Species: Alosa sapidissima

American Shad

Species

Fishes

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Species of concern in the Salish Sea

Fishes of Puget Sound and adjacent waters

Invasive species: fishes

Fishes of the Salish Sea

Encyclopedia of Puget Sound

Strongly compressed body; no scales on head; no lateral line; single dorsal fin; fatty eyelid in front of eye; no spines in fins; sharply pointed scales on belly; no teeth on jaws of adult; cheek deeper (top to bottom) than long (front to rear); mouth not strongly oblique; lower jaw extends to tip of snout or slightly beyond; green or blue back and silvery sides; blue-black spot near upper edge of gill opening, usually followed by one or two rows of smaller spots; 59-73 rakers on lower limb of first gill arch of adult. Total length up to 75 cm.

Classification

Kingdom

Animalia

Phylum

Craniata

Class

Actinopterygii

Order

Clupeiformes

Family

Clupeidae

Genus

Alosa

NatureServe

Source:
ELEMENT_GLOBAL.2.101354

Classification

Other Global Common Names

alose savoureuse

Informal Taxonomy

Animals, Vertebrates - Fishes - Bony Fishes - Other Bony Fishes

Formal Taxonomy

Animalia - Craniata - Actinopterygii - Clupeiformes - Clupeidae - Alosa - Forms a geographically disjunct species pair with A. ALABAMAE. Meristic differences have been found among different spawning populations along the Atlantic coast (see Lee et al. 1980). Nolan et al. (1991) discriminated among Atlantic coast populations using mtDNA.

Ecology and Life History

Habitat Type Description

Freshwater

Migration

false - false - true - American shad migrate up to thousands of kilometers between river spawning habitat and marine feeding habitat. In the Atlantic, most American shad are in the Gulf of Maine in summer and fall and shift southward to the mid-Atlantic region for winter. The timing of the spawning migration varies across the range.

Non-migrant

false

Locally Migrant

false

Food Comments

Planktivorous; larvae and young eat copepods, other small crustaceans, and insect larvae while in fresh water. Marine diet consists of copepods, mysids, other small crustaceans, and some small fishes. Upstream migrants eat little.

Reproduction Comments

Spawning occurs in February in the south, but not until June or July in the far north. The timing of migration and spawning also varies among years, being later when the water is colder. Eggs hatch in about a week. Larvae and juveniles spend the summer in rivers, then enter the sea by fall. They return to fresh water when mature (3-5 years old). Males are sexually mature in 3-4 years, females in 4-5 years. The percentage of individuals that spawn in two or more years decreases from north to south (0% in south). Southern populations tend to die after spawning whereas a higher proportion of the northly populations spawn in multiple years.<br><br>

Length

Conservation Status

NatureServe Global Status Rank

Global Status Last Reviewed

1996-09-09

Global Status Last Changed

1996-09-09

Distribution

Conservation Status Map

Global Range

Native range includes the Atlantic coast from Labrador to the St. Johns River, Florida. This species was introduced in the Sacramento River, California, in the 1870s; subsequently it spread north to Alaska and eastern Asia (Kamchatka Peninsula) and south to Mexico. An introduced, landlocked population occurs in Millerton Lake, California. Sources: Lee et al. (1980), Moyle (2002), and Page and Burr (2011).

ELEMENT_GLOBAL.2.101354