Schistura porthos Kottelat, 2000, a new record of nemacheilid loach for China

Marco Endruweit

（Postgraduate Training Center,Haier University, Qingdao 266000, PR China）

Schistura porthosKottelat, 2000, a new record of nemacheilid loach for China

Marco Endruweit*

（Postgraduate Training Center,Haier University,Qingdao266000,PR China）

A nemacheilid loach not recorded for China so far has been collected during a survey of the Nanxinghe River, Luosuojiang River subbasin, Mekong basin. The specimens could be identified asSchistura porthosKottelat, 2000. The occurrence in the Luosuojiang River subbasin is a distributional range extension.

Schistura; New record; Mekong River; Nemacheilidae; River loach

The genusSchisturaMcClelland, 1938 within the family Nemacheilidae, river loaches, contains numerous species inhabiting mainly the bottom strata of riverine environments and water bodies with stagnant movement. Zhu (1989) listed 17 species in the genusSchisturaoccurring in China. Since this publication a couple of new species of the genusSchisturahas been described from China (Yang, 1990; Kottelat, 2000; Chen et al, 2005; Zhou & Kottelat, 2005; Chen et al, 2005; Chen et al, 2006).

During a survey of the ichthyofauna of the Nanxinghe River, a tributary of the Luosuojiang River, Mekong basin, a species of the genusSchisturacould be collected, which I was unable to identify in the field. The key to species in Zhu (1989) was misleading in this case and led to dissatisfactory results. Further investigations of related literature unveiled the species asS. porthosKottelat, 2000, a species herewith reported from China for the first time.

1 Materials and Methods

Meristics and morphometrics follow instructions given in Kottelat (1990). Measurements taken with dial caliper and recorded to 0.1 mm. Location coordinates defined with handheld device GPS Garmin, using a minimum of four satellites for enhanced precision. Examined specimens had been placed in part in the repository collection of the Kunming Institute of Zoology (KIZ), the Chinese Academy of Sciences, and in the collection of the author (EPC).

Examined material:S. porthosKottelat, 2000, KIZ 2010003019-32, KIZ 2010003085-90, 20 ex., 67 - 54.8 mm SL, and EPC 0678, 80, 88, 3 ex., 64.7 - 59.3 mm SL; all material from Nanxinghe River (N 21° 53.457', E 101° 20.881', 556 m asl), Luosuojiang River subbasin, Mekong basin, 3 km downstream of Mengxing village, Mengla County, Xishuangbanna, Yunnan Province, China, collected by Wang J & Endruweit M, June 2010.

2 Notes on Ecology

At the time of the visit (June 2010) the Nanxinghe River had a high water level, plenty of riparian vegetation was inundated. The water was muddy colored and highly turbid with parameters (measured in a depth of 20 cm) as follows: pH 8.1, 30 °C, 290 μs/cm. Due to upstream Mengxing village the river showed traces of pollution and eutrophication. It was around 40 m wide and 1 m deep, in some potholes up to 2 m deep. The water current was slow to moderate. The bottom was covered with sand, pebbles and rocks. In backwaters there was a muddy bottom layer, up to 20 cm deep. No vascular submerged plants were recorded. There were a total of four nemacheilid species syntopicly occurring, viz.Physoschistura meridionalis(Zhu, 1982),S. macrocephalusKottelat 2000,S. kloetzliaeKottelat, 2000 andS. porthos. Seemingly each loach species inhabits different niches or microhabitats within the stream. The quantified occurrence ofS. kloetzliaewas greatest in the riffle section, where the water current was fastest. It seems to be a highly adapted, rheophilic species.Physoschistura meridionalisandS. macrocephalusseem to prefer deeper and more sluggish water, while the frequency ofS. porthoswas highest in sections with moderate to fast current.

3 Results

The examined material matches well the diagnosis and figure ofS. porthosgiven in its original description (Fig. 1): basic characteristics are a massive body with a hump in predorsal profile in individuals over 55 mm SL; caudal peduncle deep with a length/depth ratio of 0.8 -1.14, median 0.93 (0.9 - 1.1 in original description), with distinct dorsal and ventral crests; top of head with dark brown vermiform pattern; body with 3 - 4 dark brown predorsal bars, 2 - 3 subdorsal bars, 3 - 4 postdorsal bars, all bars much wider than interspaces and frequently vertically split up creating up to 17 bars totally; black caudal bar broad and with anterior and posterior projections where it reaches dorsal and ventral midlines (Kottelat, 2000).

