Validated ageing methods for blue warehou (Seriolella brama) and white warehou (S. caerulea) in New Zealand waters

Abstract

Blue warehou (Seriolella brama) and white warehou (Seriolella caerulea) (Stromateoidei : Centrolophidae) from New Zealand waters were aged from counts of zones in cross-sectioned otoliths, a technique that was validated for both species by examining the state of otolith margins from fish sampled regularly throughout the year. Von Bertalanffy parameters were calculated for blue warehou on the Stewart-Snares shelf. The fish grew rapidly up to the time of first spawning (~4 –5 years) , but growth was negligible after ~10 –12 years. A maximum age of 22 years was recorded. Von Bertalanffy parameters were calculated for white warehou from the Chatham Rise and the Campbell Plateau;there were no significant differences in growth between areas. The fish grew rapidly up to the time of first spawning (~3 –4 years) , but growth was negligible after ~6 –8 years. A maximum age of 21 years was recorded. Females of both species grow significantly faster than males. A revised growth model for silver warehou (Seriolella punctata) is also presented.