Age, growth, and reproduction of jewfish Epinephelus itajara in the eastern Gulf of Mexico
Bullock, L.H.; Murphy, M.D.; Godcharles, M.F.; Mitchell, M.E. (1992). Age, growth, and reproduction of jewfish Epinephelus itajara in the eastern Gulf of Mexico. Fish. Bull. 90(2): 243-249
In: Fishery Bulletin. US Government Printing Office: Washington, D.C.. ISSN 0090-0656; e-ISSN 1937-4518, more
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Keywords |
Age determination Aquatic organisms > Marine organisms > Fish > Marine fish Life history Otoliths Population characteristics > Population structure > Age composition Population functions > Growth Properties > Biological properties > Sexual maturity Epinephelus itajara (Lichtenstein, 1822) [WoRMS] ASW, Mexico Gulf [Marine Regions] Marine/Coastal |
Authors | | Top |
- Bullock, L.H.
- Murphy, M.D.
- Godcharles, M.F.
- Mitchell, M.E.
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Abstract |
We sampled jewfish from recreational and commercial catches in the eastern Gulf of Mexico from November 1977 to January 1990 to obtain life history information. A single annual minimum in mean marginal increment ratios during May-August supported the hypothesis that jewfish up to at least age 10 can be aged by counting the opaque marks observed on otolith sections. Annual opaque mark formation was observed for a 3- and a 4-year-old jewfish using oxytetracycline (OTC) reference marks on otoliths (sagittae). Male jewfish (N 41) ranged 3-26 years old; females, 0-37 years (N 85). Growth was similar for males and females, averaging > 100 mm/year through age 6, then slowing to about 30 mm/year by age 15, and finally declining to < 10 mm/year after age 25. Observed total length and age data were described well by the following von Bertalanffy growth model. Jewfish spawned from June through December, with peak activity from July through September. Male jewfish matured at about 1100-1150 mm when 4-6 years old; females matured at 1200-1350 mm when 6 or 7 years old. |
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