24 hours two periods of maximum food consumption were observed; starting at the beginning of the night, the second after approximately 12 hours, perhaps depending on the digestion rate. The food of the shrimp examined in July, merely existed of microzoobenthos (e.g. larvae Balanus balanoides, acorn- shell.)The average total consumption of the shrimps population on the Balgzand area amounted 1,85 gr.AVD.m-2.yr-1. The turnover of this population was determined from the estimated data on production (0,51 gr.AVD.m-2.yr-1) and biomass (0,26 gr.AVD. m-2.yr-1):P/B=2. |
