Oxyurichthys omanensis Zarei, Al Jufaili & Esmaeili, 2022

Zarei, Fatah, Al Jufaili, Saud M., Béarez, Philippe, Ponton, Dominique, Pruvost, Patrice & Chakona, Albert, 2025, Beyond Oman’s shores: records of Oxyurichthys omanensis (Teleostei: Gobiidae) from the central and southern regions of the Western Indian Ocean, Zootaxa 5633 (3), pp. 513-527 : 516-520

Oxyurichthys omanensis Zarei, Al Jufaili & Esmaeili, 2022

Oman’s eyebrow goby

( Figs. 1 & 3–4 )

Oxyurichthys omanensis Zarei, Al Jufaili & Esmaeili, 2022:365 , figs. 2–6 (Yeti, Oman).

Material from the central and southern regions of the WIO. SAIAB 96285 , 1 male, 131 mm SL, Mida Creek , Dabaso, Kenya, 3°20’42.3”S 39°59’24.2”E, collected by local fishermen, 19 November 2009 ( BOLD sequence ID: SAIAD731-13 ; GenBank accession number: PV477244) . MNHN-IC-2014-0540, 1 specimen, 75 mm SL, Hajangoua , Mayotte, 12°51’39.6”S 45°12’10.8”E, collected by D. Ponton, P. Béarez, G. Mou-Tham & P. Pruvost ,

5 April 2014 ( COI sequence ID: PMM1106-14 ; GenBank accession number: PV477245). SAIAB 98368 , 3 males, 2 females, 88–95 mm SL, Ambinanibe Lagoon , Anôsy, Madagascar, 25°04’00.0”S 46°56’00.0”E, collected by P. Laboute , 5 May 2010.

Diagnosis. Oxyurichthys omanensis is distinguished from all congeneric species in the WIO by: D2 I,12; upper jaw with 1 row of teeth; membranous nape crest and eye tentacle present; LL 45–63, usually 50–56; TFR 23–29, usually 24–28; snout 34.9–45.4% HL; no papillae rows below row d; papillae row 2 significantly short of row d; ctenoid scales on trunk past third D2 element base; pelvic fin reaches or surpasses anal-fin origin; D2 longest ray 1.1–1.6 times head depth.

Description. Body proportions in Table 1. Body moderately elongate, laterally compressed posteriorly; depth at pelvic-fin origin 19–20% SL, at anal-fin origin 16.5–20.6% SL; caudal-peduncle depth 0.9–1.0 times length. Head large, 22.7–25.1% SL, width 0.60–0.65 times HL, depth 0.65–0.7 times HL. Postorbital profile almost horizontal. Snout short, rounded, oblique, convex; length 1.4–1.9 times eye diameter, 0.35 times HL. Anterior naris tubular, short, near upper lip, rim without processes; posterior naris oval, midway between eye and anterior naris. Eyes dorsolateral, high on head, above dorsal profile, diameter 0.18–0.24 times HL. Elongate dorsoposterior eye tentacle. Membranous nape crest present. Narrow interorbital, 0.45–0.55 times eye diameter. Mouth oblique, jaws reach mid-orbit. Upper lip not constricted at symphysis. Upper jaw teeth in a single row, small gap at symphysis; lower jaw teeth in two rows. Gill opening restricted to the pectoral fin base. Urogenital papilla conical in males with pointed posterior edge; broader and rounded in females.

following Pezold & Larson (2015) definitions are marked with *.

D1 VI; D2 I/12; A I/12–13; P 21; V I/5+5/I; CSR 8/9; CBR 7/8. D1 with filamentous spines, longest first spine (1.1–1.4 times head length), decreasing to sixth spine. D2 and A rays moderately long, A lower, longest rays 1.5–1.6 times head depth, extending past caudal base. Narrow interdorsal space, covered by membrane. Anal fin origins below D2 spine. P oval, central rays longest, extending to vertical between fourth and fifth A rays (0.3–0.35 times SL). V oval, anterior to D1 origin, reaching or passing A origin; rear V membrane villose. C elongate and pointed, 2.1–2.5 times HL.

Nape scaled with small cycloid scales, naked median along crest to D1 base; scales terminate above anterior opercle half. Opercle, cheek, and pectoral base naked. Abdomen with cycloid scales. Ctenoid scales on body side behind line from third D2 element base to A origin, cycloid and smaller anteriorly. LL 53–57, TFR 26–28, TRB 15–16, PD 11–12.

