Common Bleak – Profile | Facts | Habitat | Ecology | Diet

Common Bleak
(Last Updated On: April 15, 2021)

The Common bleak is a small pelagic fish of the Cyprinid household. It is usually referred to easily as a “bleak”, although this time period can check with any species of Alburnus.


Alburnus alburnus is a small fish with a slim and streamlined body. It is pale in coloration with silver sides and simply indifferent scales. This species has a protruding decrease jaw and its mouth factors upward.

Fins of the Common bleak are colorless to barely grey or orange. Its caudal fin has 19 rays. The anal fin has 17-20½ branched rays and its origin is beneath the branched dorsal rays 4-5. It possesses 16-22 gill rakers. The ventral keel is uncovered from the anus to the pelvic base. The lateral stripe is absent or faint.

Common Bleak Description

The body of the awful is elongated and flat. The head is pointed and the comparatively small mouth is turned upwards. The anal fin is long and has 18 to 23 fin rays. The lateral line is full.

The bleak has a shiny silvery coloration, and the fins are pointed and colorless. The size of the Common bleak  is roughly 25 cm. In Europe, the awful can simply be confused with many different species.

In England, younger bream and silver bream might be confused with younger bleak, although the pointed upward turned mouth of the awful is already distinctive at younger levels. Young roach and ruffe have a wider body and a brief anal fin.


The bleak happens in Europe: in Western England, Southern Sweden, France, and eastward towards the Volga Basin and North-Western Turkey.

Common Bleak Ecology

It lives in nice faculties and feeds upon small molluscs, bugs that fall within the water, insect larvae, worms, small shellfish, and plant detritus. It is present in streams and lakes. The bleak prefers open waters and is present in massive numbers the place there’s an influx of meals from pumping stations or behind weirs.

Alburnus alburnus inhabits slow-flowing streams and temperate lakes in Europe and Asia. It is a sterohaline fish that lives in brackish water with salinities of 8-10%.

Cyprinidae fish resembling Alburnus alburnus are strictly illiberal of seawater. Common bleak sometimes inhabits waters with temperatures starting from 10°-20°C. In order for this species to breed, the minimum temperature requirement is 14°C.

Common Bleak

Common bleak can acclimate to temperatures as much as 37.7-40.6°C if temperatures are raised progressively.

Alburnus alburnus can’t tolerate low-oxygen waters however is very tolerant of air pollution. Pollutants resembling brominated flame retardants had been discovered to bioaccumulate in Alburnus alburnus that established as a nonnative fish in Spain. The institution of this species is facilitated by dams. Alburnus alburnus co-occurs with different nonindigenous species within the Iberian Peninsula.

Common Bleak Diet

Alburnus alburnus feeds throughout the day on zooplankton and bugs within the eplimnion. It additionally feeds on terrestrial bugs that fall into lakes and subsequently excretes terrestrially derived vitamins, thereby subsidizing lake nutrient swimming pools.

This Common bleak species might have an effect on water high quality by feeding on cladocerans and different small invertebrates that immediately have an effect on water high quality.

The prey of this species is geographically widespread, permitting it to determine efficiently outdoors its native vary. In comparability to a different widespread fish (Rutilus rutilus), Alburnus alburnus has a comparatively restricted diet.

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It has an excessive reproductive price and is ready to hybridize with different cyprinids. The Common bleak larvae of this species inhabit the littoral zone of rivers and lakes, whereas juveniles inhabit the pelagic zones. It is ready to hybridize with different cyprinid genera together with Squalius, Blicca, Rutilus, and Abramis

Common Bleak Spawning

The Common bleak spawns close to the shore in shallow waters. Some are present in deep water. The substrate will not be essential.


The bleak is a vital food supply for predatory fish. It is more delicate to air pollution than different cyprinids, which could clarify the decline in North-Western Europe.


Bleak are eaten and are used as bait for sport-fishing for bigger fish. Guanine is extracted from the scales of the awful and is utilized in making artificial pearls. Learn more about ornate bichir.


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