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Psilorhynchus kamengensis, new species, is described from a stream of the Kameng River, a northern tributary to the Brahmaputra drainage, Arunachal Pradesh, northeast India. The new species belongs to the P. balitora species group and can be distinguished from all other members of this group by the presence of a longer post-epiphyseal fontanelle, 3 unbranched anal-fin rays, 9 + 8 caudal-fin rays, 35 vertebrae and fin coloration. The validity of the species is also corroborated by molecular phylogenetic analysis based on the mitochondrial cyt b gene.

Schistura syngkai, new species (Fig. 1, Table 1) Holotype. ZSI FF 8317, 42.1 mm SL; India: Meghalaya: West Khasi Hills District: Twahdidoh Stream of Wahblei River (Surma-Meghna drainage) near Seinduli village, 25��39��32�� N 91��08��22�� E; 1100 m asl; D. K. B. Mukhim, June 2017. Paratypes. GUMF 304 /6, 6 specimens, 26.8���43.0 mm SL; same data as holotype. Diagnosis. Schistura syngkai is distinguished from all other Indian congeners in having (in combination) a unique colour pattern in the form of a prominent dark-brown to black mid-lateral stripe about an eye diameter or more in width, overlain on 12���18 vertically-elongate black blotches on a golden-brown to amber (fading to light brown or pale beige in preservative) body. Additionally, the species is diagnosed in having 11���17 dark-brown or greyish saddles, the dorsal-fin origin posterior or nearly opposite to pelvic-fin origin, an incomplete lateral line, and a slightly emarginate caudal fin. Description. A moderately elongate loach with body nearly oval in cross-section, compressed caudad. Head slightly depressed at nape, with an arched anterior profile up to nares. Dorsal body profile gently rising up to slightly ahead of dorsal-fin origin, following a descent through dorsal-fin base, nearly straight or (sometimes) ascending thereafter up to caudal-fin base. Ventral profile nearly straight, (rarely) arched up to pelvic-fin base, following a descent up to anal-fin origin, then concavely arched up to caudal-fin base. Short and shallow adipose crests along dorsal and ventral midlines of caudal peduncle. Mouth arched, nearly semi-circular, about 1.3���1.5 times wider than long, with thick, fleshy lips; upper lip with inconspicuous median incision and shallow, thin wrinkles; lower lip with narrow median interruption, both halves not forming ���cushions���, oriented at an obtuse angle, with 1���5 sulci medially and shallow wrinkles (or sometimes plain, without wrinkles) laterally; tip of lower jaw exposed with mouth closed (Fig. 2a). Processus dentiformis present on upper jaw, with corresponding shallow median concavity on lower jaw. Anterior nostril pierced in front of a long, pointed, tube-like flap, reaching anterior margin of eye. Barbels in three pairs: inner rostral barbel reaching gape of mouth; outer rostral reaching slightly beyond vertical through anterior margin of orbit; maxillary barbel reaching �� distance between gape of mouth and pectoral-fin base. Dorsal fin with 4 (7*) simple and 7�� (4)���8�� (3*) branched rays; its origin nearly opposite or behind pelvic fin. Anal fin with 3 (7*) simple and 5�� (7*) branched rays; adpressed fin not reaching hypural flexure. Pectoral fin with 1 (7*) simple and 9 (1)���10 (6*) branched rays; adpressed fin reaching ⅔ distance between its origin and pelvic fin. Pelvic fin with 1 (7*) simple and 7 (7*) branched rays; adpressed fin not reaching anus. Caudal fin with 8 + 8 (7*) branched rays, slightly emarginate, lobes rounded, upper lobe slightly longer than lower. Anus situated about 1�� eye diameters ahead of anal-fin origin. Body covered with minute, deeply-embedded cycloid scales, except ventrally between paired fins. Lateral line incomplete (often discontinuous) with 19���42 pores, ending slightly ahead of pelvic fin or below origin of fourth branched ray of dorsal fin. Cephalic lateral line system with 5���8 supraorbital, 3 + 9���10 infraorbital, 9���10 preoperculomandibular and 3 supratemporal pores. Intestine with a loop behind stomach (Fig. 2b). Air bladder encased in an