No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Schistura tenebrosa, a new species of loach from the Kwai Noi River system, Mae Khlong basin, Thailand (Teleostei: NemacheilidaeNemacheilidae)
Abstract
A new species of Schistura is described from the Kwai Noi, Mae Khlong basin, in the Thong Pha Phum District of Kanchanaburi Province in western Thailand. The species is distinguished from all other species of Schistura by a uniform dusky brown color pattern without marks on the dorsum or side of body and with many conspicuous supplementary neuromasts along the lateral line and on the head. It is further distinguished from other species of Schistura lacking marks on the body by its dark brown color, an incomplete lateral line extending only to beneath the dorsal fin, and the origin of the dorsal fin located above the origin of the pelvic fin. The species is small, reaching only 46.0 mm SL, 55.1 mm TL, and inhabits shallow gravel and rubble riffles in small streams.
... The study of balitorid loaches was first reported by Smith [15], and subsequently, most studies with a specific emphasis on species identification and classification were performed [16]. As recently as a decade ago, many balitorid species in Thailand have been revised and described as new species [17][18][19][20][21][22][23]. In contrast, the ecological studies of Thai balitorids are limited in the central regions, and to our best knowledge, there are only two publications in balitoridae distribution and their habitats [24,25]. ...
... All individuals were identified at the species level, enumerated, and released downstream from their capture site to avoid fish re-capturing. Since some individuals could not be identified in the field, they were first overdosed in clove oil and were preserved in 10% formalin for later identification to the species using a stereo microscope according to the taxonomic keys based on the Catalog of Fish, California [35] and a number of other publication sources [16][17][18][19][20][21][22][23][36][37][38][39][40][41]. ...
Stream degradation increases with high anthropogenic activity and climate variability, while declines occur in biodiversity. However, few studies have been undertaken on tropical waterways, a major impediment to biodiversity conservation. The present study was conducted on 95 relatively pristine small streams in Eastern Thailand with 10 reasonably uncommon species of balitorid fishes. Measurements were made of 21 physical and chemical factors and the substrate particle size. Stepwise regression identified the direct importance of substrate particle size and nitrate on the species’ richness of balitorids, whereas its abundance was negatively related with iron concentrations. A Canonical Correspondence Analysis identified three fish groups: the 1st group was negatively correlated with ammonia and positively correlated with dissolved silica, the 2nd group was positively correlated with substrate particle size and negatively correlated with stream ambient temperature and ammonia concentration, and the 3rd group was negatively correlated with low dissolved silica, respectively. The results of this study may indicate the vulnerability of balitorids under climate warming and anthropogenic pressure that alter the water physicochemical factors and river degradation including the substrate type. Thus, a conservation framework should be provided regarding the limits for water temperature, ammonia, and iron in Thailand’s Water Quality Criteria to better protect its freshwater ecosystem. Balitorid is a potential bioindicator for evaluating the river temperature effect in combination with ammonia nutrient stressors as long as the way-of-life habits of the species are taken into account.
... In his treatise on Indonchinese nemacheilids, Kottelat (1990) recorded only one species of Schistura from the Mae Khlong basin in southwestern Thailand and referred to it as Schistura desmotes. Recent collections from the basin have included Schistura mahnerti, which is widely distributed in the basin, Schistura balteata, apparently restricted in Thailand to the Pakkok River of the Mae Nam Kwai Noi system, and two recently discovered and described species, Schistura aurantiaca, also widely distributed in the basin, and Schistura tenebrosa, found only in a small region drained by the Pakkok River of the Mae Nam Kwai Noi system (Plongsesthee et al. 2011; Kangrang et al. 2012). A sixth species, discovered in 2011, is described herein. ...
... Specimens were captured in flowing water in shallow rubble and gravel riffles (Fig. 5). This is the second species of Schistura that appears to be endemic to this basin, the other being S. tenebrosa (Kangrang et al. 2012). ...
Recent fieldwork has revealed the presence of six species of Schistura McClelland 1838 in the Mae Khlong basin in south-western Thailand. These include S. sexcauda (Fowler 1937), S. balteata (Rendahl 1948), S. mahnerti Kottelat 1990, the recently described S. aurantiaca Plongsesthee et al. 2011 and S. tenebrosa Kangrang et al. 2012, and a newly discovered species described herein. Schistura sexcauda previously was the only Schistura species known in the Mae Khlong, and it was mis-identified as S. desmotes (Fowler 1934). Schistura pantherina, n. sp., is easily distinguished from all other species of Schistura by its distinctive color pattern. It appears to be endemic to the Mae Nam Kwai Noi system.
