The Natural History Journal of Chulalongkorn University 4(2): 83-98, October 2004 ©2004 by Chulalongkorn University Annotated Checklist for a Collection of Fishes from Tapi River Basin, south Thailand VACHIRA LHEKNIM * Department of Biology, Prince of Songkla University, PO Box 3 Kho Hong, Songkhla 90112, THAILAND ABSTRACT.–A collection of fishes was taken from the Tapi River Basin floodplain, small tributaries and mainstream of the river in the middle and lower reaches of the basin in 1996. In this study, 49 species in 37 genera belonging to 20 families were collected, identified and deposited in the Prince of Songkla University Zoological Collection. Notes on occurrence, ecology and taxonomy are given. An additional 3 species: Lepidocephalichthys tomaculum Kottelat and Lim, 1992, Pseudeutropius cf. moolenburghae Weber and Beaufort, 1913 and Dermogenys sumatrana (Bleeker, 1853) are newly recorded species for Thailand. An additional 15 species are new recordings for the Tapi River Basin: Clupeichthys perakensis (Herre, 1936), Sundasalanx praecox Roberts, 1981, Esomus metallicus Ahl, 1924, Oxygaster pointoni (Fowler, 1934) Rasbora daniconius (Hamilton, 1822), Trigonostigma heteromorpha (Dunker, 1904), Mystus castanaeus Ng, 2002, Kryptopterus cf. bicirrhis (Valenciennes, 1839), Micronema cf. apogon (Bleeker, 1851), Phenacostethus cf. smithi Myers, 1928, Aplocheilus panchax (Hamilton, 1822), Indostomus crocodilus Britz and Kottelat, 1999, Nandus nebulosus (Gray, 1835) Brachygobius sebanus Inger, 1958 and Helostoma temmincki Cuvier, 1829. KEY WORDS: Freshwater fishes; Tapi River Basin; Surat Thani. (1934-1939, cited in Smith, 1945), Smith INTRODUCTION (1945) and Kottelat (1989). The Tapi River Basin is the largest river basin in south The freshwater ichthyofauna of southern Thailand. The freshwater ichthyofauna of Tapi river basin in Thailand has not been examined River Basin has been preliminary studied and as thoroughly as the central, northern and reported by Storer (1978), from meadowland northeastern river basins, probably due to around Nong Thung Thong in the middle reach. relatively short drainage and small catchment Afterwards, Tarnchalanukit (1980), Chukajorn areas. More comprehensive works carried out et al. (1988), Duangsawasdi and Krachangdara covering all or part of Thailand or southern (1994) reported their works, which were Thai Peninsular included those of Fowler restricted to the Klong Sang sub-basin and Rajjaprabha Reservoir of the Tapi River Basin * Corresponding author. respectively. Tel: (6674) 288-534 Specimens used in the present study were Fax: (6674) 212-917 mostly collected while the author participated in E-mail: [email protected] Wetland Inventory program for south Thailand. 84 NAT. HIST. J. CHULALONGKORN UNIV. 4(2), OCTOBER 2004 The freshwater fishes obtained in this study are MATERIALS AND METHODS not numerous, yet this study has produced some interesting information regarding range extension Study Area of some species, which it seems warranted to The Tapi River Basin covers an area of publish, particularly in order to extend our 12,225 km2, consisting of the Phumduang River understanding on the biogeographical distribution and the Tapi River. The Phumduang River for several species. basin originates from the eastern sector of Phuket Mountain Range and covers an area of FIGURE 1. The Tapi River Basin in south Thailand. Sampling stations indicated by number in circles, 1: Fish pond in Nong Thung Thong Non Hunting Area, Kian Sa District, 2: Oxbow Lake at Ban Haan Dum, Kian Sa District; 3: Floodplain at Ban Mo Ket, Ban Na San District; 4: main Tapi River at Ban Wang Hin, Kian Sa District; 5: Main Tapi River at Ban Mae Khaek, Kian Sa District; 6: Klong Ban Mai, Bung Khun Thale, Muang District and 7: Klong Krut at Ban Krut, Phun Pin District, Surat Thani. LHEKNIM – A COLLECTION OF FISH FROM TAPI RIVER BASIN 85 6,125 km2. The Tapi River Basin originates elevation ranged from 30-40 m MSL. The area from western sector of Nakhon Sri Thammarath was first declared by the Royal Forestry Mountain Range covering about 5,460 km2. Department of Thailand in 1975, and was also These two rivers join about 15 km west of Surat included in Scott's (1989) Directory of Asian Thani, forming an extended delta as they Wetlands. In the wet season, these areas are discharge into the Gulf of Thailand (Fig. 1). entirely flooded to 1-4 m depth by flows from The climate of the Tapi River Basin, based the Tapi River, while in dry season the major on meteorological data between 1997-1998, is area is dry except for Oxbow lakes along the intermediate between equatorial and tropical river, permanent swamps and natural fish ponds monsoon types and is characterized by constant (Storer, 1978). Fish specimens were taken from high temperature and high rainfall without two sample sites within the non-hunting area. extremes