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Okamejei picta sp. nov. Figs. 1–9, Tables 1–2 urn:lsid:zoobank.org:act: 5CD9D2D9-582C-4A97-9BA3-E5AEE6AE2297 Holotype. NMMB-P 36013, 429 mm TL, adult male, ca. 19°N, 114°E, off western Dong-sha Atoll, South China Sea, depth ca. 300 m, bottom trawl, 19 February 2021, coll. C.-H. Lin. Paratype. ASIZP0081116, adult male, 405 mm TL (snout slightly damaged), collected together with the holotype. Diagnosis. A medium-sized species of Okamejei (~ 429 mm TL) with yellowish brown dorsal surface, densely mottled with small black circular to irregular spots; pale blotches present but indistinct; absence of prominent pair of pectoral markings and posterior ocellus; ventral surface entirely whitish; ventral sensory pores dark edged; and the following combination of characters: disc width 57.6–63.2% TL, disc length 75.4–78.1% disc width; tail long, length 116–118% distance from snout tip to rear of cloaca; tail very slender, height 80.0–84.4% width at its midlength; snout narrow and pointed, preorbital snout length 22.8–32.1% disc length; first dorsal-fin base length 20.9–25.0% distance from first dorsal-fin origin to tail tip; tip of clasper without component funnel; nuchal thorn small; total pectoral radials 73–76; trunk centra 27–31; total centra 123–126. . ...Continued on the next page ...Continued on the next page Description. The following data are provided for holotype, followed by the value of paratype in parentheses. Disc quadrangular, length 78.1% (75.4%) width; angle in front of spiracles 70° (64°); axis of greatest width 60.4% (48.4%) of disc length; anterior margin double concave, moderately concave anteriorly to the snout tip, convex besides eyes, considerably concave besides and posterior to spiracles; apex very narrowly rounded; posterior margin slightly convex; free rear tip rounded. Details of dorsal and ventral view of head are shown in Fig. 3. Head rather short, preorbital snout length 59.0% (43.9%) head length, distance between orbits 13.4% (13.9%) head length; pre-upper jaw length 52.2% (42.1%) ventral head length. Snout tip produced and very narrowly pointed; fleshy process absent at tip. Distance between orbits 81.2% (76.9%) orbit diameter. Spiracle medium-sized, length 58.9% (60.0%) orbit diameter; its opening in distorted teardrop-shape. Nostril suboval; anterior nasal flap somewhat expanded, lobelike, partly covered beneath nasal curtain; posterior inner margin fully covered by nasal curtain; posterior lobes forming nasal curtain, produced posterolaterally, posterior margin with prominent fringes; distance between nostrils 54.5% (48.5%) distance between first gill slits, 101% (93.0%) distance between fifth gill slits. Upper jaw prominently arched, continuous at symphysis; lower jaw in wide inverted V-shape; part of lateral teeth covered by lobe of nasal curtain. Teeth unicuspid, with subcircular bases near symphysis; arranged in longitudinal rows; main cusps slender, long, sharp, directed posteriorly in upper jaw, directed anteriorly in lower jaw, becoming shorter and oblique laterally. Pelvic fins bilobed; anterior lobe short and slender, narrowly rounded distally, lateral margin entire, inner margin considerably incised; posterior lobe greatly elongate, length 17.6% (18.5%) TL, lateral margins straight, free rear tip rounded; inner margin rather shallow, connected to anterolateral margin of clasper; anterior lobe 73.9% (69.0%) posterior lobe. Tail long and thin, moderately depressed; relatively narrow at base, slightly tapering gradually to tail tip, not expanded at midlength; width at first dorsal-fin 65.7% (54.7%) width at midlength of tail, 47.6% (32.6%) width at axil of pelvic fin; length from postcloaca 116–118% distance from snout tip to precloaca; anterior cross-section suboval, flat on dorsal and ventral surface of the whole tail; height 81.3% (58.7%) width at axil of pelvic fin, 79.8% (84.4%) width at midlength, 98.0% (93.3%) width at first dorsal-fin origin; lateral tail fold poorly developed, its origin slightly anterior to first dorsal-fin origin, extending to tail tip. Dorsal fins small, subequal in size and shape (Fig. 4C, D); first dorsal-fin height 51.6% (52.7%) in base length; second dorsal-fin height 64.9% (67.2%) in base length; fins subtriangular, anterior margins oblique, posterior margins rounded and slightly convex; interdorsal space moderately wide, 97.9% (83.5%) in first dorsal-fin base length; distance from first dorsal-fin origin to tail tip 38.9% (38.0%) tail length; caudal-fin length 27.4% (25.4%) distance from first dorsal-fin origin to tail tip; first dorsal-fin base length 76.3% (98.1%) caudal-fin length. Caudal-fin epichordal lobe well developed, base long and low; its height greater posteriorly; tip pointed, its posterodorsal margin somewhat convex; well separated from second dorsal fin; hypochordal lobe poorly developed. Orbital thorns small, smaller than alar and malar thorns, 2 (4) on preorbit, 5 (5) on orbit, directed posteriorly; one rudimentary nuchal thorn present; no thorns on scapular regions. Malar thorn patch with 20 (20) enlarged, strongly curved thorns in ca. 3 rows; main patch small, curved slightly, located at disc margin near eye and spiracle; thorns merging with bunches of smaller thornlets laterally, thorns near disc edge smaller; thornlets at anterior disc larger, decreasing in size posteriorly. Alar thorn patch with 34 (33) thorns, size subequal to tail thorns; embedded and directed posteromedially, in about 2–3 rows; patch narrow, length slightly longer than malar patch. Tail thorns variously