Freshwater catfish
Encyclopedia
Siluridae is a family of catfish
(order
Siluriformes). They are sometimes known as sheatfish, although that name may also be used more specifically for Silurus glanis, the wels catfish
. There are about 100 living species
of silurids.
Although silurids occur across much of Europe
and Asia
, they are most diverse in southeast Asia
, beyond which their diversity decreases in temperate east Asia, the Indian subcontinent
, southwest Asia, and Europe. Silurids are apparently absent from much of central Asia. The family can be divided into two groups, a temperate Eurasian clade and a more diverse subtropical/tropical south and southeast Asian clade.
These catfish do not have a spine before their dorsal fin
, do not have an adipose fin, and the pelvic fins are either small or absent. The anal fin base is usually very long. The largest species in this family is Silurus glanis, the Wels Catfish
.
Catfish
Catfishes are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the heaviest and longest, the Mekong giant catfish from Southeast Asia and the second longest, the wels catfish of Eurasia, to detritivores...
(order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
Siluriformes). They are sometimes known as sheatfish, although that name may also be used more specifically for Silurus glanis, the wels catfish
Wels catfish
The wels catfish , also called sheatfish, is a large catfish found in wide areas of central, southern, and eastern Europe, and near the Baltic and Caspian Seas. It is a scaleless fresh and brackish water fish recognizable by its broad, flat head and wide mouth...
. There are about 100 living species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of silurids.
Although silurids occur across much of Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
and Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
, they are most diverse in southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
, beyond which their diversity decreases in temperate east Asia, the Indian subcontinent
Indian subcontinent
The Indian subcontinent, also Indian Subcontinent, Indo-Pak Subcontinent or South Asian Subcontinent is a region of the Asian continent on the Indian tectonic plate from the Hindu Kush or Hindu Koh, Himalayas and including the Kuen Lun and Karakoram ranges, forming a land mass which extends...
, southwest Asia, and Europe. Silurids are apparently absent from much of central Asia. The family can be divided into two groups, a temperate Eurasian clade and a more diverse subtropical/tropical south and southeast Asian clade.
These catfish do not have a spine before their dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
, do not have an adipose fin, and the pelvic fins are either small or absent. The anal fin base is usually very long. The largest species in this family is Silurus glanis, the Wels Catfish
Wels catfish
The wels catfish , also called sheatfish, is a large catfish found in wide areas of central, southern, and eastern Europe, and near the Baltic and Caspian Seas. It is a scaleless fresh and brackish water fish recognizable by its broad, flat head and wide mouth...
.