Badis autumnum, Valdesalici, Stefano & Voort, Stefan Van Der, 2015

Valdesalici, Stefano & Voort, Stefan Van Der, 2015, Four new species of the Indo-Burmese genus Badis from West Bengal, India (Actinopterygii: Perciformes: Badidae), Zootaxa 3985 (3), pp. 391-408 : 396-399

Badis autumnum , new species

( Figs. 4–6 )

Holotype. MSNG 57567, 35.8 mm SL, male, 20 September 2013; India: West Bengal: Cooch Behar district: Petla: near Dinhata town: Singimari River drainage, Rathbari stream, 26°12’84.7”N 89°43’65.15”E; coll. Andrew A. Rao.

Paratypes. MSNG 57568, 1 male, 35.9 mm SL, 8 July 2013: same location as holotype. MSNG 57569, 1 male, 29.4 mm SL C&S, 8 July 2013: same location as holotype. MSNG 57570, 5, 27.5–32.7 mm SL, 20 September 2013: same location as holotype.

Diagnosis. Badis autumnum differs from all remaining Badis species by a colour pattern which includes two autapomorphies. Badis autumnum can be distinguished from every member of the B. badis group (included species: B. badis , B. chittagongis , B. dibruensis , B. ferrarisi , B. kanabos , B. soraya and B. tuivaiei ) by absence of a blotch on the superficial part of the cleithrum above pectoral-fin base, from all members of the B. assamensis group (included species: B. assamensis and B. blosyrus ) by absence of a posterodorsal opercular blotch and absence of two parallel rows of dark spots and alternating light and dark stripes along its physique, from every member of the B. ruber group (included species: B. khwae , B. ruber and B. siamensis ) by absence of a cleithral blotch and absence of a blotch on the dorsolateral aspect of the caudal peduncle, from all members of the B. corycaeus group (included species: B. corycaeus and B. pyema ) by absence of an ocellus on the caudal-fin base, from B. kyar by presence of a conspicuous median black blotch on the caudal peduncle, from B. singenensis by absence of a posterodorsal opercle blotch and absence of three dorsal-fin blotches and a single round blotch on the anal-fin base, from B. juergenschmidti by absence of white margins on dorsal and ventral aspects of the caudal fin in males and presence of a strongly curved caudal-fin base bar, and from B. britzi by presence of a conspicuous median black blotch on the caudal peduncle. The new species most closely resembles B. andrewraoi and B. kyanos in terms of colour pattern, from which it can be distinguished by two exclusive characters that also distinguish it from all other species of the genus: presence of a blotch above the base of the opercular spine, and of a conspicuous dark blotch on pectoral-fin base. It also differs from B. kyanos in having fewer circumpeduncular scales (16–18 vs. 18–19). Furthermore, B. autumnum differs from all remaining species by presence of a black caudal-fin margin, outlining entire fin. Additionally, B. autumnum can be biometrically separated from B. andrewraoi by having fewer circumpeduncular scales (16–18 vs. 18).

Description. General body shape as in Figures 4–5 . Morphometric characters are listed in Table 2 . Body moderately elongate and laterally compressed. Snout and head rounded in lateral aspect. Orbit situated in anterior half of head and upper mid-axis of body. Opercular spine triangular, with a single tip. Predorsal contour concave, in smaller specimens straighter. Dorsal-fin base slightly concave. Caudal peduncle nearly straight, longer than deep. Abdominal contour concave in males, somewhat convex in females.

Dentary pores 1–3, anguloarticular pores 1, preopercular pores 1–6, nasal pores 2, frontal pores 2–3–4, extrascapular pores 1–2–3, posttemporal opening pores 1–2, coronalis pore 1, lachrymal pores 1–3, infraorbital pores 1–4. Predorsal scales 4 anterior to coronalis pore, 7 posteriorly.

Scales on side strongly ctenoid, on top of head cycloid, scales on side of chest cycloid. Opercular scales ctenoid, preopercular and subopercular scales cycloid. Circumpeduncular scales 7–8 above and 7–8 below lateral line, totalling 16–18 scales. Scales in vertical row 1½–2 above and 6–7, below lateral line. Scales in lateral row 25– 27, modally 25, 26. Tubed scales in lateral line 20/4–25/6. Dorsal-fin base scaled with 1 scale row anteriorly and 1½–2 posteriorly, anal-fin base with 1 scale row. Caudal-fin base with 3–5 scale rows.

Dorsal-fin rays XV+10–XVII+11, modally XVI+10. Anal-fin rays III+ 7–III +9, modally III+8. Pectoral-fin rays 12–14, modally 13. Vertebrae 26.

Colouration. In preservative, base colour brown to dark brown. Side of head grey to brown-grey. Postorbital stripe, when discernible, dark grey-brown and crossing eye to lower jaw. Suborbital stripe grey-brown. A small, distinct dark blotch posterodorsally on opercle, above base of opercular spine, forming a short, downward and slightly oblique stripe in a single specimen. Oblique dark brown bar on opercle, more or less parallel to suborbital stripe. A conspicuous dark blotch on pectoral-fin base in subadult specimens, dark brown pigment in smaller specimens, no pigment in adult individuals. Five to six dark grey-brown bars on sides, more distinct posteriorly. Dark grey-brown caudal peduncle blotch. Dorsal, anal and caudal fins grey to grey-brown, darker between fin rays. Dorsal fin darker proximally with a narrow white margin and red-brown submarginal band, and dark blotches between fin spines along middle of fin, frequently forming a complete black band, distinct up to posterior soft part of fin, indistinct onwards. Soft portion of dorsal fin with a dark, arched band. Anal fin with a narrow white perimeter. Pectoral fin pale-hyaline, pelvic fin pale-hyaline, dusky medially. Caudal fin with a black margin, outlining the entire fin.