developed, in three rows (Fig. 4A, B); row not staggered; 26 (21) predorsal thorns, weakly curved, with very small bases, size subequal to orbital thorns; interdorsal thorns small, 3 (1); median row poorly developed; thorns in median row weak, 11 (5) thorns, emerging near pelvic-fin rear tip, extending along length of predorsal tail in a single row; dorsolateral rows of similar size; with 15 (16) similar thorns on each side, almost continuous, extending from near pelvic-fin rear tip to first dorsal-fin origin (to first dorsal-fin base end in the paratype), located above mid-lateral tail, closer to thorns of median row. Denticles poorly developed, disc and tail mostly naked; confined to a moderately developed patch on snout tip dorsally; long, widely spaced, thorn-like denticles along anterior margin of disc from snout tip to an area anterior to alar thorn patch; confined to a small patch at snout tip ventrally; tail and posterior disc entirely naked; denticles short, prickle-like, sparsely distributed in patches. Clasper well developed, stout, depressed, length 23.5% (26.3%) TL; tip pointed. Clasper external features included boss (bs), cleft (cf), spike (sk), terminal bridge (tb), pseudorhipidion (ps), rhipidion (rh), shield (sh) and sentinel (st) (Fig. 5); bs rather expanded, situated between lower part of cf and sk; cf narrow, partitioned by tb; ps rod-like, situated between upper cleft and rh; rh bilobed, its distal tip barely extend to proximal end of cf; st moderately developed, positioned among rh, tb, bs and sk; sk sharp, rather straight, not hook-like; sh long, with sharp outer edge; component funnel not evident. Clasper skeleton highly calcified, consists of basal, axial and terminal cartilages. Basal cartilages contain beta cartilage (β), basipterygium (bpv), and intermediate segments 1 (b1) and 2 (b2) (Fig. 6); β cartilage long, situated dorsally of posterior half of b1 and the whole b2 cartilages; bpv slightly arched outwards, linked with pelvic girdle anteriorly and with b1 posteriorly; b1 and b2 short, length about half of bpv, both rod-like. Pelvic girdle with large, slightly arched puboischiadic bar; iliac region enlarged, with two obturator foramina (of) on each side; iliac process (ip) slightly curved inwards; lateral prepelvic process (lpp) long and narrow; lateral process (lp) very short, with rounded tips. Terminal cartilages comprise nine components: axial cartilage (ax), three dorsal terminal cartilages (dt1–3), two accessory terminal cartilages (at1, at2), ventral marginal cartilage (vm), dorsal marginal cartilage (dm), and ventral terminal cartilage (vt) (Fig. 7A); ax longest, slender, with a rounded tip; at1 Y-shaped, deeply forked, distal tip paddle-shaped, attaching proximally to vm and forming st externally; at2 slender, hook-like, with a flattened tip, alongside at1, joining the tip of at1 distally, and forming sk externally; dm long, slightly concave, with distal end very weakly bifurcated, both lateral and medial tips broadly rounded; dt1 moderate, shield-like, slightly concave proximally, covering ax, with a blunt tip; dt2 moderately short, attached to dm proximally, and dt3 distally; dt3 very slender, with pointed tips, proximally attaching dt2, distally attaching vt; vm long and forked, wide posteriorly, attached to ax and dm, distal tip forming ps externally; vt positioned at outer aspect of clasper glans, J-shaped, bifurcated proximally, broadly widened distally, tip spoon-shaped, forming sh and dk externally (Fig. 8); not showing externally as component funnel. Neurocranium (Fig. 9) with a bullet-shaped anterior fontanelle (af); posterior fontanelle (pf) bottle-shaped, shorter than af; rostral cartilage (rc) long, length 59.0% (43.9%, note that the rostral cartilage is slightly broken in the paratype) of dorsal head length; rostral base (rb) moderately narrow, its width about one quarter of rc; antorbital cartilages (ac) thin, arched, attaching nasal capsule (nc) and the second segments of propterygium (pr); nc ovalshaped, preorbital canal foramen (poc) situated proximally to the leading edge of nc; preorbital process (prep) and postorbital process (postp) scarcely developed. Distribution of ventral sensory pores overall W-shaped, denser on head, but sparsely distributed on other parts; pores in 1–2 rows at rostral cartilage, nasal curtain, area between gill silts, and pectoral fins before their maximum width; sensory pores present on anterior to middle edge of abdomen, absent from pelvic fins; pores generally small (slightly larger in paratype than holotype), those on area between gill gilts and on abdomen edge slightly larger, others rather small. Meristics:Also provided in Table 2. Tooth rows in upper jaw 40 (41); lower jaw 40 (40). Pectoral-fin propterygial radials 29 (28); mesopterygial radials 10 (8); metapterygial radials 37 (37); total basal radials 76 (73). Pelvic-fin radials 1 (1) + 19 (20). Trunk centra 31 (27); predorsal caudal centra 44 (43); predorsal centra 75 (70); centra between origins of dorsal fins 16 (16); diplospondylous centra 95 (96); total centra ca. 126 (123). Coloration. When fresh (Figs. 1–2), dorsal surface of disc, posterior pelvic-fin lobes, claspers and tail yellowish brown, densely covered by small black irregular spots; scattered larger blotches but indistinct; no prominent pair of pectoral markings and posterior ocellus; pectoral-fin margins translucent without spots or blotches; rostral cartilage uniformly pale brown, except for the posterior part with a few black speckles; dorsal fins and caudal fin translucent; eyelid brownish to translucent, eye