Cottus perifretum

Description

Cottus perifretum is a species of fish in the family Cottidae. It is found on both sides of the English Channel. It also inhabits Atlantic drainages from the Garonne River (tributaries draining from Massif Central) to the Scheldt in France and Belgium, and the Moselle and Sieg in Germany. It is considered invasive in the Rhine drainage in Germany and the Netherlands. This invasive population in the Rhine is an intermediate between this species and Cottus rhenanus. It reaches a maximum length of 13.4 cm. It prefers small streams to medium-sized rivers.