Biological Parameters and Population Structure of Frigate Tuna (Auxis thazard) along Chennai coast, Southeast India
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Paplin Prince. B
[1]
;
Santhoshkumar. S
[1]
;
Pavinkumar. P
[1]
;
Lloyd Crispin. C
[1]
;
John Chembian. A
[2]
;
Sudhan. C
[1]
;
Sasikumar. R.G
[1]
-
[1] Tamil Nadu Dr. J. Jayalalithaa Fisheries University (TNJFU)
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[2] Fishery Survey of India, Chennai Base of FSI, Fishery Harbour Complex
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- Localización: Thalassas: An international journal of marine sciences, ISSN 0212-5919, Vol. 41, Nº. 3, 2025
- Idioma: inglés
- Texto completo no disponible (Saber más ...)
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Resumen
This study investigates the population structure, growth dynamics, and exploitation status of the frigate tuna (Auxis thazard) along the Chennai coast, Southeast India. The species exhibited a positive allometric growth pattern, with the length–weight relationship described by the equation LWR = 0.1285L3.1184. Gut content analysis indicated that A. thazard is an opportunistic carnivore, feeding primarily on small fish. The length at first maturity was estimated at 30.7 cm for males and 31.8 cm for females, with fecundity ranging from 2,73,823 to 10,86,302 eggs. Spawning occurred year-round, with a peak observed between February and April 2024. Growth parameters, estimated using the ELEFAN I module in FiSAT II software, indicated an asymptotic length (L∞) of 57.75 cm, a growth coefficient (K) of 0.98 year⁻1, and a theoretical age at zero length (t₀) of − 0.0128. Estimated mortality rates were: natural mortality (M) = 1.47, total mortality (Z) = 2.98, and fishing mortality (F) = 1.51. The resulting exploitation rate (E) was 0.51, suggesting moderate overexploitation of the stock. These findings highlight the need for reduced fishing pressure to promote the long-term sustainability of A. thazard populations in the region.
