On an approach for applying per-recruit methods to a protogynous hermaphrodite, with an illustration for the slinger Chrysoblephus puniceus (Pisces: Sparidae)

A. E. Punt, P. A. Garratt, A. Govender

Research output: Contribution to journalArticle

41 Citations (Scopus)

Abstract

A yield-per-recruit model is developed for use on a protogynous hermaphrodite. It allows for sex change followed by a growth spurt. An approach is outlined which can be used to account qualitatively for the consequences of a stock-recruitment relationship. The model is used to make predictions for the stocks of slinger Chrysoblephus puniceus off South-East Africa. Model predictions of sex ratios compare favourably with field observations. Predictions of yield-per-recruit models that ignore any relationship between spawner stock size and recruitment can be misleading. Three scenarios concerning recruitment to the Natal stock of slinger can be postulated from the present robust nature of the stock to a high level of fishing mortality. Either recruitment is not dependent only on the number of males in the stock, or there is sufficient migration of 0-year-olds from nearby regions into the Natal stock, or recruitment is related to spawner stock size by the Ricker relationship. If lack of males is a limiting factor for recruitment, intensive exploitation of the virtually pristine stocks in the St Lucia Marine Reserve and off southern Moçambique could collapse the Natal stock and even the entire resource.

Original languageEnglish
Pages (from-to)109-119
Number of pages11
JournalSouth African Journal of Marine Science
Volume13
Issue number1
DOIs
Publication statusPublished - 1993

Fingerprint

Sparidae
hermaphrodite
Pisces
prediction
methodology
Saint Lucia
sex reversal
fishing mortality
marine park
Eastern Africa
limiting factor
sex ratio
method
South Africa
resource

ASJC Scopus subject areas

  • Aquatic Science
  • Ecology, Evolution, Behavior and Systematics

Cite this

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