Pogies
Menhaden are dull silver with a greenish back. A prominent black spot is found behind the gill cover, followed by a row of smaller spots. Two similar species, the yellowfin menhaden, Brevoortia smithi, in the eastern Gulf, and the finescale menhaden, Brevoortia gunteri, in the western Gulf, lack the row of smaller spots. All three species have yellowish fins. Menhaden filter-feed on plankton, typically near the surface. The small splashes made by a school of fish are used both by live bait castnetters and commercial purse seiners to locate them.
All Gulf menhaden begin their lives between December and February in offshore waters. An average of 23,000 eggs is produced by each female. The eggs drift with water currents until they hatch, usually within 48 hours. The larvae, after hatching, are also helpless, drifting with the current. At their very early stages they feed on large phytoplankton (microscopic floating plants). As they grow larger and become able to swim, they shift their diet to zooplankters (microscopic floating animals). Finally, they lose their teeth and develop long, complex, forward-pointing projections on each gill, called gill rakers, to strain their adult diet of plankton from the water. At this time, the stomach develops into a gizzard.
While still in their planktonic stage, Gulf menhaden larvae make their way into low-salinity estuaries for early growth. Whether this movement occurs only due to currents or whether some active swimming is involved is not known, but entry into estuaries is critical to their survival. Once in an estuary and large enough to swim well, they frequently move into fresh water, often over 30 miles up rivers. In estuaries they grow rapidly and by summer they move to higher-salinity waters. Migration offshore occurs later in the summer and in the fall.
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