MEPS 334:205-212 (2007)  -  doi:10.3354/meps334205

Comparative nutritional condition of larval dab Limanda limanda and lesser sandeel Ammodytes marinus in a highly variable environment

Arne Michael Malzahn1,*, Catriona Clemmesen2, Karen Helen Wiltshire1, Silke Laakmann1,3, Maarten Boersma1,4

1Alfred Wegener Institute for Polar and Marine Research, Biologische Anstalt Helgoland, Ostkaje 1118, 27498 Helgoland, Germany
2Leibniz Institute of Marine Sciences (IFM-GEOMAR), Düsternbrooker Weg 20, 24105 Kiel, Germany
3University of Bremen, Bibliothekstraße 1, 28359 Bremen, Germany
4GKSS Research Centre, Institute for Coastal Research, Max-Planck-Straße 1, 21502 Geesthacht, Germany

ABSTRACT: We investigated the nutritional condition of larval fishes caught in daily ichthyoplankton hauls in the ‘Helgoland Roads’ (54°11.18’N and 07°54.00’E) from February to June 2004. We concentrated on larvae of dab Limanda limanda and lesser sandeel Ammodytes marinus in order to compare early life stages of iteroparous and nearly semelparous fish. We analysed length, weight and RNA:DNA ratios as a proxy for condition of the larvae. The relationship between larval nutritional condition and larval size provided an indication of condition-selective mortality due to a loss of larvae in poor condition from the larger size-classes. For the sandeel, larvae in good condition were present in all size-classes, whereas for the dab maximum larval condition increased with increasing size. Variability in both standard length and condition was high in the 2 species during their planktonic stage. Both species showed good nutritional condition in the early to mid portion of the recruitment period and declines in condition in late April. This was more pronounced in larval dab, which showed a higher dependency on feeding conditions than larval sandeel. Together, these findings indicate a more conservative strategy of early life stages of the nearly semelparous sandeel compared with the iteroparous dab.


KEY WORDS: Larval fishes · RNA:DNA ratio · Helgoland Roads · North Sea


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