4 Discussion

Schistura porthosis originally described from the upper reaches of the Nam Tha River, a tributary of the Mekong in Louangnamtha Province, northern Laos (Kottelat, 2000). Kottelat (2000; 2009) also reports this species from several collecting sites in the Nam Ou subbasin, Mekong basin, Phongsali Province, northern Laos. Guessing from the frequency of occurrence at plenty of collecting sites it seems to be a common species in northern Loatian streams. Both Laotian Louangnamtha and Phongsali Provinces are neighboring the southernmost tip of Xishuangbanna. Due to its geographical proximity and the absence of major topographical barriers a conjunct distributional pattern ofS. porthoswithin the upper-middle Mekong basin can be assumed. This assumption entails the occurrence in suitable habitats within the Nanlahe River subbasin, Xishuangbanna. The herein reported occurrence in the Luosuojiang River subbasin extends its range and reflects a new northwestern boundary of its natural occurrence.

Fig. 1 Schistura porthos, KIZ 2010003032, 58.5 mm SL, Lateral (a), dorsal (b), ventral(c) view (scale bar 10 mm)

Acknowledgements:I am thankful to Junxing YANG, Xiaoyong CHEN and Lina DU (all from KIZ) for giving me access to literature and the collection room of KIZ, to Jing WANG for her tremendous help during the planning, preparation and conduction of the survey and to numerous nameless people of Mengxing village for their pragmatic supportin situ.

Chen L, Lu ZM, Mao WN. 2006. A new species ofSchisturadiscovered in Yunnan, China [J].Guizhou Agric Sci, 34 (5): 54. (in Chinese)

Chen XY, Kong DP, Yang JX. 2005.Schistura cryptofasciata, a new loach (Cypriniformes: Balitoridae) from Salween drainage in Yunnan, southwestern China [J].Raffles Bull Zool, 13 (Suppl): 27-32.

Chen ZM, Yang JX, Qi WL. 2005. Description of a new loach ofSchisturafrom Lancang River basin, Yunnan, China [J].Acta Hydrobiol Sin, 29 (2): 146-149.

Kottelat M. 1990. Indochinese Nemacheilines [M]. München: Verlag Dr Friedrich Pfeil.

Kottelat M. 2000. Diagnoses of a new genus and 64 new species of fishes from Laos (Teleostei: Cyprinidae, Balitoridae, Bagridae, Syngnathidae, Chaudhuriidae and Tetraodontidae) [J].J South Asian Nat Hist, 5 (1): 37-82.

Kottelat M. 2001. Fishes of Laos [M]. Colombo: Wildlife Heritage Trust Publications.

Kottelat M. 2009. Fishes of the Upper Nam Ou Drainage in Laos [R]. WWF-Community Fisheries: Supporting Food Security and Aquatic Biodiversity (ComFish Project), 27.

Yang JX. 1990. Nemacheilinae (Cypriniformes: Cobitidae)[M]//Chu X, Chen Y. The Fishes of Yunnan, China: Part 2. Beijing: Science Press, 12-63 (in Chinese).

Zhou W, Kottelat M. 2005.Schistura disparizona, a new species of loach from Salween drainage in Yunnan (Teleostei: Balitoridae) [J].Raffles Bull Zool, 13 (Suppl): 17-20.

Zhu SQ. 1989. The Loaches of the Subfamily Nemacheilinae in China [M]. Nanjing: Jiangsu Science & Technology Publishing House. (in Chinese)

中國條鰍新紀錄種——Schistura porthosKottelat, 2000

Marco Endruweit*

（海爾大學(xué) 研究生培訓(xùn)中心，山東 青島 266000）

在對瀾滄江的亞流域羅梭江支流南星河的考察中, 采集到一個中國條鰍新記錄種。該物種經(jīng)鑒定為Schistura porthosKottelat, 2000。該物種在羅梭江亞流域的發(fā)現(xiàn)延伸了其分布范圍。

Schistura; 新紀錄; 湄公河; 條鰍; 河鰍

Q959.468；Q959.468.09

A

0254-5853-(2011)05-0572-03

2011-02-11；接受日期：2011-06-16

10.3724/SP.J.1141.2011.05752

date: 2011-02-11; Accepted date: 2011-06-16

*Corresponding author (通信作者), E-mail: me@aquariophil.org