A new loach, Schistura liyaiensis, is described from the upper reaches of the Barak River at Liyai village, Senapati District, Manipur, India. It is distinguished from its congeners in having a unique combination of characters: 7-9 brown saddles each continuing onto the flank and forming 7-8 broad to slightly narrow bars with a rounded ventral margin, incomplete lateral line, 4 simple and 8½ branched dorsal-fin rays, a black spot at the origin of dorsal fin, a black basicaudal bar, pectoral and pelvic fins sub-acuminate, respectively, with 10 and 7 rays, prominent processus dentiformis.
There are 3108 valid and named native fish species in the inland waters of
Southeast Asia between the Irrawaddy and Red River drainages, the small coastal drainages
between the Red River and Hainan, the whole Indochinese Peninsula, Andaman and Nicobar
Islands, Indonesia (excluding Papua Province, Waigeo, Aru [but Kai is included]), and the
Philippines. They belong to 137 families. Their taxonomy and nomenclature are reviewed. The
original descriptions of all 7047 recorded species-group names and 1980 genus-group names
have been checked in the original works for correct spelling, types, type locality and bibliographic references. The bibliography includes about 4700 titles. Synonymies are given, based on published information as well as unpublished observations.
The names of 49 introduced species and 347 extralimital taxa cited in the discussions have
also been checked. The original descriptions of all species not present in the covered area but
cited as type species of genera have been checked for availability, authorship, date and correct
spelling. The availability of some family-group names has been checked when there was suspicion of possible nomenclatural problems.
Bibliographic notes include new informations on the dates of publication of works by, among
others, Bleeker, Bloch, Heckel and Steindachner and discussion of authorship of names in various works.
Schistura udomritthiruji, new species, is described from streams draining to the Andaman Sea in southern Thailand between Takua Pa and Ranong. It is distinguished from congeners by the following characters: dark bars on the body much thinner in the anterior half of the body than in the posterior half; 9+8 branched rays in the caudal fin; males with suborbital flap; lateral line ends above base of anal fin; caudal fin hyaline and dark bars on posterior half of body more than twice as wide as interspaces.
Schistura callidora, new species, is described from the Myitnge River drainage, Irrawaddy basin (Myanmar). It is distinguished by dark bars on the body much thinner in the anterior half of the body than in the posterior half; a high dorsal crest on the caudal peduncle; 8 1 /2-10 1 /2 branched dorsal-fin rays; and the lateral line reaching behind the base of the anal fin. Pteronemacheilus, new genus, is characterised by the presence of elongated skinfolds on the dorsal side of the second and third branched pectoral-fin rays in males. Pteronemacheilus lucidorsum, new spe-cies, is described from the Myitnge River drainage, Irrawaddy basin (Myanmar). It differs from its only congener, P. meridionalis, by having the dorsal midline without pigmentation and usually 8 + 8 branched caudal-fin rays.
A new genus (Laocypris) and 64 new species of fishes are described from Laos. The new species belong to the genera Acrossocheilus (1), Crossocheilus (1), Danio (3), Garra (1), Laocypris (1), Mystacoleucus (1), Poropuntius (4), Puntius (1), Rasbora (2) (Cyprinidae), Hemimyzon (2), Homaloptera (1), Schistura (39), Sectoria (1), Vanmanenia (2) (Balitoridae), Pseudomystus (1) (Bagridae), Doryichthys (1) (Syngn ath id ae), C hauduria (1) (C hau d h u riid ae) and M onotrete (1) (Tetraodontidae). Introduction Fish surveys conducted in Laos between 1996 and 1999 have increased the number of species known in the country from some 210 recorded in the literature as at 1996 to 481 (15 of them not native to the country) recognized in a just-completed field guide (Kottelat, 2000a). Several of the species discovered during these surveys have been described elsewhere (e.g., Britz & Kottelat, 1999a, b; Chen et al., 1999; Chen & Kottelat, 2000; Fang & Kottelat, 1999,2000; Kottelat, 1998; Kottelat & Brehier, 1999; Kottelat & Ng, 1999; Larson & Vidthayanon, 2000; Ng, 1999a-b; Ng & Kottelat, 1998, 1999,2000a-c). The field guide is due to be published in the second quarter of 2000 (a time-frame beyond my control) and clearly, it is desirable that the large number of species still unnamed should be named and identified in this work. It would be counterproductive to omit them from the fieldguide or to list them without valid names. The purpose of the present paper is to make names formally available for them.
