A new deep-bodied species of Antigonia (Teleostei, Antigoniidae) from the Andaman Sea (northeastern Indian Ocean) Author Prokofiev, Artem M. A. N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences Author Psomadakis, Peter N. Food and Agriculture Organization of the Inoted Nations Author Gon, Ofer South African Institute for Aquatic Biodiversity o.gon@saiab.ac.za text Zootaxa 2020 2020-04-09 4763 2 203 216 journal article 10.11646/zootaxa.4763.2.4 1a06eb9e-ef0a-4613-840f-6b46a8c49cb6 1175-5334 3758230 urn:lsid:zoobank.org:pub:1D3B1289-B0D0-4957-A6D4-DEA11A74E17D Antigonia emanuela , new species (New English name: Emanuela’s boarfish) ( Figs. 1 , 2 , Table 1 ) Holotype . SAIAB 203818 , 60.3 mm SL ( Figs. 1A, 1B ), off Ayeyarwady Delta , Myanmar , Andaman Sea , Indian Ocean , 13°3.21’ N , 96°41.62’ E , R/V Dr Fridtjof Nansen station 123, 121– 129 m , P.N. Psomadakis , 21 May 2015 . Paratype . SAIAB 207256, 66.4 mm SL ( Fig. 1C ), off Ayeyarwady Delta, Myanmar , Andaman Sea, Indian Ocean, 12°22.31’ N , 97°12.44’ E , R / V Dr Fridtjof Nansen station 119, 99– 100 m , P.N. Psomadakis, 21 September 2018 . Note: The right pectoral fin of both type specimens is damaged. The whole fin of the paratype and part of it in the holotype were removed for genetic tissue samples. Diagnosis. A species of Antigonia unique within the genus in the following character combination: 9 dorsal-fin spines, 13 pectoral-fin rays, deeply rhomboid body with greatest depth 113.8–118.8% SL, premaxilla strongly bent in middle, scales with deep apical crest armed with numerous spines arranged in several rows distributed in almost all lateral surface of crest, with bright-yellow soft dorsal, anal and caudal fins in life. FIGURE 1. Antigonia emanuela , new species , holotype (A, B) and paratype (C, D): (A, C) lateral view of freshly captured specimens; (B) x-ray; (D) lateral view of maxilla (larger bone on the left) and premaxilla (smaller, right), soft tissue removed. Black arrow (C) pointing to elongated skinny filament of spinous dorsal fin. Scale bars: (A–C) 5 mm; (D) 2 mm. Description. Counts and proportional measurements are given in Table 1 . Data in parentheses are of the paratype . Body deeply rhomboidal, its greatest depth clearly exceeds SL, 0.8 in or 118.8 % SL (0.9 and 113.8, respectively). Dorsal contour of body forming an almost right angle at dorsal-fin origin, strongly concave above the eye, shallowly concave and very steeply rising between tip of supraoccipital crest and dorsal-fin origin. Ventral contour of body rounded. Posterodorsal and posteroventral profiles of body very weakly and almost equally convex. Head small, 2.6 (2.5) in SL, horizontal eye diameter 2.8 (3.1) in head length, snout 1.2 (1.05) in eye diameter. Mouth gape almost horizontal. Lips somewhat thickened; alveolar ramus of premaxilla bent at almost right angle, its descending portion having a convex ventral margin, tapering toward a bluntly pointed tip. Posteroventral angle of maxilla somewhat extended anteroventrally ( Fig. 1D ). Jaw teeth minute, in two series at symphysis, tapering to a single series laterally in both jaws. Upper jaw length 1.4 (1.3) in horizontal diameter of eye. Ventral margin of lachrymal with 10–12 (11) short, pointed spines. Retroarticular with 1 or 2 small, blunt spines. Gill rakers slender, wider at base, about one third of gill filaments length, with series of short thin spines along inner edge. Third dorsal-fin spine longest. The tips of some dorsal-fin spines are broken in both specimens (3 rd– 6 th in the holotype and 3 rd– 7 th in the paratype ). In the holotype the membrane between 3 rd and 4 th and between 4 th and 5 th dorsal-fin spines extends as two elongated skinny filaments (partly damaged). The paratype has only one such extension, between 3 rd and 4 th dorsalfin spines ( Fig. 1C ). Pelvic-fin spine inserted on vertical through third dorsal-fin spine. Anal-fin origin positioned on vertical through last dorsal-fin spine. Sixth interneural space vacant. Scales above anal-fin base with deep apical crest (2.4–2.8 of scale horizontal length, measured in 3 scales); crest’s lateral surface densely covered with numerous spines arranged in about 10 more or less irregular transverse rows; lateral surface of scales with 10–12 (counted in 3 scales) moderately long and sharply pointed ctenii, longest about 1.6 in crest depth ( Fig. 2 ). FIGURE 2. Antigonia emanuela , new species , holotype, scale morphology: (A) general view of scale (white arrow highlights the apical crest; black arrow indicates ctenii); (B) armament of apical crest; (C) ctenii on scale surface. Scale bars: (A) 0.5 mm; (B, C) 0.2 mm. TABLE 1. Measurements and counts of the type specimens of Antigonia emanuela .