ossified capsule, its halves connected by a manubrium; a small, free posterior chamber present (Fig. 2c). Axillary pelvic lobe small, inconspicuous. Coloration. In preservative: Anterior lateral one-fifth of body light brown to pale beige dorsally, fading to cream or pale white ventrally. Dorsal region of head up to level of infraorbital-pore canal darker brown than body, sometimes greyish, except lighter nasal flaps; cream to pale white ventrally. A prominent dark brown to black midlateral stripe about an eye diameter or more in width, overlain on 12���18 vertically-elongate black blotches, starting immediately behind opercular margin and extending up to caudal base. Stripe often discontinuous or interrupted in specimens below 35 mm SL. Saddles 11���17, not very contrasted, dark-brown (or greyish black), equal to or wider than interspaces, (rarely) extending ventrally to interconnect with lateral blotches; predorsal saddles mostly broken into irregular blotches. An oblique black stripe from tip of snout to anterior margin of eye. Rostral barbels greyish dorsally, cream ventrally; maxillary barbel cream. Caudal bar pattern consisting of a medial black bar occupying about two-thirds of caudal-fin depth, connected with mid-lateral stripe or separated by a narrow gap, and an oblique or oval blotch over the dorsal procurrent rays. All fins hyaline, except dorsal fin, which has a prominent black blotch proximally just above the fin base covering last unbranched ray, first branched ray and interradial membrane connecting them, and two rows of spots: first medially along unbranched and first branching points of branched rays, and second along distal one-third of branched rays; distal two-thirds of unbranched and first branched pectoral-fin rays sometimes blackish; caudal-fin with two irregular vertical rows of black or brown spots on fin rays. In life: Similar to that described above, except golden-brown to amber background dorso-laterally, fading to pale yellow or cream ventrally. Fins amber or golden brown. All markings black. Anterior margin of opercular bone often with a faint, greyish-black ���comma-like��� punctuation. Rostral barbels reddish brown dorsally. When stressed (e.g., immediately after collection), anterior half of the mid-lateral stripe may appear faded (Fig. 1c). Sexual dimorphism. No sexually dimorphic characters (viz., modified pectoral-fin rays, suborbital flap/slit, aggregation of tubercles, unculiferous pads or puffed cheeks) observed. Distribution and habitat. Presently, the new species is known only from its type locality, near Seinduli (village) in West Khasi Hills District, Meghalaya (Fig. 3). The Twahdidoh stream is a right bank tributary to the Wahblei River and itself a complex of several streamlets flowing through tropical evergreen forest interspersed with conifers. The new species was collected adjacent to a rice paddy in its lower stretch. The stream has a muddy bottom with stretches of pebbles and rocks, and the habitat is covered with dense perennial grasses (Fig. 4). Etymology. From the Khasi (an ethnic community of Meghalaya) word ��� Syngkai ��� meaning a loach-like fish. A noun in apposition., Published as part of Choudhury, Hrishikesh, Mukhim, D. Khlur B., Dey, Abhinit, Warbah, Deisakee P. & Sarma, Dandadhar, 2019, Schistura syngkai, a new fish species (Teleostei: Nemacheilidae) from Meghalaya northeast India, pp. 185-191 in Zootaxa 4701 (2) on pages 186-188, DOI: 10.11646/zootaxa.4701.2.5, http://zenodo.org/record/3557973

Schistura rebuw, new species (Figs. 1 & 2) Type material. Holotype. GUMF 0 301, 69.8 mm SL; India: Arunachal Pradesh: East Kameng District: Pachai stream near Seppa: Kameng River (Brahmaputra basin); 27��23��20�� N, 93��03��20�� E, 400 m above sea level; A. Dey & party, 16 February 2017. Paratypes. GUMF 0302 /5, 5 specimens, 41.8���71.1 mm SL, data same as holotype. ZSI FF7956, 53.0 mm SL, data same as holotype. Diagnosis. Schistura rebuw is distinguished from its congeners by the combination of the following characters: 10���11 blackish bars on a greyish-beige body; pre-dorsal bars mostly broken and/or incomplete, coalescing