We investigated the nutritional condition of larval fish caught in daily ichthyoplankton hauls carried out 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. Larvae were analysed for length, weight and their RNA/DNA ratios as a proxy for the 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 poorly-conditioned larvae at larger size-classes. In larval sandeel, well-conditioned larvae were present in all size-classes, whereas in larval dab the maximum larval condition rose with size. Variability in both standard length and condition was high in the two species during their planktonic stage. Both species showed good nutritional condition in the early-mid season phase 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 indicated for a more conservative strategy of early life stages of the nearly semelparous sandeel compared with the iteroparous dab.
Helmholtz Research Programs > MARCOPOLI (2004-2008) > CO2-Coastal diversity - key species and food webs