Cypriniformes: Nemacheilidae

Schistura callichromus (Zhu & Wang, 1985)

Synonyms:
Nemacheilus callichromus Zhu & Wang, 1985
original description; misspelled as Noemacheilus
Schistura callichroma (Zhu & Wang, 1985)

new combination; wrong combination
Vernacular names:
美斑南鳅, 美斑条鳅
Mandarin

Figure 1. Schistura callichromus, mature fish, lateral view, caught 2009-12-31, not preserved, EW-CN 66-09, Mengyejiang River, Red River basin, Puer County, Yunnan Province, China.
Figure 1. Schistura callichromus, mature fish, lateral view, caught 2009-12-31, not preserved, EW-CN 66-09, Mengyejiang River, Red River basin, Puer County, Yunnan Province, China.

Etymology:
The generic name ‘schistura’ is a compound of two Greek words; ‘skhizeîn’: to split, ‘oura’: tail; an allusion to a forked caudal fin. Gender: feminine.
Size / Weight:
48-78 mm SL, 20 samples, Babianjiang River, Jingdong County, Yunnan Province, China (Zhu, 1989).
87.8 mm SL, 105.5 mm TL, female, EPC 0520, largest specimen of collection, Mengyejiang River, Puer County, Yunnan Province, China.
Diagnosis:
D IV,8; A III-IV,5; P I,10; V I,6-7; C 17 (Zhu, 1989).

Figure 2. Map of southern Yunnan Province, China.
Figure 2. Map of southern Yunnan Province, China.

Sex differentiation:
Females larger; females up to 87.8 mm SL, 105.5 mm TL, EPC 0520; males up to 69.5 mm SL, 85.7 mm TL, EPC 0521.
No sexual dichromatism, but dimorphism: dorsal higher, pectoral longer in males (ME, pers. obs. 2010-02-21).

Figure 3. Biotope of S. callichromus, northward view, biotope code EW-CN 66-09, Mengyejiang River, Red River basin, Puer County, Yunnan Province, China.
Figure 3. Biotope of S. callichromus, northward view, biotope code EW-CN 66-09, Mengyejiang River, Red River basin, Puer County, Yunnan Province, China.

Distribution:

The terra typica is referenced as Babianjiang River, Jingdong County, Yunnan Province, China (Zhu & Wang, 1985).
EW-CN 66-09, riffle section, 40 m broad, 20-40 cm deep, over rock and pebble substratum, Mengyejiang River 勐野江, tributary to Lixianjiang River李仙江, Red River 红河 basin, Yunnan Province, China (ME, 2009-12-30, 2010-01-06).
In fact, at the conflux of the southwards flowing Babianjiang River and the northwards flowing Mengyejiang River both rivers form the Langmajiang River, which is a tributary of the Lixianjiang River, Red River basin. Biotope EW-CN 66-09 is 15 km away from Loatian border. Thus S. callichromus is likely to occur in Laotian waters.
Expected to occur in northern Vietnam (Kottelat, 2001), since the lower Red River flows through the northern part of Vietnam before it empties into the Gulf of Tonkin.

Figure 4. Schistura callichromus, female, mature fish, 104 mm TL, lateral view, caught 2010-01-06, later on preserved, EW-CN 66-09, Mengyejiang River, Red River basin, Puer County, Yunnan Province, China.
Figure 4. Schistura callichromus, female, mature fish, 104 mm TL, lateral view, caught 2010-01-06, later on preserved, EW-CN 66-09, Mengyejiang River, Red River basin, Puer County, Yunnan Province, China.

Ecology:
Benthic, adults live in social aggregation up to 6 individuals; in EW-CN 66-09 syntopic with other benthic species such as Schistura laterivittata (Zhu & Wang, 1985), Schistura sp., Sinogastromyzon tonkinensis Pellegrin & Chevey, 1935, Beaufortia daon (Mai, 1978), Pseudecheneis paviei Vaillant, 1892, and Glyptothorax quadriocellatus (Mai, 1978); in riffle section, fast flowing, 20-50 cm deep water over rock substratum; predominating species.
Data of EW-CN 66-09: 898 m asl, N 22º 35′, E 101º 45′; 17 ºC, 8.8 pH, 170 µS/cm, 85 mg/l (ppm; TDS), measured on 2009-12-30, 16:00; a tributary of Lixianjiang River, Red River basin, Yunnan Province, China (ME, pers. obs., 2009-30-12; 2010-01-06).
Insectivorous, feeding upon aquatic insect larvae hidden in rock interspaces (ME, pers. obs., 2009-12-30, 2010-01-06).
Conservation status:
IUCN Red List: DD; Data Deficient; ver 3.1.; unknown if there are any conservation measures in place.
Aquarium maintenance:
Not yet kept in aquaria. Probably a hardy species; maintenance in aquaria should be easy.
Massive feeding with Tubifex should be avoided.

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