Spatial variation in life history reveals insight into connectivity and geographic population structure of a tropical estuarine teleost: king threadfin, Polydactylus macrochir

Authors

Bradley R. Moore, James Cook University, Australia
Colin A. Simpfendorfer, James Cook University, Australia
Stephen J. Newman, Department of Fisheries, Western AustraliaFollow
Jason Stapley, Fisheries Queensland, Department of Employment, Economic Development and Innovation, Northern Fisheries Centre, Australia
Quentin Allsop, NT Fisheries, Department of Resources, Darwin, Northen Territory, Australia
Michelle J. Sellin, Sustainable Fisheries Unit, Agriscience Queensland, Department of Employment, Economic Development and Innovation, Brisbane, Queensland
D. J. Welch, James Cook University, Australia

Document Type

Article

Publication Date

2-28-2012

Journal Title

Fisheries Research

ISSN

Print: 0165-7836 Electronic: 1872-6763

Keywords

Life history, Demography, Age, Growth, Sex change, Stock structure, Fisheries management, Polynemidae, Australia

Disciplines

Aquaculture and Fisheries | Behavior and Ethology | Environmental Indicators and Impact Assessment | Environmental Monitoring | Marine Biology | Natural Resources and Conservation | Natural Resources Management and Policy | Physical and Environmental Geography | Population Biology | Sustainability

Abstract

Understanding the life history of exploited fish species is not only critical in developing stock assessments and productivity models, but has a dual function in the delineation of connectivity and geographical population structure. In this study, patterns in growth and length and age at sex change of Polydactylus macrochir, an ecologically and economically important protandrous estuarine teleost, were examined to provide preliminary information on the species’ connectivity and geographic structure across northern Australia. Considerable variation in life history parameters was observed among the 18 locations sampled. Both unconstrained and constrained (t0 = 0) estimates of von Bertalanffy growth function parameters differed significantly among all neighbouring locations with the exception of two locations in Queensland's east coast and two in Queensland's Gulf of Carpentaria waters, respectively. Comparisons of back-calculated length-at-age 2 provided additional evidence for growth differences among some locations, but were not significantly different among locations in the south-eastern Gulf of Carpentaria or on Queensland's east coast. The length and age at sex change differed markedly among locations, with fish from the east coast of Australia changing sex from males to females at significantly greater lengths and ages than elsewhere. Sex change occurred earliest at locations within Queensland's Gulf of Carpentaria, where a large proportion of small, young females were recorded. The observed differences suggest that P. macrochir likely form a number of geographically and/or reproductively distinct groups in Australian waters and suggest that future studies examining connectivity and geographic population structure of estuarine fishes will likely benefit from the inclusion of comparisons of life history parameters.

Recommended Citation

Bradley R. Moore, Colin A. Simpfendorfer, Stephen J. Newman, Jason M. Stapley, Quentin Allsop, Michelle J. Sellin, David J. Welch,Spatial variation in life history reveals insight into connectivity and geographic population structure of a tropical estuarine teleost: king threadfin, Polydactylus macrochir, Fisheries Research, Volumes 125–126, 2012, Pages 214-224, ISSN 0165-7836, https://doi.org/10.1016/j.fishres.2012.02.028.