Age, growth, mortality, and reproduction of red porgy, Pagrus pagrus, from the eastern Gulf of Mexico


Hood, Peter B., and Andrea K. Johnson
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The red porgy (Pagrus pagrus) is an important component of the Gulf of Mexico reef-fish fishery, yet little information is available on this species’s life history. We sampled 877 red porgy (194–489 mm TL) from the eastern Gulf of Mexico during 1995 and 1996 to assess their age structure, growth, mortality, spawning season, size and age at maturity, and batch fecundity. The average length of males was significantly greater than that of females, and the overall sex ratio (1:1.6 in favor of females) was significantly different from 1:1. Marginal-increment analysis indicated that one opaque ring is formed on red porgy otoliths during the late spring or early summer of each year. Ages ranged from 1 to 17 years, and most fish were 3 and 8 years old. Von Bertalanffy growth model parameters were L∞=459 mm TL, K=0.111/yr, and t0=–6.6 years for all aged fi sh. Growth rates in our study were lower than those in previous studies of Gulf of Mexico red porgy—perhaps the result of size-selective fishing. Pooled estimates of total instantaneous mortality were 0.62–0.87/yr based on recreational landings data and 0.54/yr based on commercial landings data. Red porgy are protogynous hermaphrodites. The length and age at which males composed 50% of the population was 345.5 mm TL and 5.3 years. Few immature females were observed in our collections (n=10). All females greater than 302 mm TL and age 4 were mature. Red porgy spawn during the winter and spring, and ripe females were caught from January to April.