Common bream
Abramis brama
The common bream is a deep-bodied, laterally compressed freshwater fish primarily found in slow-moving or standing waters. It features a protractile mouth used to sift through bottom sediment for food. Older individuals often develop a bronze or golden-brown coloration, whereas juveniles are typically silvery.
Details
Identification
Deep-bodied and laterally compressed, long anal fin (23-29 rays), protractile mouth, dark grey to blackish fins.
Social behavior
Gregarious schooling fish, appearing in large groups especially when foraging on the water body floor.
Diet
Benthivorous diet: consumes midge larvae, tubifex, small mollusks, crustaceans, and occasionally zooplankton.
Hunting strategy
Bottom-grubbing: sifts through the sediment for edible organisms using its protractile mouth.
Spawning substrate
Aquatic plants, flooded grasses, or root systems (phytophilous spawner).
Overwintering
Retreats to deeper, low-flow water zones and significantly reduces metabolic activity.
Ecology
Ecological role
Important consumer of benthos; facilitates sediment mixing (bioturbation) through its bottom-grubbing behavior.
Natural predators
Northern pike, zander, wels catfish, cormorant, Eurasian otter; juveniles also preyed upon by perch.
Competitor species
Silver bream, roach, common carp (food competition in the benthic zone).
Ecosystem service
Nutrient redistribution within the water body; serves as a significant food source for large predatory fish.
Threats
Loss of shallow-water spawning habitats due to bank stabilization, river barriers, and water pollution.
Scientific profile
Morphology & ID
Coloration
Back dark olive-grey to black; sides silvery in juveniles, turning bronze or golden in adults; belly whitish with a pearly luster; fins are dark grey.
Distinguishing features
Protractile, tube-like mouth; very long anal fin (23-30 branched rays); no barbels; single row of pharyngeal teeth (5-5); scales smaller than those of the silver bream.
Confusion species
Silver bream (Blicca bjoerkna), Blue bream (Ballerus ballerus), White-eye bream (Ballerus sapa), Ide (Leuciscus idus).
Sexual dimorphism
Males develop distinct spawning tubercles (small white nodules) on the head and body during the breeding season; females are generally deeper-bodied.
Habitat
Fish region
Bream zone (lower reaches of lowland rivers)
Preferred zone
Benthic / Demersal (bottom-dwelling)
Flow preference
Limnophilous to eurytopic (prefers stagnant or slow-flowing waters).
Substrate preference
Muddy or sandy bottom with high organic content (fine sediment).
Oxygen requirement
Low; tolerant of low dissolved oxygen levels (euryoxybiont).
Migration
Migration behaviour
Potamodromous; undertakes migrations between feeding, wintering, and spawning habitats, often into shallower coastal areas or tributaries.