Zootaxa 4422 (4): 478 492 http://www.mapress.com/j/zt/ Copyright 2018 Magnolia Press Article https://doi.org/10.11646/zootaxa.4422.4.2 http://zoobank.org/urn:lsid:zoobank.org:pub:bafdc18c-081d-48cf-a4af-fc3fd1ece89b ISSN 1175-5326 (print edition) ZOOTAXA ISSN 1175-5334 (online edition) A new species of Schistura (Teleostei: Nemacheilidae) from the south-western lowlands of Sri Lanka HIRANYA SUDASINGHE 1,2 1 Evolutionary Ecology and Systematics lab, Department of Molecular Biology and Biotechnology, University of Peradeniya, Peradeniya, Sri Lanka 2 Postgraduate Institute of Science, Faculty of Science, University of Peradeniya, Sri Lanka. E-mail: hsudasinghe@gmail.com Abstract Schistura scripta, new species, is described from Nakiyadeniya in the south-western lowlands of Sri Lanka. It can be distinguished from all other congeners from Sri Lankan and peninsular India by the combination of the following characters: an incomplete lateral line with 53 76 pores, ending beneath the dorsal-fin base or slightly beyond; 7 13 post-dorsal bars; 7½ branched dorsal-fin rays; absence of an axillary pelvic lobe; and absence of a suborbital flap. Key words: Schistura notostigma, Schistura madhavai, biodiversity hotspot, microendemism Introduction With over 230 valid species (Eschmeyer et al. 2018) ranging from the Indian subcontinent to Vietnam and southern China (Bohlen and Šlechtová 2009; Kottelat 2012), Schistura McClelland is the most speciose genus of nemacheilid loaches. Kottelat (1990) characterized the genus by, among other features, having a moderately-arched mouth; the mouth 2.0 3.5 times wider than long; a median interruption in the lower lip; and the absence of a free posterior chamber of the air bladder in most species. Though the interrelationships within the members of Schistura are not yet clearly understood, the accretion of molecular, morphological and distributional data suggest the genus to be paraphyletic (Freyhof et al. 2016; Kottelat 2017). Schistura notostigma was for long considered the sole representative of the genus in Sri Lanka, until Sudasinghe (2017) described a second species, S. madhavai, from the island. Recent fieldwork in the south-western lowlands of the island, in the Gin River basin, revealed a species of Schistura immediately distinguishable from both S. madhavai and S. notostigma by the greater number of bars and lateral line pores on its body. This is described here as Schistura scripta, new species. Material and methods Measurements were taken point-to-point using digital calipers, on the left side of specimens whenever possible, and recorded to nearest 0.1 mm. Counts and measurements follow Kottelat (1990). The distance between the posterior end of the lateral line and the median base of the caudal fin is termed the post-lateral line length (Kottelat 1990: fig. 2: BB). Additionally, the following measurements were made: post-dorsal length was measured from the dorsal-fin origin to the median base of the caudal fin; and post-dorsal head length from the posterior margin of the eye to hindmost point of the opercle. Head length (HL) and measurements of the body are given as proportions of standard length (SL). Subunits of the head are presented as proportions of dorsal-head length. The dark vertical bands on the body are counted as bars and the pale bands as interspaces. Any bar bifurcated on the side of the body was counted as two bars. Post-dorsal bars and post-dorsal interspaces refer to bars and interspaces posterior to the dorsal-fin origin. 478 Accepted by R. Pethiyagoda: 19 Mar. 2018; published: 25 May 2018
