Life-history traits and commercial catch composition of Chelidonichthys kumu in south-eastern Australia

Abstract

The red gurnard (Chelidonichthys kumu) is a coastal benthic fish supporting substantial fisheries in the Indo-West Pacific. Despite this, biological knowledge of the species is limited to New Zealand, placing other fished populations at risk of overexploitation if they are less productive. We determined the age, growth, reproductive biology and commercial catch composition of C. kumu from the trawl fishery in New South Wales (NSW). We also tested the hypothesis that growth rates and body size in NSW would be smaller than New Zealand, given the less productive marine environment in NSW and relative food limitation. Similar to New Zealand, individuals from NSW ranged in length from 13 to 56 cm FL and 1 to 13 years of age, with the largest and oldest fish being predominantly female. Females grew faster and to a greater maximum size than males. Growth was broadly similar between populations in NSW and New Zealand. Spawning period in NSW was protracted (11 months) and peaked in winter, contrasting with a peak in spring/summer in New Zealand. Size-at-maturity was similar between the two regions. The current study provides fundamental biological information to inform stock assessment and management of C. kumu in NSW.