Badis limaakumi, Praveenraj, 2023

Praveenraj, Jayasimhan, 2023, Badis limaakumi, a new species of badid fish from Nagaland, Northeast India (Teleostei: Percomorpha: Badidae), Zootaxa 5351 (3), pp. 371-379 : 372-376

Badis limaakumi , new species

( Figures 1 , 2 , 3 , 4A )

Holotype. APRC/ZSI/V/P-2083 , male, 67.0 mm SL; India, Nagaland, Mokochung District, Milak River; 26°26.6270’N, 94°29.0880’E; Limaakum, 13 February 2022.

Paratype. APRC/ZSI/V/P-2084 , 42.1–56.1 mm SL (4 male and 4 female); CIARI/FF-92 , 1 ex., male, 51.8 mm SL, cleared and stained for osteology, same data as holotype .

Diagnosis. Badis limaakumi belongs to the Badis assamensis SG and is thus distinguished from all members of the other species groups by the presence of the opercular blotch, absence of the cleithral botch and a relatively large size. Badis limaakumi is distinguished from other members of the B. assamensis SG , i.e. B. assamensis and B. blosyrus , by the absence of irregular blotches along sides of the body (vs. presence of two rows of irregular blackish blotches on sides) ( Fig. 3 ), presence of 10 pairs of distinct vertical bars on body (vs. absence of vertical bars), snout rounded in lateral view (vs. pointed) ( Fig. 4 ) and a shallower body (body depth 23.2–28.0 vs. 29.9–34.9% SL). Badis limaakumi is additionally distinguished from B. blosyrus by its larger body size (> 60 mm vs. <40 mm SL), shorter upper (8.3–10.2 vs. 12.0–13.6% SL) and lower jaw, (11.9–15.0 vs. 16.3–18.5% SL), more lateral-line scales (29–31 vs. 27–28), and absence of a prominent angle at lower jaw articulation (vs. presence of prominent angle).

Additional characters distinguishing Badis limaakumi from members of the other SGs including Badis badis SG , Badis corycaeus SG , Badis ruber SG , Badis autumnum SG , and other congeners from Northeast India, the Western Ghats, Bangladesh, Myanmar and Thailand are provided in the discussion.

Description

General appearance as in Figs. 1 and 2 , and morphometric data provided in Table 1 . Body elongate, moderately compressed laterally. In males, predorsal profile ascending in a straight line from tip of snout up to vertical through posterior region of eye, gently convex more posteriorly, and almost straight to base of caudal fin. Ventral contour descending gently until below preopercle, almost straight more posteriorly to anal-fin origin, and gently ascending to base of caudal fin. Eye situated midlaterally in anterior half of head. Snout shorter than eye diameter, rounded in lateral view. Jaws almost equal anteriorly, with lower jaw slightly projecting; maxilla reaching vertical through anterior margin of orbit, lower jaw articulation below middle of orbit. Opercular spine slender, with sharp tip. In females, predorsal and ventral profile slightly convex, and maximum size less than 50 mm SL. Adult males are more elongate than females. Gravid females appear plumper with distended abdomen.

Dentary pores 4 (d1–d2), anguloarticular pores 2 (aa1–aa2), preopercular pores 6 (p1–p6), nasal pores 2 (n1– n2), supraorbital pores 4 (f1–f4), extrascapular pores 3 (ex1–ex3), posttemporal pores 2 (po1–po2), coronalis pore 1 (cor), lachrymal pores 3 (l1–l3), infraorbital pores 4 (io1–io4), pterotic pores 3 (pt1–pt3).

