Description and characteristics
The whitefish (Coregonus sp.) is a cold-water fish with a fusiform body covered with small, silvery scales. It has a small mouth, terminal or directed downwards, and a visible lateral line, belonging to the salmonid family.
Habitat and distribution
It prefers clear, cold, oxygen-rich waters — branches and deeper areas of the Danube Delta, with sandy or hard bottoms. It is sensitive to water quality and temperature.
Diet and behaviour
It feeds on plankton, small crustaceans, insect larvae and benthic invertebrates. It lives in schools and moves depending on food availability.
Reproduction
Spawning occurs in autumn or winter depending on the species, with females laying eggs on hard bottoms. The fry grow slowly and mature late.
Economic and ecological importance
The whitefish has value for commercial and sport fishing. Ecologically, it is an indicator of water quality, being sensitive to pollution.
Threats and conservation
It is strongly affected by pollution, water warming and habitat alteration. Protecting clean waters is essential for its survival.
Fishing and legal minimum size
It is fished with nets and specific baits. In the table of minimum legal sizes, the whitefish (Coregonus sp.) has a minimum legal size of 22 cm.
Conclusion
The whitefish is demanding about water quality, representing an indicator of the health of the aquatic ecosystems of the Danube Delta.