Schistura aurantiaca, new species, is described from the Mae Khlong basin in western Thailand. It is distinguished from all other species of Schistura by a unique color pattern of 3-9 orange bars on the side of the body, with the 1st bar immediately behind the head and the 2nd bar near the dorsal-fin origin and widely separated so that most of the nape and the anterior side of the body are uniformly brown. The species reaches only 41 mm SL and in-habits shallow gravel and rubble riffles in small streams.
Schistura diminuta, new species, is described from the lower Sekong River, Mekong drainage, Cambodia. It is distinguished from congeners by the following characters: tiny adult body size (maximum known size 19.5 mm SL); lateral line incomplete, with 14-17 pores, terminating on the flank anterior to vertical through pelvic-fin origin; absence of axillary pelvic lobe; processus dentiformis weakly developed; dorsal-fin rays iii-iv.8.i; principal caudal-fin rays 8 + 8 (7 + 7 branched caudal-fin rays); a distinct dark brown spot at centre of caudal-fin base; and 9-10 irregular light brown bars along dorsal body surface.
Total relative abundance of fish and species richness at 95 sites in small rivers varied significantly with physicochemical
factors. Species richness was negatively and positively related with pH and dissolved oxygen, respectively. Relative abundance
varied inversely with discharge and ambient ammonia and, directly with depth, substratum, ambient oxygen and alkalinity. Fish
were represented by 62 species, the most common being Rasbora paviei, Puntius binotatus and Channa gachua. Canonical correspondence analysis related species and their relative abundances with eight environmental variables into four
groups. The most species-rich group was associated with approximately average values for the significant variables. The group
with the fewest species was associated with high oxygen and low ammonia and alkalinity. The other two groups had similar numbers
of species, one being associated with high ammonia and alkalinity and low oxygen. Species in the other group were found at
locations where rivers were relatively wide with comparatively high oxygen and low ammonia concentrations.
Schistura pumatensis Nguyen X. K. et Nguyen H. D. sp. nov.
Holotype: PM020170; SL: 64.2 mm; sample in Pumat national park, Nghean province.
Paratype: 5 PM020171, SL: 59.6 mm; PM020172, SL: 58.1 mm; PM030173, SL: 54.8 mm; PM020174, SL: 55.2 mm; PM020175, SL: 55.7 mm. Same data as holotype.
Diagnosis: the new species distinguished from all other species of genus in Southeast Asia by following combination characters: snout pointed, outer rostral barbel not reaching margin of orbital, body slender with small embred scales except abdomen.
Description: see figures 1 and 2 for appearance and morphometric data are given on table 1. Small size, elongate body: depth 14-16.5%SL, caudal peduncle slender, depth 11.5-13.6%SL, 1.18-1,4 times in length. Head short, lateral length 21.2-23.7%SL, eye diameter 3.6-4.7%SL, located dorsally and interorbital width 5.6-6.9%SL. Caudal peduncle 1.18-1.40 longer than its deep, its depth 11-13.6% SL. Dorsal fin origin slightly in front of ventral fin origin, both lip fleshy, upper lip notched medially. Dentiformis present. Lower jaw not incision. Pectoral fin reaches 1/3 of the distance to base pelvic fin. Auxiliary pelvic lobe present but reduced. Pelvic fin just reaches anus. Caudal fin forked, margin round. Lateral line complete. Dorsal crest on caudal peduncle absent.
D = 3 - 4. 7; A = 2.5; P = 1. 9 - 10; V = 1. 5 - 6, C = 5 + 14.
Colour pattern: body with 14-17 black bar, as wider or thinner than interspaces, quite regularly set. Black bar at caudal - fin base complete. Dorsal fin with one black spot in simple dorsal ray.
Remarks: this species near with S. bolavenensis Kottelat, S. chapaensis Rendalh but distinguished from them by branched caudal ray, color pattern, pelvic fin and pectoral fin ray, anus situation. More detail see table 2.
