Waikhomia hira, Katwate & Kumkar & Raghavan & Dahanukar, 2020

Katwate, Unmesh, Kumkar, Pradeep, Raghavan, Rajeev & Dahanukar, Neelesh, 2020, Taxonomy and systematics of the ‘ Maharaja Barbs’ (Teleostei: Cyprinidae), with the description of a new genus and species from the Western Ghats, India, Zootaxa 4803 (3), pp. 544-560 : 548-553

Waikhomia hira , sp. nov.

( Figure 3 , 4 )

Holotype. BNHS FWF 602 , 42.9 mm SL, male; India: Karnataka: Uttara Kannada District: Kali River near Chandewadi , Kamra , 15°22’13.8’’N, 74°24’36.0’’E, 592 m a.s.l., U. Katwate, P. Kumkar, N. Dahanukar, N. Sawant, N. Sood and R. Britz, 05 February 2016.

Paratypes. BNHS FWF 603 , 604 , 607 , 1002 , 4 ex., 38.3–45.2 mm SL, same data as holotype ; BNHS FWF 605 , 997 , 2 ex., 20.7–36.2 mm SL, same coll. locality data as holotype, P. Kumkar and N. Sawant, 27 March 2014 .

Diagnosis. Waikhomia hira is distinguished from its only congener, W. sahyadriensis , by a combination of characters that includes small size (maximum recorded standard length 45.2 mm); lateral line straight, with 23–25 perforated scales; pre-dorsal and pre-pelvic scales 10; 4–½4 scales between dorsal-fin origin and lateral-line scale row, 3½ between lateral line row and pelvic-fin origin. Furthermore, W. hira is distinguished by having a distinct body coloration consisting of: small rhomboidal spots (7–8) largely restricted to lateral-line scale row; nape and dorsal-base spot absent; cleithral spot small, confined to the first scale of lateral line scale row; post-pectoral and super-anal spots small; a lateral spot present on or between 8 th– 9 th lateral-line scales; two spots on caudal peduncle; no spots coalescing into blotches, bars or bands. Gill rakers 2–3 on distal end of epibranchial 1; infraorbital 2 narrow; supraneural 3 broad, separated from neural spine 4.

Description. A small cyprinid, maximum adult size 45.2 mm SL. For general shape and appearance see Figure 3 . Morphometric and meristic data of the holotype and five paratypes are provided in Table 2.

Body elongate, deep, its standard length 2.6–3.3 times of maximum body depth, compressed laterally; predorsal contour almost straight, steadily rising to dorsal fin origin, thereafter, gradually sloping ventral towards caudal-fin base. Ventral profile convex up to pelvic-fin base, abruptly sloping dorsal along anal-fin base, thereafter gradually sloping dorsal to caudal-fin base. Caudal peduncle slender, elongate, its length 1.4–1.6 times its depth. Head small, stout, compressed, its length 1.2–1.4 times its depth. Snout long (3.2–4.1 times in head length), pointed, lateral fold present, its length marginally shorter than eye diameter. Eyes large, mid-laterally positioned, closer to snout tip than posterior margin of operculum, diameter almost equal to (0.8–1.2 times) interorbital width. Mouth small, terminal, ventrally U-shaped, angle of gape not reaching vertical from anterior margin of eye. Lips thin, not interrupted, upper lip relatively fleshier than lower lip. Barbels absent. Nuptial tubercles present in mature males, scattered across snout, lower sides of head and ventral surface as far back as pelvic-fin base; also scattered over outer margins of unbranched rays of pectoral and pelvic fins.

Dorsal fin high, length 0.9–1.2 times head length, originating approximately above pelvic-fin origin, its origin situated closer to tip of snout than to base of caudal fin; posterior margin deeply concave, extending beyond vertical through middle of anal fin, tip pointed. Dorsal fin with three unbranched rays (two supernumerary and one serially associated unbranched ray) and eight branched rays, the single unbranched serially associated ray feeble, length of segmented apex half that of entire fin ray. Pectoral fin with one simple and 11(1) or 12(6) branched rays, its tip rounded, when adpressed overlapping pelvic-fin base in mature males (4), but falling well short of pelvic-fin base in females (2). Pelvic fin with one simple and eight branched rays, its tip rounded, reaching vent when adpressed. Anal fin with three unbranched (two supernumerary and one serially associated unbranched ray) and five branched rays, its distal margin concave, with pointed tip. Caudal fin deeply forked, lobes measuring almost two-thirds of caudal-fin length, tips pointed. Principal caudal-fin rays 9+8; procurrent rays dorsally 7(2) or 8(5) and ventrally 6(1) or 7(6).