dark; thorns pale, contrasted against darker dorsal surface of tail; tail strongly bicolored laterally, yellow dorsolaterally, pale ventralaterally; ventral surface of disc and tail uniformly whitish, pectoral fins slightly translucent; sensory pores dark edged, some surrounded by blotches. Coloration of female and juvenile unknown. In preservative, dorsal surface and sensory pores darker in general, others similar to fresh coloration. Distribution. Known only from deep waters off western Dong-sha Atoll, South China Sea, at depth ca. 300 m. Size. The types are both mature males (to 429 mm TL) and no information on females, juveniles and egg cases. Females presumably attain larger sizes. Etymology. Derived from the Latin pictus, which means painted or colored, referring to the densely distributed black spots on the contrasting yellowish brown dorsal disc. Vernacular: Fine-spotted Skate. Remarks. Among the genus Okamejei, O. picta sp. nov. resembles two other western Pacific species, viz., O. hollandi, and O. mengae. Both species share the characters of densely distributed black spots on the dorsal disc, and a ‘W-shaped’ distribution of ventral sensory pores (Jeong et al. 2007; Misawa et al. 2022). However, the new species is readily distinguished from the two species by coloration patterns, morphometrics and vertebral counts (Table 2). The coloration and patterns of skates are sensitive to environmental influences, that the same species may have different colorations, and sympatric species may exhibit overlapping coloration patterns (Weigmann 2017; Misawa et al. 2019; Gabbanelli et al. 2022). Thus, cautions should be taken when using coloration as diagnostic character in description of new species. Nevertheless, O. picta shows notable difference in several coloration patterns from O. hollandi (Fig. 10): a yellowish brown dorsal disc (vs. grayish to dark brown in O. hollandi); shape of the black spots on the dorsal disc circular to irregular (vs. uniformly circular); blotches indistinct (vs. distinct); posterior ocellus absent (vs. sometimes present); ventral disc mostly white (vs. pale to dark brown). By comparing the morphometrics, O. picta sp. nov. differs from O. hollandi in having shorter disc (45.0–47.7, vs. 51.6–55.8% TL); a larger head (dorsal-head length 24.5–24.8, vs. 19.3–21.5% TL); a longer distance between cloaca to first dorsal-fin origin (32.1–32.3, vs. 25.1–29.2% TL); a longer distance between cloaca to second dorsal-fin origin (41.1–41.9, vs. 34.1–39.6% TL); a longer tail (distance between cloaca to caudal-fin tip 53.6–55.1, vs 47.8–53.4% TL); space between nostrils relatively narrow, its length 23.5–23.6% (vs. 24.1–25.7% ventral-head length); a longer anterior pelvic lobe (12.8–13.0, vs. 10.3–12.1% TL); a longer posterior pelvic lobe (17.6–18.5, vs. 14.5–17.4% TL); distance between first dorsal-fin origin and caudal-fin tip small (20.9, vs. 22.2–25.7% TL); distance between second dorsal-fin origin and caudal-fin tip small (11.4–12.2, vs. 13.2–14.5% TL); and a shorter caudal fin (5.3–5.7, vs. 5.8–8.0% TL). In meristics, O. picta differs from O. hollandi in having more diplospondylous centra (95–96, vs. 66–83); more total centra (123–126, vs. 95–112); relatively few propterygials (28–29, vs. 29–32) and fewer total basal radials (73–76, vs. 82–86). When comparing clasper skeleton, the vt of O. picta is J-shaped, with a bifurcate proximal tip, while the vt of O. hollandi is weakly-curved in shape, with a blunt proximal tip (Fig. 11). In O. picta, the component funnel at the tip of clasper is not evident, but it is prominent in O. hollandi. Furthermore, O. hollandi is a shallow water species, typically found in coastal waters not deeper than 100 m, while the two specimens of O. picta were captured in deepwaters (ca. 300 m). Okamejei picta sp. nov. is also similar to O. mengae known only from the holotype, for which the validity is often questioned (e.g. Last et al. 2016; Misawa et al. 2022). Nevertheless, the new species is readily separated from O. mengae by having a combination of characters (data obtained from Jeong et al. 2007): blotches on the dorsal disc indistinct but present (vs. absent); a shorter disc (45.0–47.7, vs. 55.7% TL); a shorter snout (10.9–14.5, vs. 17.6% TL); a longer tail, distance between cloaca to caudal-fin tip 53.6–55.1 (vs. 48.5% TL); a much longer distance from second dorsal-fin origin to caudal-fin tip (11.4–12.2, vs. 5.8% TL); more trunk centra (31 vs. 23); and fewer total basal radials (73–76, vs. 96). Further comparisons on clasper morphology and skeleton are needed when adult males of O. mengae are available. The presence of a component funnel at the tip of clasper was generally considered a diagnostic character of the genus (e.g. Last & Yearsley 2002; Last & Gledhill 2008; Last et al. 2010; Misawa et al. 2022), but Weigmann et al. (2015) excluded it from the diagnosis. In the description of O. ornata, Weigmann et al. (2015) found out that the component funnel was not evident, but the species share typical characters of genus Okamejei. Our results support Weigmann et al. (2015) that the presence of the component funnel may not be a diagnostic character of the genus. Okamejei picta sp. nov., shares all the diagnostic characters of Okamejei (defined in introduction) except for the absence of a component funnel, so the assignment of the new species to genus Okamejei is undoubted. Okamejei picta and O. ornata are the only two species without the component funnel in the claspers, but O. picta can be readily distinguished from O. ornata by having densely distributed