Alburnus

Alburnus is a genus of small, freshwater fish belonging to the family Cyprinidae, the carp and minnow family. These fish are commonly known as bleak or shelding. They are primarily found in Europe and Western Asia.

Characteristics:

Alburnus species are typically slender and silvery in appearance. They are generally small, rarely exceeding 25 centimeters in length. They possess a laterally compressed body and an upturned mouth, adapted for feeding on surface insects and zooplankton. Their scales are easily detached, giving them a slippery feel.

Habitat and Distribution:

Bleak inhabit a variety of freshwater habitats, including rivers, lakes, and streams. They are adaptable and can tolerate a range of water conditions. Their distribution extends across much of Europe, from the British Isles to Russia, and into parts of Western Asia.

Ecology and Behavior:

Alburnus species are gregarious and typically form large shoals. They are active swimmers and often found near the surface of the water. Their diet consists mainly of insects that fall onto the water's surface, as well as zooplankton and algae. They are an important food source for larger predatory fish and birds.

Reproduction:

Spawning usually occurs in the spring or early summer. Females lay their eggs on submerged vegetation or gravel beds. The eggs hatch quickly, and the young fish grow rapidly.

Conservation Status:

The conservation status of Alburnus species varies depending on the specific species and their geographic location. Some species are relatively common and widespread, while others are threatened by habitat loss, pollution, and the introduction of non-native species. Conservation efforts are focused on protecting their habitats and managing populations sustainably.

Taxonomy:

The genus Alburnus has undergone several taxonomic revisions. The exact number of species within the genus is subject to ongoing research and debate. Some common species include Alburnus alburnus (the common bleak), Alburnus arborella, and Alburnus mento.