Principal component analysis (PCA) of the character correlation matrix was carried out to distinguish the variables that best discriminate among the species and to reduce the dimensionality of the continuous morphological variables. The optimal interpretability of variation among the characters was chosen by testing various axis rotations. Caudal-fin dimensions were excluded in order to include the maximum number of samples for the PCA. A Shapiro-Wilk test was carried out to test whether number of bars on the body of S. notostigma and S. scripta are normally distributed. Following the results of the Shapiro-Wilk test, an independent sample t-test was carried out to assess whether there was a significant difference in the mean number of bars on the body between S. notostigma and S. scripta. All statistical analyses were carried out in IBM SPSS Statistics (Version 20 for Windows). To represent the distribution of selected meristic counts among the species, boxplot graphs were plotted using IBM SPSS Statistics (Version 20 for Windows). Specimens referred to in the text are deposited in the collection of the National Museum of Sri Lanka (NH); Evolutionary Ecology and Systematics Lab, Department of Molecular Biology and Biotechnology, University of Peradeniya, Sri Lanka (DZ); the collection of the Wildlife Heritage Trust (WHT) of Sri Lanka now in the National Museum of Sri Lanka; and the collection of the National Bureau of Fish Genetic Resources, Kochi, India (NBFGRKU). Comparative data for Schistura altipedunculata and S. rendahli were taken from Bănărescu & Nalbant (1968); S. kodaguensis, S. mukambbikaensis, S. nilgiriensis, S. semiarmata and S. striata from Menon (1987); S. nagodiensis and S. sharavathiensis from Sreekantha et al. (2006); and S. bhimachari from Hora (1937). Results Schistura scripta, sp. nov. (Figures 1 2, 5 6) Holotype: NH 2018.4.1, 42.5 mm SL; Sri Lanka, Gin River basin, Seethala Dola, Nakiyadeniya Estate, 6 09'06"N 80 18'36"E, 83 m asl. H. Sudasinghe. Dec 2017. Paratypes: NH 2018.3.1, NH 2018.3.2, NH 2018.3.3, 3, 32.7 41.7 mm SL, same data as holotype. DZ3902, 9, 30.5 40.8 mm SL, same data as holotype. Diagnosis. Schistura scripta is distinguished from all Sri Lankan and peninsular-indian congeners by the combination of the following characters: an incomplete lateral line with 53 76 pores, ending beneath the dorsal-fin base or slightly beyond it; 7 13 post-dorsal bars, separated by narrower, lighter interspaces; the dorsal fin with 7½ branched rays; the absence of an axillary pelvic lobe; an emarginate caudal fin with 8+8 branched rays; and the absence of a suborbital flap. Description. General appearance as in Figures 1 2 and 5 6; morphological data are given in Table 1. A medium-sized Schistura, up to 42.5 mm SL. Body moderately deep, slightly compressed anteriorly, moderately compressed posteriorly. Body depth maximum between distal margin of adpressed pectoral fin and origin of dorsal fin. Body depth almost uniform from dorsal-fin origin to caudal-fin base. Head slightly depressed. Lateral head length and dorsal head length greater than head width. Snout rounded in lateral and dorsal views. Eyes small, located dorsolaterally, not visible ventrally. Depth of caudal peduncle 0.8 0.9 times its length. Caudal peduncle with small dorsal adipose crest, originating just posterior to vertical through anal-fin origin, reaching caudal-fin origin. Ventral adipose crest originating posterior to base of anal fin, reaching caudal-fin base. Axillary pelvic lobe absent. Origin of dorsal fin slightly anterior to vertical through origin of pelvic fin. Dorsal fin with four simple and 7½ branched rays. Tip of adpressed dorsal fin just reaching or falling just short of vertical through anal-fin origin. Anal fin with three simple and 5½ branched rays. Anal fin not reaching