Marine and Freshwater Research Marine and Freshwater Research Society
Advances in the aquatic sciences

Just Accepted

This article has been peer reviewed and accepted for publication. It is in production and has not been edited, so may differ from the final published form.

Gender-specific differences in growth, mortality and migration support population resilience in a heavily exploited migratory marine teleost, Mugil cephalus (Linnaeus 1758).

John Stewart , Anne-Marie Hegarty , Caitlin Young , Ashley Fowler

Abstract

Understanding mechanisms supporting the resilience of exploited fish populations is fundamental to sustainable management. We identify gender-specific differences in life-history traits that confer resilience in the heavily exploited population of Mugil cephalus along eastern Australia. M. cephalus in this region emigrate from estuaries and undergo an annual northerly spawning migration that is dominated by males. Males mature on average at younger ages than females and were most abundant in the spawning migration at age 4 whereas females were most abundant at age 5. Females grew significantly faster and larger than males, with both sexes being aged up to 14 years. These gender specific differences relate directly to the population stability of M. cephalus under the reproductive strategy of a spawning migration. Males participate in the spawning migration at younger ages and in greater numbers than females to ensure a sufficient number of males for successful spawning. Females partition more energy to growth than males, maturing and participating in the spawning migration at older ages and larger sizes. The larger body size of females is related to increased fecundity, increased survivorship and more efficient swimming ability. These traits, combined with population strategies of both delayed and skipped spawning, convey substantial resilience

MF17135  Accepted 20 September 2017

© CSIRO 2017