In life, male ( Fig. 6 ) colouration mood-dependent. Base colour yellow-brown. Dorsum of head yellow. Preorbital, postorbital and suborbital stripes black and prominent. Oblique dark brown bar on opercle, more or less parallel to suborbital stripe. A small distinct dark blotch posterodorsally on opercle, above the opercular spine base, intermittently forming a short downward and slightly oblique stripe in some individuals. A conspicuous dark blotch on pectoral-fin base in subadult specimens, dark brown pigment in smaller specimens, no pigment in adult individuals. Twelve vertical black bars on sides, six of which displaying as undulated lines on flanks, most prominent centrally and ventrally, two bars on nape. All bars complete less than infrequently. Often bars 1 to 4 prominent and complete, remaining bars fainter and strongly reduced, present only dorsolaterally. Bars 3–10 each corresponding with a conspicuous black blotch on scaly basal cover of dorsal fin. Bars 3 and 4 individually corresponding with a faint black blotch on scaly basal cover of anal fin. Distinct median black blotch on caudal peduncle, often connecting with bar 1. Bar 1 broader than remaining bars, often broader medially, displaying as a second, partially absorbed blotch. A number of scales, especially between bars, with orange spots, 1 scale wide and often an orange spot on the bar. All fins dark, dorsal, anal and caudal fins with orange tinge. Dorsal, anal and pelvic fins with a narrow, bright white marginal band. Dorsal fin with a narrow black submarginal band and dark blotches between fin spines along middle of fin, often forming a complete black band, distinct up to posterior soft part of fin, indistinct thereon. Soft portion with an additional dark, arched band. Anal fin with a broad, black submarginal band, often absorbing most of the orange colouration and a faint but dark band, approximately in the middle of the fin. Caudal fin with a black margin, outlining the entire fin and an additional dark, arched vertical band proximally. Female comparable to male specimens, however duller coloured.

When stressed, Badis autumnum becomes very pale and nearly colourless.

Distribution. Badis autumnum is presently only known from the type locality at Petla, near Dinhata town, Cooch Behar district, Singimari River drainage, Rathbari stream, West Bengal, India ( Fig. 3 ).

Ecological notes. Badis autumnum was collected from a swamp-like area (A. A. Rao, pers. comm.).

Reproductive notes. Badis autumnum represents a cave (e.g. coconut shells, photo canisters) brooding species. Two pairs have been observed for fifteen months. The male individual guards and fans the eggs and guards a small area surrounding the cave. The eggs are almost completely transparent and adhere to the floor, sides and roof of the cave. Paternal care ends as soon as the larvae reach the free-swimming stage.

Etymology. The Latin species epithet autumnum , a noun meaning autumn, is in allusion to numerous colours of autumn which the new species can display during various moods; combinations of brown, black, yellow and orange.

Remarks. Badis autumnum was first introduced into the aquarium trade as ‘ Badis sp. (New) Torpedo’ (A. A. Rao, pers. comm.).

The new species is, amongst additional traits, characterised by two autapomorphies; a small conspicuous dark blotch posterodorsally on the opercle above the base of the opercular spine and a conspicuous dark blotch on the pectoral-fin base in subadult specimens. The latter single occurrence apomorphy is only present in individuals ranging 23.7–32.9 mm SL, before completely disappearing in adults. Some individuals slightly smaller than 32.9 mm SL had already lost the blotch. Specimens of smaller sizes only depict dark brown pigment, not unlike that on other parts of the body, at the pectoral-fin base. It is presently unknown why the blotch is absent in adult individuals, however obviously its function is no longer relevant in larger entities.

Figures

FIGURE 3. Type localities of Badis andrewraoi (inverted triangle), B. autumnum (square), B. kyanos (rhomboid) and B. soraya (star) in West Bengal, India.

FIGURE 4. Badis autumnum, MSNG 57568, paratype, male, 35.9 mm SL; India: West Bengal, Singimari River drainage, Rathbari stream at Petla. Note the oblique stripe on operculum.

FIGURE 5. Badis autumnum, MSNG 57570, paratype, female, 29.4 mm SL; India: West Bengal, Singimari River drainage, Rathbari stream at Petla. Note the blotch above base of opercular spine.

FIGURE 6. Live male individual of Badis autumnum, ca 35 mm SL (not included in type series); India: West Bengal, Singimari River drainage, Rathbari stream at Petla.

Tables

TABLE 2. Morphometric characters of holotype (MSNG 57567) and seven paratypes (MSNG 57568, MSNG 57569, MSNG 57570) of Badis autumnum, new species, expressed as a percentage of standard length (SL) or head length (HL).

	Holotype	Paratype range Mean ± S.D.
Standard length (SL) in mm	35.8	27.5–35.9 31.6 ± 3.0
As percentage of SL
Head length	29.8	27.5–34.6 30.5 ± 2.0
Snout length	7.2	5.5–8.5 6.4 ± 0.9
Orbital diameter	10.0	7.2–10.0 9.0 ± 0.9
Interorbital width	6.9	4.3–8.1 6.3 ± 1.3
Upper jaw length	10.6	7.5–10.8 10.0 ± 1.0
Lower jaw length	13.1	10.8–13.6 12.3 ± 0.9
Body depth	29.8	27.6–33.6 29.6 ± 1.8
Pelvic fin length	24.5	22.5–28.3 24.8 ± 2.3
Pelvic to anal distance	30.7	25.7–35.0 29.7 ± 2.7
As percentage of HL
Snout length	21.6	18.1–24.5 20.6 ± 2.3
Orbital diameter	30.0	26.2–33.6 29.3 ± 2.7