caudal-fin base. Caudal fin emarginate, with 8+8 branched rays; lobes rounded, of equal length. Pelvic fin with one simple and six branched rays, reaching half-way to anal-fin origin, surpassing anus; origin beneath first branched dorsal-fin ray. Pectoral fin with one simple and eight branched rays, reaching slightly beyond half-way to pelvic fins. Distal margins of anal, dorsal and pelvic fins convex. Lateral line incomplete, with 53 76 pores, ending beneath dorsal-fin base or slightly beyond it, but not reaching vertical through anal-fin origin. Body entirely scaled, scales more prominent in post-dorsal and sub-dorsal regions. Cephalic lateral line system with 6 7 supraorbital, 4+7 9 infraorbital, 7 9 pre-operculo-mandibular and 3 supratemporal pores. SCHISTURA SCRIPTA Zootaxa 4422 (4) 2018 Magnolia Press 479
Schistura scripta S. madhavai S. notostigma S. scripta Schistura scripta S. notostigma S. madhavai 480 Zootaxa 4422 (4) 2018 Magnolia Press SUDASINGHE
FIGURE 1. Variability of coloration in Schistura scripta in its natural habitat, not collected. Sri Lanka, Seethala Dola, Nakiyadeniya, Gin River basin. A C, adults, over 35 mm SL; C, adult male; D, sub-adult, ~30 mm SL. SCHISTURA SCRIPTA Zootaxa 4422 (4) 2018 Magnolia Press 481
FIGURE 2. A, Lateral; B, dorsal; and C, ventral views of the holotype of Schistura scripta (NH 2018.4.1), 42.5 mm SL. Mouth, large, inferior, curved. Lips thick; upper lip with slight median incision; lower lip with narrow medial interruption in most specimens (n=10; Fig. 3A), others (n=3) with deep medial interruption (Fig. 3B). Both lips with indistinct furrows along entire length (Fig. 3A,B). Processus dentiformis present, rounded, wide. Anterior nostril tubular, pierced anteriorly, terminating in an elongate flap (Figure 4). Inner rostral barbel reaching slightly beyond vertical through nostrils; outer rostral barbel ending halfway between verticals through anterior and posterior margins of eye; maxillary barbel extending just beyond vertical through posterior margin of eye. Suborbital flap absent. No apparent sexual dimorphism. Coloration. In 70% alcohol (Figure 2,5 6): adults (>30 mm SL) with head and body greyish brown dorsally, light brown laterally, creamish-white ventrally. Head darker than body. Maxillary barbels creamy white; base of inner rostral barbel with greyish-brown pigments, becoming creamy white towards tip; base of outer rostral barbel creamy white, becoming greyish-brown towards tip. Pre-dorsal bars 4 7, brown, separated by lighter interspaces, ending below lateral-line pores. Pre-dorsal interspaces distinctly narrower than bars, fused with each other ventro-laterally. Postdorsal bars 7 13, brown, separated by lighter interspaces. Post-dorsal bars extending almost to the ventrum (Figure 2,5). Some specimens with interspaces incomplete (not extending to dorsal or ventral surfaces: Fig. 5C,D) or bifurcated. Pre-dorsal and post-dorsal interspaces ¼ ½ and ½ 1 times width of bars, respectively. Pre-dorsal interspaces coalescing relatively more along dorsal midline, more frequently bifurcated dorsally than post-dorsal interspaces (Figure 6). Black bar at caudal-fin base not reaching 482 Zootaxa 4422 (4) 2018 Magnolia Press SUDASINGHE