Character	Holotype	Paratype
SAIAB 203818	SAIAB 207256
SL, mm	60.3	66.4
Head length, mm	23.25	26.75
In % of SL
Greatest body depth	118.8	113.8
Least depth of caudal peduncle	15.1	14.5
Caudal peduncle length	7.0	6.5
Head length	38.6	40.3
Snout length	12.2	13.4
Horizontal eye diameter	13.4	13.0
Bony inteorbital width	10.2	10.0
Upper jaw length	9.8	10.2
Lower jaw length	14.0	15.7
Predorsal distance	71.5	72.0
Preanal distance	78.1	77.6
Prepectoral distance	40.8	41.1
Prepelvic distance	75.5	73.6
Pelvic-anal distance	12.0	12.4
Dorsal fin base length (spinous portion)	19.3	19.3
Dorsal fin base length (soft portion)	55.4	52.9
Dorsal fin base length (combined)	73.2	70.2
Anal fin base length (spinous portion)	9.5	10.6
Anal fin base length (soft portion)	55.1	54.4
Anal fin base length (combined)	64.0	63.0
Pectoral fin length	33.3	32.4
Pelvic fin spine length	32.0	31.3
First dorsal-fin spine length	2.2	3.3
Second dorsal-fin spine length	5.1	5.4
Third (longest) dorsal-fin spine length	ca.38.1	ca.31.6
Fourth dorsal-fin spine length	ca.32.8	ca.30.5
First (longest) anal-fin spine length	17.3	18.5
In % of head length
Snout length	31.6	30.7
Horizontal eye diameter	34.8	32.2
Bony inteorbital width	26.5	24.5
Upper jaw length	25.4	25.4
Counts
Dorsal-fin spines	IX	IX
Dorsal-fin soft rays	29	29
Anal-fin spines	III	III
Anal-fin soft rays	28	28
Pectoral-fin rays	i, 12	i, 12
Pelvic-fin rays	i, 5	i, 5
Caudal-fin rays	iii, 12, ii	iii, 12, ii

......continued on the next page TABLE 1. (Continued)

Character	Holotype	Paratype
SAIAB 203818	SAIAB 207256
Gill rakers in outer row of first arch (developed / total)	4 + 14 / 4 + 15	4 + 13 / 5 + 13
Number of scales in longitudinal row from gill opening to caudal-fin base	47	46
Number of transverse scale rows between origins of dorsal and anal fins	48	55
Number of scale rows below eye	5	5
Vertebrae	10 + 12	Not radiographed

Colour in life. Pink, silvery on cheeks, opercle, breast and belly; bases of soft dorsal and anal fins, and caudal peduncle reddish; somewhat diffuse transverse band from dorsal fin, behind pectoral-fin base to pelvic fin, becoming indistinct ventrally; diffuse reddish patches between origins of soft dorsal and anal fins. Narrow reddish orange stripe from eye to ventral margin of breast, arching posteriorly along ventral edge of body to pelvic-fin base. Soft dorsal, anal and caudal fins bright-yellow; pectoral fin transparent; spinous portion of dorsal fin and pelvic fin (except spine and outermost soft ray) reddish; apex of spiny dorsal-fin with 1–2 red skinny pennants. Iris of eye yellow ( Figs. 1A, 1C ). Colour in alcohol. Body pale brown to creamy white, darker brown internally above eye, and around abdominal cavity and opercle, both of which exhibit silvery areas externally. Spiny dorsal fin and pelvic fins with black dots on membrane and may appear dusky; other fins pale. Distribution. Antigonia emanuela is currently known only from the type locality, off Myanmar’s Ayeyarwady Delta, in the Andaman Sea. It was collected at a depth range of 99– 129 m . FIGURE 3. Antigonia spp., premaxilla and maxilla, lateral view: (A) A. indica , SAIAB 208016, soft tissue removed; (B) A. gr. rubescens , SAIAB 35599, soft tissue removed; (C) A. undulata , SAIAB 80116; (D) A. ovalis , SAIAB 203819. Scale bars: 2 mm. Etymology. The species epithet honours Ms Emanuela D’Antoni, FAO’s scientific illustrator—in recognition of her valuable contribution to our knowledge of the world’s aquatic biodiversity through the production of more than 30.000 drawings of species included in FAO’s national, regional and global species identification tools for fisheries purposes. It is treated as a noun in apposition.