The Denison barb, Denison's barb, Miss Kerala, red-line torpedo barb, or roseline shark (''Dawkinsia denisonii'') is an endangered

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

cyprinid Cyprinidae is a Family (biology), family of freshwater fish commonly called the carp or minnow family, including the carps, the true minnows, and their relatives the barb (fish), barbs and barbel (fish), barbels, among others. Cyprinidae is the ...

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the fast-flowing hill streams and rivers of the Western Ghats in

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

. It is commonly seen in the

aquarium An aquarium (: aquariums or aquaria) is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. fishkeeping, Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aquati ...

trade; pet collection caused it to become endangered and is its single major threat.

Physical characteristics

The fish is characterized by a torpedo-shaped body with silver scales, a red line running from their snout, through the eye, back towards the middle of the body; and below the red line, a black line that runs the length of the fish to the tail. As they mature, a distinctive green/blue marking on top of the head develops. This species reputedly reaches a length of TL, but typically will only reach . They are active shoaling fishes. The species was described by

Francis Day Francis Talbot Day (2 March 1829 – 10 July 1889) was an army surgeon and naturalist in the Madras Presidency who later became the Inspector-General of Fisheries in British Raj, India and British rule in Burma, Burma. A pioneer ichthyologist, ...

and named after Sir

William Denison Sir William Thomas Denison (3 May 1804 – 19 January 1871) was Lieutenant Governor of Van Diemen's Land from 1847 to 1855, Governor of New South Wales from 1855 to 1861, and Governor of Madras from 1861 to 1866. According to Percival Se ...

Habitat and threats

Denison barb is endemic to the

Achenkovil Achankovil is a long west flowing river in Kerala, India. It flows through the districts of Kollam, Pathanamthitta and Alappuzha. The river drains vast tract of fertile plains of Upper Kuttanad in the Alappuzha and Pathanamthitta districts. I ...

, Pamba and

Chaliyar Chaliyar River () is the fourth longest river in Kerala at 169 km in length. The Chaliyar is also known as Chulika River, Nilambur River or Beypore River as it is near the sea. Pothukal, Chungathara, Nilambur, Mampad, Edavanna, Kavano ...

rivers. Specifically, they are found in four locations — Cheenkannipuzha (a major tributary of Valapattanam River), the Achankovil river, the Chaliyar river and near

Mundakayam Mundakayam, is a town in Kanjirappally Taluk in the Kottayam District of Kerala. It is the doorway to the high ranges of southern Kerala, and is at the border of Kottayam and Idukki districts. The next nearest town, Kanjirappally, is & Erumely ...

town. The

has an estimated range of . ''S. denisonii'' is a

benthopelagic The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer of ...

species that is gregarious and

shoals In oceanography, geomorphology, and geoscience, a shoal is a natural submerged ridge, bank, or bar that consists of, or is covered by, sand or other unconsolidated material, and rises from the bed of a body of water close to the surface or ...

are known to occur in rocky pools with thick vegetation along their banks. They thrive in a

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Ge ...

climate in water with a 6.8–7.8 pH, a water hardness of 5–25

dGH Degrees of general hardness (dGH or °GH) is a unit of water hardness, specifically of general hardness. General hardness is a measure of the concentration of divalent metal ions such as calcium (Ca2+) and magnesium (Mg2+) per volume of wate ...

and a temperature range of . As reported by

Practical Fishkeeping ''Practical Fishkeeping'' (also known as ''PFK'') is a United Kingdom-based aquarium magazine. It is published every four weeks by Warners Publications Plc. The title covers the entire aquatic market from tropical freshwater and tropical mari ...

in January 2009, new research by team of scientists from India suggests that the species is being

over-exploited Overexploitation, also called overharvesting or ecological overshoot, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to ...

for the aquarium trade, potentially placing it at risk of extinction. In spite of being listed as

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

by local assessment reports the fish had been promoted as an 'export item' by several government agencies. The population structure, age, growth, mortality and harvest intensity in the

Valapattanam River The Valapattanam River is a 110 km long river which flows through the Kannur district in North Kerala. It is the longest river in the Kannur district. Course The Valapattanam River originates from the Brahmagiri hills of Western Ghats in ...

was studied and suggests that the species is being over-exploited. The fish was most likely collected and exported out of India in 1996. In 1997, it won the third prize at 'Aquarama 1997' (world exhibition on Ornamental fish) under the 'New Species Category'. By 2007–08 it constituted about 60–65% of the total live ornamental fish exported from India which was worth US$1.54 million. Though the Government of Kerala banned the fishing and export of the endangered barb, it is yet to be listed under the National Wildlife Protection Act. The golden form of this Denison barb is extinct from the wild but few Aquarium hobbyists have it in their collection.

In the aquarium

This fish is a relatively new addition to the fish keeping hobby. The Denison's barb is a schooling fish that is usually kept in groups. It tends to be peaceful but some have been known to be slightly aggressive around food, especially if kept in less space than they require. They eat bloodworms,

shrimp A shrimp (: shrimp (American English, US) or shrimps (British English, UK)) is a crustacean with an elongated body and a primarily Aquatic locomotion, swimming mode of locomotion – typically Decapods belonging to the Caridea or Dendrobranchi ...

, meat, fish flake and some vegetation. A similar fish, ''

Dawkinsia chalakkudiensis ''Dawkinsia chalakkudiensis'' is a species of cyprinid fish endemic to the Chalakkudy River, Kerala Kerala ( , ) is a States and union territories of India, state on the Malabar Coast of India. It was formed on 1 November 1956, follow ...

'' is sometimes confused with this fish, but it is a larger, less colourful and a more aggressive species.

Breeding

Over the years many efforts have been made to breed this rapidly depleting species in captivity, initially with limited success. In 2009, success came from the work carried out at the Fisheries College, Kerala by Bony Joseph. Breeding efforts have also been carried out by

Chester Zoo Chester Zoo is a zoo in Upton-by-Chester, Cheshire, England. Chester Zoo was opened in 1931 by George Mottershead and his family. The zoo is one of the UK's largest zoos at and the zoo has a total land holding of approximately . Chester Zoo ...

and two amateur fish-lovers from

Chennai Chennai, also known as Madras (List of renamed places in India#Tamil Nadu, its official name until 1996), is the capital city, capital and List of cities in Tamil Nadu by population, largest city of Tamil Nadu, the southernmost states and ...

(India), Venkatesh and Murali. These efforts may pave the way for standardizing the process and would be a major boost to conservation and the ornamental fish trade in India. Large numbers are now being bred in captivity at commercial facilities.

References

External links

''Puntius denisonii'' breeding - Photos of Puntius denisonii’s epic journey from egg to hatchling, from www.fishesninverts.comPhotos at FishbaseMadan Subramanian at Bangalore, India

* ttp://www.iucnredlist.org/news/threatened-freshwater-fish-fall-through-net-of-mismanaged-aquarium-pet-trade Threatened freshwater fish fall through net of mismanaged aquarium pet trade(

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...