Stream catfish

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Stream catfishes
Acrochordonichthys rugosus.jpg
Acrochordonichthys rugosus
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Siluriformes
Superfamily: Sisoroidea
Family: Akysidae
Gill, 1861
Genera

Subfamily Akysinae
  Akysis
  Pseudobagarius
Subfamily Parakysinae
  Acrochordonichthys
  Breitensteinia
  Parakysis

Contents

The stream catfishes comprise the family Akysidae of catfishes.

Distribution and habitat

Akysids are known from across a large area in Southeast Asia. [1] They are found in fresh water. [2] Fish of the subfamily Parakysinae are primarily found in the Malay Peninsula, Sumatra, Sarawak, and western and southern Borneo. [2] Most species are generally found in deeper parts of relatively swift rivers and forest streams. [3]

Taxonomy

It includes at least 57 species in five genera; many species are only recently described. The family is divided into two subfamilies, Akysinae and Parakysinae. [2] The Parakysinae had previously been listed as an independent family. [2] [4]

This family is sister to a clade formed by Sisoridae, Erethistidae, and Aspredinidae. [2]

Description

Akysids are small to minute fishes with cryptic colouration, tiny eyes, and completely covered with unculiferous plaques or tubercles. In some genera, some of the tubercles on the body are enlarged and arranged in distinctive longitudinal rows, the number of which may be diagnostic. [1] The dorsal fin has a strong spine and a short base, and usually four or five soft rays and four pairs of barbels are found. [2] Unusually among catfish, they have a low principal caudal fin ray count and more rays in the upper caudal fin lobe than the lower. [5]

In the Akysinae, the body has small unculiferous tubercles arranged in longitudinal rows, a median mid-dorsal row, usually in four lateral rows. The dorsal fin usually has five soft rays. An adipose fin is present and moderate. The pectoral fin has a strong spine, and the anterior margin has a notch visible dorsally and usually serrated posteriorly. The gill openings are relatively narrow and the eyes are small. [2]

In the Parakysinae, the dorsal fin has four soft rays. The pectoral fin spine is not serrated. The anal fin has eight to 13 soft rays. The mandibular barbels usually have short accessory barbels. Gill rakers and lateral line pores are absent. The head and body are covered with rounded tubercles arranged in longitudinal rows in Acrochordontichthys and Breitensteinia or evenly distributed in Parakysis. The adipose fin is absent in Breitensteinia and Parakysis and is present as an adipose ridge; the fin is present and long in Acrochordontichthys. The eyes are minute. They have 3032 vertebrae. [2]

Related Research Articles

<i>Akysis</i> Genus of catfish

Akysis is the largest genus of catfishes of the family Akysidae.

<i>Auchenipterichthys</i> Genus of fishes

Auchenipterichthys is a genus of driftwood catfishes found in South America.

Parakysis is a genus of catfishes of the family Akysidae. It includes six species.

Breitensteinia is a genus of catfishes of the family Akysidae. It includes three species.

<i>Acrochordonichthys</i> Genus of catfish

Acrochordonichthys is a genus of catfishes of the family Akysidae. It includes ten species.

Synodontis polli, known as Poll's synodontis, is a species of upside-down catfish endemic to the Democratic Republic of the Congo, Burundi, Zambia, and Tanzania, where it is only known from Lake Tanganyika. It was first described by Belgian ichthyologist Jean-Pierre Gosse in 1982, from specimens collected at multiple points along the shore of Lake Tanganyika. The species name comes from the Latin word "granulum", meaning of grain, and refers to the granular papillae present on the skin of the fish's body.

Lake Victoria squeaker Species of fish

The Lake Victoria squeaker is a species of upside-down catfish that is native to Kenya, Burundi, Tanzania and Uganda where it is found in Lakes Kioga and Victoria and the Victorian Nile the lower Kagera River and the Malagarasi River drainage. It was first described by British-Belgian zoologist George Albert Boulenger in 1906, from specimens collected in the Lake Victoria at Buganga, Uganda and Entebbe, Uganda by Mr. E. Degen. The species name victoriae is derived from the location where the species was originally discovered, Lake Victoria.

<i>Synodontis filamentosus</i> Species of fish

Synodontis filamentosus, known as the longfin synodontis, is a species of upside-down catfish that is native to the basins of the Nile, Volta and Niger Rivers as well as the Chad Basin. It was first described by British-Belgian zoologist George Albert Boulenger in 1901, from specimens obtained near the mouth of Lake No, on the White Nile in Sudan. The species name filamentosus comes from the elongated rays of the dorsal and caudal fins.

<i>Synodontis grandiops</i> Species of fish

Synodontis grandiops is a species of upside-down catfish endemic to the Democratic Republic of the Congo, Burundi, and Tanzania, where it is only known from Lake Tanganyika. It was first described by Jeremy John Wright and Lawrence M. Page in 2006, from specimens collected at multiple points along the shore of Lake Tanganyika. The species name is a Latinized combination of the Latin "grandi", meaning large or big, and the Greek "ops", meaning eye, a reference to the relatively large eyes of this fish.

Synodontis ilebrevis is a species of upside-down catfish endemic to Zambia, where it is only known from Lake Tanganyika. It was first described by Jeremy John Wright and Lawrence M. Page in 2006, from specimens collected from Lake Tanganyika at Cape Chaitika, Zambia. The species name comes from the Latin word "ile", meaning intestine, and the Latin word "bevis", meaning short, and refers to the relatively short gut of this species.

