Advertisement

You can sponsor this page

Alosa fallax  (Lacepède, 1803)

Twaite shad
Add your observation in Fish Watcher
| Native range | All suitable habitat | PointMap | Year 2050 |
This map was computer-generated and has not yet been reviewed.
Alosa fallax   AquaMaps   Data sources: GBIF OBIS
Upload your photos and videos
Pictures | Google image
Image of Alosa fallax (Twaite shad)
Alosa fallax
Picture by Stergiou, K.I.

Classification / Names Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa

Actinopterygii (ray-finned fishes) > Clupeiformes (Herrings) > Clupeidae (Herrings, shads, sardines, menhadens) > Alosinae
Etymology: Alosa: Latin, alausa = a fish cited by Ausonius and Latin, halec = pickle, dealing with the Greek word hals = salt; it is also the old Saxon name for shad = "alli" ; 1591 (Ref. 45335).

Issue
5 subspecies known.

Environment / Climate / Range Ecology

Marine; freshwater; brackish; pelagic-neritic; anadromous (Ref. 51243); depth range ? - 300 m (Ref. 10541).   Temperate; 70°N - 27°N, 25°W - 42°E

Length at first maturity / Size / Weight / Age

Maturity: Lm 32.5  range ? - ? cm
Max length : 60.0 cm SL male/unsexed; (Ref. 35388); common length : 40.0 cm SL male/unsexed; (Ref. 2945); max. published weight: 1.5 kg (Ref. 188); max. reported age: 25 years (Ref. 556)

Short description Morphology | Morphometrics

Dorsal spines (total): 4 - 6; Dorsal soft rays (total): 12-16; Anal spines: 3-4; Anal soft rays: 16 - 22; Vertebrae: 55 - 59. Body slightly compressed, fairly deep with scutes along belly. Upper jaw notched, lower jaw fitting into it (Ref. 188). 31-50 (rarely up to 60) thick gill rakers on the lower arc (Ref. 59043). Large, thin scales (Ref. 51442). Deep blue dorsally, becoming greenish brown or golden on the sides and silvery ventrally. A dark spot posterior to gill opening followed by 6-10 similar spots (sometimes faint or absent) along flank (Refs. 188, 88187). Also Ref. 2196.

Distribution Countries | FAO areas | Ecosystems | Occurrences | Point map | Introductions | Faunafri

Northeast Atlantic: from the British Isles and southern Norway to Morocco, including the Baltic, Mediterranean and Black Seas (Refs. 188, 26334, 51442)). Several subspecies have been recognized based on the number of gill rakers and geographical location (Ref. 10541) and some have since been given species-status (Ref. 59043). Listed in Appendix III of the Bern Convention (2002). Listed in Annex II and V of the EC Habitats Directive (2007).

Biology     Glossary (e.g. epibenthic)

Amphihaline species (Ref. 51442), schooling and strongly migratory (Ref. 188). Adults are usually found in open waters along the coast (Refs. 59043, 89486); juveniles are usually found along estuaries and near the shore (Ref. 59043), possibly making vertical diurnal movements synchronized with the tides; they remain in estuaries for over one year (Ref. 89630). Migrates to major rivers to spawn; also reported to spawn in small rivers. Several landlocked (lake) non-migratory populations exist (Ref. 10541). Ichthyophagous, feeds on small fishes and crustaceans, the young taking the fry of herrings, sprats and gobies (Ref. 188, Ref. 51442). Females grow faster and are always larger than males of the same age (Ref. 10541). Very locally distributed due to pollution and impoundment of large rivers throughout Europe and most populations declined during the first decade of the 20th century, but seem to have stabilized at a low level since then (Ref. 59043). It has been suggested that members of the genus Alosa are hearing specialists with the American shad (Alosa sapidissima) having been found to detect and respond to sounds up to at least 180 kHz (Ref. 89631). This may aid in predator avoidance (e.g. cetaceans) (Ref. 89632). Hybridization between this species and the allis shad (Alosa alosa) has been reported from the Rhine (Ref. 89633) as well as rivers in France and Algeria (Ref. 10541). There is some evidence that indicates that shad hybrids may reproduce (Ref. 27567).

Main reference Upload your references | References | Coordinator | Collaborators

Whitehead, P.J.P., 1985. FAO Species Catalogue. Vol. 7. Clupeoid fishes of the world (suborder Clupeioidei). 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.

IUCN Red List Status (Ref. 90363)

CITES (Ref. 94142)

Not Evaluated

Threat to humans

  Harmless




Human uses

Fisheries: minor commercial
FAO(fisheries: production; publication : search) | FisheriesWiki | Sea Around Us

More information

Countries
FAO areas
Ecosystems
Occurrences
Introductions
Stocks
Ecology
Diet
Food items
Food consumption
Ration
Common names
Synonyms
Metabolism
Predators
Ecotoxicology
Reproduction
Maturity
Spawning
Fecundity
Eggs
Egg development
Age/Size
Growth
Length-weight
Length-length
Length-frequencies
Morphometrics
Morphology
Larvae
Larval dynamics
Recruitment
Abundance
References
Aquaculture
Aquaculture profile
Strains
Genetics
Allele frequencies
Heritability
Diseases
Processing
Mass conversion
Collaborators
Pictures
Stamps, Coins
Sounds
Ciguatera
Speed
Swim. type
Gill area
Otoliths
Brains
Vision

Tools

Special reports

Download XML

Internet sources

Estimates of some properties based on empirical models

Phylogenetic diversity index (Ref. 82805):  PD50 = 0.5000   [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00617 (0.00491 - 0.00774), b=3.05 (3.00 - 3.10), based on LWR estimates for this species (Ref. 93245).
Trophic Level (Ref. 69278):  3.6   ±0.60 se; Based on food items.
Resilience (Ref. 69278):  Medium, minimum population doubling time 1.4 - 4.4 years (K=0.21-0.38; tm=2-7; tmax=25; Fec>10,000).
Vulnerability (Ref. 59153):  Moderate to high vulnerability (50 of 100) .
Price category (Ref. 80766):   Low.