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Age and growth of the Cape knifejaw Oplegnathus conwayi, an endemic South African teleost

Age and growth of the Cape knifejaw Oplegnathus conwayi, an endemic South African teleost The South African spearfishery targets a variety of data-deficient species, which are consequently poorly managed. This study aimed to describe the age and growth of one of these species, the Cape knifejaw, Oplegnathus conwayi, which is endemic to the southern and eastern coasts of South Africa. Monthly biological samples were collected through research spearfishing (n = 170) and augmented by recreational spearfishers’ catches (n = 135). The results indicated that the O. conwayi population sex ratio was skewed towards males (1M:0.6F). The length- and age-frequency distributions were similar between sexes. Oplegnathus conwayi is a relatively slow-growing species, with a maximum-recorded age of 27 years. No significant differences were observed between male and female growth, with the overall population growth curve being best described as L(t) = 697.15(1 − e−0.06(t−6.30)). The slow growth observed in this species is characteristic of a species that is vulnerable to overexploitation, and accordingly a precautionary approach to future management is recommended. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png African Zoology Taylor & Francis

Age and growth of the Cape knifejaw Oplegnathus conwayi, an endemic South African teleost

Foster, RM; Childs, A-R; Mann, BQ; Potts, WM
African Zoology , Volume 57 (1): 11 – Jan 2, 2022
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Age and growth of the Cape knifejaw Oplegnathus conwayi, an endemic South African teleost

Abstract

The South African spearfishery targets a variety of data-deficient species, which are consequently poorly managed. This study aimed to describe the age and growth of one of these species, the Cape knifejaw, Oplegnathus conwayi, which is endemic to the southern and eastern coasts of South Africa. Monthly biological samples were collected through research spearfishing (n = 170) and augmented by recreational spearfishers’ catches (n = 135). The results indicated that the O. conwayi...
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Publisher
Taylor & Francis
Copyright
© 2022 Zoological Society of Southern Africa
ISSN
2224-073X
eISSN
1562-7020
DOI
10.1080/15627020.2022.2035254
Publisher site
See Article on Publisher Site

Abstract

The South African spearfishery targets a variety of data-deficient species, which are consequently poorly managed. This study aimed to describe the age and growth of one of these species, the Cape knifejaw, Oplegnathus conwayi, which is endemic to the southern and eastern coasts of South Africa. Monthly biological samples were collected through research spearfishing (n = 170) and augmented by recreational spearfishers’ catches (n = 135). The results indicated that the O. conwayi population sex ratio was skewed towards males (1M:0.6F). The length- and age-frequency distributions were similar between sexes. Oplegnathus conwayi is a relatively slow-growing species, with a maximum-recorded age of 27 years. No significant differences were observed between male and female growth, with the overall population growth curve being best described as L(t) = 697.15(1 − e−0.06(t−6.30)). The slow growth observed in this species is characteristic of a species that is vulnerable to overexploitation, and accordingly a precautionary approach to future management is recommended.

Journal

African Zoology – Taylor & Francis

Published: Jan 2, 2022

Keywords: citizen science; growth curves; management; otoliths; spearfishery

References

  • Life history, distribution and seasonal movements of a threatened South African endemic seabream
  • A method for comparing the precision of a set of age determinations
  • Aspects of the biology and life history of white steenbras Lithognathus lithognathus in southern Africa
  • Model selection and Akaike’s Information Criterion (AIC): The general theory and its analytical extensions
  • Age, growth and feeding of the blue hottentot Pachymetopon aeneum (Pisces: Sparidae) with notes on reproductive biology
  • The biology of the bronze bream, Pachymetopon grande (Teleostei: Sparidae) from the south-east Cape coast, South Africa
  • Accuracy, precision and quality control in age determination, including a review of the use and abuse of age validation methods
  • Otoliths, increments and elements: keys to a comprehensive understanding of fish populations
  • Evaluating methods for setting catch limits in data-limited fisheries
  • Catch statistics and biology of two knifejaw species (Teleostei: Oplegnathidae) from Natal, South Africa
  • Comparing body-size growth curves: the Gallucci-Quinn index, and beyond
  • Breathing life into fisheries stock assessments with citizen science
  • The age and growth of hottentot seabream Pachymetopon blochii before and after the South African linefish state of emergency in 2000
  • Long-term trends in catch and effort of commercial linefish off South Africa’s Cape Province: Snapshots of the 20th century
  • Effective fisheries management instrumental in improving fish stock status
  • Age and growth of the estuarine-dependent sparid Acanthopagrus berda in northern KwaZulu-Natal, South Africa
  • Marine fish life history strategies: applications to fishery management
  • Validation of age estimates in sparid fish using fluorochrome marking
  • Ocean warming alters species abundance patterns and increases species diversity in an African sub-tropical reef-fish community
  • Age and growth of Diplodus sargus capensis and D. cervinus hottentotus (Sparidae) on the Tsitsikamma coast, South Africa
  • An evaluation of participation in and management of the South African spearfishery
  • Growth characteristics in the otoliths of selected South African sparid fish
  • A simplex method for function minimization
  • A Century of Linefish Research in South Africa: Bibliography and review of research trends
  • Editorial overview: recommendations for the promotion of a resilient linefishery in the Anthropocene
  • Validation of the periodicity of opaque zone formation in the otoliths of four temperate reef fish from South Africa
  • South African marine citizen science -– benefits, challenges and future directions
  • Age and growth of the red steenbras Petrus rupestris (Pisces: Sparidae) on the south-east coast of South Africa
  • Life history strategies, population regulation, and implications for fisheries management
  • Sectioned or whole otoliths? A global review of hard structure preparation techniques used in ageing sparid fishes
  • Integrating physiology and life history to improve fisheries management and conservation