of heat. Mean relative humidity is First, a natural fish pond approximately 20 m in 81% (range from 61-95%). Mean monthly width, on the left bank of Tapi River floodplain temperature ranges from 26 °C, usually in the (Station 1), is a temporary fresh water habitat wettest month, to 32 °C, usually in April. The with seasonal dry out situated near the Non- wet season starts in May and lasts until Hunting Area Headquarters Office at Ban Nong December; during this season monthly rainfall Thung Thong, Kian Sa District, on March 11th, ranges from 77 mm to 412 mm. The highest 1996. The second site, an Oxbow lake at Ban amount of rainfall was in August. Lower Haan Dum (Station 2), is a permanent freshwater rainfall and a higher evaporation rate habitat on the left bank of the floodplain on characterizes the dry season, from January to March 12th, 1996. This Oxbow lake is April. surrounded by freshwater scrub and swamp The Tapi River Basin is predominantly an trees, with a substratum of mud, twigs, logs and agricultural land for rubber plantations, oil branches and decomposing plant materials, with palms and orchards in the middle and lower maximum width ca. 30 m and maximum length reaches, while urban areas are centered in ca. 200 m. lower reach district. The middle and especially An another supplement sample outside lower reaches of the Tapi River Basin are fairly Nong Thung Thong Non-Hunting Area was industrialized. There are several large and collected from fishermen in the Tapi River medium scale industrial units besides the large Floodplain, at Ban Mo Ket (Station 3), Ban Na number of urbanization along the river. San District, Surat Thani on 25 May 2001. Sampling Sites Mainstream River Habitat Specimens examined in this study were Samples from the mainstream of the Tapi obtained during a visit to Nong Thung Thong River were obtained at Ban Wang Hin, Kian Sa Non-Hunting Area, Bung Khun Thale and District and Ban Mae Khaek, Phunphin District others wetland in the Tapi River Basin. Three on March 12th, 1996 (Stations 4 and 5 habitats were sampled during the month of respectively). These are in the middle reaches March and December 1996, namely floodplains, of the basin with a maximum width of about 30 the mainstream river and small tributaries. m and a maximum depth of 2.5 m, relatively slow current, moderate turbidity, sandy-mud River floodplains substratum and sparse emergent and submerged Nong Thung Thong Non-Hunting Area is a vascular plants along the banks. 2,960 ha reserve within a 6,450 ha complex of swamps and wet meadows on the Tapi River Tributary floodplain in Kian Sa and Phra Sang Districts, Tributary samples were taken from location Surat Thani Province. It is located at 8° 44′ N nearby Bung Khun Thale, Muang District and to 8° 54′ N and 99° 12′ E to 99° 16′ E, with Klong Krut at Ban Krut, Phunpin District, Surat 86 NAT. HIST. J. CHULALONGKORN UNIV. 4(2), OCTOBER 2004 Thani. Bung Khun Thale originated from ichthyological nonation is used for fin ray freshwater swamp and floodplain nearby Nikom counts, with stiff spines represented by Roman Sang Ton Eng Khun Thale and drain in to Bung numerals and soft rays by Arabic numbers. Khun Thale, before discharging to the lower reach of the Tapi River. Bung Khun Thale CLUPEIDAE sample were taken on the March, 14th 1996 at Clupeichthys perakensis (Herre, 1936) Klong Ban Mai (Station 6), a small tributary Materials – PSUZC-19960312-02.10, 3 creek about 10 m in width and 2.5 m in depth. (18.5-23.0 mm SL), Main Tapi River, Ban Klong Krut is a small creek empty to the Wang Hin. mainstream of the Tapi River (Sample 7), Remarks – This is one of the small maximum width app. 10 m and 2 m in depth, freshwater pellonulines in Southeast Asia, with samples were taken during the early stage of abdominal scutes 12-14. Herre (1936) described flooding period on the December, 9th 1996 this species from Perak River in Peninsula Malaysia. Recently, Vidthayanon (2002) Collecting Methods reported this species from tributary canals of Specimens were obtained mainly from a peat swamp at Phru Tao Dang, Narathiwat. small beach seine net (10 m x 1.5 m, 5-mm This is the first record of this species in the stretched mesh) and a hand net with diameter Tapi River Basin and it extends the known 30 cm and 5-mm stretched mesh, while distribution of Clupeichthys perakensis north- specimens from Klong Krut were obtained from wards to the Tapi River Basin, which is local fishermen using lift nets. Capture probably the northernmost of the distribution specimens were preserved in 10% neutral range for this species. formalin and returned to laboratory for identification. SUNDASALANGIDAE All measurements are in millimeters. The Sundasalanx praecox Roberts, 1981 standard length is measured from the tip of the Materials – PSUZC-19960312-03.04; 1 (17 snout to the base of the caudal peduncle.