black spots on the dorsal disc (vs. only patchy distributed blotches present) and a bifurcated proximal tip of vt (vs. tip not bifurcated). Comparative materials. Okamejei hollandi: NMMB-P15670 (1, 476), Donggang fishing port, Pingtung, southwestern Taiwan, 31 Dec. 2010. NMMB-P15678 (1, 415), Donggang fishing port, Pingtung, southwestern Taiwan, 18 Aug. 2010. NMMB-P15680 (1, 460), Donggang fishing port, Pingtung, southwestern Taiwan, 3 Mar. 2010. NMMB-P15682 (1, 460), Donggang fishing port, Pingtung, southwestern Taiwan, 3 Mar. 2010. NMMBP16393 (1, 350), Ke-tzu-liao fishing port, Kaohsiung, southwestern Taiwan, 9 May 2010. NMMB-P16757 (1, 426), Donggang fishing port, Pingtung, southwestern Taiwan, 10 Jul. 2010. NMMB-P17093 (1, 462.5), Donggang fishing port, Pingtung, southwestern Taiwan, 9 Aug. 2012. NMMB-P17262 (1, 480), Donggang fishing port, Pingtung, southwestern Taiwan, 6 Aug. 2012. EBFS uncatalogued specimen (1, 432), Donggang fishing port, Pingtung, southwestern Taiwan, 10 Jan. 2022.

Apristurus nakayai Iglésias, 2012 Figs. 1–7; Table 1 Diagnosis. Pre-outer nostril length 4.2–4.9 % TL; upper labial furrows longer than the lower furrows; first dorsal fin smaller than second dorsal fin; first dorsal-fin origin situated well behind pelvic-fin insertion, at or slightly behind a vertical line through pelvic-fin tip; second dorsal-fin insertion above or just slightly anterior to anal-fin insertion; snout rather long, tip rounded; abdomen very short; pectoral-fin tip at or slightly extending after the midpoint of P1- P2 space; intestinal spiral valves 14–16; monospondylous centra 32–36; precaudal diplospondylous centra 34–37; clasper hook present on the inner margin of exorhipidion; body uniformly brownish black to black; iris shiny white when fresh; maturing size at about 400 mm TL in both sex. Description of the specimens from the South China Sea. Proportional measurements are given in Table 1. Body slender, cylindrical before pelvic fins, gradually compressed laterally after pelvic fins. Caudal-peduncle height 49.2–67.6% head height. Abdomen narrow, pectoral-fin free rear tip to pelvic-fin origin 54.3–86.2% internarial width; pectoral-fin tip at or slightly extending after midpoint of space between pectoral and pelvic fins. Midpoint of the total length well behind cloaca. Head dorsoventrally flattened, its height 66.9–98.6% greatest width of head. Snout rather long, tip rounded (Fig. 3). Pre-outer nostril length 42.2–49.4% preorbital length, 83.6–101.3% interorbital width. Nostril large, its length subequal to orbit length and internarial width, expanding obliquely inward towards mouth. Mouth considerably arched, its length 58.4–72.3% width. Labial furrows well developed, length of lower labial furrows 44.5–77.3% upper furrows; length of upper furrows 51.3–57.8% mouth width. Orbit narrowly elliptical, with a poorly developed subocular fold. Spiracle small, bean-shaped, situated below a horizontal line through mid-eye. Five gill slits present; the 5th gill slit located above pectoral-fin origin. Pectoral fin broadly triangular, its width subequal to base length. Pelvic fin slightly elongated, its length 59.2– 65.7% (92.2% for the female specimen) distance between pelvic-fin and anal-fin origin. Anal fin long, narrowly triangular, anal-fin base length (ceratotrichia) longer than distance between origins of the first and the second dorsal fins, its height (muscle) 21.0–33.0% base length (muscle). First dorsal fin situated well behind pelvic-fin insertion, at or slightly behind a vertical line through pelvic-fin tip; first dorsal fin much smaller than second dorsal fin, the height of first dorsal fin 41.2–62.2% height of second dorsal fin; apexes of dorsal fin rounded. Second dorsal-fin length 66.9–88.7% distance between origins of the first and the second dorsal fins. Second dorsal-fin insertion above or just slightly anterior to anal-fin insertion. Caudal fin very long, its length 43.0–46.5% precaudal length; ventral lobe broad, apex rounded. Caudal terminal lobe well developed, its length 69.5–93.9% caudal-fin height. Teeth small and numerous on both jaws, 28–37 + 32–36 = 61–73 on upper jaw and 28–31 + 28–31 = 56–60 on lower jaw. Each tooth with a long central cusp, with mostly a pair of smaller lateral cusps, or additional rudimentary lateral cusps. Streaks present on central cusps. No naked space at symphysis of upper jaw. Naked space present at symphysis of lower jaw in males, but absent in the female specimen (Fig. 4). Denticles small, overlapping each other, tricuspid, central cusp with strong median ridge and distinctly longer than lateral cusps; lateral cusps with weak ridges; surface of denticles with reticulations (Fig. 5). Denticles present around gill openings, but absent from palate and tongue, and on dorsal margin of caudal fin. Clasper robust at base, gradually tapering posteriorly; ventral and outer surface densely covered with denticles; dorsal surface naked, except for outer half of exorhipidion; exorhipidion flat, its inner margin with small clasper hooks; pseudosiphon narrow and deep; cover rhipidion not developed; pseudopera fairly long (Fig. 6). Duodenum developed but not especially elongated. The sole female specimen with ripe ova in the left ovary only. No egg case was found. Intestinal spiral valves 14–16; Monospondylous vertebrae 32–34; precaudal diplospondylous vertebrae 34–37. Coloration. (When fresh) body and fins uniformly brownish black to black; palate and tongue black; iris distinctly shiny white (Fig. 7). (In preservative) Body color less dark; iris pale. ......continued on the next