|Scientific Name:||Cirrhinus microlepis Sauvage, 1878|
Cirrhina aurata Sauvage, 1878
Cirrhina microlepis Sauvage, 1878
Labeo aurovittatus Sauvage, 1878
Labeo pruol Tirant, 1885
|Red List Category & Criteria:||Vulnerable A2ade ver 3.1|
|Reviewer(s):||Conway, K.W. & Allen, D.J.|
The species is recorded from the Chao Phraya, from where it has been extirpated, and from the Mekong basin in Thailand, Laos PDR, Cambodia and Viet Nam. It is still a commercial species in the Mekong and there are specific fisheries that target the species.
The species is known to be impacted by pollution, dams and overfishing (C. Vidthayanon pers. comm. 2011). The remaining populations in the Mekong are likely to be greatly impacted by proposed mainstream dams that are scheduled for development, however the number of dams and the time frame for their construction is uncertain at present.
The species is assessed as Vulnerable (A2ade) due to recent (the last ten years) declines in the Mekong of more than 30% (and possibly as much as 50%), primarily as a result of fishery pressures. However, it is likely that populations would recover if fisheries were reduced, as shown by the population recovery from 1975-1980. However, populations could be expected to decline further if the mainstream dams on the Mekong were developed, leading to disruption of migrations within the Mekong. The scale of the impacts from dams are difficult to estimate because of the uncertainty over the number of dams and their time frame, and it is likely that the species would qualify for a higher threat category if the dams were to be constructed.
|Range Description:||Recorded from the Chao Phraya and Mekong basins in Thailand, Lao PDR, Cambodia and Viet Nam. The Chao Phraya population has been extirpated over the last 25 years as a result of pollution, dams and overfishing (C. Vidthayanon pers. comm. 2011)|
Native:Cambodia; Lao People's Democratic Republic; Thailand; Viet Nam
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||In the Mekong River, populations increased considerably when fisheries were stopped during the Khmer Rouge period in Cambodia. The population has declined since the late 1970s. Populations in the Mekong have declined in recent years as a result of fishery pressures by up to 50% (I. Baird, pers. comm.; Roberts 1993; Baird et al. 1999; Baird et al. 2003; Baran et al. 2005; Baird 2011. The Chao Phraya population has been extirpated over the last 25 years as a result of pollution, dams and overfishing (C. Vidthayanon pers. comm. 2011).|
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||Inhabits large rivers and lowland floodplains (Rainboth 1996), occurring in riffles and deep slow reaches. Moves out into the flooded forest where it feeds on leafy plant matter, phytoplankton and insects. Highly migratory. The species probably enters flooded floodplain forest in Cambodia.|
Migration pattern is markedly different above and below the Khone Falls in the Mekong basin. Below the falls, it makes an upstream migration from Phnom Penh to the Khone Falls between November and February, consisting mainly of sub-adults of sizes 10 to 50 cm (Baran et al. 2005). From April to July, it migrates in the opposite direction, from Khone Falls and downstream, constituting mainly of sub-adults up to about 50 cm (Sokheng 1999). Above the Khone Falls, from Klong Kaem District, Ubolratchatani in Thailand, fish migrates upstream in February; at Khemmaratch further upstream in Ubolratchatani, it moves upstream in March-April; and at Mukdahan, it goes upstream in May. However, it migrates downstream at Klong Kaem in June-July. Only downstream migrations are reported in the Mekong Delta in Viet Nam, constituting mainly of juveniles (2-20 cm), with the smallest fish mainly in June-July and fish between 10 and 20 mainly from September to November. From Xayabouri in Laos to Chiang Saen in Thailand, upstream migrations take place from March to August. This appears to be two distinct migrations: one of sub-adults measuring 15-50 cm during March-April and another one of larger fishes of sizes 40 to 90 cm during June-July (Sokheng et al. 1999).
|Generation Length (years):||3-4|
|Movement patterns:||Full Migrant|
|Use and Trade:||
Utilised in commercial and local fisheries; highly valued and popular food fish. Individuals caught with dais or traps are often immediately kept alive in fish cages for future sale. Marketed fresh and sometimes dried and salted (Rainboth 1996). Known to reach up to 15 kg in Thailand.
Captive cultivation has been attempted in southern Lao PDR, Viet Nam and Cambodia.
|Major Threat(s):||Likely to be impacted by pollution and overfishing, as well as the loss of suitable habitat (riverine and floodplain forest) and obstruction of migration routes from the construction of mainstream dams, factors which have already led to the extirpation of the Chao Phraya population.|
|Conservation Actions:||Research is required on the species distribution, harvest and population trends, habitat and ecology. Specific information is needed on the impact of the disruption of mainstream dams on migration routes.|
|Citation:||Baird, I. 2011. Cirrhinus microlepis. The IUCN Red List of Threatened Species 2011: e.T180904A7654985.Downloaded on 26 September 2018.|
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