dorsal or ventral midline, arched dorsally, its posterior margin vaguely indented at base of first branched caudalfin ray (Fig. 7A,B), becoming narrower and fragmented below 16th branched caudal-fin ray (Fig. 7A,B). Pectoral, pelvic and anal fins hyaline. A black spot at dorsal-fin origin, straddling bases of unbranched dorsal-fin rays and first branched dorsal-fin ray. Second, less distinct black spot behind it, along base of dorsal fin, straddling bases of branched rays 3 5. Two or three rows of distinct black spots on rays of dorsal fin. Interradial membrane of dorsal fin hyaline. Two or three rows of black spots on rays of caudal fin. FIGURE 3. Mouth of Schistura scripta, A, NH 2018.3.1, 41.7 mm SL; B, DZ3902E, 37.0 mm SL. FIGURE 4. Left nostril of Schistura scripta, NH 2018.3.1, 41.7 mm SL. Scale bar 1 mm. In life (Figure 1): adults (>30 mm SL) with brown bars and light-brown interspaces of width as in preserved specimens. Some with incomplete interspaces (not extending to dorsal or ventral surfaces or bifurcated: Fig. 1A C). Barbels light brown. Black bar at caudal-fin base incomplete. Pectoral, pelvic and anal fins with lightyellow pigmentation on rays. Rays of caudal and dorsal fins yellowish orange. In adult males, rays of caudal and dorsal fins reddish orange (Fig. 1C). A black spot at dorsal-fin origin, with a smaller, less distinct one behind it, straddling bases of branched rays 3 5. Two or three rows of distinct black spots on rays of dorsal and caudal fin. SCHISTURA SCRIPTA Zootaxa 4422 (4) 2018 Magnolia Press 483
FIGURE 5. Lateral view of paratypes of Schistura scripta, indicating color-pattern variation. A, NH 2018.3.1, 41.7 mm SL; B, DZ3902E, 37.0 mm SL; C, NH 2018.3.2, 35.7 mm SL; D, NH 2018.3.3, 32.7 mm SL. Habitat and distribution. Schistura scripta is at present known only from its type locality, a stream about 3 4 m wide, flowing through the palm-oil plantations of Nakiyadeniya Estate in an unprotected area of the Gin River basin, at an elevation of about 80 m above sea level (Figures 8, 9). The substrate consists of small boulders and 484 Zootaxa 4422 (4) 2018 Magnolia Press SUDASINGHE
pebbles. Schistura scripta prefers the faster-flowing regions of the stream and was observed sharing its habitat with Garra ceylonensis Bleeker, Rasbora dandia (Valenciennes) and Belontia signata (Günther). The species appears to be locally abundant: the habitat was sampled during a relatively dry period in December 2017 and about 100 adults, including several gravid females, were observed in a stretch of ~50 m along the length of the stream. Schistura notostigma was recorded in similar habitats sampled in Udugama about 8 km from the type locality of S. scripta. As presently understood, S. scripta and S. notostigma do not co-occur. Etymology. The species-name is a reference to the pattern of bars on the side of the body of this species resembling alphabetical characters; scripta, Latin, written words. FIGURE 6. Dorsal view of paratypes of Schistura scripta, showing color-pattern variation. A, NH 2018.3.1, 41.7 mm SL; B, DZ3902E, 37.0 mm SL; C, NH 2018.3.2, 35.7 mm SL; D, NH 2018.3.3, 32.7 mm SL. SCHISTURA SCRIPTA Zootaxa 4422 (4) 2018 Magnolia Press 485
FIGURE 7. Variation of caudal-fin bar in A, NH 2018.4.1, 42.5 mm SL, B, DZ3902M, 30.5 mm SL, Schistura scripta; C, DZ3900A, 46.6 mm SL, D, DZ3860, 40.2 mm SL, S. notostigma; E, 2017.02.01.NH, 49.7 mm SL, F, 3458A, 44.2 mm SL, S. madhavai. Statistical analysis. In the Principal component analysis (Fig. 10A, Table 2), the PC(1) axis is a size axis with all the variables loaded heavily with high positive values; it explains 78.5% of the variance. The PC(2) axis represents 6.35% of the variance, with the measurements of the lateral line length, post lateral-line length and maxillary-barbel length contributing most heavily. Schistura madhavai separates from both S. notostigma and S. scripta on the PC(1) axis with only a slight overlap with S. notostigma. All the specimens of S. notostigma, except DZ3422A, 33.7 mm SL from Athwelthota, Kalu River basin, separate distinctly from S. scripta on the PC(2) axis. In DZ3422A, the lateral line length is relatively long (57.6% SL) when compared with samples of S. notostigma (24.0 40.7% SL). A Shapiro-Wilk test showed the number of total bars on the body of both S. notostigma and S. scripta to be normally distributed (p>0.05). Though the ranges of total bars on the body overlap between S. scripta (11 20, mean=15.4, s.d.