Aspects of the Biology of the Red Drum, Sciaenops ocellatus, in Mississippi

Abstract

Several hundred specimens of the red drum from Mississippi were critically assessed. Regression equations for standard-length (SL) versus total-length differed between males and females and between small and large members of the same sex. A single regression line represented the weight-SL relationship for males with females. For condition coefficients to be helpful, fish had to be grouped at least by sex, season, and length or stage of maturity. By 12 months of age, most fish were about 30 to 32 cm SL and their distribution ranged throughout Mississippi Sound rather than being restricted to inshore bayou and marsh habitats like younger individuals. Juvenile fish tended to have a high hepatosomatic index (HSI) in winter, and adultshadalow one following spawning. The gonosomatic index (GSI) was typically lower than the HSI except for gravid fish in spring and summer. The number of oocytes available for spawning appeared to be much higher than cited in previous reports. The highest calculated fecundity, occurring in a 758 mm SL fish, was 62 million using a volumetric displacement method and 95 million using a gravimetric one. Extrapolated estimates for larger fish were much higher. Resting and yolk-vesicle stage oocytes typically had an irregular shape, an eccentrically located nucleus, and an abundance of highly basophilic substance in the ooplasm. Throughout a seasonal histological examination, both gonads contained, often in an abundance, Periodic-acid-Schiff-positive granular leukocytes. Spawning took place in late September and October one year, but apparently has occurred over longer periods when conditions of temperature and photoperiod were appropriate. No tagged, 1-year-old fish were returned from farther than 33 km from the point of release.

Population connectivity of red drum in the northern Gulf of Mexico

“…Observed fidelity of subadult and adult red drum to natal sites may be due to localized retention or limited inter-estuary movement, which is common for species in the family Sciaenidae, including red drum (Baker & Matlock 1993, Murphy et al 1998, Adams & Tremain 2000. Mark-recapture studies on red drum in the Gulf of Mexico and along the eastern seaboard of the US have shown that the majority of individuals originated from nurseries within the same estuary or region as the capture location (Osborn et al 1982, Overstreet 1983, Nicholson & Jordan 1994. Moreover, Tremain et al (2004) observed high site fidelity of red drum from a no-take zone in Florida, with over 95% of the recaptures occurring at the tagging location within the reserve.…”

“…Alternatively, lower survival of migrants originating from outside nurseries may also explain the lower contribution rates and/or mixing of individuals from other regions. Although the dispersal potential of adult red drum is assumed to be high (Overstreet 1983), additional information on movement away from estuarine nurseries is needed to confirm that homing, rather than retention, was the primary behavior responsible for red drum being in tidal passes or coastal environments nearest to their putative nursery. The combined effects of localized retention and natal homing explain findings from tagging, genetics and otolith chemistry, but the degree to which each behavior is responsible for observed patterns remains unresolved.…”

Opercular lesion in wild black drum, Pogonias cromis (Linnaeus, 1766), associated with attachment of the sea louse Sciaenophilus tenuis (Copepoda: Siphonostomatoida: Caligidae)

“…In the Gulf of Mexico, S. tenuis has been reported by Bere (1936), Heegaard (1966), and Overstreet (1983) from banded drum, Larimus fasciatus Holbrook, 1855, black drum, and red drum, respectively. Lesions and pathologic responses to sea louse infection were described in several other teleosts (e.g.…”

Fish Resources of the Gulf of Mexico

“…Spawning red drum can be found in both open and nearshore waters in the Gulf of Mexico and tend to spawn near shorelines during late summer and fall (Tables 9.27 and 9.28). There is little evidence of seasonal migration of red drum, and they have been found in rivers and tidal creeks during Bass and Avault (1975) Common predators of juveniles Amberjack, large piscivorous fishes, sharks, and birds; typically not normal part of diet of any common estuarine predator Overstreet (1983), Porch (2000) Common predators of adults Sharks; not a normal part of the diet of any common estuarine predator the winter. Tides and water temperatures influence daily movement from shallow to deepwaters.…”

“…Tagging studies suggest that juvenile red drum have limited dispersal but that adults can travel considerable distances in the Gulf of Mexico (Osburn et al 1982;Overstreet 1983). Metapopulation structure may exist for the red drum in the Gulf of Mexico, and despite the likely complex spatial structure of the stock, red drum in the Gulf of Mexico is considered as a single stock, which implicitly assumes no spatial heterogeneity in the Gulf of Mexico red drum population.…”