Scientific Name
Alosa alosa
Common Name
Allis shad
Biology
Amphihaline species, spending most of its life in sea (Ref. 51442); at sea, pelagic, in deep water down to 300 meters; juveniles resides close to the shore and estuaries (Ref. 59043). Schooling and strongly migratory species, penetrating far up rivers, spawning in main river or entering large and warm tributaries; spawning sites usually situated near a confluence (Ref. 188, 59043). Males migrate upriver at 3-9 years; females first reproduce 1-3 years later than males. Adult individuals approach coasts at end of February and enter rivers when 22-24?C is reached, usually in May. Spawning starts at when 15?C is reached; spawns in large, very noisy schools at night near the surface; eggs sink to the bottom. Spent fish migrate back to the sea, and most die after reproduction, having mated once. Most juveniles migrate to river mouth during first summer to remai