=2.2) and different populations of S. notostigma (8 15, mean=11.3, s.d.=1.5), the distribution of these bars between S. scripta and S. notostigma are significantly different (t (51) = -7.58, p<0.000). Schistura scripta has a relatively greater number of bars on the body in both size classes of specimens (> 35 mm SL, < 35 mm SL) than S. notostigma (Figure 11). 486 Zootaxa 4422 (4) 2018 Magnolia Press SUDASINGHE
TABLE 2. Component loadings of principal component analysis of the morphometric measurements of Schistura scripta, S. madhavai and S. notostigma. Measurement Component 1 Component 2 standard length 0.973 0.162 total length 0.959 0.148 predorsal length 0.965 0.118 postdorsal length 0.968 0.181 prepelvic length 0.964 0.152 preanus length 0.975 0.077 preanal length 0.965 0.178 body depth 0.940 0.171 caudal peduncle length 0.889 0.195 caudal peduncle depth 0.951 0.094 body width at dorsal-fin origin 0.917 0.076 body width at anal-fin origin 0.872-0.117 height of dorsal fin 0.719-0.058 length of pectoral fin 0.893-0.074 length of pelvic fin 0.949-0.056 length of anal fin 0.912 0.049 lateral line length 0.306 0.922 lateral line absent 0.725-0.622 dorsal head length 0.883-0.241 lateral head length 0.974-0.097 head depth at eye 0.923-0.295 head depth at nape 0.972-0.061 head width at nares 0.915-0.236 head width 0.970-0.060 snout length 0.951-0.009 eye diameter 0.473 0.195 post orbital head length 0.922-0.136 inter orbital width 0.958 0.068 length of maxillary barbel 0.729-0.355 length of inner rostral barbel 0.768 0.213 length of outer rostral barbel 0.795-0.131 Discussion Comparative remarks. Schistura scripta is distinguished from the two Sri Lankan species of Schistura, S. notostigma (Fig. 12A B) and S. madhavai (Fig. 12C D), by possessing a greater number of lateral-line pores (53 76 vs. 27 53 in S. madhavai (n=7); 20 53 in S. notostigma (n=42, 10 locations: Fig. 10B). In addition, S. scripta is distinguished from S. madhavai by the adpressed pelvic fin distinctly overlapping the anus (vs. just reaching the anus); the dorsal-adipose crest commencing just posterior to (vs. anterior to) a vertical through the anal-fin origin; body entirely scaled (vs. scalation absent anterior to dorsal-fin origin); 7 9 (vs. 9 10) pre-operculo-mandibular pores; furrows on lips indistinct (vs. distinct); two rows of distinct black spots (vs. melanophores scattered throughout) on the rays of the dorsal fin; the black bar at the caudal-fin base not reaching (vs. reaching: Figure 7) the distal margin of dorsal and ventral adipose crest; and having a longer lateral line (40.7 60.3% SL vs. 27.4 SCHISTURA SCRIPTA Zootaxa 4422 (4) 2018 Magnolia Press 487
36.0). In all 24 specimens of S. notostigma examined from eight locations, except DZ3422A (a 33.7 mm SL specimen from Athwelthota in the Kalu River basin), the lateral line is relatively short (24.0 40.7% SL vs. 40.7 60.3 in S. scripta). FIGURE 8. Habitat of Schistura scripta: Seethala Dola, Nakiyadeniya Estate, Nakiyadeniya, Gin River basin, Sri Lanka. FIGURE 9. Distribution of Schistura scripta (star), S. madhavai (cross) and S. notostigma (circles) in Sri Lanka. 488 Zootaxa 4422 (4) 2018 Magnolia Press SUDASINGHE
