Dario kajal , Britz, Ralf, 2013
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Dario kajal , new species
Holotype. BMNH 2006.8. 2.1, male, 17.8 mm SL. India, Meghalaya, Jaintia Hills, Seinphoh stream at Umolong, 7 km from Jowai town, 25 ° 31 ’ 36 ’’N 92 °08’ 27 ’’E, 1320 m asl; A. Rao and P. Cottle, 2 Feb 2006.
Paratypes. BMNH 2006.8.2.2-26, 25, 14.4 –20.0 mm SL; same data as holotype.—NRM 47440 (2), 47441 (1), 47442 (2), 5, 11.4–16.8 mm SL. India, Meghalaya, Jaintia Hills, Seinphoh stream at Umolong; H. Bleher, 22 Sep 2009.
Diagnosis. A small badid species, not exceeding 20 mm SL, distinguished from all other species of Dario by the presence of a postorbital stripe that continues behind eye in line with preorbital stripe (vs. postorbital stripe forming an oblique angle with the preorbital stripe in D. dario and D. urops or postorbital stripe absent in D. hysginon and D. dayingensis ) and by the presence in males of a series of double bars restricted to the upper half of the body (vs. complete bars across the body in D. dario , complete bars restricted to the posterior body in D. urops and bars absent in D. hysginon and D. dayingensis ). It differs further from D. urops in the absence of a caudalpeduncle blotch and the absence of a horizontal suborbital stripe, by dorsal-fin lappets in males extending beyond the spine tip (vs. not extending beyond the spine tip) and a lower vertebral number (24–26 vs. 28–29). It can be distinguished further from D. urops and D. dayingensis in having a lower transverse scale count (8 vs. 9–10) and by the absence of palatine teeth (vs. presence), from D. dario by the presence in males of a black spot anteriorly in the dorsal fin and modally 7 (vs. 6) anal-fin rays, and from D. hysginon by the absence of an anguloarticular lateralline canal (vs. presence).
Description. For general appearance see Figs. 1–2View FIGURE 1View FIGURE 2; morphometric data are provided in Table 1. Body elongate, moderately laterally compressed. Predorsal contour straight to slightly convex, prepelvic contour convex. Eye situated in anterior half of head, snout short. Mouth terminal, directed slightly obliquely upwards with lower jaw projecting. Angle of jaws situated at vertical through anterior third of eye. Dorsal contour of body slightly arched, convex, less so in females, ventral contour of body straight; both contours slightly converging towards caudal peduncle. Caudal peduncle only slightly attenuated posteriorly. Teeth developed in a circular posterior patch on parasphenoid, also present on vomer, but absent from palatine, basihyal and hypobranchial 3.
Lateral-line canal pores present only on head, absent from body. Head canal pores comprise: preopercular pores 6 (p 1 –p 6), nasal pores 2 (n 1 –n 2), supraorbital pores 5 (f 1 –f 5), extrascapular pores 3 (ex 1 –ex 3), posttemporal pores 2 (po 1 –po 2), coronalis pore 1 (cor), lachrymal pores 2 (l 1, l 3); no dentary, angulo-articular or infraorbital pores, instead series of free neuromasts developed. Scales ctenoid on sides, cycloid on top of head.Tubed lateralline scales absent. Scales in longitudinal row 24. Scales in transverse row 8. Circumpeduncular scales 16.
Dorsal-fin lappets in males slightly prolonged, rising distinctly above spine tips, in females about as long as spines; soft dorsal fin rounded, extending to about caudal-fin base or beyond. Soft anal fin rounded, often not reaching to caudal-fin base in females, reaching beyond caudal-fin base in males. Caudal fin subtruncate. Pectoral fin rounded, extending about ⅔ to vertical from anal-fin origin. Pelvic fin pointed, first and second ray equally long, forming tip, sexually dimorphic: reaching to vent or shorter in females, to base of first or second anal-fin spine in males.
