Rutilus rutilus

Overview

Rutilus rutilus, commonly known as the roach, spurious red feather, or swallow, is a species of freshwater fish belonging to the family Leuciscidae. It is widely distributed across Europe and West Asia.

Physical Characteristics

The roach reaches a length of 25 to 50 centimeters (10-20 inches) and weighs up to 3 kilograms (6.6 pounds). Its body has a high-backed shape with greenish upper sides and white abdominal sides. The eyes and fins are reddish in color, which is thought to be the origin of its name.

The roach's body shape and coloration can vary depending on the type of water it inhabits. In flowing waters, they tend to be slimmer and have a silvery scale coloration on their sides. In still waters, such as lakes, they may develop a high-backed shape with a slight golden coloration.

Morphology

One of the distinctive features of the roach is its bright red iris. It also lacks jaw teeth but has throat teeth that allow it to crush its food.

Habitat and Distribution

The roach is found in Europe and West Asia, where it is often one of the most common freshwater fish species. However, in waters with high turbidity and sparse vegetation, other species such as the common bream and carp may outcompete them for biomass.

Behavior

Rutilus rutilus is a gregarious fish that makes short movements within its territory. It is not considered a migratory fish, but during the cold season, it may migrate to deeper waters where it can be found in dense schools of hundreds of individuals.

Diet and Habitat Preferences

Adult roach tend to prefer plant-rich waters, which provide them with food and shelter. Young or adult roach may consume plants, and fry are easily hidden among vegetation.

Adaptability

The roach is able to adapt to environments with varying levels of invertebrate presence, making it a resilient species in different aquatic ecosystems.

Confusion with Red Feather (Scardinius erythrophthalmus)

Rutilus rutilus is often confused with the related species Scardinius erythrophthalmus, also known as the red feather. However, the two species can be distinguished by their abdominal fin position and other morphological differences.