FIGURE 10. A, Factor scores of PC1 vs. PC2 of the principal component analysis of measurements of Schistura scripta (green, n=13), S. notostigma (red, n=23) and S. madhavai (blue, n=6); B, boxplots of the distribution of lateral-line pores in S. scripta, S. notostigma and S. madhavai. FIGURE 11. Boxplots of the distribution of bars on the body of Schistura scripta and S. notostigma in A, specimens above 35 mm SL; B, specimens below 35 mm SL. The color pattern in species of Schistura is often considered a reliable and useful diagnostic character among the different species, but is known to be ontogenetically variable (Kottelat 2001). The number of total bars in specimens of S. notostigma and S. scripta overlap only slightly. Except for a single specimen (DZ3902E, 37.0 mm SL) which has only 11 bars on the body (Fig. 5B, 6B), all eight remaining specimens of S. scripta longer than 35 mm SL that were examined have 13 20 (mode=15) bars, whereas specimens of S. notostigma over 35 mm SL (n=23) have 8 15 (mode=10) (Fig. 11A). Such variation is not unexpected in this genus (Kottelat 2001). Specimens of S. scripta less than 35 mm SL (n=4) have 16 17 (mode=17) bars on the body, whereas those of S. notostigma in this size-class (n=19) have 9 15 (mode=11, 12) (Fig. 11B). The differences in the number of bars between S. scripta and S. notostigma is driven by the number of post-dorsal bars (7 13, mode=9 vs. 5 9, mode=6 in S. notostigma) whereas the number of pre-dorsal bars is almost same in the two species (4 7 vs. 3 7 in S. notostigma). In addition, S. scripta can be distinguished from S. notostigma by having the black bar at the caudalfin base not reaching (vs. reaching: Figure 7) the distal margin of the dorsal adipose crest. SCHISTURA SCRIPTA Zootaxa 4422 (4) 2018 Magnolia Press 489
FIGURE 12. Schistura notostigma, A, ~35 mm SL, Kudawa, Kalu River basin (not preserved); B, DZ3860, 40.2 mm SL, Kitulgala, Kelani River Basin; Schistura madhavai, C, ~65 mm SL, Morningside, Walawe River Basin (not preserved); D, DZ3458A, 44.2 mm SL, Suriyakanda, Walawe River Basin. There are ten valid species of Schistura from southern India, viz., S. altipedunculata (Bănărescu & Nalbant); S. bhimachari (Hora); S. denisoni (Day); S. kodaguensis (Menon); S. mukambbikaensis (Menon); S. nagodiensis Sreekantha, Gururaja, Remadevi, Indra & Ramachandra; S. nilgiriensis (Menon); S. semiarmata (Day); S. sharavathiensis Sreekantha, Gururaja, Remadevi, Indra & Ramachandra; and S. striata (Day) Kottelat (2012). 490 Zootaxa 4422 (4) 2018 Magnolia Press SUDASINGHE
Schistura scripta differs from all its South Indian congeners by possessing 7½ (vs. 8½ in S. altipedunculata, S. denisoni, S. kodaguensis, S. mukambbikaensis, S. nagodiensis, S. nilgiriensis, S. semiarmata, and S. sharavathiensis; 10½ in S. bhimachari and S. striata) branched dorsal-fin rays. Further, S. scripta can be distinguished from S. altipedunculata, S. bhimachari, S. kodaguensis, S. nagodiensis, S. nilgiriensis, S. sharavathiensis, S. semiarmata, and S. striata by having an incomplete lateral line ending beneath or slightly beyond the dorsal-fin base (vs. incomplete lateral line terminating anterior to dorsal-fin origin, or above the adpressed pectoral fin in S. altipedunculata, S. kodaguensis, S. nagodiensis, S. nilgiriensis and S. sharavathiensis; and a complete lateral line in S. bhimachari, S. semiarmata, and S. striata). Additionally, S. scripta differs from S. bhimachari by the adpressed anal fin not reaching (vs. reaching) the base of the caudal fin; from S. denisoni by the absence (vs. presence) of an axillary pelvic lobe; from S. nagodiensis by its lower lip lacking (vs. possessing) black markings on either side of the median interruption and having a black bar (vs. blotch) at the caudal-fin base; from S. semiarmata by the body coloration lacking any spots (vs. distinct spots scattered throughout the body) and by having the caudal fin emarginate (vs. slightly forked); from S. sharavathiensis by having a small (vs. conspicuously large) dorsal adipose crest and lacking (vs. possessing) a black spot on the proximal one-fourth of the dorsal fin; and from S. striata by having a small (vs. conspicuously large) dorsal adipose crest and the caudal-fin lobes equal in length (vs. upper lobe slightly longer than the lower). Further, S. scripta can be distinguished from S. rendahli Bănărescu & Nalbant (placed in the synonymy of S. denisoni by Menon 1987), by having the mouth with distinct lips (vs. lips absent according to Bănărescu & Nalbant s (1968) original description of the holotype, possibly an aberrant specimen); and having 7½ (vs. 8½) branched dorsal-fin rays. Distribution and conservation. The members of Schsitura in Sri Lanka are distributed mainly in the island s southwest quadrant and its central hills (rainfall > 2000 mm/y) drained by the major rivers Kelani, Kalu, Gin, Nilwala, Walawe and Mahaweli. However, the range of S. notostigma extends also to some parts of the dry and intermediate zones in which suitable habitats occur. The lowest elevation from which S. notostigma has been observed is about 25 m above sea level, in the Yagirala Forest Reserve, while the highest elevation is about 1500 m above sea level at Kolapathana falls. Schistura madhavai was first recorded from a single locality in Suriyakanda (Sudasinghe 2017). However, fieldwork since Sudasinghe (2017) has revealed S. madhavai to occur also in the Morningside Forest Reserve, at an elevation of about 1140 m above sea level (Figure 9). Schsitura scripta is presently known only from its type locality, with an Area of Occupancy of <10 km 2, which suggests an IUCN Red List assessment of Critically Endangered (criteria B2/D: IUCN 2012). A definitive conservation assessment should, however, await further sampling within the Gin River basin. However, since the type locality is located outside a protected area, and given the anthropogenic disturbance of its habitat, conservation action to protect the type locality is clearly necessary. Comparative material Schistura denisoni: NBFGRKU2013.01.154, 38.8 mm SL; India, Agali, Kerala (Cauvery basin). S. madhavai: All from Sri Lanka: Holotype: 2017.02.01.NH, 49.7 mm SL, Walawe River basin, Suriyakanda. Paratypes: 2017.03.01.NH, 55.3 mm SL, 2017.03.02.NH, 45.8 mm SL, same data as holotype. DZ 3418C, 51.2 mm SL, DZ 3458 (3), 34.8 44.2 mm SL, same data as holotype. S. notostigma: All from Sri Lanka: DZ 3756 (3), 34.2 38.7 mm SL, Attanagalu River basin, Wahareka. DZ3860, DZ 3861, DZ 3868, 40.2 38.0 mm SL, Kelani River basin, Makandawa Forest reserve, Kitulgala. DZ 3620 (2), 40.4 41.5 mm SL, Kelani River basin, Deraniyagala. WHT 30034 (2), 27.7 33.2 mm SL, Kelani River basin, Heen ela, Waga. WHT 30457 (2), 32.5 34.7 mm SL, Kelani River basin, Wak Oya, Kahahena. DZ 3420 (3), 31.2 35.7 mm SL, Kalu River basin, Malwara Forest reserve, Halwala. DZ 3368, 42.7 mm SL, Kalu River basin, Malwara Forest reserve, Halwala. DZ 3421 (3), 38.3 46.6 mm SL, Kalu River basin, Kukuleganga south, Kalawana. DZ 3462 (3), 31.1 39.6 mm SL, Kalu River basin, Athwelthota. DZ 3422 (4), 26.1 33.7 mm SL, Kalu River basin, Athwelthota. DZ 3419 (3), 38.7 41.2 mm SL, Kalu River basin, Padukka. WHT 120 (4), 42.2 47.4 mm SL, Kalu River basin, Walandure, Kuruwita. WHT 30491 (4), 34.6 43.5 mm SL, Kalu River basin, Koskulana, Panapola. DZ 3424 (2), 30.8 33.5 mm SL, Bentara River basin, Pitigala. WHT 30218 (2), 29.2 33.4 mm SL, Gin River basin, Kottawa, Galle. WHT 2010 (3), 29.5 40.6 mm SL, Gin River basin, Kottawa forest reserve, Galle. WHT 30668 (4), 27.0 33.6 mm SL, Gin River basin, Udugama ela. DZ 3870 (8), 34.1 26.3 mm SL, SCHISTURA SCRIPTA Zootaxa 4422 (4) 2018 Magnolia Press 491