page Size. The largest known specimen is the holotype, which is a mature male measuring 676 mm TL (Iglésias 2012). The sole female specimen measuring 408 mm TL, and the smallest male specimen measuring 415 mm TL were mature. Distribution. Known from western Pacific, including New Caledonia (Iglésias 2012), Papua New Guinea (White et al. 2017; Ebert et al. 2021), and the South China Sea. This species may eventually be found in other regions within the western Pacific. Remarks. Apristurus nakayai can be assigned to the ‘ brunneus group’ as defined by Nakaya & Sato (1999) by having the following combination of characters: wide and relatively short snouts, pre-outer nostrils length less than 6% total length TL; intestine spiral valves 13–22; and upper labial furrows longer than lower furrows. Within this group, A. nakayai superficially resembles A. platyrhynchus, which also co-occurs in all known distributions of A. nakayai. Both species share the combination of characteristics: abdomen short, space between pectoral and pelvic fins much shorter than anal-fin base length (ceratotrichia); first dorsal fin much smaller than second dorsal fin; and origin of the first dorsal fin situated well behind pelvic-fin base (Iglésias 2012; Nakaya & Kawauchi 2013). Iglésias (2012) found some morphometrical differences between the two species (i.e., pre-branchial length; mouth width; nostril length; distance between origins of dorsal fins; distance between insertions of dorsal fins; and pelvic-fin length). However, when comparing all the known A. nakayai specimens to the data of A. platyrhynchus in Nakaya & Kawauchi (2013), the above morphometrics significantly overlapped, thus solely using morphometrics may not separate the two species. Counts of intestinal spiral valves (14–16 vs. 16–20 in A. platyrhynchus; Nakaya & Kawauchi 2013), monospondylous vertebrae (32–34 vs. 33–40), and precaudal diplospondylous vertebrae (34–37 vs. 37–45) may separate the two species, but the values still overlap slightly. Nevertheless, the two species can be readily distinguished by several aspects: iris shiny white when fresh in A. nakayai (vs. black in A. platyrhynchus); body brownish black to black (vs. light to dark brown); second dorsal-fin insertion above or slightly in front of the anal-fin insertion (vs. well before the anal-fin insertion); denticles absent inside mouth (vs. present in specimens larger than 500 mm TL); and maturing at about 400 mm TL in both sexes (maturing size larger than 550 mm TL) (Data of A. platyrhynchus are modified from Nakaya & Kawauchi 2013). The specimens from the South China Sea are mostly consistent with the holotype of A. nakayai in morphometrics, but are slightly different in counts. For example, the holotype has slightly more monospondylous centra (36, Iglésias 2012 vs. 32–34); and higher tooth counts (79/72, Iglésias 2012 vs. 61–73/56–60). The difference may be attributed to intraspecific or geographical variations, which require more specimens from different localities to confirm. In addition, the sole female specimen (NMMB-P36993) differs from the male specimens by lacking a naked space at symphysis of lower jaw (Fig. 4), which may be a character of sexual dimorphism. Apristurus nakayai was formerly known from three specimens, one from New Caledonia (Iglésias 2012), and two from Papua New Guinea (White et al. 2017; Ebert et al. 2021). The occurrence of A. nakayai in the South China Sea is very far away (ca. 4665 km) from its previous record in Papua New Guinea (White et al. 2017), which is also the first record in the northern hemisphere. Most of the Apristurus species show high level of endemism, which are often confined to one single ocean region, with only a few exceptions (e.g., A. macrostomus, A. melanoasper, A. laurussonii, A. platyrhynchus; Ebert et al. 2021). In addition, no evidence shows that the deepwater catsharks, including genus Apristurus, have large scale horizontal migration or high dispersal ability.. This example suggests that at least some Apristurus species may have a much wider distributional range than previously recognized. Further exploration of remote deepsea habitats may further elucidate the distribution of deepsea chondrichthyans, including those of the genus Apristurus. Materials examined. A. nakayai: EBFS 00138, 425 mm TL, adult male, NMMB-P 36993, 408 mm TL, adult female, NMMB-P 36994, 451 mm TL, adult male, NMMB-P 36995, 415 mm TL, adult male, NMMB-P 36996, 424 mm TL, adult male, NMMB-P 36997, 435 mm TL, adult male, ca. 19°N, 114°E, off western Dongsha Atoll, South China Sea, ca. 500 m depth, bottom trawl, 12 May 2022., Published as part of Ng, Shing-Lai, Liu, Kwang-Ming & Joung, Shoou-Jeng, 2023, Occurrence of the milk-eye catshark Apristurus nakayai (Carcharhiniformes: Pentanchidae) from the South China Sea, pp. 51-60 in Zootaxa 5244 (1) on pages 52-59, DOI: 10.11646/zootaxa.5244.1.4, http://zenodo.org/record/7645767, {"references":["Iglesias, S. P. (2012) Apristurus nakayai sp. nov., a new species of deepwater catshark (Chondrichthyes: Pentanchidae) from New Caledonia. Cybium, 36 (4), 511 - 519.","White, W. T., Mana, R. R. & Naylor, G. J. P. (2017) Description of a new species of deepwater catshark Apristurus yangi n. sp. (Carcharhiniformes: Pentanchidae) from Papua New Guinea. Zootaxa, 4320 (1), 25 - 40. https: // doi. org / 10.11646 / zootaxa. 4320.1.2","Ebert, D. A., Dando, M. & Fowler, S. (2021) Sharks of the World: A complete guide. Princeton University Press, Princeton, New Jersey, 607 pp. https: // doi. org / 10.1515 / 9780691210872","Nakaya, K. & Sato, K. (1999) Species grouping within the genus Apristurus (Elasmobranchii, Scyliorhinidae). In: Seret, B. & Sire, J. Y. (Eds.), Proceedings of the Indo-Pacific Fish Conference, Noumea. Societe Francaise d'Ichtyologie & Institut de Recherche pour le Developpement, Paris, pp. 307 - 320.","Nakaya, K. & Kawauchi, J. (2013) A review of the genus Apristurus (Chondrichthyes: Carcharhiniformes: Scyliorhinidae) from Taiwanese waters. Zootaxa, 3752 (1), 130 - 171. https: // doi. org / 10.11646 / zootaxa. 3752.1.9"]}

