Marine Biology

, Volume 159, Issue 3, pp 583–599

Seasonal and interannual variations in size, biomass and chemical composition of the eggs of North Sea shrimp, Crangon crangon (Decapoda: Caridea)

Authors

    • Christian-Albrechts-Universität zu Kiel
    • Biologische Anstalt Helgoland, Alfred-Wegener-Institut für Polar und Meeresforschung
  • Kurt Paschke
    • Instituto de AcuiculturaUniversidad Austral de Chile
  • Paulina Gebauer
    • Centro de Investigaciones I-MARUniversidad de Los Lagos
  • Klaus Anger
    • Biologische Anstalt Helgoland, Alfred-Wegener-Institut für Polar und Meeresforschung
Original Paper

DOI: 10.1007/s00227-011-1837-x

Cite this article as:
Urzúa, Á., Paschke, K., Gebauer, P. et al. Mar Biol (2012) 159: 583. doi:10.1007/s00227-011-1837-x

Abstract

In the shrimp Crangon crangon, an important fishery resource and key species in the southern North Sea, we studied temporal variations in size, biomass (dry weight, W) and chemical composition (C, N, protein and lipid) of eggs in an initial embryonic stage. Data from 2 years, 1996 and 2009, consistently revealed that egg size and biomass varied seasonally, with maxima at the beginning of the reproductive season (January), decreasing values throughout spring, minima in June–July, and a slight increase thereafter. This cyclic pattern explains why “Winter eggs” are on average larger and heavier than “summer eggs”. Using a modelling approach, we estimated the duration of oogenesis in relation to seasonally changing seawater temperatures. According to an additive model of multiple explanatory variables, the C content per newly laid egg showed in both years a highly significant negative relationship with day length (r² = 0.38 and 0.40, respectively; P < 0.0001), a weak positive relationship with temperature (r² = 0.08 and 0.09; P < 0.05), and a weak negative relationship with phytoplankton biomass (r² = 0.11 and 0.12; P < 0.05) at the estimated time of beginning oogenesis. Phenotypic plasticity in initial egg size and biomass is interpreted as an adaptive reproductive trait that has evolved in regions with strong seasonality in plankton production and periods of larval food limitation. In contrast to biomass per egg, the percentage chemical composition remained similar throughout the reproductive period. Both the absolute and percentage values also showed significant interannual variations, which caution against generalizations based on short-term studies of reproductive traits of C. crangon and other species of shrimp.

Copyright information

© Springer-Verlag 2011