Lateral line complete, with 23(1), 24(3) or 25(3) perforated scales, originating at cleithral spot, proceeding horizontally to caudal-fin base. Scales in transverse row 4(5) or ½4(2)/1/3½, pre-dorsal and pre-pelvic scales 10, pre-anal scales 17(1) or 18(6), circumpeduncular scales 12. Pelvic axillary scale present, one-fourth the length of pelvic-fin.

Osteology. The skeletal anatomy of cleared and double stained W. hira paratype BNHS FWF 604 is illustrated in Figure 4 . Infraorbital 2 narrow, slender, less wide than infraorbital 4; Infraorbital 3 largest among infraorbital series, deep, broadest at the middle; infraorbital 4 rectangular, narrower than infraorbitals 1 and 3; infraorbital 5 with well-developed anterior and posterior laminae ( Figure 4B ). Proximal process of maxilla rounded; premaxilla with vertically extended anterior and blunt posterior tip; dentary with large, expanded posterodorsal coronoid process ( Figure 4 C–E). Wing shaped, large epibranchial 1 with posterior lamina plain, anterior lamina on medial margin protruding; gill rakers simple, sparsely placed, 2–3 on lateral and 3–4 on medial margin of epibranchial 1; basihyal large, 2 gill rakers on lateral and 9–10 on medial margin of ceratobranchial 1 ( Figure 4F, G ). Total vertebrae 30, including 17 abdominal and 13 caudal vertebrae, inclusive of last caudal centrum; supraneural 3 broad, not extending over anterior plane of proximal-middle radial of dorsal-fin, leaving prominent gap between posterior most supraneural and proximal-middle radial of dorsal fin; lateral process of second vertebral centrum large, elongate, extending over base of outer arm of os suspensorium and up to medial base of neural arch 4. Epural curved ( Figure 4H ).

Coloration in life. Body bright iridescent silver, becoming reddish in mature males ( Figure 1 , 3A ). Head and dorsum olive green. Lower head, chest, and abdomen silvery. Iris iridescent silver, a dark bar above and below pupil, running vertically across iris. Numerous (7 (3) or 8 (4)) small dark rhomboidal spots on side of body, restricted to lateral-line scale row: first (cleithral) spot small, mostly confined to first scale of lateral-line row, rarely extending onto scale above; post-pectoral spot small, between pectoral fin and pelvic-fin origin, covering 7 th scale of lateral line, marginally extending over ventral half of scale above; lateral spot small, above pelvic fin base, on or between 8 th– 9 th lateral-line scales; 1 (2) or 2 (5) post-pelvic spots between base of pelvic fin and anal-fin origin; small superanal spot above anal-fin base; two small caudal spots ( Figure 2A ). Dorsal-fin red in both sexes, however its anterior margin and tip black in mature males; pelvic fin jet black with white tip; pectoral, anal and caudal fins hyaline, with no markings. Each body scale bordered with melanophore at base.

Coloration in preservative. Body pale cream; snout, head, dorsum, lower lip, cheek and gill cover dark brown; lower head, chest and abdominal region uniformly pale cream ( Figure 3B ). Iris whitish. Body markings as described for live specimens. Dorsal-fin hyaline in both sexes with tip of fin black in mature males; pelvic, pectoral, anal and caudal fins are as described for live specimens.

Etymology. The species epithet hira (phonetic hira means diamond and refers to the small symmetrical, rhomboidal spots on the side of the body. A noun in apposition.

Common name. Kohinoor Barb, after the Indian Koh-i-Noor diamond, which is now a part of the crown jewels of the United Kingdom, in reference to the rhomboidal, ‘diamond-shaped’ spots along the lateral-line scale row of this fish.

Distribution. Waikhomia hira is currently known only from the upstream catchment of the west-flowing Kali River system in the northern Western Ghats, with the type series collected near Chandewadi, Kamra, Uttara Kannada District, Karnataka, India ( Figure 1 ).

Habitat and ecology. Waikhomia hira occurs in large, deep (~ 1 m) pools in the main river channel, in which the flow is sluggish, with fallen branches and other detritus, sand, large boulders and gravel as substratum. Co-occurring fishes in the type locality of W. hira included Haludaria sp., Hypselobarbus pulchellus (Day, 1870) , Osteochilichthys cf. nashii (Day, 1869), Pethia longicauda Katwate, Paingankar, Raghavan & Dahanukar 2014 , Devario malabaricus (Jerdon, 1849) (Cyprinidae) ; Balitora chipkali Kumar, Katwate, Raghavan & Dahanukar 2016 (Balitoridae) , Aplocheilus cf. lineatus (Valenciennes, 1846) ( Aplocheilidae ), Mastacembelus armatus (Lacepède, 1800) (Mastacembelidae) , Glyptothorax sp. ( Sisoridae ), and Ophichthys cf. indicus (Silas & Dawson, 1961) ( Synbranchidae ).