Iago garricki Fourmanoir & Rivaton, 1979 Figs. 1–5; Table 1 Iago garricki Fourmanoir & Rivaton, 1979: 434, figs. 22 (Efate, Vanuatu, western-central Pacific Ocean). Compagno 1984: 395–396; Last & Stevens 1994: 212–213; White et al. 2006: 190–191; White et al. 2018: 120–121 Ebert et al. 2021: 475. Materials examined. Holotype. MNHN-IC-1978-0694, 620 mm TL, mature female, 17°05’S; 167°05’E, Vanuatu, Coral Sea, 350 m depth, 1978. Non-types. MHNH-IC- 1997-3572, 508 mm TL, adult male, 16°65’S; 168°02’E, Vanuatu, western-central Pacific Ocean, 541–577 m depth, 1994. MHNH-IC- 2008-1304, 244 mm TL, juvenile male, 15°69’S; 167°01’E, Vanuatu, western-central Pacific Ocean, 509–659 m depth, 2006. MHNH-IC- 2008-1346, 250 mm TL, juvenile female, 15°68’S; 167°01’E, Vanuatu, western-central Pacific Ocean, 503–600 m depth, 2006. ASIZP 81240, 280 mm TL, juvenile female, ca. 19°N, 114°E, off western Dongsha Atoll, South China Sea, ca. 300 m depth, bottom trawl, 19 February 2021, coll. Y.- T. Lee. ASIZP 81241, 435 mm TL, adult male, NMMB-P 36356, 495 mm TL, adult male, NMMB-P 36357, 500 mm TL, adult male, ASIZP 81242, 515 mm TL, adult male, ca. 19°N, 114°E, off western Dongsha Atoll, South China Sea, ca. 300 m depth, bottom trawl, 19 February 2021, coll. C.-H. Lin. Diagnosis. A species of Iago with a long, narrow snout, preoral length 35.1% (34.9–38.7%) head length; eye large, length 18.5% (17.0–24.1%) head length; gill slit rather short, the first gill slit height 47.8% (31.4–51.6%) eye length; anterolateral teeth straight to slightly oblique, blade-like, with 1–3 broad, smooth distal cusplets (Fig. 4c); first dorsal-fin origin not reaching a vertical line through pectoral-fin base; caudal-fin ventral lobe moderately developed in adults; body color generally grey, with faint dark edges on dorsal-fin apexes, more prominent in juveniles (Fig. 2). Description. Morphometric data are provided in Table 1. The following data are provided for the holotype, followed by the range of measured or counted non-types in parentheses. ......Continued on the next page TABLE 1. (Continued) ......Continued on the next page TABLE 1. (Continued) Body subtriangular in cross-section at first dorsal-fin base; pectoral–pelvic space 19.0% (18.1–24.1%) TL, pelvic–caudal space 28.8% (23.9–28.1%) TL; second dorsal-fin origin to anal-fin origin 88.4% (66.7–99.1%) analfin base length; anal–caudal space 20.5% (16.1–18.2%) preanal length; a distinct hump present at dorsal profile above pectoral fins in holotype (hump absent in other non-types); interdorsal and postdorsal ridge absent. Caudal peduncle long, slender, elliptical in cross-section, tapering towards caudal fin, without lateral keels; height 128% (129–252%) width at upper caudal-fin origin, 25.0% (17.5–38.2%) dorsal–caudal space. Precaudal pits absent. Head length 108% (90.5–112%) pectoral–pelvic space; head slightly depressed, rather flat in lateral view, slightly convex over eye, slightly concave on preorbital snout, post-oral head straight. Snout tip narrowly rounded in dorsoventral view; moderately pointed in lateral view, narrowly rounded in ventral view in both juveniles and adults (Fig. 3); preoral snout 35.1% (34.9–38.7%) head length. Eyes elliptical, large, eye length 18.5% (17.0–24.1%) head length; positioned laterally on head; fleshy subocular ridges vestigial; anterior notch absent, posterior notch not prominent; nictitating lower eyelids external; subocular pouches shallow, scaled with secondary lower eyelids. Spiracles very small, bean-shaped, positioned below middle of eye. Gill slits rather short; first and second gill slits tallest, fifth shortest; height of the fifth 74.8% (56.8–87.8%) height of the first; height of the first 8.8% (7.6–9.2%) head, 47.8% (31.4–51.6%) eye length. Upper margin of gill slits barely reaching a horizontal line through lower margins of eyes. Nostrils moderately large, with circular incurrent apertures; well separated from mouth; width 57.8% (45.5– 79.5%) internarial space, 43.9% (33.3–61.5%) eye length, 91.9% (80.0–137%) in first gill slit height; excurrent apertures small, bean-shaped; anterior nasal flaps broadly triangular, large; mesonarial flaps and posterior nasal flaps poorly developed. Mouth considerably arched (less arched in juveniles), width 36.9% (25.7–41.6%) head length; length 48.5% (37.1–65.5%) width; tongue very large, flat, blunted apically, covering almost the entire floor; buccal papillae absent, buccopharyngeal denticles present on anterior part of the palate to the level of spiracle. Labial furrows moderately elongate; lower furrows distinctly shorter than upper furrows, length 71.6% (39.2–91.9%) length of upper furrows; length of upper furrows 73.6% (58.7–91.3%) mouth length; anterior tip of upper furrows anterior to vertical mid-orbit, reaching about level of lower jaw symphysis. Teeth including symphysials in 50/44 (43–54/36–41) rows, 2–4 series functional. Tooth formula of upper jaw 24+3+23 (20–25+1–4+20–25), lower jaw 22+1+21 (18–20+1–2+17–20). Teeth not arranged in diagonal files, no toothless spaces at symphysis. Tooth size similar between jaws, but