North African Shad

Diagnosis: This species is distinguished from other species of Alosa entering freshwater in the Mediterranean basin by: dorsal profile convex; 40-60 thin gill rakers in individuals larger than 200 mm standard length, with 25 to 38 on its lower part; and no teeth on palatine (Ref. 10538, 59043).Description: Dorsal profile convex (Ref. 59043). Upper jaw with median notch (Ref. 59043). There are 40-60 gill rakers on the first arch with 25-38 on its lower part (Ref. 10538, 13696, 59043). Total number of dorsal fin rays 18-22; total number of anal fin rays 20-25; total number of pelvic fin rays 9 (Ref. 10538). Scales in a longitudinal series 58; scales in a transverse series 20; elongated scales at base of caudal fin lobes (Ref. 11601, 59043). Number of pre-pelvic ventral scutes 19-23; number of post-pelvic ventral scutes 13-16; total number of ventral scutes: 33-39 (Ref. 10538). Number of vertebrae: 53-57 (Ref. 10538).

Most juveniles migrate to river mouth in first summer and remain at sea until they mature. Males migrate upriver at 3-4 years, females at 4-5. They start entering rivers when temperatures reach 14-18°C, mainly in May to spawn when temperatures rises above 20°C. After spawning, spent individuals migrate back to sea, but many die before they do (Ref. 59043).

Anadromous. Fish that ascend rivers to spawn, as salmon and hilsa do. Sub-division of diadromous. Migrations should be cyclical and predictable and cover more than 100 km.

Dorsal spines (total): 0; Dorsal soft rays (total): 18 - 22; Analspines: 0; Analsoft rays: 20 - 25; Vertebrae: 53 - 57

This species undertakes anadromous breeding migrations from the sea, where it spends most of its life, into the freshwater sections of rivers; it can also live permanently in brackish water (Ref. 10538). Males migrate upriver at 3-4 years, females at 4-5 years; it starts entering rivers when temperatures reach 14-18°C, mainly in May, and spwaning commences when temperature rises above 20°C in May and June (Ref. 59043). The spawners return downstream immediately after spawning (Ref. 10538).

This species undertakes anadromous breeding migrations from the sea, where it spends most of its life, into the freshwater sections of rivers; it can also live permanently in brackish water (Ref. 10538). Males migrate upriver at 3-4 years, females at 4-5 years; it starts entering rivers when temperatures reach 14-18°C, mainly in May, and spawning commences when temperature rises above 20°C in May and June (Ref. 59043). The spawners return downstream immediately after spawning, but many die after spawning; most juveniles migrate to river mouth in first summer and remain at sea until they mature (Ref. 10538, 59043). Spawning occurs close to estuaries in fresh and brackish water (Ref. 59043).In the marine and brackish water habitats, this shad consumes small fishes, such as species of Engraulis, Sardina, and Sardinella, and small benthic crustaceans, mainly isopods and amphipods (Ref. 10538).

fisheries:

Alosa algeriensis, the North African shad, is a Mediterranean species of clupeid fish in the shad genus Alosa.