Engyprosopon keliaoense Amaoka & Ho 2022, sp. nov.
Creators: name: Amaoka, Kunio
name: Ho, Hsuan-Ching
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Pleuronectiformes
Bothidae
Engyprosopon
Engyprosopon keliaoense

description: Engyprosopon keliaoense sp. nov.
New English: Keliao lefteye flounder
Figures 1A‒D, 5A‒C; Tables 1‒3
Holotype. NMMB-P25662, male, 67.7 mm SL, off Ke-tzu-liao, Kaohsiung, southwestern Taiwan, bottom trawl, 10–30 m, 26 Jun. 2016.
Paratypes. HUMZ 232504 (formerly NMMB-P25663), female, 66.7 mm SL and NMMB-P25686, female, 72.4 mm SL, collected with the holotype; NTUM 17310, male, 69.0 mm SL, field no. WJC 9802, off Ke-tzu-liao, Kaohsiung, 23 May 2020, coll. Pakorn Tongboonkua.
Etymology. The specific name is derived from Chinese Ñ寮 (Ke Liao), meaning oyster hut. Named for the type locality, a small village that raised oysters and collected fishes for living since century ago.
Diagnosis. A species of Engyprosopon characterized by having a pair of black spots on the caudal fin, small upper and lower eyes (3.48–3.77 in HL), narrow interorbital width in both sexes (5.96–9.78 in HL), and short pectoral fin on the ocular side (1.25–1.43 in HL).
Description. Proportional data (as in SL and HL) for the holotype are provided first, followed by those of paratypes in parentheses. Morphological (as percentages of SL) and meristic data are provided in Tables 1–2.
Dorsal-fin rays 81 (81–84), anal-fin rays 59 (62–63), ocular-side pectoral-fin rays 11 (11–12), blind-side pectoral-fin rays 9 (9–10), caudal-fin rays 3+10+4 (3+11+3), ocular-side pelvic-fin rays 6 (6), blind-side pelvic fin rays 6 (6), scales in lateral line 47 (46–51), gill rakers 0+6 (0+5–7), vertebrae 10+24 (10+24).
Proportions in SL: HL 4.05 (4.02–4.09), body depth 1.8 (1.82–1.85). Proportions in HL: snout 5.06 (4.74–4.97), upper eye diameter 3.55 (3.66–3.77), lower eye diameter 3.48 (3.56–3.75), interorbital width 5.96 (6.48 in male, 7.90–9.78 in females), ocular-side upper jaw 3.09 (2.96–3.16), blind-side upper jaw 3.09 (3.13–3.23), ocular-side lower jaw 2.11 (2.13–2.20), blind-side lower jaw 1.96 (1.98–2.08), caudal peduncle depth 1.92 (1.83–1.95), ocularside pectoral fin 1.25 (1.30–1.43), blind-side pectoral fin 1.74 (1.95–2.07), ocular-side pelvic fin 1.59 (1.94–2.08), blind-side pelvic fin 2.17 (2.16–2.35), base of ocular-side pelvic fin 2.20 (2.38–2.59), base of blind-side pelvic fin 6.42 (7.55–8.98), longest dorsal-fin ray 1.78 (2.02–2.13), longest anal-fin ray 1.80 (1.89–2.10), middle caudal-fin ray 1.09 (1.17–1.22).
Body deeply ovate, deepest about middle of body, body depth slightly deeper than half of body length; dorsal and ventral profiles of body almost symmetrically convex in both sexes. Head small, a little shorter than 1/4 of SL; anterior profile of head not steep in male, and a slight concavity anterior to middle of interorbital space. Snout short, much shorter than eye diameter. Short and obtuse small rostral spine in male and no spine in female.
Eyes small, eye diameter shorter than length of maxilla length; lower eye slightly in advance of upper eye. No orbital spine in each sex. Interorbital space very narrow, male slightly wider than female or almost equal. Ocularside nostrils anterior to interorbital region, anterior nostril a short tube with small round flap posteriorly, posterior nostril without flap; blind side nostrils rudimental or absent, closely set below origin of dorsal fin.
Mouth large, oblique; maxilla extending to below near anterior 1/3 of lower eye; anterior tip of upper jaw about same vertical line to tip of lower jaw. Teeth on upper jaw biserial at anterior half, those in outer series stouter and sparse; lower jaw teeth uniserial, about similar to anterior teeth in inner row of upper jaw in size and space. Gill rakers on first arch short, not serrate, absent on upper limb. Ocular-side scales ctenoid with short ctenii, very small and deciduous, both jaws and snout naked; blind-side scales cycloid.
Dorsal fin originating before middle of interorbital space, no elongate rays, longest ray at near middle of body. Anal fin origin below base of pectoral fin, subsymmetrical to dorsal fin of posterior half of body in shape. Ocularside pectoral fin very short, distinctly shorter than head length in both sexes. Ocular-side pelvic fin origin at tip of isthmus, fifth ray of ocular side opposite to first ray of blind side. Tip of isthmus below middle of lower eye. Caudal fin rays branched, except for three uppermost and four (three) lowermost simple rays.
Coloration. When preserved, ocular-side body uniformly greyish light brown. All fins greyish; caudal fin with a pair of large prominent black blotches, each extending between third and fifth rays from dorsal and ventral margins of the fin, respectively. On blind-side, posterior half of body with faintly black pigmentation in males and uniformly white in females (Fig. 1B, D).
Sexual dimorphism. This species shows sexual dimorphism, of which males have snout spine, broader interorbital width, longer pectoral fin and faintly black pigmentation on the blind side of body, but these are not especially prominence (Table 1; Figs. 1, 5).
Distribution. Known from the type series collected from off Ke-tzu-liao, Kaohsiung, southwestern Taiwan, at depth 10–30 meters.
description: Published as part of Amaoka, Kunio & Ho, Hsuan-Ching, 2022, Engyprosopon keliaoense, a new lefteye flounder (Teleostei: Bothidae) from Taiwan, pp. 222-232 in Zootaxa 5189 (1) on pages 223-229, DOI: 10.11646/zootaxa.5189.1.20, http://zenodo.org/record/7119483