different in shape between and along jaws (Fig. 4). Symphyseal teeth in upper jaw only slightly smaller than anterolateral teeth, with erect, slender, symmetrical cusp, notched medially and laterally, medial and lateral margins smooth, moderately notched (Fig. 4A). Anterolateral teeth in upper jaw with somewhat broad, straight to slightly oblique, blade-like cusps; mesial margins weakly convex basally, straight distally; 1–3 broad, smooth distal cusplets present; both margins and basal cusplets without serrations (Fig. 4C). Lateral teeth in upper jaw becoming more oblique gradually towards posterolateral side. Symphyseal teeth size in lower jaw same as anterolateral teeth (Fig. 4B). Anterolateral teeth shape in lower jaw similar to upper jaw, but with straight cusps, becoming somewhat oblique gradually towards posterolateral side (Fig. 4D). Lateral trunk denticles below first dorsal fin small and imbricated; crowns narrowly pointed distally; apices narrowly pointed; crowns with 2–4 longitudinal ridges; no prominent reticulations on crown; crown length much longer than width (Fig. 5). Pectoral fins triangular; subequal or slightly larger than first dorsal fin; anterior margin straight; posterior margin 78.6% (58.9–79.6%) anterior margin; base narrow, its length 30.4% (29.6–41.2%) anterior margin; apex broadly rounded; posterior margin moderately concave; free rear tips broadly round; inner margins straight; origin under fourth gill opening to midway between fourth and fifth gill openings. Pelvic fins very narrowly subtriangular; anterior margin somewhat convex, 33.8% (36.2–42.3%) pectoral-fin anterior margin; apex very broadly rounded; posterior margin concave; free rear tip acutely pointed; inner margins straight. Claspers of four adult males long, slender and narrow-based; length (56.8–82.0%) pelvic-anal space; apex narrowly rounded, extending to near midway of pelvic-anal space. First dorsal fin falcate; anterior margin concave basally, slightly convex distally; apex narrowly rounded (broadly rounded in juveniles); posterior margin deeply concave to the free rear tip; free rear tip narrowly pointed; inner margin straight; origin reaching a vertical line through anterior half of middle pectoral-fin inner margin, before pectoral-fin base; free rear tip slightly posterior to midway between pectoral-fin base and pelvic fin origin; insertion about opposite to pectoral fin apex; first dorsal-fin base 29.7% (28.1–40.5%) interdorsal space, 71.1% (54.6–95.2%) dorsal–caudal-fin space; fin height 70.8% (68.6–93.5%) base length; inner margin 39.4% (47.4–84.3%) height, 27.9% (37.5–68.7%) base length. Second dorsal fin slightly falcate, smaller than the first dorsal fin, height 74.5% (48.9–86.1%) first dorsal-fin height, base length 76.4% (56.6–107%) first dorsal-fin base length; anterior margin slightly concave basally, straight distally; apex narrowly rounded (broadly rounded in juveniles); posterior margin upright, deeply concave before the free rear tip; free rear tip pointed, terminating barely anterior to anal-fin free rear tip; inner margin straight; origin slightly anterior to anal-fin origin; insertion well posterior to fin apex, opposite to anal-fin insertion; second dorsalfin base length 54.4% (40.8–81.0%) dorsal–caudal space; height 69.1% (57.0–77.5%) base length; inner margin 77.2% (35.8–67.9%) height, 53.4% (26.6–39.9%) base length. Anal fin low and weakly falcate, about half of second dorsal fin; height 69.1% (35.8–62.3%) second dorsalfin height, base length 82.6% (62.4–96.1%) second dorsal-fin base length; anterior margin weakly convex; apex broadly rounded; posterior margin concave; free rear tip short, narrowly pointed, well separated from lower caudalfin origin; inner margin straight; insertion nearly opposite to fin apex, just posterior to second dorsal-fin insertion; anal-fin base length 40.8% (40.6–61.4%) anal–caudal space; fin height 57.8% (27.7–69.6%) base length; inner margin 78.8% (39.7–93.3%) height, 45.6% (27.7–53.8%) base length; preanal ridges and grooves absent. Caudal fin asymmetrical, upper lobe moderately narrow; terminal lobe enlarged, ventral lobe narrow, moderately developed in adults, weakly developed in juveniles; dorsal margin moderately long, 28.8% (27.6–33.3%) precaudal length, nearly straight to weakly convex, slightly concave above terminal lobe, without lateral undulations; preventral margin slightly convex, 73.3% (59.2–83.3%) in dorsal–caudal space, apex broadly rounded; lower postventral margin very short, moderately concave; upper postventral margin slightly concave anteriorly, slightly convex near subterminal notch; subterminal notch very short; subterminal margin weakly convex, terminal margin nearly straight to slightly convex; subterminal margin length 67.1% (71.8–88.5%) terminal margin length; terminal lobe margins straight to slightly concave; terminal lobe length 75.7% (63.6–73.8%) dorsal-caudal margin. Total vertebral centra 156 (149–157), precaudal centra 98 (94–102), monospondylous centra 41 (39–42), diplospondylous precaudal centra 57 (53–61). Coloration. When fresh, grey to brownish grey dorsally, gradually becoming paler ventrally. In adults, dorsal fins dusky, with narrow dark edges on apexes; dark blotches on dorsal-fin apexes present in juveniles. Caudal fin generally greyish brown with narrow white margins on terminal and lower lobe; weak black edges on dorsal margin, more prominent in juveniles; anal fin dusky, with inconspicuous white margin on apex; pectoral fins mostly dusky, with narrow dark edges on anterior margins; posterior margins somewhat whitish; pelvic