Alosa aestivalis (Mitchill, 1814)
Blueback shad
Alosa aestivalis
photo by Flescher, D.

 Family:  Clupeidae (Herrings, shads, sardines, menhadens), subfamily: Alosinae
 Max. size:  40 cm SL (male/unsexed); max.weight: 200.0 g; max. reported age: 8 years
 Environment:  pelagic-neritic; depth range 5 - 55 m, anadromous
 Distribution:  Western Atlantic: Cape Breton, Nova Scotia south to the St. John's River, Florida; also in lower parts of rivers.
 Diagnosis:  Dorsal spines (total): 0-0; Dorsal soft rays (total): 15-20; Anal spines: 0-0; Anal soft rays: 15-21; Vertebrae: 47-53. Moderately compressed, belly with distinct keel of scutes. Upper jaw with a distinct notch; lower jaw rising steeply within mouth; minute teeth present at front of jaws (disappearing with age). Lower gill rakers 41 to 52 (fewer in fishes under 10 cm standard length), slender. Back dark blue, sometimes bluish-grey; a dark spot on shoulder (Ref. 188). Peritoneum black (Ref. 7251). Branchiostegal rays 7 (Ref. 4639).
 Biology:  Form schools and possibly wintering near the bottom and out from the coast, approaching the shore in the late spring. Feed on small fishes, copepods and small shrimps. Spawn in brackish- or freshwaters of rivers, arriving in coastal waters a month or so later than A. pseudoharengus (in April at Chesapeake Bay, apparently when the water is above 70° C and later further north). Eggs are essentially pelagic, demersal in still water (Ref. 4639). Larvae are found in fresh and brackish rivers (Ref. 4639). Juveniles leave fresh and brackish nursery grounds at about 5 cm, migrating downstream (Ref. 4639). Marketed mostly fresh and salted (Ref. 188). Parasites found are acanthocephalan and nematodes (Ref. 37032).
 IUCN Red List Status: Vulnerable (A2b) (Ref. 96402)
 Threat to humans:  harmless
 Country info:   
 

 Entered by: Binohlan, Crispina B. - 17.10.90
 Modified by: Bailly, Nicolas - 15.07.13
 Checked by: Binohlan, Crispina B. - 23.07.94

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