Alosa aestivalis
Blueback Herring
NS
G3
Taxonomic Hierarchy
Actinopterygii (Ray-finned Fishes)
Clupeiformes (Herrings, Anchovies and Sardines)
Clupeidae (Herrings)
Alosa
Alosa aestivalis (Blueback Herring)
Description
This species account was compiled from
Composite (multiple sources) (Carpenter, K.E. (ed.) 2002. The living marine resources of the Western Central Atlantic. FAO Species Identification Guide for Fishery Purposes. FAO, Rome.)
and processed using AI-assisted text extraction.
It may contain errors in spelling, punctuation, or formatting.
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Synonymy
Pomolobus aestivalis (Mitchill, 1814). / Alosa pseudoharengus
(Wilson, 1811).
Characters
Body fusi form, 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 rak-
ers slender, 41 to 51 on lower limb of anterior gill arch (fewer in fishes less than 10 cm st andard 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 st andard length); peritoneum
dark; fins slightly yellow to green in life.
Body shape: fusiform / normal. 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). Striking features: none.
Distribution
Western north Atlantic (east coast
of Florida from St. Johns River northward to
Cape Breton, Nova Scotia). Uncertain if l and-
locked in Great Lakes.
Alosa alabamae Jordan and Evermann, 1896 CUA
Frequent synonyms / misidentifications: None / None.
FAO names: En - Alabama shad; Fr - Alose de l’Alabama; Sp - Sábalo de Alabama.
Diagnostic characters: Body fusi form, moderately compressed, body depth increasing somewhat with size;
abdomen with distinct keel. Upper jaw with distinct median notch; lower jaw not rising steeply within
mouth; no teeth in jaws; no teeth on vomer. Gill rakers slender, 41 to 48 on lower limb of anterior gill arch
(fewer in fishes less than 30 cm st andard length). Dorsal fin placed slightly anterior to centre point of body; anal
fin short and placed well posterior to vertical through posterior dorsal-fin base; 8 branched pelvic-fin rays, pel-
vic-fin origin at vertical through middle region of dorsal-fin base. Colour: dorsum bluish grey, with dark streaks
along scale rows; shading to silver on sides, vague dark shoulder spot behind upper operculum; fins
hyaline.
Size: Maximum 51 cm st andard length, commonly to 45 cm st andard length.
Habitat, biology, and fisheries: Euryhaline, anadromous, ascending rivers and streams to breed in winter
and spring (January through April), young returning to salt water (at 50 to 100 mm) at end of their first summer.
Actual spawning occurs at 18 to 22(cid:1)C over coarse s and and gravel sediments swept by moderate currents.
Adults app arently not feeding during spawning run. Annual fecundity ranging from 100 000 to 250 000 eggs/fe-
male. Spawning adults primarily age-2, some
age-1 fish also capable of spawning. Longevity 3
to 6 years Adults probably feed mainly on sm all
fish; juveniles feeding on sm aller invertebrates.
Princip ally caught in rivers during spawning mi-
grations. Separate statistics not reported for this
species. Caught with seines. Marketed mostly
fresh, but populations declining throughout
range.
Distri bution: Eastern Gulf of Mexico drainages,
from Suwannee River, Florida, to Mississippi
River; also in rivers from Iowa to Arkansas. Pres-
ently r are throughout much of former range in
larger rivers tri butary to Gulf of Mexico.
Habitat Associations
Coastal, pelagic, euryhaline. Anadromous, adults migrate inshore and as-
cend 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. pseudoh arengus (Chesapeake Bay in April), later
far ther north, app arently when water temperatures are above 22(cid:1)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/fe-
male. Eggs pelagic, semi-demersal, yellowish, semi-transp arent, 0.87 to 1.11 mm. Often forms large schools. Vertical migrator; feeds on planktonic animals
(i.e., copepods), sm all fishes, and shrimps. Prob-
ably not distinguished from A. pseudoh arengus
in nor thern part of the range, but catches in
sou thern parts of its range are negligible. Caught
with pound nets, weirs, seines, gill nets, fyke
nets, and occasion ally with otter trawls.
Biology
Maximum about 38 cm st andard length, commonly to 30 cm st andard length.
Inhabits rivers, estuaries, coastal waters, lakes and reservoirs (Ref. 117456). Adults are found in saltwater except during the spawning season and occur up to at least 200 km offshore (Ref. 117456). Forms schools and possibly wintering near the bottom and out from the coast, approaching the shore in the late spring. Feeds on small fishes, copepods and small shrimps. Spawns 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 7.0° 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). In freshwater habitat, this species usually occurs in current over rocky bottom (Ref. 86798). Marketed mostly fresh and salted (Ref. 188). Parasites found are acanthocephalan and nematodes (Ref. 37032).
Reproductive mode: dioecism; fertilization: external; nonguarders (open water/substratum egg scatterers); parental care: none. Upriver movement to spawning areas occur in late afternoon or at night (Ref. 4639).
IUCN Red List Status: Vulnerable (VU), assessed 2011-10-13. Resilience: Medium (K=0.18; tm=4; Fec=45,800).
Commercial or Environmental Importance
Mar-
keted mostly fresh and salted, and used as a
baitfish in crustacean fisheries.
References
Whitehead, P.J.P. (1985) FAO Species Catalogue. Vol. 7. Clupeoid fishes of the world (suborder Clupeoidei). An annotated and illustrated catalogue of the herrings, sardines, pilchards, sprats, shads, anchovies and wolf-herrings. FAO Fish. Synop. 125(7/1):1-303. Rome: FAO.
Jones, P.W., F.D. Martin and J.D. Hardy Jr. (1978) Development of fishes of the Mid-Atlantic Bight. An atlas of eggs, larval and juvenile stages. Vol. 1. Acipenseridae through Ictaluridae. U.S. Fish Wildl. Ser. Biol. Serv. Program FWS/OBS-78/12. 336 p.
Scott, W.B. and M.G. Scott (1988) Atlantic fishes of Canada. Can. Bull. Fish. Aquat. Sci. 219:731 p.
Robins, C.R. and G.C. Ray (1986) A field guide to Atlantic coast fishes of North America. Houghton Mifflin Company, Boston, U.S.A. 354 p.
Bowman, R.E., C.E. Stillwell, W.L. Michaels and M.D. Grosslein (2000) Food of northwest Atlantic fishes and two common species of squid. NOAA Tech. Memo. NMFS-NE 155, 138 p.
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