''Cottus perifretum'', the bullhead or miller’s thumb, is a species of freshwater

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or h ...

belonging to the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Cottidae The Cottidae are a family of fish in the superfamily Cottoidea, the sculpins. It is the largest sculpin family, with about 275 species in 70 genera.Kane, E. A. and T. E. Higham. (2012)Life in the flow lane: differences in pectoral fin morphology ...

, the typical sculpins. It is found on both sides of the

English Channel The English Channel, "The Sleeve"; nrf, la Maunche, "The Sleeve" (Cotentinais) or ( Jèrriais), (Guernésiais), "The Channel"; br, Mor Breizh, "Sea of Brittany"; cy, Môr Udd, "Lord's Sea"; kw, Mor Bretannek, "British Sea"; nl, Het Kana ...

, native to

Great Britain Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It i ...

. It also inhabits Atlantic drainages from the

Garonne The Garonne (, also , ; Occitan, Catalan, Basque, and es, Garona, ; la, Garumna or ) is a river of southwest France and northern Spain. It flows from the central Spanish Pyrenees to the Gironde estuary at the French port of Bordeaux – ...

River (tributaries draining from

Massif Central The (; oc, Massís Central, ; literally ''"Central Massif"'') is a highland region in south-central France, consisting of mountains and plateaus. It covers about 15% of mainland France. Subject to volcanism that has subsided in the last 10,0 ...

) to the

Scheldt The Scheldt (french: Escaut ; nl, Schelde ) is a river that flows through northern France, western Belgium, and the southwestern part of the Netherlands, with its mouth at the North Sea. Its name is derived from an adjective corresponding to ...

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...

and

Belgium Belgium, ; french: Belgique ; german: Belgien officially the Kingdom of Belgium, is a country in Northwestern Europe. The country is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to th ...

, and the Moselle and

Sieg The Sieg is a river in North Rhine-Westphalia and Rhineland-Palatinate, Germany. It is a right tributary of the Rhine. The river is named after the Sicambri. It is in length. The source is located in the Rothaargebirge mountains. From h ...

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

. It is considered invasive in the

Rhine ), Surselva, Graubünden, Switzerland , source1_coordinates= , source1_elevation = , source2 = Rein Posteriur/Hinterrhein , source2_location = Paradies Glacier, Graubünden, Switzerland , source2_coordinates= , so ...

drainage in Germany and the

Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

. This invasive population in the Rhine is an intermediate between this species and '' Cottus rhenanus''. Although this species is native to England and Wales it is considered to be a non-native invasive species in Scotland. This species was described as a separate species from the

European bullhead The European bullhead (''Cottus gobio'') is a freshwater fish that is widely distributed in Europe, mainly in rivers. It is a member of the family Cottidae, a type of sculpin. It is also known as the miller's thumb, freshwater sculpin, common bu ...

(''C. gobio'') in 2005 by

Jörg Freyhof Jörg Arthur Freyhof (born 4 November 1964 in Ludwigshafen) is a German ichthyologist specializing on Old World cypriniform fishes.

Maurice Kottelat Maurice Kottelat (born 16 July 1957 in Delémont, SwitzerlandC ...

and Arne W. Nolte. The specific name ''perifretum'' is a combination of ''peri'', meaning “around”, and ''fretum'', meaning “straits”, an allusion to the species distribution on either side of the

, called ''Fretum Gallicum'' in

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

. It reaches a maximum length of 13.4 cm. It prefers small streams to medium-sized rivers.

References

Cottus (fish) Freshwater fish of Europe Fish described in 2005 {{Scorpaeniformes-stub