Mekong freshwater stingray (Dasyatis laosensis)

Description

Mekong freshwater stingray fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Mekong freshwater stingray description

The Mekong freshwater stingray (Dasyatis laonenis) shows a vibrant orange colour on its upper surface ⁽³⁾ with a more uniform brown colour on the underside ⁽⁴⁾. The slim tail of the Mekong freshwater stingray is nearly twice the size of the width of its disc shaped body, a unique trait specific to this species ⁽⁵⁾.

Not much else is known about the Mekong freshwater stingray, but like other species of the Dasyatidae family, a group of whiptailed stingrays ⁽⁶⁾, the head, body and pectoral fins of the Mekong freshwater stingray are fused to a flattened round disc with a long, lean tail ⁽⁷⁾.

Size

Length: up to 60 cm ⁽²⁾

Weight

up to 6000 g ⁽²⁾

Mekong freshwater stingray biology

Little is known about the Mekong freshwater stingray. Other species in the genus Dasyatis will typically incubate the eggs of their young inside their bodies until the embryos have fully developed and are ready to hatch ⁽⁸⁾.

The diet of most species of whiptailed stingray consists of small fish and invertebrates that inhabit the river bed ^{(5) (7)}. 

Mekong freshwater stingray range

The Mekong freshwater stingray has a very restricted range, only being found in two Southeast Asian rivers: the Mekong river and the Chao Phraya river ⁽⁴⁾. The Mekong freshwater stingray has been found as far north as the Chiang Rai province in Thialand and as far south as Stung Treng in Cambodia, though its range may well extend down to the Mekong delta. It is thought to have been introduced to the Chao Phraya river ⁽¹⁾.

Mekong freshwater stingray habitat

As its name suggests, the Mekong freshwater stingray only inhabits freshwater rivers ⁽⁴⁾. It is a river-bed-dwelling species, preferring rocky or sandy bottoms in moderately fast-flowing water ⁽¹⁾.

Mekong freshwater stingray status

The Mekong freshwater stingray is classified as Endangered (EN) on the IUCN Red List ⁽¹⁾.

Mekong freshwater stingray threats

One major cause for the decline of the Mekong freshwater stingray is thought to be intensive fishing within its habitat. Though not directly fished, this species is often found in fishing nets as unwanted bycatch ⁽¹⁾.

Increased industrial and agricultural development also presents a danger to the Mekong freshwater stingray population through habitat loss ⁽⁴⁾. Building projects may contribute to an increase in water pollution ⁽¹⁾, while plans to build dams on the Mekong river and its tributaries are also predicted to exacerbate the decline of this species by isolating and splitting populations ⁽⁴⁾. The total population of the Mekong freshwater stingray is thought to have declined by roughly 50 percent in the last 20 years ⁽¹⁾.

Mekong freshwater stingray conservation

One major cause for the decline of the Mekong freshwater stingray is thought to be intensive fishing within its habitat. Though not directly fished, this species is often found in fishing nets as unwanted bycatch ⁽¹⁾.

Increased industrial and agricultural development also presents a danger to the Mekong freshwater stingray population through habitat loss ⁽⁴⁾. Building projects may contribute to an increase in water pollution ⁽¹⁾, while plans to build dams on the Mekong river and its tributaries are also predicted to exacerbate the decline of this species by isolating and splitting populations ⁽⁴⁾. The total population of the Mekong freshwater stingray is thought to have declined by roughly 50 percent in the last 20 years ⁽¹⁾.

Recommended conservation measures for the Mekong freshwater stingray include further research into its behaviour, life cycle and ecology as well as increased protection ⁽⁹⁾. 

Find out more

Find out more about the Mekong freshwater stingray:

• FishBase
  http://www.fishbase.org/summary/speciessummary.php?id=15389

Authentication

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This species information was authored as part of the ARKive and Universities Scheme.

Glossary

Bycatch

In the fishing industry, the part of the catch made up of non-target species.

Genus

A category used in taxonomy, which is below ‘family’ and above ‘species’. A genus tends to contain species that have characteristics in common. The genus forms the first part of a ‘binomial’ Latin species name; the second part is the specific name.

Incubate

To keep eggs warm so that development is possible.

Pectoral fins

In fish, the pair of fins that are found on either side of the body just behind the gills. They are generally used for balancing and braking.

References

1. IUCN Red List (February, 2010) 
   http://www.iucnredlist.org/
2. Fishbase (January 2012) 
   http://www.fishbase.org/
3. Roberts, T.R and Karbasuta, J. (1987) A new whiptailed stingray (family Dasyatidae), from the Mekong River of Laos and Thailand. Environmental Biology of Fishes, 20(3): 161-167.
4. Fowler, S.L., Cavanagh, R.D., Camhi, M., Burgess, G.H., Cailliet, G.M., Fordham, S.V., Simpfendorfer, C.A. and Musick, J.A. (2005) Sharks, Rays and Chimaeras: The Status of the Chondrichthyan Fishes. Status Survey. IUCN/SSC Shark Specialist Group, IUCN, Gland Switzerland and Cambridge, UK. Available at: 
   http://data.iucn.org/dbtw-wpd/edocs/2005-029.pdf
5. Chen, Z.M., Zhang, X.Y., Qi, W.L., Li, J.H. and Xiao, H. (2010) A new record of Dasyatid fish in China: Dasyatis laosensis. Zoological Research, 31: 675-676.
6. Michael, S.W. (1993) Reef Sharks and Rays of the World. A Guide to their Identification, Behaviour and Ecology. ProStar Publications, Annapolis.
7. Ebert, D.A. (2003) Sharks, Rays and Chimaeras of California. University of California Press, California.
8. Sarkar, A. (2003) Sexual Behaviour in Animal. Discovery Publishing House, New Delhi.
9. Lucas, M.C. and Baras, E. (2001) Migration of Freshwater Fishes, Sharks and Rays (Elasmobranchii). Blackwell Science Ltd, Oxford.