Acheilognathus elongatus 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Actinopterygii Cypriniformes Cyprinidae

Scientific Name: Acheilognathus elongatus
Species Authority: (Regan, 1908)
Common Name(s):
English Elongate Bitterling
Acanthorhodeus elongatus Regan, 1908
Acanthorhodeus grahami Nichols, 1918
Acheilognathus elongatus Chen & Li in Chu & Chen 1989
Taxonomic Notes: Originally Acanthorhodeus elongatus by Regan (1908). Acanthorhodeus grahami Nichols (1918) was its synonym by Wu (1964). Valid as Acheilognathus elongatus (Regan) by Chen & Li in Chu & Chen 1989.

Assessment Information [top]

Red List Category & Criteria: Critically Endangered B1ab(ii,iii,v) ver 3.1
Year Published: 2008
Date Assessed: 2008-01-01
Assessor(s): Chen, X.-Y. & Yang, J.
Reviewer(s): Kullander, F. (Freshwater Fish Red List Authority) & Smith, K. (IUCN Freshwater Biodiversity Assessment Unit)
This species is endemic to Lake Dianchi (surface area 292.6 km²), Yunnan Province, China where it occurs only in the inshore area of the lake giving the species an extent of occurrence of less than 100 km² (total estimated to be around 58 km²). In the past few decades Lake Dianchi has been badly polluted leading to the declining quality of habitat for this species. In addition this pollution has led to the loss of many bivalves which are the host of the young Acheilognathus elongates. Many species of alien fishes have been introduced into the lake since the 1960s and have outcompeted Acheilognathus elongus, in particular Acheilognathus macropterus, A. chankaensis and A. taenianalis. It is likely that A. elongates disappeared from the lake in the 1980’s, but more surveys are required to confirm this.
Previously published Red List assessments:
1996 Endangered (EN)
1994 Indeterminate (I)

Geographic Range [top]

Range Description: Endemic to Dianchi Lake (surface area 292.6 km²), Yunnan Province, China. This species occurs only in the inshore areas of the lake, giving a total range area of around 58 km².
Countries occurrence:
Possibly extinct:
China (Yunnan)
Estimated area of occupancy (AOO) - km2: 58
Continuing decline in area of occupancy (AOO): Yes
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 58
Number of Locations: 1
Lower elevation limit (metres): 1874
Upper elevation limit (metres): 2220
Upper depth limit (metres): 10
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: Only ever known from the Lake, the population is unknown.
Current Population Trend: Unknown
Additional data:
Continuing decline of mature individuals: Yes

Habitat and Ecology [top]

Habitat and Ecology: Clear water usually with indigenous macrophytes.This species is a small fish. Female fishes have an ovipositor which is used to deposit eggs inside bivalves, juveniles hatch and remain in the bivalve until they can swim.
Systems: Freshwater
Continuing decline in area, extent and/or quality of habitat: Yes
Generation Length (years): 2
Congregatory: Congregatory (and dispersive)

Threats [top]

Major Threat(s): The population has badly declined in Lake Dianchi due to introduced fishes, especially closely related species, e.g., Acheilognathus macropterus, A. taenianalis, A. chankaensis and Rhodeus ocellatus. These species share the same habitat with Acheilognathus elongates and have competed with it. Water pollution has also caused the loss of breeding sites due to the local extinction of many bivalves which are the host of the young Acheilognathus elongates.

Conservation Actions [top]

Conservation Actions: Not in a formal protected area and no measures have been taken for the species conservation.

Citation: Chen, X.-Y. & Yang, J. 2008. Acheilognathus elongatus. The IUCN Red List of Threatened Species 2008: e.T212A13052083. . Downloaded on 26 November 2015.
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