Hypseleotris ebneri, Keith & Mennesson, 2023

HYPSELEOTRIS EBNERI SP. NOV.

( FIGS 1–4, 10; TABLES 4, 5)

Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. o r g: a c t: E 0 2 5 A D 4 3 - 0 6 9 1 - 4 1 8 D - A A 6 F - B6AEB9E5DF1C

Material examined: Five specimens from New Britain ( PNG) : two males, two females and one juvenile; size range 20–48 mm SL; largest male 48 mm SL, largest female 39 mm SL.

Holotype: MNHN-IC-2021-0296, male (46.5 mm SL); Papua New Guinea, New Britain, Nut Village, Water Lily Hole , 23 Oct. 2018, Keith, Amick, Lord & Causse coll.; tag 2756.

Paratypes: MNHN-IC-2021-0297, one male (48 mm SL, tag 2757), one female (39 mm SL, tag 12540); same data as holotype . MNHN-IC-2021-0298, one juvenile (20 mm SL, tag 2755), one female (28.4 mm SL, tag 12581); same data as holotype .

Diagnosis: The new species has 13 pectoral fin rays, 18–19 scales in pre-dorsal series, the anal fin is usually I,9, and the head is 29–31% SL.

Description: The ray and scale counts are given in Table 4 and selected morphometrics in Table 5. Below, the holotype counts are given first, followed in brackets, if different, by the paratype counts.

The body is compressed laterally. Males often with a greater body depth than females: the body depth at anus is 20–22% SL for females and 23(24)% SL for males, at first dorsal fin 21–22% SL for females and 25% SL for males, and the caudal peduncle depth is 13(11–14)% SL. Pre-dorsal length 45(42–45)% SL and preanal length 61(55–60)% SL. Size: up to 5 cm SL.

The head is 31(29–30)% SL, rounded dorsally with a broad interorbital, the snout is pointed. The mouth (terminal) and jaw length 8(7–8)% SL are small; jaws oblique with several rows of conical teeth, 14–18 on first upper outer row (the biggest in front are usually curved), 6–8 on the first lower outer row. Posterior end of maxillary ending below or just before posterior nostril before eye. Anterior nostril at the end of a short tube above upper lip; posterior nostril a simple pore in front of eye. Eye diameter 8(6–8)% SL and interorbital length 7(6–8)% SL.

Dorsal fins VI–I,8(8–9), with no filamentous rays. The first dorsal fin is with second, third, fourth and fifth rays longer. Anal fin usually I,9(9–10) directly opposite to the second dorsal fin. The caudal fin is with 11 branched rays and its posterior margin is straight or slightly rounded. Pelvic fins separate, I,5. Pectoral fins 13. Lateral scales 27(27–29), with ctenoid scales on flanks and caudal peduncle. Pre-dorsal scales cycloid anteriorly from snout adjacent to anterior nostril to anterior part of the head, and with several ctenoid scales on a medium line before anterior part of D1. Ctenoid scales on operculum, on base of pectoral fins and on belly extending to anus. Cheek with cycloid and ctenoid scales. Scales in transverse back series 9(9–10), in transverse forward 11(10–12), in pre-dorsal 19(18–19) and in zigzag usually 6(6–7), interorbital scales 3(3–5). Vertebrae 25. Gill opening extending to below posterior preopercular margin.

Males have a more elongated second dorsal fin (30– 36 vs. 25–27% SL) and anal fin (31–35 vs. 25–28% SL) than females and a higher first dorsal fin. Males with a slightly triangular urogenital papilla with a small angular lateral extension on each side on the distal part. The females have a rectangular or chalice-shaped bulbous urogenital papilla with crenulated outer edges around distal opening.

Cephalic sensory pore system as described by Akihito et al. (1988) with oculoscapular canal nasal to post-temporal with the pores C’, D, E’ (sometimes missing), K’, L’; preopercular canal long with the pores M’, N, O, P’ (sometimes missing).

Colour in preservation ( Fig. 10): Male and female usually nearly similar except for fins. Background of body dark brown on the back and the flanks; belly brown or beige. A greyish blotch on middle part of caudal fin base. Head dark brown. A well-marked dark brown stripe from preoperculum and operculum, below midline ending at the base of caudal fin. Males: First dorsal fin blackish to greyish with a distal thin white band, and white dots at the base. Second dorsal fin with 2–3 rows of ovoid white spots. Anal fin greyish. Caudal fin greyish with 6–7 vertical rows of ovoid white spots. Females: Fins greyish.