dorsally in a more or less alternate fashion to form irregular saddles; bars below and behind the dorsal fin mostly regular, rarely broken or incomplete, coalescing dorsally to form regular saddles; a complete caudal bar; all bars over-layered on a faint mid-lateral stripe, mostly discernible as a connection between the caudal and its preceding bar, sometimes continuous and reaching vertically through pectoral fin base; vermiculated head and cheeks; a small suborbital slit in females and a suborbital flap in males; a complete lateral line; a prominent axillary pelvic lobe; and a forked caudal fin. Description. See Figure 1 for general appearance and Table 1 for morphometric data. Body elongate, nearly oval in cross-section up to dorsal fin, compressed caudad. Head slightly depressed at nape, its anterior profile arched up to nares. Dorsal body profile gently arched up to a point slightly ahead of dorsal fin, followed by a small depression, then descending gently up to caudal-fin base. Ventral body profile nearly straight, with a gentle ascent after anal-fin origin. Short adipose crests along dorsal and ventral midlines of caudal peduncle, often appearing notched in some specimens when viewed laterally. Mouth arched, nearly semi-circular, about 1.5���2.1 times wider than long, with thick, fleshy, pleated lips; upper lip with median incision, lower lip with wide median interruption. Prominent processus dentiformis present on upper jaw, with corresponding median depression on lower jaw (Fig. 3a). Anterior nostrils pierced in front of short, broadly-pointed tube-like flaps. Barbels in three pairs: inner rostral reaching slightly beyond the angle of mouth; outer rostral reaching the anterior margin of the orbit; maxillary barbel extending up to anterior margin of opercular bone. Lips, barbels covered by numerous unculi. Dorsal fin with 4 (7) simple and 7�� (2), 8�� (5) branched rays; its origin slightly ahead of pelvic fin. Anal fin with 3 (7) simple and 5�� (7) branched rays; fin not reaching hypural fold when adpressed. Pectoral fin with 9 (1) or 10 (6) branched rays; adpressed fin reaching nearly half (or slightly more than) the distance between pectoral and pelvic origins. Pelvic fin with 6 (1) or 7 (6) branched rays; adpressed fin reaching about two-third the distance between its origin and anus. Caudal fin forked, with 8+7 (2) or 9+8 (5) branched rays; its lower lobe equal to or slightly longer than the upper. Anus situated posteriorly, just about an eye diameter ahead of anal fin. Body covered by minute, deeply-embedded cycloid scales, except on head and ventrally up to anal-fin origin. Lateral line complete, with 76���97 pores. Cephalic lateralis system consists of 6���7 supra-orbital, 3 + 8���10 infraorbital, 9 preoperculomandibular and 3 supra-temporal pores. Intestine nearly straight, without any discernible loop behind stomach (Fig. 3b). Air bladder within ossified capsule, with a small free posterior chamber (Fig. 3c). Axillary pelvic lobe present. Minute tubercles on entire body and in rows along interradial membranes of fins. Vertebrae: 37 (1) or 38 (1). Coloration. In preservative (Fig. 1): Ground colour grey or greyish-beige dorso-laterally, darker dorsally, fading ventrad up to three-fourths or level of pectoral-fin laterally; dull creamy-white ventrally. Dorso-lateral region of head up to level of rostral barbels along the infra-orbital pore canal darker grey than body, except lightgreyish nasal flaps; light beige to creamy-white ventrally. Unless otherwise stated, all markings blackish. Body with 10���11 bars, weakly contrasted (except in holotype: 69.8 mm SL, and smallest specimen: 41.8 mm SL); those in front of dorsal fin somewhat irregular, sometimes broken and/or incomplete, usually wider or subequal to interspaces, reaching up to level of pectoral-fin base, coalescing dorsally in an alternate pattern to form Y-like (rarely X-like) saddles; those below dorsal fin complete, sometimes broken, reaching up to level of pelvic fin origin; those behind dorsal fin mostly regular, complete, subequal to or narrower than interspaces, reaching up to level of anal fin base, except