Blueback Herring - Alosa aestivalis
Diagnostic characters: Body fusiform, moderately compressed; abdomen with scutes forming distinct keel. Upper jaw with distinct median notch; lower jaw rising steeply within mouth; minute teeth present at front of jaws (but disappearing with age); no teeth on vomer. Eye diameter less than snout length. Gill rakers slender, 41 to 51 on lower limb of anterior gill arch (fewer in fishes less than 10 cm standard length). Dorsal fin slightly anterior to centre point of body; anal fin short and situated well posterior to vertical through posterior base of dorsal fin; 8 branched pelvic-fin rays, pelvic-fin origin about at vertical through centre point of dorsal-fin base. Colour: dorsum blue, sometimes with more or less definite dusky lines in adults, shading to silver on sides; dark spot on shoulder (often absent in fishes less than 10 cm standard length); peritoneum dark; fins slightly yellow to green in life.
Size: Maximum about 38 cm standard length, commonly to 30 cm standard length.
Habitat, biology, and fisheries: Coastal, pelagic, euryhaline. Anadromous, adults migrate inshore and ascend rivers to spawn in fresh water or in slightly brackish pools with an outlet to the sea. Possibly overwintering near bottom and out from coast, approaching shore in late spring.Spawns in brackish or fresh waters of rivers, having arrived in coastal waters a month or so later than A. pseudoharengus (Chesapeake Bay in April), later farther north, apparently when water temperatures are above 22 C; young probably returning to salt water at the end of their first summer. Minimum age at maturity 3 years Estimated fecundity 30,000 to 400,000 eggs/female. Eggs pelagic, semi-demersal, yellowish, semi-transparent, 0.87 to 1.11 mm.Often forms large schools. Vertical migrator; feeds on planktonic animals (i.e., copepods), small fishes, and shrimps. Probably not distinguished from A. pseudoharengus in northern part of the range, but catches in southern parts of its range are negligible. Caught with pound nets, weirs, seines, gill nets, fyke nets, and occasionally with otter trawls. Marketed mostly fresh and salted, and used as a baitfish in crustacean fisheries.
Distribution:Western north Atlantic (east coast of Florida from St. Johns River northward to Cape Breton, Nova Scotia). Uncertain if landlocked in Great Lakes.