Chrosomus

Chrosomus is a genus of small freshwater fishes in the family Cyprinidae. Its exact taxonomic status has varied among authorities; some recognize Chrosomus as a distinct genus, while others treat it as a subgenus within Phoxinus. Species placed in Chrosomus are commonly referred to as chrosomids or redbelly minnows in field guides.

Description and biology

Chrosomus species are typically small, with a slender, laterally compressed body that generally reaches only a few centimeters in length. They often exhibit a dark lateral stripe across the body, which may be interrupted near the midline, and breeding individuals can show brighter coloration on the fins or sides.

Distribution and habitat

These fishes are native to freshwater systems in North America, especially streams and rivers with clear, cool water. They prefer habitats with gravel or rocky bottoms, moderate vegetation, and riffles or run sections where they can feed and reproduce.

Ecology and life history

Chrosomus species are omnivorous, feeding on small aquatic invertebrates, crustaceans, and algae. They are typically short-lived and reach sexual maturity within the first year. Reproduction is generally by broadcast spawning, with eggs deposited among vegetation or gravel and subjected to ambient water conditions rather than parental care.

Taxonomy and conservation

The genus has undergone revision, with molecular studies prompting transfers of certain species between Phoxinus and Chrosomus. As a result, the exact number of recognized species and their distribution can vary by source. Some populations are affected by habitat degradation, water pollution, and alterations to stream channels, leading to conservation concerns in certain regions.