<i>Synodontis multimaculatus</i> Species of fish

Synodontis multimaculatus, known as the dotted synodontis, is a species of upside-down catfish that is native to the Democratic Republic of the Congo where it is found in the Ubangi River. It was first described by British-Belgian zoologist George Albert Boulenger in 1902, from a specimen collected in the Ubangi River in Mobayi-Mbongo, the Democratic Republic of the Congo. The species name multimaculatus is derived from the word multi, meaning many, and the Latin word maculatus, meaning spots, referring to the many spots on the fish.

<i>Synodontis ocellifer</i> Species of fish

Synodontis ocellifer, known as the ocellated synodontis, is a species of upside-down catfish native to the rivers of northern and western Africa. It has been reported in 10 countries, including Burkina Faso, Cameroon, Chad, Gambia, Ghana, Guinea, Mali, Niger, Nigeria, and Senegal. It was first described by Belgian-British zoologist George Albert Boulenger in 1900, from specimens collected in Kunchow Creek, in Gambia. The species name ocellifer comes from the Latin word ocellus, meaning "eye", and the Latin word ifer, meaning "to carry", which refers to the black spots, possibly with white centers found on the sides.

<i>Synodontis omias</i> Species of fish

Synodontis omias is a species of upside-down catfish native to the Niger River basin of Guinea, Mali, Niger and Nigeria. It was first described by German-born British zoologist, ichthyologist, and herpetologist Albert Günther in 1864, from a specimen collected in Jebba, Nigeria, on the Niger River. There have been very few specimens of this species identified, and it may be the same species as S. budgetti from the Upper Niger.

Synodontis pardalis is a species of upside-down catfish that is endemic to Cameroon where it occurs in the Dja River drainage. It was first described by British-Belgian zoologist George Albert Boulenger in 1908, from specimens collected in the Dja River in southern Cameroon. The species name pardalis is derived from the Greek word pardalis, which means "leopard", which refers to the spotted pattern on the fish.

<i>Synodontis robbianus</i> Species of fish

Synodontis robbianus, known as the russet synodontis, is a species of upside-down catfish that is native to Nigeria where it is found in the Cross and lower Niger Rivers. It was first described by John Alexander Smith in 1875, from specimens collected in the Calabar River, Nigeria. The species name robbianus is named after Rev. Alexander Robb, a Scottish missionary, who collected the original species samples.

<i>Synodontis serratus</i> Species of fish

Synodontis serratus, known as the shield-head squeaker, is a species of upside-down catfish that is native to the Nile basin of the Democratic Republic of the Congo, Egypt, Ethiopia and Sudan. It was first described by German naturalist and explorer Eduard Rüppell in 1829, from specimens obtained near Cairo, Egypt. The species name serratus comes from the Latin word serra, meaning "saw", which refers to the serrated pectoral spines of the species.

<i>Synodontis sorex</i> Species of fish

Synodontis sorex is a species of upside-down catfish that is widely distributed in the rivers of northern Africa. It was first described by German zoologist Albert Günther in 1864, from specimens obtained in the upper Nile River, near Khartoum, Sudan. The species name sorex comes from the Latin word for shrew or shrew-mouse, the allusion was not explained. It possibly describes the pointed snout or the long, slender teeth.

Synodontis lucipinnis is a species of upside-down catfish endemic to Zambia, where it is only known from the Musende Rocks area (Mpulungu) of Lake Tanganyika. It was first described by Jeremy John Wright and Lawrence M. Page in 2006. The species name "lucipinnis" is derived from a combination of the Latin luci, meaning bright or clear, and the Latin pinnis, meaning fin. This refers to the light coloration in a patch on the base of the fins of this species.

<i>Synodontis melanostictus</i> Species of fish

Synodontis melanostictus is a species of upside-down catfish endemic to Lake Tanganyika and its tributaries. It has been found in Zambia, the Democratic Republic of the Congo, and Burundi. It was first described by British-Belgian zoologist George Albert Boulenger in 1906, based upon a specimen from the Lofubu River. The species name "melanostictus" is derived from a combination of the Greek melano, meaning black, and the Greek stiktos, meaning punctured or spotted. This refers to the black spotted pattern that occurs on the body of this species.

Synodontis irsacae is a species of upside-down catfish endemic to Zambia, the Democratic Republic of the Congo, and Tanzania, where it is only known from Lake Tanganyika. It was first described by Belgian ichthyologist Hubert Matthes in 1959, from specimens collected from Lake Tanganyika at Kalundu, in what is now the Democratic Republic of the Congo. The species name " irsacae" is derived from the abbreviation "I.R.S.A.C.", or Institut pour la Recherche Scientifique en Afrique Centrale. For many years, specimens of the species were considered to be juvenile members of S. dhonti, but in 2006, J.J. Wright and L.M. Page identified unique characteristics of this species that established that they were a unique species.

References

  1. 1 2 Ng, Heok Hee; Siebert, Darrell J. (2004). "A new species of the catfish genus Akysis (Siluriformes: Akysidae) from southern Borneo" (PDF). Zootaxa . 733: 1–8. Retrieved 2009-06-25.
  2. 1 2 3 4 5 6 7 8 Nelson, Joseph S. (2006). Fishes of the World . John Wiley & Sons, Inc. ISBN   0-471-25031-7.
  3. Ng, H. H.; Ng, P. K. L. (2001). "A revision of the akysid catfish genus Acrochordonichthys Bleeker" (PDF). Journal of Fish Biology. 58 (2): 386–418. doi:10.1111/j.1095-8649.2001.tb02260.x. hdl: 2027.42/75446 .
  4. Froese, Rainer, and Daniel Pauly, eds. (2007). "Parakysidae" in FishBase . Mar 2007 version.
  5. Ng, H. H.; Siebert, D. J. (1998). "A revision of the akysid catfish genus Breitensteinia Steindachner with descriptions of two new species". Journal of Fish Biology. 53: 645–657. doi:10.1111/j.1095-8649.1998.tb01008.x.