Horabagrus

Taxobox
name = "Horabagrus"


image_width = 250px
image_caption = "Horabagrus brachysoma"
regnum = Animalia
phylum = Chordata
classis = Actinopterygii
ordo = Siluriformes
familia = "incertae sedis"
genus = "Horabagrus"
genus_authority = Jayaram, 1955
subdivision_ranks = Species
subdivision =
"Horabagrus brachysoma"
(Günther, 1864)
"Horabagrus nigricollaris"
Pethiyagoda & Kottelat, 1994

"Horabagrus" is a small genus of catfishes (order Siluriformes). It comprises two species, "H. brachysoma" and "H. nigricollaris".cite journal|url=http://silurus.acnatsci.org/ACSI/library/biblios/2007_Ferraris_Catfish_Checklist.pdf|title=Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types|first=Carl J., Jr.|last=Ferraris|journal=Zootaxa|volume=1418|pages=1–628|year=2007|format=PDF] "H. brachysoma" is an important food fish, and both species are available as aquarium fish.

Common names

"H. brachysoma" is known as "Günther's catfish" or "yellow catfish".cite journal|url=http://www.springerlink.com/content/616578362350w1u1/fulltext.pdf|title=Threatened fishes of the world: "Horabagrus brachysoma" (Gunther, 1864)(Bagridae)|first=P.H. Anvar|last=Ali, R. Raghavan & G. Prasad|journal=Environmental Biology of Fishes|year=2007|volume=78|pages=221|format=PDF|doi=10.1007/s10641-006-0022-4] It is also known as "manjakoori" in its native range. It is also known by a host of other names, such as "bullseye catfish", "golden red tail catfish", "solar catfish", and "sun catfish". "H. nigricollaris" is known as the "Black Collared Catfish".

Taxonomy

"Horabagrus brachysoma" was described by Albert C. L. G. Günther in 1864 under the name "Pseudobagrus brachysoma".FishBase species|genus=Horabagrus|species=brachysoma|year=2007|month=May] "Horabagrus nigricollaris" was described by Pethiyagoda and Kottelat in 1994.FishBase species|genus=Horabagrus|species=nigricollaris|year=2007|month=May]

The genus "Horabagrus" is usually classified under the family Bagridae, but there are disagreements. The genus name is after the Indian zoologist Sunder Lal Hora. Though listed under Bagridae, "Horabagrus" is not listed under either of the two Bagrid subfamilies by the All Catfish Species Inventory. [cite web| url = http://silurus.acnatsci.org/ACSI/taxa/Genera_by_Family/Genera_Bagridae.html | title = Bagridae genera | publisher = All Catfish Species Inventory | accessdate = 2007-03-31] In Nelson (2006), the genus is provisionally placed in the family Schilbeidae, where it is sometimes recognized as its own subfamily. In de Pinna (1998), this genus is classified as sister to the catfishes Pangasiidae and above, which would require a separate family.cite book|title=Fishes of the World|last=Nelson|first=Joseph S.|publisher=John Wiley & Sons, Inc|year=2006|isbn=0-471-25031-7] This genus has also been classified in its own family "Horabagridae".cite journal|journal=Mol Phylogenet Evol.|year=2006|volume=41|issue=3|pages=636–62|title=A phylogenetic analysis of the major groups of catfishes (Teleostei: Siluriformes) using rag1 and rag2 nuclear gene sequences|last=Sullivan|first=JP|coauthors=Lundberg JG; Hardman M|doi=10.1016/j.ympev.2006.05.044] In a 2007 paper, "Horabagrus" was not classified under any current catfish families.cite journal|url=http://silurus.acnatsci.org/ACSI/library/biblios/2007_Ferraris_Catfish_Checklist.pdf|title=Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types|first=Carl J., Jr.|last=Ferraris|journal=Zootaxa|volume=1418|pages=1–628|year=2007|format=PDF]

Distribution

These two species have a relatively restricted range. They are both restricted to India.cite journal|url=http://www.catfishstudygroup.org/pdf/catfishes_of_asia2.pdf|title=The Catfishes of Asia Family Bagridae part two|last=Linder|first=R. Shane|journal=Cat Chat|volume=1|issue=2|date=June 2000|format=PDF] "H. brachysoma" is known only from the Kerala Backwaters, Vembanad Lake and the Uttara Kannada district of Karnataka.cite journal|url=http://www.geocities.com/fishyanu/horabagrus.pdf|title=New Report of the Species, "Horabagrus brachysoma" in Uttara Kannada district of Karnataka|first=Anuradha|last=Bhat|journal=Journal of the Bombay Natural History Society|year=2001|volume=98|issue=2|pages=294–296|format=PDF] "H. nigricollaris" is only found in the Chalakudy River in Kerala, India. "H. brachysoma" is found in smooth flowing areas with much vegetation.