the single bar immediately behind anal fin, which sometimes reaches the ventral midline to form a complete ring. In some specimens (Fig. 1e), bars much faded, showing only remains of saddles (possibly due to preservation). Caudal bar complete, sometimes not reaching dorsal or ventral midlines. Bars overlaid on a faint, thick mid-lateral stripe, mostly discernible as a connection between the caudal and its preceding bar, sometimes (a few specimens below 53 mm SL) continuous, reaching vertical through pectoral fin base. Head and cheeks vermiculated. In the smallest specimen (Fig. 1d, 41.8 mm SL), pre-dorsal bars coalesce dorsally in a more irregular and vermiculated pattern. Bars sharply contrasted and overlaid on a thin mid-lateral stripe, which appear to connect them. Caudal bar incomplete, connected to its preceding bar by thick, prominent mid-dorsal and mid-lateral stripes. Fins with hyaline interradial membranes; dorsal fin rays proximally blackish until a little beyond branching points, sometimes prominent as an oblique band; proximal two-thirds of first four or five fin rays of pectoral and pelvic fins blackish; anal fin rays sometimes with faint blackish oblique band; caudal fin rays blackish, sometimes with two closely-set V-shaped bands (often indiscernible). Black blotch sometimes present at origin of dorsal-fin base, surrounding the simple and first two branched rays. Barbels greyish black except for maxillary barbell, which is creamy white, its base sometimes blackish. Coloration in life (Fig. 2): Ground colour metallic beige to golden yellow dorso-laterally, creamy white ventrally. Bars dark-greyish black, distinct, with shiny olive tinge. Head slightly darker than body; vermiculated patterns on head and cheek iridescent olive. Fins hyaline, reddish in freshly caught males, gradually fading in aquarium; all markings on fins blackish. Nasal and rostral barbels reddish-brown, maxillary barbel creamy, with slight olive tinge. Sexual dimorphism. Males with a short suborbital flap, approximately parabolic in shape (Fig. 4a). Females with a suborbital slit in the position corresponding to the posterior edge of the flap in males (Fig. 4b). Notes on Biology. One dissected female (GUMF 0302/5, 71.1 mm SL) contained about 700 immature ova of approximate diameter of 0.6 mm. Distribution and Habitat. Presently, the species is known only from the Pachai stream, joining the Kameng River, Brahmaputra drainage, near Seppa, East Kameng District, Arunachal Pradesh, India (Fig. 5). The species was collected from a fast-flowing stretch of the stream about 10���20 m width and 0.5���2.0 m depth. The river bed comprises of pebbles and large rocks, mostly covered in algae (Fig. 6). Analyzed during the month of February 2016, the water was clear, pH 7.5, D.O. 6.3 ppm, temperature 16��C, salinity 0.04 ppt and conductivity 9.12 ��S. Other associated fish species caught along were Amblyceps apangi, Garra annandalei, Glyptothorax striatus, Devario aequipinnatus, Pseudecheneis sulcata and Psilorhynchus arunachalensis. Etymology. The specific epithet is derived from the Nishing (an ethnic community in Arunachal Pradesh) word ��� rebuw ���, referring to loach-like fish. A noun in apposition., Published as part of Choudhury, Hrishikesh, Dey, Abhinit, Bharali, Ratul Ch., Sarma, Dandadhar & Vishwanath, Waikhom, 2019, A new species of stone loach (Teleostei: Nemacheilidae: Schistura) from Arunachal Pradesh, India in Zootaxa 4551 (1), DOI: 10.11646/zootaxa.4551.1.2, http://zenodo.org/record/2622558

