Using otolith increment widths to infer spatial, temporal and gender variation in the growth of sand whiting Sillago ciliata

Abstract

Abstract Two methods of otolith increment analysis were used to describe spatial, temporal and gender variation in growth of sand whiting, Sillago ciliata (Cuvier), in four south-east Australian estuaries. Mean annual standardised otolith increment widths were used as indices of individual lifetime growth rates, while raw otolith increment widths were used to describe variation in growth throughout the life of S. ciliata. Temporal variation in growth was observed at an annual scale, while spatial variation in growth was observed between estuaries. Growth rates increased significantly with decreasing latitude and greater mean sea surface temperatures. A divergence in growth rates between sexes was detected, with females growing faster than males after sexual maturity. This study highlights how otolith increment analyses can: (1) be used to analyse temporal trends in growth from a single sample and (2) provide insight into juvenile growth when samples have an absence of undersized fish.