MEPS 494:267-279 (2013)  -  DOI: https://doi.org/10.3354/meps10509

ABSTRACT: Flatfishes drastically change their habitat, body form, and feeding during metamorphosis; thus, the early juvenile and larval stages are viewed as being critical for early survival. However, to the best of our knowledge, no studies have tested the growth-mortality hypothesis for both larval and juvenile stages of flatfishes. Therefore, we investigated the relationship between growth rate and environmental factors and tested the hypothesis for both larval and juvenile stages of marbled sole Pseudopleuronectes yokohamae in Hakodate Bay, Japan from 2001 to 2003. For both larval and juvenile stages, otolith growth correlated with water temperature. Eye-migrating larvae were defined as survivors of planktonic life (SV _pelagic). Large juveniles captured in late June and July were defined as survivors of shrimp predation (SV_juvenile). To test the growth-mortality hypothesis, otolith growth was compared between the SV and the original population. During the pelagic larval stage, growth-selective survival was not detected in any of the 3 yr. During the early juvenile stage, fast-growing individuals survived selectively in 2002 but not in 2003. In 2002, population growth of juveniles was slow because water temperatures were low. Thus, juveniles in 2002 required time to exceed the size spectrum that is vulnerable to shrimp predation; consequently, the individuals that grew more rapidly were able to survive selectively. Our results show the importance of the early juvenile stage for the survival of flatfishes.

KEY WORDS: Flatfish · Growth-selective survival · Juveniles · Larvae · Prey density · Pseudopleuronectes yokohamae · Temperature