Gin River basin, Homadola, Udugama. DZ 3900 (7), 46.6 36.3 mm SL, Gin River basin, Deniyaya. DZ 3589 (6), 26.3 39.8 mm SL, Mahaweli River basin, Peradeniya, Kandy. DZ 3417 (5), 42.6 51.8 mm SL, Mahaweli River basin, Peradeniya, Kandy. WHT 30629 (3), 49.1 63.1 mm SL, Mahaweli River basin, Paradeka, Pussellawa. WHT 38 (5), 41.9 54.9 mm SL, Mahaweli River basin, Mousakanda, Gammaduwa, Knuckles. Acknowledgments I am grateful to the Director General of Wildlife Conservation and the Conservator General of Forests, Sri Lanka, for permits to carry out field work. I thank Binesh Pananwala (CEO), Chamika Naranapitiya (DGM- South) and the staff (Ruwan Gunaratne, Malinda Jayasundara and Dinuka Lanka and others) of Watawala Plantations for providing me the opportunity to carry out field work at Nakiyadeniya and Homadola Estates, and for their kind hospitality during my visits. I am grateful to Rohan Pethiyagoda for providing valuable comments to improve an earlier draft of the manuscript and permitting the use of the base map in Figure 9. Finally, I thank Kumudu Wijesooriya and R.H. Tharindu Ranasinghe for assisting me in the field, and two anonymous reviewers for providing valuable comments that helped improve this manuscript. References Bănărescu, P. & Nalbant, T.T. (1968) Cobitidae (Pisces, Cypriniformes) collected by the German India Expedition. Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 65, 327 351, pls. 1 2. Bohlen, J. & Šlechtová, V. (2009) Schistura udomritthiruji, a new loach from southern Thailand (Cypriniformes: Nemacheilidae). Ichthyological Exploration of Freshwaters, 20 (4), 319 324. Eschmeyer, W.N., Fricke, R. & van der Laan, R. (Eds.) (2018) Catalog of Fishes: Genera, Species, References. Electronic Version. Available from: http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp (accessed 23 January 2018) Freyhof, J., Geiger, M.F., Golzarianpour, K. & Patimar, R. (2016) Sasanidus, a new generic name for Noemacheilus kermanshahensis Bănărescu & Nalbant, with discussion of Ilamnemacheilus and Schistura (Teleostei; Nemacheilidae). Zootaxa, 4107 (1), 65 80. https://doi.org/10.11646/zootaxa.4107.1.3 Hora, S.L. (1937) Notes on fishes in the Indian Museum. XXVIII. On three collections of fish from Mysore and Coorg, South India. Records of the Indian Museum, 39, 5 28. Kottelat, M. (1990) Indochinese nemacheilines. A revision of nemacheiline loaches (Pisces: Cypriniformes) of Thailand, Burma, Laos, Cambodia and southern Viet Nam. Pfeil, München, 262 pp. Kottelat, M. (2001) Fishes of Laos. WHT Publications, Colombo, 198 pp. Kottelat, M. (2012) Conspectus cobitidum: an inventory of the loaches of the world (Teleostei: Cypriniformes: Cobitoidei). The Raffles Bulletin of Zoology, 26 (Supplement), 1 199. Kottelat, M. (2017) Three new species of loaches of the genus Schistura from the Nam Ngiep drainage, central Laos (Teleostei: Nemacheilidae). Raffles Bulletin of Zoology, 65, 691 706. Menon, A.G.K. (1987) The fauna of India and the adjacent countries. Pisces. IV Teleostei Cobitoidea. Part 1. Homalopteridae. Zoological Survey of India, Calcutta, x + 259 pp., 16 pls. Sreekantha, Gururaja, K.V., Remadevi, K., Indra, T.J. & Ramachandra, T.V. (2006) Two new fish species of the genus Schistura McClelland (Cypriniformes: Balitoridae) from Western Ghats, India. Zoos Print Journal, 21 (4), 2211 2216. https://doi.org/10.11609/jott.zpj.1386.2211-6 Sudasinghe, H. (2017) Schistura madhavai, a new species of hill-stream loach from Sri Lanka, with redescription of S. notostigma (Teleostei: Nemacheilidae). Zootaxa, 4311 (1), 96 110. https://doi.org/10.11646/zootaxa.4311.1.6 492 Zootaxa 4422 (4) 2018 Magnolia Press SUDASINGHE