Length structure of deep-pelagic fishes sheds new light to their life histories
Heino, Mikko; Boukal, David S.; Falkenhaug, Tone; Piatkowski, Uwe; Porteiro, Filipe M.; Sutton, Tracey T.
Working paper
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http://hdl.handle.net/11250/102674Utgivelsesdato
2008Metadata
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Here we use a new technique to study life history variation in deep-pelagic fishes from a midocean
ridge system. Shape of length distribution in a population is to a significant extent determined
by the degree to which an average individual approaches its asymptotic maximum
size. Analysing the material from the pelagic trawl hauls taken during the 2004 Mar-Eco expedition
along the northern Mid-Atlantic Ridge, we show that length distributions in many
deep-pelagic fish species are characterised by negative skew (the left tail of the distribution is
longer). In other words, a large proportion of individuals had a size close to species-specific
maximum size. Provided that our sampling can be considered representative, this finding suggests
that deep-pelagic fishes have a low mortality rate relative to the rate at which they grow
towards their asymptotic size.
Keywords: Life history, growth trajectory, mortality