Allis shad

D-Maifisch, Alse; GB-Allis shad; DK-Majsild; PL-Aloza; LT-Alsė; LV-Aloza; EST-Aloosa; RU-европейская алоза; FIN-Pilkkusilli; S-Majfisk

Characters

1) mouth opening reaching up to the height of the caudal edge of eye.
2) operculum with a pattern of stripes.
3) 1 to 6 black spots on the side.
●) abdominal keel present.
●) mouth slightly superior (lower jaw overtoping the maxilla).
●) 90 to 120 hooks on the gill rakers and 70 to 80 scales on the lateral line.
Usually about 40 cm, but up to 80 cm length and 4 kg weight.

Similar species

Twaite shad - 6-10 black spots on flank; 40-60 gill rakers; 60-65 scales in lateral series.

Herring - mouth shorter: not reaching posterior margin of eye.

Sprat - mouth shorter: not reaching posterior margin of eye.

Biology

Lives in stocks in deeper free waters; for spawning they migrate very far upstream. Males become sexually mature with 3 to 9 years and females with 4 to 12 years. Many adults die after spawning.

Diet

Feeds on zooplankton, often smaller crustaceans and their larvae.

Importance

In former times of high commercial importance as food fish; today, because of declined stocks, only of local interest in some areas of the Mediterranean Sea.

Endangerment

Became very rare due to water pollution, damming, river regulation and slow reproduction rate.