Scales ctenoid on sides, cycloid on top of head. Predorsal scales anterior to coronalis pore 3 (7) or 4* (3), posteriorly 7* (7) or 8 (3). Cheek and opercular scales ctenoid, cheek scales extending posteriorly from termination of gape. Scales rows on cheek 4 (1), 5 (6) or 6* (3), opercle with 3 rows of scales, 1 row each on preopercle, subopercle and interopercle. Scales in lateral row 30 (6) or 31* (4). Lateral-line canal on body in pored-scales, arranged into two segments. Upper lateral-line canal starting above operculum with 24 (1), 25 (3) and 26* (6) pored scales, lower lateral-line canal starting at one scale anterior to vertical through posterior base of anal fin with 4 (1), 5* (8) and 6 (1) pored scales. Circumpeduncular scales 20, with 9 (10) scales above, 9 (10) below lateral line. Dorsal-fin scale cover 2–4 scales wide; anal-fin scales cover 3 scales wide. Vertical scale rows 2 (2), 2½ (2), 3 (4), 3½* (2) above, and 7 (3), 7½ (4), 8(2), 8½*(1) below lateral line. Dorsal fin with 17* (8) or 18 (2) spines and 9 (10) soft rays, its origin vertically above pectoral-fin origin, and ending at two scales beyond vertical through base of last anal-fin ray. Dorsal- and anal-fin lappets with rounded tips. Posterior tips of dorsal fin reaching to anterior third of caudal fin when adpressed. Anal fin with 3* (10) spines and 6* (6) or 7 (4) soft rays, reaching base of caudal fin when adpressed. Caudal fin rounded, with 14 principal rays. Pectoral fin rounded, with 13 (5), 14 (1) or 15 * (4) rays, extending to about 1/4 of distance to anal-fin origin when adpressed. Pelvic fin pointed with 1 spine and 5 (10) rays. Gill rakers on first gill arch 7 (3). Branchiostegal rays 6 (10). Vertebrae 30 in total, with 17 abdominal and 13 caudal. Dorsal fin with 1 st pterygiophore inserted between neural spines of 2 nd and 3 rd vertebrae. Anal fin 1 st pterygiophore inserted between haemal spines of 17 th and 18 th vertebrae. Both jaws with tiny unicuspid teeth arranged in wide band of about four rows anteriorly in each jaw and two rows posteriorly. Anterior-most teeth larger than others. Vomer, adjacent palatine, parasphenoid, and hypobranchial 3 toothed; basihyal not toothed.

Colouration in ethanol. Body pale grey, becoming darker towards dorsal-fin base and scaled portion of finrays, interradial fin membranes grey with tinges of black. Bars on body faint. Anal fin dark-grey. Caudal fin greyish, scaled portion dark grey. Caudal blotch black. Pectoral and pelvic fin pale grey. Preorbital and post orbital stripe greyish. Cheek greyish, preopercle and opercle dark grey. Opercular blotch black. Lower jaw greyish.

Colouration in life. Ground color of body brownish-red, head olive-green or greyish, with black scales on nape. Preorbital stripe dark-grey, continuing to posterior region of lower jaw. Postorbital stripe with black or bluish scales. No supraorbital or suborbital stripe. Opercle with bluish iridescent blotch at base of opercular spine, two scales high and three scales wide. Cleithral blotch absent. Body with 10 pairs of distinct black vertical bars: 6 pairs between head and anal-fin origin, 2 pairs between anal-fin origin and posterior insertion of it, and remaining 2 between posterior of anal-fin origin and caudal fin. Bars 1–5, 9 and 10, broad and straight; bars 6–8 slightly curved. Bar 10 on caudal peduncle composed of a medial bluish caudal spot, which usually elongate and extending across last scale of side and base of caudal fin. Bars becoming darker towards dorsal-fin base, and continuing onto scaled portion of dorsal fin. Dorsal fin anterior portion begins with broad, brownish submargin, and narrow, orange and pale-blue dorsal margin continued up to spinous portion only; posterior soft end of dorsal fin hyaline, its dorsal margin bluish. Anal fin hyaline, spines greyish with white margins. Pectoral fin hyaline. Pelvic fin hyaline, interradial membranes and basal margin greyish. Caudal fin hyaline, yellowish at scaled portion, posterodorsal and posteroventral margins pale-blue.

Distribution and habitat. Badis limaakumi is presently known only from the Milak River in Mokokchung district, Nagaland, Northeast India. The type locality during January 2022 had a depth of 0.5 m, with substrate comprising numerous boulders and rocks ( Fig. 5 ). Co-occurring species include Esomus danrica , Amblyceps apangi , Garra sp. , and Psilorhynchus sp. .

Etymology. The species name honours Limaakum, Assistant Professor at the Fazl Ali College, Nagaland, who discovered this new species.

Figures

FIGURE 1. Badis limaakumi (a) Holotype, APRC/ZSI/V/P-2083, male, 66.8 mm SL (b) Paratype, APRC/ZSI/V/P-2084, male, 42.1 mm SL (c) paratype, APRC/ZSI/V/P-2084, female, 45.3 mm SL.

FIGURE 2. Badis limaakumi, in life, holotype, APRC/ZSI/V/P-2083, 66.8 mm SL.

FIGURE 3. (A) Badis assamensis, CIARI/FF-93, 49.5 mm SL (B) Badis blosyrus, CIARI/FF-95, 34.6 mm SL.

FIGURE 4. Details of head of (A) Badis limaakumi, holotype, APRC/ZSI/V/P-2083, 66.8 mm SL (B) Badis assamensis, CIARI/FF-93, 49.5 mm SL, and (C) Badis blosyrus, CIARI/FF-95, 34.6 mm SL.

FIGURE 5. Type locality of Badis limaakumi, Milak River at Mokochung District, Nagaland, India.