Frontiers in Marine Science (Nov 2015)

Early life stages of plaice Pleuronectes platessa in cold-water nurseries

  • Filipe Martinho,
  • Vânia Freitas,
  • Vânia Freitas,
  • Paulo T Santos

DOI
https://doi.org/10.3389/conf.fmars.2015.03.00090
Journal volume & issue
Vol. 2

Abstract

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Plaice Pleuronectes platessa (Linnaeus, 1758) is one of the most important commercial flatfish in the European continent, whose captures have reduced considerably in recent decades due to the high pressure of fisheries. Despite the wide distribution of this species, most studies have focused on the North Sea, its central area of occurrence, and very little information is available concerning the populations living at the northern limit of its distribution. Age determination is essential to study population dynamics of commercially important species such as plaice, and can be inferred through otolith microstructure analysis. The aim of this work was to investigate the timing of early life events (spawning, larval, metamorphosis and settlement stage duration) and growth of juvenile plaice in two cold-water nursery areas in northern Norway (Valosen estuary and Storfjord). A latitudinal cline was observed in the main life-history events, such as spawning, and the onset of larval and metamorphosis stages. Settlement to benthic habitats (which coincides with metamorphosis) was estimated to have occurred between mid-May and early-September (peak from the end May and mid July) in the Valosen, and between the end of May and early July (peak in June) in the Storfjord. In the Storfjord area, larval and metamorphosis stage duration seemed to be shorter, probably due to a reduced window of opportunity for growth and survival at the northernmost extremes. Size at settlement was negatively related with hatch day, implying that the older larvae were larger at settlement, a consequence of higher fecundity of females earlier in the spawning season. A significant relationship between size at settlement and total length reinforced this evidence. The results demonstrate the influence of latitude in the early life stages of plaice, mainly by the regulatory effect of temperature in the growth and survival of larvae and juveniles.

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