A new record of Dasyatid fish in China: Dasyatis laosensis

CHEN Zi-Ming, ZHANG Xiao-Yan QI Wen-Long, LI Jiang-Hong, XIAO Heng

(1. School of Life Science, Yunnan University, Kunming 650091, China;2. Fishery Management Station, Xishuangbanna Prefecture, Jinghong 666100, China)

A new record of Dasyatid fish in China:Dasyatis laosensis

CHEN Zi-Ming1,#,*, ZHANG Xiao-Yan1,#, QI Wen-Long2, LI Jiang-Hong2, XIAO Heng1,*

(1.School of Life Science, Yunnan University, Kunming650091,China;
2.Fishery Management Station, Xishuangbanna Prefecture, Jinghong666100,China)

One specimen was collected from the main course of Lancangjiang River (upper reach of Mekong) in Guanlei Port, Xishuangbanna, Yunnan, China in April, 2008. It is identified asDasyatis laosensis, a new record of Dasyatidae species in China. It could be distinguished from otherDasyatisspecies by a combination of the following characteristics: one enlarged venomous spine on the tail, ventral surface of body with orange marginal coloration, tail length greater than body length.

Dasyatis laosensis; Fish; New species record; Lancangjiang River; China

In April 2008, a fish specimen was collected from the main course of Lancangjiang River in Guanlei Port,Xishuangbanna, Yunnan province. It is identified asDasyatis laosensisRoberts and Karnasuta, 1987, a new record of Dasyatidae species in China. The specimen is deposited in the museum of the School of Life Science,Yunnan University, the catalogue number of this specimen is YNU200804001.

1 Morphological characteristics

YNU200804001, collected from the main course of Lancangjiang River in Guanlei Port, Xishuangbanna,Yunnan province, total length 1 449.0 mm, body length 866.0 mm, disc length 471.2 mm. disc width 537.9 mm,tail length 955.1 mm. Weight about 7 000 g.

Disc length 1.1 in disc width. Preorbital snout length 3.9 in disc length. Eye diameter 6.7 in preorbital snout length, interorbital width 1.3 in priorbital snout length. Disc length 2.0 in tail length.

Disc thick and diamond-shaped, disc width a little broader than disc length; snout tip obtuse; anterior margin of disc slightly convex, posterior margin of disc rounded; outer angles of disc and posterior angles rounded. Preorbital snout length 4.5 in disc width,preoral snout length 4.1 in disc width, preorbital snout length longer than interorbital width. Eyes small, smallerthan spiracle, slightly prominent, eye diameter 6.7 in preorbital snout length, 5.3 in interorbital width. Mouth small, weakly arched, mouth width 2.0 in preoral snout length; mouth with small teeth, floor of mouth with papillae. spiracle large, oval or a little rhombusy. 5 pairs of gill opening, the distance between the former four of each side is about equidistant, and the last is a little far away from the fourth. Cloaca longitudinal split.

No dorsal fin. Pectoral fins wide, becoming the edge of body, the front of pectoral fin stretching up to tip of snout. Pelvic fins located rearward of the Body,triangular and its corner slightly angular. Tail slender,long and whip-like; tail length 1.5 in total length; tail with one spine (the spine lost in this specimen).

A vertical line of spines from the head to the front of the spine, latter 15 relatively larger, spine-like;shoulder area with tubercles, inner side of eyes and spiracles with small tubercles cluster.

Color of frozen specimen: dorsal surface of disc brown with orange margin, interorbital and nuchal region dark brown, the edge meat-red. Ventral surface of disc white with orange margin. Dorsal surface of pelvic fin brown with orange margin; ventral surface of pelvic fin white with orange margin. Dorsal surface of tail including keel dark brown, ventral tail white, distal half of tail blackish.

2 Habitat and ecology

Dasyatis laosensislives in freshwater, the habitat is large rivers with sand substrate, and it feeds on the benthic invertebrates (Rainboth, 1996).

3 Distribution

Dasyatis laosensisis usually found in the Mekong waters of Laos and Cambodia, (Rainboth, 1996; Kottelat,2001). This study indicates that this species occasionally enter the lower reaches of the Lancangjiang River in China.

Fig. 1 Dasyatis laosensis Roberts and Karnasuta, 1987, Total length 1 449.0 mm

4 Discussion

At present, China has recorded 13 species ofDasyatisfish (Zhu et al, 2001). Only one kindDasyatisakajeican migrate along West River to Nanning, and lives in fresh water. The remaining 12 species are marine fish.Dasyatis laosensisis currently the onlyDasyatisspecies that lives only in the fresh waters in China.

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

Rainboth WJ. 1996. Fishes of the Cambodian Mekong [M]. Rome:Food and Agriculture Organization of the United Nations.

Zhu YD, Meng QW. 2001. Fauna Sinica (Cyclostomata and Chondrichthyes) [M]. Beijing: Science Press. (in Chinese)

中國魟科魚類一新紀錄——老撾魟

陳自明1,#,*，張曉妍1,#, 祁文龍2, 李江紅2, 肖 蘅1,*

(1. 云南大學生命科學學院，云南 昆明 650091;2. 云南省西雙版納州水產漁政站，云南 景洪 666100)

2008年4月在云南省西雙版納瀾滄江干流關累段采集到魚類標本1尾，經鑒定為中國魟科魚類的新紀錄——老撾魟(Dasyatis laosensisRoberts and Karnasuta, 1987)。本種的主要鑒別特征為：尾部具有一根較大的毒刺，腹部圓盤邊緣為橘黃色，尾長大于體長。

老撾魟; 魚類; 新紀錄; 瀾滄江; 中國

Q959.3

A

0254-5853-(2010)06-0675-02

2010-04-15；接受日期：2010-06-04

10.3724/SP.J.1141.2010.06675

date: 2010-04-15; Accepted date: 2010-06-04

s: This study was supported by the National Science Foundation of China (30970326, U0936602, 30870291)and the Scientific Research Foundation of Yunnan University (2008YB004).

*Corresponding authors (通訊作者), E-mail: cziming@hotmail.com#The authors contributed equally to this work.