Identification
The allis shad is a large herring-like fish of 30 to 60 cm with a silvery, laterally compressed body. The back is dark blue-green, flanks silvery. Characteristic is a single dark spot behind the gill cover. The largest herring family member in Dutch inland waters.
Behavior & ecology
An anadromous migratory fish: lives in the sea but ascends rivers in spring to spawn in fresh water on gravel banks, splashing noisily at the surface at night.
In the Netherlands
Until the 19th century an important river fish in the Rhine and Maas. Now virtually extinct in the Netherlands due to overfishing and habitat loss. With only 61 records, extremely rare. Protected under the Habitats Directive.