Schistura larketensis, new species (Figs. 1 & 2) Holotype. GUMF 0 261, female, 54.5 mm SL; India: Meghalaya: East Jaintia Hills District: Krem Khung about 1.5 km from Larket village (25°23ʹ22ʺ N, 92°34ʹ49ʺ E; 880 m above sea level); D. K. B. Mukhim & party, 24 February 2016. Paratypes. GUMF 0262/3, 3 specimens, 41.0– 54.7 mm SL; same data as holotype. GUMF 0263 /2, 63.1–68.1 mm SL, 2 specimens; same locality as holotype; D.K.B. Mukhim & party, October 2012. GUMF 0264 /3, 3 specimens, 49.6–61.3 mm SL; same locality as holotype; D. K. B. Mukhim & party, 30 October 2016. ZSI FF7225, 60.4 mm SL; same data as holotype. Diagnosis. Schistura larketensis is distinguished from its congeners in possessing a combination of the following characters: a pale to weakly-pigmented body; a thick and short basicaudal bar immediately below the lateral-line scale row (often appearing broken in some individuals); the eyes vestigial or absent; a smooth ventrolateral surface of the head; the anterior nostrils forming long and pointed triangular tube-like flaps; an incomplete lateral-line; a small and cylindrical, axillary pelvic-lobe; the chest naked; and an emarginated caudal-fin. Description. Figure 1 illustrates the general appearance and Table 1 presents the morphometric data for the holotype and nine paratypes. Body moderately elongate, nearly circular in cross-section anteriorly to dorsal-fin origin, compressed posteriorly. Head depressed at nape, its anterior profile rising evenly above nares. Dorsal body profile gently rising, appearing almost straight up to dorsal-fin origin, then descending slightly along dorsal-fin base, then straight up to caudal-fin base. Mouth semi-circular, about 1.2–1.6 times wider than long, with thick, fleshy, pleated lips; upper lip with small median incision (absent in specimens below 54.7 mm SL); lower lip with wide median incision, its median lobes with 5–8 well marked furrows; rest of lip plain (Fig. 3a). Broad, flat processus dentiformis present on upper jaw, with corresponding shallow median concavity on lower jaw. Eyes, when present, vestigial, subcutaneous, absent in larger specimens (above 63.1 mm SL). Anterior nostrils pierced in front of long and pointed tube-like flaps, not reaching (vestigial) eyes. Barbels in three pairs: inner rostral barbels reaching angle of mouth, outer rostral and maxillary barbels reaching anterior margin of (vestigial) eyes. Dorsal-fin with four simple and 8 (n = 1) or 8½ (n = 9) branched rays, its origin slightly ahead of pelvic-fin origin. Anal-fin with three simple and 5 (n = 1) or 5½ (n = 9) branched rays, fin not reaching caudal-fin base. Caudal-fin with 9 + 8 (n =10) branched rays, deeply emarginated, upper lobe about 1.0–1.1 times longer than lower, both lobes with broadly pointed tips. Pelvic-fin with 6 (n = 1) or 7 (n = 9) branched rays, reaching anus when adpressed (except in specimens below 54.7 mm SL); its origin vertically below second branched dorsal-fin ray. Pectoral-fin with 10 (n = 8) or 11 (n = 2) branched rays, reaching about midway between bases of pectoral and pelvic fins. Anus situated posteriorly, nearer to anal-fin origin, about ⅔ pelvic-anal distance from pelvic-fin origin. Body entirely covered by minute deeply-embedded cycloid scales, except on head, and chest between pectoral fins. Lateral-line incomplete, reaching vertical through first, fourth or last branched ray of dorsal-fin, with about 27–38 pores (pores indistinct, hence difficult to count). Cephalic lateralis system consists of 7 supra-orbital, 4 + 7– 9 infra-orbital, 10–11 pre-operculomandibular, and 3 supra-temporal pores. Intestine with small loop behind posterior end of stomach (Fig. 3b). Air bladder without any free posterior chamber (Fig. 3c). Lips, barbels covered by numerous unculi. Axillary pelvic lobe present, small, cylindrical, deciduous (detached from some specimens). Short and shallow adipose crests on dorsal and ventral midline of caudal peduncle. Vertebrae: 37. Coloration. In preservative (Fig. 1a–i): Colour pattern variable (possibly due to age variation or preservation). In two specimens (54.5 mm SL; 53.4 mm SL; Fig. 1a, f), ground colour dull-beige to light-cream with dorso-lateral half (about ½ or ⅔) of body darker beige to dull brownish. Head and cheeks darker, with much lighter nasal flaps. Barbels dull-brown. Two faded dorsal and four or five post-dorsal saddles continue as indistinct, irregular bars, usually wider than interspaces, reaching up to two-third of lateral half of body. Black spot at base of simple and first branched dorsal-fin rays; faint blackish stripe along entire dorsal-fin base, from third branched ray. Faded, short, thick, incomplete black caudal bar present below lateral-line scale row. In the holotype (Fig. 