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). More on author: Linnaeus.
Environment: milieu / climate zone / depth range / distribution range
Marine; freshwater; brackish; pelagic-neritic; anadromous (Ref. 89642); depth range 10 - 300 m (Ref. 10536). Temperate; 61°N - 20°N, 17°W - 22°E
Eastern Atlantic: from southern Norway and along the coasts of Europe to northern Mauritania (Ref. 188, 6683), including the Western Baltic Sea up to the Kaliningrad Oblast (Ref. 12801, 26334, 59043), the western part of Mediterranean Sea (Ref. 188, 6683, 59043) and the coasts of northern Africa (Ref. 3509). However, presently only very locally distributed outside France, victim of pollution and impoundment of large rivers throughout Europe (Ref. 59043).
Listed in Appendix III of the Bern Convention (2002).
Listed in Annex II and V of the EC Habitats Directive (2007).
Length at first maturity / Size / Weight / Age
Maturity: Lm 48.1, range 45 - 50 cm
Max length : 69.0 cm TL male/unsexed; (Ref. 10536); 83.0 cm TL (female); common length : 40.0 cm TL male/unsexed; (Ref. 2945); common length :70 cm TL (female); max. published weight: 4.0 kg (Ref. 30578); max. reported age: 10 years (Ref. 10536)
soft rays: 20 - 27;
Vertebrae: 57 - 58. Diagnosis: Body somewhat compressed, fairly deep with depth at pectoral fin more than head length, scutes apparent along belly (Ref. 188, 51442). Upper jaw with a distinct median notch, lower jaw fitting into it; no teeth on vomer; gillrakers long, thin and numerous, a total of 85 to 130 on first arch, longer than gill filaments (Ref. 188, 6683). A dark spot posterior to gill opening, but sometimes absent, occasionally 1 or 2 more spots (Ref. 188). Alosa alosa resembles Alosa fallax, which has fewer and shorter gillrakers and 7 or 8 black spots along flank (Ref. 188).
Adults in the sea begin to move towards the coast in February and congregate near or in estuaries (Ref. 10536). They ascend rivers in April and May when water temperature is 9-12 °C, peaking at 13-16 °C. Adults may migrate up to 700 km from the sea into major rivers and occasionally into the largest tributaries of these rivers to spawn (Ref. 10536). Males migrate upriver at 3-9 years; females first reproduce 1-3 years later than males. Gametogenesis occurs during spawning migration.
Males arrive first in the upper reaches and occupy appropriate spawning sites, with females arriving 1-2 weeks later (Ref. 10536). Spawning sites are usually shallow areas (<1.5 m depth) of rivers near a confluence with strong currents and clean gravel bottoms (Refs. 188, 10536, 59043). Spawning occurs at night (over several nights), in large and very noisy schools that form near the surface.when water temperature reaches at least 15 °C and is believed to be optimal between 22-24 °C. (Ref. 88171). Coupling happens side by side, thrashing caudal fins on water surface and swimming in circles while expulsing eggs and sperms in the surrounding water. Eggs are fertilized in mid-water and then sink to the gravel bottom. Eggs hatch after 4-8 days (22-24 °C) (Ref. 89630). After spawning, adults return to the sea but many die before reaching it (Ref. 188, 51442, 59043). Only 5-6 % of the adults spawn more than once in their lifetime (Ref. 89655). After 3-4 months juveniles (8-12 cm length) move towards the sea until mature (Ref. 10536). Individual fish apparently return to their natal spawning site (Ref. 59043). Also Refs. 5744, 5745.
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. (Ref. 188)
IUCN Red List Status (Ref. 120744)
CITES (Ref. 118484)
Threat to humans
Fisheries: minor commercial; gamefish: yes
Estimates based on models
Preferred temperature (Ref. 115969
): 7 - 15.6, mean 10.1 (based on 480 cells).
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00776 (0.00636 - 0.00948), b=3.03 (2.99 - 3.07), in cm Total Length, based on LWR estimates for this species (Ref. 93245
Trophic Level (Ref. 69278
): 3.0 ±0.2 se; Based on diet studies.
Resilience (Ref. 120179
): Medium, minimum population doubling time 1.4 - 4.4 years (K=0.19-0.29; tm=3.5; tmax=10).
Vulnerability (Ref. 59153
): Moderate vulnerability (36 of 100) .