Molecular analysis. The best partition scheme and nucleotide substitution model for the partition was TPM3u+I+G4 (BIC=63891.691, lnL=-30030.611, df=513) for the combined partition of the first two codon positions of cox1 and cytb, and TIM2+R3 (BIC=63201.904, lnL=-30215.861, df=371) for the combined partition the of third codon positions of cox1 and cytb. Maximum likelihood analysis revealed W. hira and the widely distributed W. sahyadriensis to have a sister-group relationship ( Figure 5 ). These two species form a well-supported (ultrafast bootstrap =100) monophyletic clade, which is recovered as the sister group to Puntius but with weak node support (ultrafast bootstrap = 42). The genetic distances between W. hira and W. sahyadriensis are 4.3–4.9% in cox1 and 7.0–8.2% in cytb. The genetic gap between W. hira and W. sahyadriensis , based on the maximum intraspecific distances and minimum interspecies distances, was 3.4% in cox1 and 4.3% in cytb gene ( Figure 6 ).

Figures

FIGURE 1. Type locality and collection locations of Waikhomia hira in yellow (paratype, BNHS FWF 604, 41.2 mm SL) and Waikhomia sahyadriensis (BNHS FWF 591, 48.8 mm SL) in red in the Western Ghats of India. Star indicates type locality of each species.

FIGURE 2. Schematic drawing of colour pattern in (A) Waikhomia hira and (B) Waikhomia sahyadriensis. Abbreviations: Cs, caudal spot; Cls, cleithral spot; Dbs, dorsal-base spot; Ls, lateral spot; Sans, Super-anal spot; Ppcs, post-pectoral spot; Ppls, post-pelvic spot; Nps, Nape spot.

FIGURE 3. Waikhomia hira holotype (male, BNHS FWF 602, 42.9 mm SL) in (A) life and (B) preserved.

FIGURE 4. Comparison of the skeleton of Waikhomia hira (paratype, BNHS FWF 604, 41.2 mm SL) and Waikhomia sahyadriensis (male, BNHS FWF 588, 49.1 mm SL). (A) Lateral view of cleared and double-stained specimens. (B) Infraorbital series, lateral view. (C) Left maxilla, lateral view. (D) Left premaxilla, lateral view. (E) Left dentary, lateral view. (F) Dorsal gill arch, ventral view. (G) Ventral gill arch, dorsal view. (H) Hypural plate, lateral view. Abbreviations: IO1–5, infraorbital 1–5; So, supraorbital; PP, palatine process; Ana, anguloarticular; Cm, coronomeckelian; De, dentary; MC, Meckel’s cartilage; Ra, retroarticular; Bb1–3, basibranchial 1–3; Bb4C, basibranchial 4 cartilage; Bh, basihyal; Cb1–5, ceratobranchial 1–5; CC, compound centrum; CIHPU3–4, inter-hemal spine cartilage of preural centrum 3–4; Eb1–4, epibranchial 1–4; Eb5C, epibranchial 5 cartilage; Ep, epural; Gr, gill rakers; H1–6, hypurals 1–6; Hb1–3, hypobranchial 1–3; HS, hemal spine; NS, neural spine; Pb2–3, pharyngobranchial 2–3; Pb4C, pharyngobranchial 4 cartilage; Ph, parhypural; Pls, pleurostyle; PU2–3, preural centra 2–3. Asterisk (*) in red for W. sahyadriensis left premaxilla indicates mechanical damage occurred while dissecting the specimen or anomaly detected. Scale bar 1 mm.

FIGURE 5. Phylogenetic position of Waikhomia hira based on maximum likelihood analysis using best partition scheme. Species of Garra are used as the out-group. Values along the nodes are percent bootstraps for 1000 iterations. Bootstrap values less than 50% are not shown.

FIGURE 6. Genetic gap analysis for Waikhomia hira and Waikhomia sahyadriensis based on intra and inter species genetic distances for (A) cytochrome oxidase subunit 1 (cox1) and (B) cytochrome b (cytb). There is a genetic gap of 3.4%, which separates the two species based on cox1, and 4.3%, which separates them based on cytb.