fins uniformly dusky, without any dark edges; ventral surface completely white. In preservative, eyes white, others very similar to fresh color. Size. To about 750 mm TL (Fourmanoir & Rivaton 1979). Length-at-birth is estimated approximately 280 mm TL, given the presence of umbilical scar in the small specimens (ASIZP 81240). Distribution. Known from Indo-Pacific, from the South China Sea to northwestern and northeastern Australia, including Indonesia, the Philippines, Papua New Guinea and Vanuatu. Bathymetric range 250– 659 m.The occurrence of I. garricki from the South China Sea represents the northernmost distributional record (ca. 700 km northward extension from the Philippines). Ecology. Stomach contents of one specimen (ASIZP 81242) and six adult males (470–500 mm TL, not retained) included small Macrouridae (Hymenocephalus sp., Nezumia sp., Ventrifossa spp.), crustaceans (Penaeoidea, Munidae) and cephalopods. This species is assumed benthic and has a generalist diet. Remarks. Fourmanoir & Rivaton (1979) described I. garricki based on five specimens. One of the specimens was designated as holotype and preserved in MHNH, but the whereabouts of other specimens is unknown. A search for those paratypes in MHNH by HCH was unsuccessful. Iago garricki can be distinguished from its only congener, I. omanensis, by having a shorter head, its length 20.2–22.2% TL (vs. 23.0–27.5% TL) and longer upper labial furrow (2.2–3.4% TL, vs. 1.1–2.0% TL). The two species can further be separated by the preoral length, which is slightly longer in I. garricki (7.2–8.3% TL, vs. 5.7–7.6% TL in I. omanensis), although the values slightly overlap. The shape of lateral teeth is also unique in I. garricki, in which small cusplets on lateral side present basally (vs. cusplets absent in I. omanensis). Vertebral count also separates the two species, I. garricki has more diplospondylous centra (53–61, vs. 45–52 in I. omanensis), more precaudal centra (94–102, vs. 81–91), and more total centra (149–157, vs. 129–147) (data taken from Compagno & Springer, 1971). According to Ebert et al. (2021), I. garricki is further distinguished from I. omanensis by having much smaller gill slits, their length smaller than eye length (vs. longer than eye length in I. omanensis), and the first dorsal-fin origin over pectoral-fin inner margin (vs. situated well over the pectoral-fin base). Geographically, the distribution of I. garricki does not overlap with that of I. omanensis, the former is restricted to the western Pacific and the southeastern Indian Ocean, while the latter occurs in the northern Indian Ocean, including the Red Sea. Although having similar morphometrics, juveniles of I. garricki generally process broader dorsal-fin tips, a less arched mouth, and a poorly developed caudal-fin ventral lobe when compared to adults. Juveniles have large dark blotches on the dorsal fins (vs. only narrow dark margins present on fin edges in adults), and prominent black edges on caudal fin dorsal margin (vs. poorly-defined black edges present in adults). Difference in morphometrics and counts between the holotype and the other non-types are observed. For example, the holotype has three more lower jaw teeth than the other non-types. Some morphometrics (e.g. first dorsal-fin height, caudal-fin proportions) of the holotype are also not within the range of the non-types. Furthermore, the holotype processes a distinct hump on the dorsal profile above pectoral fins, but it was not observed in other examined specimens. The hump is not likely a result of preservation condition, as it already existed when fresh (Fourmanoir & Rivaton 1979: fig. 22a). We assume the difference as sexual dimorphism, mature female processes a humped dorsal profile above pectoral fins, and may have difference in morphometrics and counts. Since only one mature female (the holotype) was examined, however, it warrants further investigation given the smaller size of other examined male specimens comparing to the holotype., Published as part of Ng, Shing-Lai, Ho, Hsuan-Ching, Liu, Kwang-Ming & Joung, Shoou-Jeng, 2022, Redescription of the longnose houndshark Iago garricki (Carcharhiniformes Triakidae), based on specimens recently collected from the South China Sea, pp. 67-77 in Zootaxa 5189 (1) on pages 68-76, DOI: 10.11646/zootaxa.5189.1.9, http://zenodo.org/record/7119763, {"references":["Fourmanoir, P. & Rivaton, J. (1979) Poissons de la pente recifale externe de Nouvelle-Caledonie et des Nouvelles-Hebrides. Cahiers de l'Indo-Pacifique, 1 (4), 405 - 443.","Compagno, L. J. V. (1984) Sharks of the world: an annotated and illustrated catalogue of shark species known to date: FAO Species Catalogue, volume 4, sharks of the world, part 2, carcharhiniformes. In: Fischer, W. & Nauen, C. E. (Eds.), FAO Fisheries Synopsis, Italy. United Nations Development Programme","Last, P. R. & Stevens, J. D. (1994) Sharks and rays of Australia. CSIRO Publishing, Melbourne, Australia, 513 pp. https: // doi. org / 10.2307 / 1446735","White, W. T., Last, P. R., Stevens, J. D., Yearsly, G. K., Fahmi & Dharmadi (2006) Economically important sharks and rays of Indonesia. Australian Centre for international Agricultural research, Canberra, Australia, 329 pp.","Ebert, D. A., Dando, M. & Fowler, S. (2021) Sharks of the world: a complete guide. Princeton University Press, Princeton, New Jersey, United States, 607 pp. https: // doi. org / 10.1515 / 9780691210872","Compagno, L. J. V. & Springer, S. (1971) Iago, a new genus of carcharhinid sharks, with a redescription of I. omanensis. Fishery Bulletin, 69 (3), 615 - 626."]}