Vertebrae 12 + 12 (3), 12 + 13 (19), 13 + 13 (1), 12 + 14 (2), and 13 + 12 (1), total 24–26. Dorsal-fin spines and rays XIV+ 7 (14), XIII+ 8 (1), XIII+ 7 (2), XIV+ 6 (3), XV+ 6 (4), XIII+ 6 (1), or XV+ 7 (1). Anal-fin spines and rays III+ 6 (6), III+ 7 (19), and III+ 8 (1). Caudal-fin with 11–13 principal and 3–4 dorsal and 3–5 ventral procurrent rays: 4 + 6 + 6 + 3 (4), 4 + 6 + 6 + 4 (17), 3 + 6 + 6 + 3 (2), 3 + 7 + 6 + 4 (1), 4 + 6 + 5 + 5 (1), and 4 + 6 + 6 + 5 (1).
Coloration in preservative. Background colour on head and body beige. Preorbital and postorbital stripes well developed, black. A number of dark-brown to black scales on nape. A series of five faint, dark-brown doublebar saddles originating from base of dorsal fin and extending ventrally for up to three scales on body and one incomplete double bar on caudal peduncle. Anterior dorsal fin with dark blotch covering membranes between dorsal-fin spines 1–3. Rest of dorsal fin, anal and pelvic fins, and base of caudal fin with dusky interradial membranes. Spinous dorsal fin, leading edges of pelvic and anal fins and ventral edge of caudal fin with white rim. Pectoral fin translucent.
Coloration in life. Overall pattern of colour markings in specimens right after capture similar to preserved specimens ( Fig. 2View FIGURE 2). Subdistal white rim of spinous dorsal fin bordered distally by black narrow band. Cheek, opercle and cleithrum with some iridescence.
In acclimatized specimens subdistal band in dorsal fin, leading edge of pelvic fins, and distal rim of anal fin bright bluish white ( Fig. 2View FIGURE 2). Pre- and postorbital stripes conspicuous. Double bar saddles orange brown, belly region a uniform lighter brown. Anteriormost two membranes of dorsal fin up to subdistal band with dense covering of melanophores. More posterior fin membranes of dorsal fin and those of caudal and anal fins with fewer melanophores and more orange-brown chromatophores.
Distribution and habitat ( Figs. 3View FIGURE 3, 4View FIGURE 4). Dario kajal is currently known from the type locality, Seinphoh stream near Jowai in the Jaintia hills in Meghalaya, India. Seinphoh stream is a tributary of the Myntdu River. The fish were collected from a small, shallow pool with stagnant to slow-flowing water. The pool was turbid at the time of collection and had no aquatic vegetation. Because the Myntdu River continues into Bangladesh, this species is also likely to occur there.
Etymology. The species name is derived from the Hindi word kajal meaning black eyeliner, especially used by traditional Indian dancers, in allusion to the prominent orbital stripes of the new species.
Remarks. This species has been referred to as Dario sp. “Jaintia Hills” in the aquarium literature (see Werth 2009).
|BMNH 2006.8.2.1 + BMNH 2006.8.2.2-26 (n=10)||range||mean ± SD|
|Standard length (SL) in mm||14.4–20.0 (17.8)|
|In percent of standard length|
|Head length||30.1–33.3 (30.9)||31.9 ± 1.1|
|Snout length||4.2–6.1 (5.6)||5.1 ± 0.6|
|Eye diameter||10.0–11.5 (10.7)||10.8 ± 0.5|
|Interorbital width||9.8–10.6 (9.8)||10.2 ± 0.3|
|Upper-jaw length||8.2–10.4 (8.4)||9.3 ± 0.7|
|Lower-jaw length||11.8–13.1 (12.4)||12.4 ± 0.5|
|Body depth||30.5–32.6 (32.6)||31.4 ± 0.7|
|Pelvic fin-length||23.4–32.8 (32.6)||27.5 ± 3.5|
|Pelvic to anal distance||28.2–33.8 (29.2)||30.5 ± 1.7|
|In percent of head length|
|Snout length||13.7–18.9 (18.2)||16.3 ± 2.0|
|Eye diameter||31.3–35.7 (34.5)||33.8 ± 1.4|
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