Biology of the redspotted tonguesole Cynoglossus zanzibarensis (Pleuronectiformes: Cynoglossidae) on the Agulhas Bank, South Africa
Booth, A.J.; Walmsley-Hart, S.A. (2000). Biology of the redspotted tonguesole Cynoglossus zanzibarensis (Pleuronectiformes: Cynoglossidae) on the Agulhas Bank, South Africa. S. Afr. J. Mar. Sci./S.-Afr. Tydskr. Seewet. 22: 185-197
In: South African Journal of Marine Science = Suid-Afrikaanse Tydskrif vir Seewetenskap. Marine & Coastal Management: Cape Town. ISSN 0257-7615, meer
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| Trefwoorden |
Commonwealth of nations > Threshold countries > Southern africa > Anglophone africa > Developing countries > South africa > Eastern cape
Fauna > Aquatic organisms > Aquatic animals > Fish
Population functions > Growth
Sole
Austroglossus pectoralis (Kaup, 1858) [WoRMS]; Pisces [WoRMS]; Sparidae Rafinesque, 1818 [WoRMS]
Marien/Kust |
| Author keywords |
Cape south; Austroglossus-pectoralis; Coast; Predation patterns |
| Auteurs | | Top |
- Booth, A.J.
- Walmsley-Hart, S.A.
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| Abstract |
The biology of the redspotted tonguesole Cynoglossus zanzibarensis, a common African cynoglossid inhabiting the Agulhas Bank, South Africa, is described. Growth studies based on sectioned sagittal otoliths revealed that C. zanzibarensis is relatively fast-growing and long-lived, attaining ages >8 years. Growth in length was rapid in immature fish, fish attaining 56% of their maximum size within their first year. By sexual maturity, fish had attained 28% of their maximum age and 68% of their maximum length. Total length-at-age was best described by the Von Bertalanffy growth model with combined-sex growth described as L-t = 354.78(1-e-0.43(t+1.17)) mm TL. Sexually dimorphic growth patterns were evident, females attaining larger lengths, but at a slower growth rate than males. Despite the similar mean size of adult fish, the trawl-sampled adult population was dominated by females, with a sex ratio of 1 male:2.4 females. Female C. zanzibarensis mature in their second year of life (275 mm TL), after which they spawn small, pelagic eggs throughout the year. Approximations of the rates of total, natural and fishing mortality were estimated to be 0.62, 0.48 and 0.14 year -1 respectively. |
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