Anterior oculoscapular canal with 11 pores (A’BCDFH’), all except D doubled; posterior oculoscapular and preopercular canals absent ( Fig. 4 ). Preorbital papillae rows: r long, oblique, opposite posterior nostril; s 1 short, oblique, medial to posterior nostril; s 2 transverse, posterior to A’; s 3 above upper lip, anterior to s 2 ( Fig. 4 ). Lateral preorbital rows: c 2 with two oblique rows between nostrils, lower row longer; c 1 and c 2 as long joint transversal row (c 1 +c 2) between anterior nostril and suborbital row 1; c 1 short, oblique, between upper lip and suborbital row 1. Suborbital rows: five transverse (1–5) and two longitudinal rows (b, d) on cheek; 1–2 before b, long; 3 and 4 divided by b (superior: 3s, 4s; inferior: 3i, 4i); additional rows between 2 and 3i, and 3i and 4i; 5 as 5s, short; b long, reaching 2 anteriorly, preopercle edge posteriorly; d long, reaching e 2 posteriorly, 1 anteriorly. Preoperculo-mandibular rows: e, i, f; e and i divided at lower jaw articulation (e 1, e 2, i 1, i 2); i 1 continuous with with symphyseal row f. Oculoscapular rows: five transverse (z, trp, y, as 1, as 2) and three longitudinal rows (x 1, x 2, la 1). Row y short and immediately behind x 2; row u proliferated in 10–13 short vertical rows above upper edge of opercle. Opercular rows: three rows (ot, os, oi). Occipital series: three rows (n, g, m).

Colour of fresh specimen ( Fig. 3 ): Head and body yellowish-grey, ventrally whitish. Nape with brown crescent behind each eye. Orbital tentacle brownish orange, darker at tip. Nape crest grey with narrow dark brown margin. Four inconspicuous brown saddles on back below dorsal fins, fifth saddle over caudal peduncle darkest. Triangular dark brown blotch on caudal base. Vertical bars along body, distinct and oblique on anterior part. Comma-shaped dark brown mark on pectoral base, greenish spot dorsally; greenish area at base center. Anterior narial tube with dark spot medially, posterior naris with brown rim. Rectangular tear-shaped mark along ventral eye edge to upper lip. Dorsal fins translucent, with dark brown spots and streaks. Anal fin with dark brown membrane. Caudal fin dark brown at base, streaks indistinct. Pectoral fin golden. Pelvic disc dark brown near base. Colour in preservative ( Fig. 5 ): head and body yellowish to greyish brown, slightly darker dorsally. Dorsal saddles obscure; fifth saddle over caudal peduncle distinct in some specimens. Caudal base with dark brown blotch. Body bars faded. Pectoral base with comma-shaped dark brown mark. Anterior narial tube with central black spot; posterior naris rim dusky to blackish. Ventral eye to upper lip with dark brown rectangular tear-shaped mark. Dorsal fins greyish, spotted and streaked dark brown. Anal fin uniform grey to blackish. Pectoral fins greyish, ventral half with faint rows of diffuse dark grey spots. Pelvic disc greyish, dark grey to brown streaks adjacent to rays.

Vertebral column ( Fig. 5 ): The following counts are based on five specimens: 3 predorsal, 10 precaudal, and 16 caudal vertebrae (including urostyle); total vertebral count 26. D1 pterygiophore insertion pattern: 3-12210; number of anal pterygiophores anterior to the first haemal spine 2.

Habitat and distribution. Coastal habitats, estuaries, mudflats and mangroves of the WIO: Oman, Kenya,

Mayotte and Madagascar ( Fig. 6 ).

Figures

FIGURE 1. Uncatalogued live specimens of Oxyurichthys omanensis from Yeti, Oman (collected on 11 January 2025 by Saud M. Al Jufaili).

FIGURE 3. Fresh specimen of Oxyurichthys omanensis from Hajangoua, Mayotte (MNHN-IC-2014-0540, 75 mm SL). (© D. Ponton).

FIGURE 4. Cephalic sensory pores system and papillae of Oxyurichthys omanensis (SAIAB 96285, 131 mm SL) from Mida Creek, Dabaso, Kenya. Terminology is described in the text.

FIGURE 5. Preserved specimens and radiographs of Oxyurichthys omanensis from (A–B) Kenya: Mida Creek, SAIAB 96285, 131 mm SL; (C–D) Madagascar: Ambinanibe Lagoon, Anôsy, SAIAB 98368, 93.3 mm SL.

FIGURE 6. Updated geographical distributions of the four species/clades within the Oxyurichthys ophthalmonema species complex: O. omanensis, O. cornutus, O. ophthalmonema, and Oxyurichthys sp. [records from this study, Zarei et al. (2022), Froese & Pauly (2025), Pezold & Larson (2015), Isari et al. (2017), Chang et al. (2017), Viswambharan et al. (2015), and Ty et al. (2021)].