1a), caudal bar reaching upper end of caudal-fin base, broken midway along level and slightly above lateral-line. Caudal-fin with faint, oblique brownish bars towards bases; additional irregular markings on fin rays. Vertically elongate, brownish blotch immediately above pectoral-fin base below lateral-line, behind operculum, partly covering cleithrum. Proximal two-thirds of pectoral and dorsal-fin rays with faint black coloration. Pelvic, anal fins hyaline. In some specimens, ground colour faded beige to creamy-white with slightly darker dorso-lateral half. Faint black spot at base of simple and first branched dorsal-fin rays sometimes present (61.3 mm SL, Fig. 1g; 49.6 mm SL). Faint brownish caudal bar below lateral-line scale row. Caudal-fin with faint oblique grayish marks. Dorsal aspect of pectoral and dorsal-fin rays with faint brownish colour. Four or five pale brownish post dorsal saddles sometimes present. In one individual (49.6 mm SL; Fig. 1e), faint blackish-brown blotches aggregate to give appearance of a stripe along lateral-line, more distinct towards posterior end. In another individual (60.4 mm SL, Fig. 1h), several light brown bars present below lateral-line; barbels dull white. In large specimens (68.1 mm SL, Fig. 1i; 63.1 mm SL), overall body coloration faded beige to dull white, with faint remains of caudal bar and blotch above pectoral base. Fins hyaline except for faint brownish markings on caudal-fin lobes. Barbels dull-white. In juveniles (41.0 mm SL, Fig. 1d; 45.1 mm SL): Ground colour dull white, with darker dorso-lateral half. Three dorsal and five post-dorsal saddles present, together with narrow mid-lateral stripe (apparently an aggregation of blotches) along entire body length present. Caudal bar short, thick, just below lateral-line scale row. Caudal-fin with oblique brownish marks. Barbels dull-white. Coloration in life (Fig. 2): Ground colour pinkish beige. About ⅔ of dorso-lateral half of body brownish with aggregated melanophores, anterior half darker than posterior. Chest, abdomen whitish with thin translucent skin. Vertical brownish blotch behind operculum, below lateral-line; short, thick, faint brownish basicaudal bar below lateral-line scale row; dark brownish-black spot at base of simple and first branched dorsal-fin rays; faint blackish stripe along entire dorsal-fin base from third branched ray present. Eyes appear as black spots below thin layer of transparent skin. Two dark-brownish dorsal and four post-dorsal faint saddles continue as bars, much darker along mid-lateral half of body, appearing as blotches. Fins hyaline, except for faint brownish to blackish markings on dorsal-fin rays, towards base of caudal-fin lobes, and in dorsal aspect of bases of pectoral and pelvic-fin rays. Barbels dark-pink. Notes on biology. One dissected paratype (GUMF 0263/2, 63.1 mm SL), a ripe female, contained about 250 eggs with an approximate diameter of 0.6 mm. Dissection of the stomach revealed no identifiable remains. Sexual dimorphism. No apparent external dimorphism. The sex of the holotype could be determined, however, while it was alive, with ripe eggs easily visible through its thin translucent belly. Distribution. Presently, the species is known only from Krem Khung, located about 1.5 km from the Larket Village, East Jaintia Hills District, Meghalaya, India (Fig. 4). Habitat. The new species was collected from a small stagnant pool a few square meters in area and about 1 m in depth, located in a wet passage some 500 m from the main entrance of Krem Khung. The pool bed is mostly sandy with scattered pebbles (Fig. 5). The water was clear, pH 8.6, and a very low D.O. of 1.1 ppm when analyzed in the month of April 2015. No other macrofauna were recorded inside the cave except weakly-pigmented crabs and crayfish, crickets, cockroaches and millipedes. Etymology. The species name is derived from the ‘Larket’ village, the locality of Krem Khung. This name is proposed so as to encourage the village to take up biodiversity conservation as it is already in the process of constituting a Biodiversity Management Committee under the Indian Biodiversity Act.