Appearance and anatomy

"H. brachysoma" has a large head and a wide mouth. The eyes are large and can be seen from below the fish. There is a dorsal fin with a hard spine as well as an adipose fin. There are four pairs of barbels, one nasal, one maxillary (sides of the mouth), and two mandibular (chin). "H. nigricollaris" is sleeker in body shape than "H. brachysoma". "H. brachysoma" reaches about 45 centimetres (18 in). "H. nigricollaris" reaches about 27 cm (11 in). These two species are quite similar in appearance. "H. brachysoma" hosts a large black shoulder spot on either side with light outlines. However, in "H. nigricollaris" the marking extends over the neck, forming a "black collar" (hence the scientific name). "H. brachysoma" also has a more yellowish body than "H. nigricollaris".cite web|url=http://www.planetcatfish.com/cotm/cotm.php?article_id=107|title=PlanetCatfish::Catfish of the Month::September 2001|date=2005-07-14|accessdate=2007-05-17]

Habitat and ecology

"H. brachysoma" is found in smooth flowing areas with much vegetation. This species occupies lowland areas of rivers and backwaters with mud or sand substrate. It has also been recorded in deep pools and hill streams. "H. nigricollaris" inhabits hill streams at upper reaches of rivers.

The diet of "H. brachysoma" has been studied. It is an unspecialized feeder and eats a variety of meaty foods. Food items include crustaceans, molluscs, and fish. Adults may consume terrestrial insects and even frogs. Stomachs of these fish contain detritus which is indicative of its bottom-feeding habits. This flexible diet is beneficial in its variable habitat, in which food availality is affected by monsoons.cite journal|url=http://www.blackwell-synergy.com/doi/pdf/10.1111/j.1095-8649.2006.01134.x|title=The diet of "Horabagrus brachysoma" (Gunther), an endangered bagrid catfish from Lake Vembanad (South India)|first=N.|last=Sreeraj|coauthors=Raghavan, R.; Prasad, G.|journal=Journal of Fish Biology|year=2006|volume=69|pages=637–642|doi=10.1111/j.1095-8649.2006.01134.x] Feeding rate is known to increase during the breeding season in the months following the monsoon season. Spawning occurs before the monsoons and finishes by the southwest monsoon in the summer.

In the aquarium

"H. brachysoma" is a common fish in the aquarium trade. "H. nigricollaris" is more seldomly seen because it is not commercially farmed like the former. Nevertheless, the care for these two species is similar. These fish are said to have a lot of "personality". These fish are adaptable and are not picky about water conditions; also, they are hardy and easy to feed. However, these fish are light-shy and require plants or decorations to hide underneath for darkness; these fish are relatively secretive during the day.cite web|url=http://www.planetcatfish.com/catelog/species.php?species_id=159|title=PlanetCatfish::Cat-eLog::Horabagrus brachysoma|date=2006-02-26|accessdate=2007-05-18]

Conservation

Neither species is listed on the IUCN Red List. However, "H. brachysoma" is considered to be an endangered species and "H. nigricollaris" is considered a critically endangered species.cite journal|url=http://www.lars2.org/unedited_papers/unedited_paper/Kurup.pdf|title=Biodiversity Status of Fishes Inhabiting Rivers of Kerala (S.India) with Special Reference to Endemism, Threats, and Conservation Measures|first=B.Madhusoodana|last=Kurup|coauthors=Radhakrishnan, K.V.; Manojkumar, T.G.|format=PDF] "H. brachysoma" is marketed live and supports a local fishery during the rainy season. Overexploitation, habitat alteration, pollution and related anthropogenic pressures on their natural habitats have considerably reduced populations of this species by 60–70% during the last few years. Research is currently being funded to study "H. brachysoma", especially its captive breeding. Due to the importance of "H. brachysoma" as a food and ornamental fish, it embodies the problems that must be resolved for sustainable management, and could be used as a flagship species to provide focus for media attention for conservation.

ee also

*List of freshwater aquarium fish species

References