Scientia Marina, Vol 68, No 2 (2004)

Age, growth and mortality of Hake larvae (Merluccius hubbsi) in the north Patagonian shelf


https://doi.org/10.3989/scimar.2004.68n2273

Daniel Roberto Brown
Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), Argentina

Ezequiel Leonarduzzi
Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), Argentina

Laura Machinandiarena
Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), Argentina

Abstract


Age and growth and mortality rates were estimated in Argentinean hake (Merlucius hubbsi) larvae by counting and measuring otolith daily increments. Larvae were captured with a Bongo net in January and February 2001. Length-at-age data were represented by a linear model whose fitted expression was: L(t) = 0.156 t + 1.7. Slope represented mean the daily growth rate (0.156 mm/day). This value was quite similar to the values recorded by other authors for larvae of other Merluccius species. Individual growth rates were not significantly different between January and February. This homogeneity in the larval growth was coincident with the great thermal homogeneity recorded between months. Statistical analysis of the larval growth rates from different areas did not show significant differences. Daily mortality coefficients derived from the exponential decline models were 0.27 and 0.12 for January and February respectively. The difference between the two mortality coefficients could be attributable to the patchinnes, or larval recruitment pulses of distinct intensity between the two months.

Keywords


hake; Merluccius hubbsi; larvae; age; growth; mortality; otoliths

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