Distribution: Khe Bu stream in Pumat national park belonging to Lam river basin.
Etymology: named for Pumat national park.
Habitat: this species is found in a stream with rapid running water. Associated with Vanmanenia sp., Tor brevifilis.
UF 173049, 1 ex., 31.8 mm SL; Lin Tin River
- Kwai Noi River
Kwai Noi River,
stream near km 32 on Route 323, 14 o 58'17"N, 98 o 38'24"E, 12 Jun. 2008. UF 173049, 1 ex., 31.8 mm SL; Lin Tin
River, Route 323 at km 95, near Sai Yok, 14 o 33'44"N, 98 o 47'16"E, 12 Jun. 2008. UF 176388, 6 ex., 20.1-32.9 mm
SL;
UF 176447, 4 ex., 24.3-30.3 mm SL; Ban Rai River, near Tong Pha Phum, 14 o 43'10"N, 98 o 30'21"E
- Kring Ta Ko River
Kring Ta Ko River, 14 o 45'10"N, 98 o 30'02"E, 2 Jan. 2010. UF 176447, 4 ex., 24.3-30.3 mm SL; Ban Rai River,
near Tong Pha Phum, 14 o 43'10"N, 98 o 30'21"E, 2 Jan. 2010. UF 176461, 1 ex., 27.3 mm SL;
UF 176575, 1 ex., 21.0 mm SL; Ban Rai River, near Tong Pha Phum, 14 o 42'49"N, 98 o 31'26"E, 2
- Lin Tin River
Lin Tin River, Route
323 at km 95, 14 o 3216"N, 98 o 47'16"E, 1 Jan. 2010. UF 176575, 1 ex., 21.0 mm SL; Ban Rai River, near Tong Pha
Phum, 14 o 42'49"N, 98 o 31'26"E, 2 Jan 2010. Burapha Univ. uncat., 15 ex., 31.9-39.5 mm SL; Khayeng River,
14 o 33'22"N, 98 o 34'20"E, 22 Apr. 2010. Burapha Univ. uncat., 10 ex., 31.3-39.7 mm SL; Khayeng River,
14 o 33'22"N, 98 o 34'20"E, 25 Apr. 2010.
Schistura mahnerti: THAILAND: SALWEEN RIVER BASIN: MAE HONG SON PROV.: NIFI 855, 1
Schistura suber: LAOS: MEKONG BASIN: Vientiane Prov.: ZRC 45383, holotype, 29.7 mm SL; small forest stream along road from Thad Leuk to Nam Leuk dam site
- Khayeng Kwai Noi River
- River
Kwai Noi River, Khayeng River, hwy 3272 bridge, 14 o 39'35"N, 98 o 32'01"E, 3 Jan. 2010. USNM 295767, 13 ex.,
21.0-27.0; Kwai Noi River between Kanchanaburi and Sai Yok, 13-14 Apr. 1973.
Schistura suber: LAOS: MEKONG BASIN: Vientiane Prov.: ZRC 45383, holotype, 29.7 mm SL; small forest
stream along road from Thad Leuk to Nam Leuk dam site, 18°27'05"N, 103°04'06"E, 25 Feb. 1997.
Ca Nuoc Ngot Viet Nam. Tap II
- V H Nguyen
Nguyen, V.H. (2005) Ca Nuoc Ngot Viet Nam. Tap II. [Freshwater fishes of Vietnam].
Schistura pridii, a new nemacheiline loach (Teleostei: Balitoridae) from Upper Chao Phraya drainage, northern Thailand
- C Vidthayanon
Vidthayanon, C. (2003) Schistura pridii, a new nemacheiline loach (Teleostei: Balitoridae) from Upper Chao Phraya drainage,
northern Thailand. Ichthyological Exploration of Freshwaters, 14, 307-310.
- C Vidthayanon
- K Jaruthanin
Vidthayanon, C. & Jaruthanin, K. (2002) Schistura kaysonei, (Teleostei: Balitoridae) a new cave fish from the Khammouan
karst, Laos PDR. Aqua, Journal of Ichthyology and Aquatic Biology, 6, 17-20.
Schistura pridii, a new nemacheiline loach (Teleostei: Balitoridae) from Upper Chao Phraya drainage, northern Thailand
- F W H Beamish