Pristipomoides amoenus ( Snyder, 1911 )

Nakagawa, Ryuichi, Sakurai, You & Motomura, Hiroyuki, 2022, Distributional Range Extension of the Pale Ornate Jobfish Pristipomoides amoenus (Teleostei: Perciformes: Lutjanidae) in the Western Pacific Ocean, with Notes on Newly Recognized Diagnostic Coloration, Species Diversity 27 (1), pp. 15-23 : 16-19

publication ID	https://doi.org/ 10.12782/specdiv.27.15
DOI	https://doi.org/10.5281/zenodo.13934840
persistent identifier	https://treatment.plazi.org/id/1C4F3676-FA20-8101-FEFA-92A2FB31DAFF
treatment provided by	Felipe
scientific name	Pristipomoides amoenus ( Snyder, 1911 )
status

Treatment

Pristipomoides amoenus ( Snyder, 1911) View in CoL

[English name: Pale Ornate Jobfish; standard Japanese name: Usuhanafuedai]

( Figs 1A–C View Fig , 2A–D View Fig , 3 View Fig , 4 View Fig ; Table 1 View Table 1 )

Platyinius amoenus Snyder, 1911: 530 (type locality: Naha , Okinawa-jima island, Japan).

Pristipomoides argyrogrammicus (not of Valenciennes in Cuvier and Valenciennes 1832): Nakae et al. 2018: 285 [in part, Amami-oshima island, Kagoshima, Japan; 1 (KAUM–I. 108165) of 7 listed specimens]; Hata 2019: 169, unnumbered fig. [Amami-oshima island, Kagoshima, Japan; KAUM–I. 108165 (erroneously given as 10865)]; Tanaka 2019: unnumbered figs (Dong-gang, Pingtung, Taiwan; NMMB-P11951, KAUM–I. 113361).

Pristipomoides amoenus: Shimose et al. 2020: 472 , figs 1B, 2B, 3, (Okinawa-jima and Ishigaki-jima islands, Okinawa, Japan); Shimose 2021: 99, fig. K (Yaeyama Islands).

Material examined. 14 specimens (149.0– 221.2mm SL) from the western Pacific Ocean . JAPAN: KAUM–I. 108165, 212.2 mm SL, off Amami-oshima island , Amami Islands, Kagoshima , 28°28′N, 129°28′E, purchased at Naze Fish Landing Port, 29 May 2017, T. Maekawa ; GoogleMaps KAUM–I. 156090, 201.2 mm SL, KAUM–I. 156091, 177.3 mm SL, KAUM–I. 156093, 221.2 mm SL, off Amami-oshima island, Amami Islands, Kagoshima , 28°28′N, 129°28′E, purchased at Naze Fish Landing Port, 22 February 2021, T. Maekawa GoogleMaps ; KAUM–I. 68343 186.0 mm SL, southern Ryukyu Islands, purchased at Iyumachi fish market, Tomari, Naha, Okinawa-jima island , 31 July 2014, Y. Sakurai ; KAUM–I. 141847 186.7 mm SL, KAUM–I. 141848 161.7 mm SL, KAUM–I. 141849, 182.2 mm SL, southern Ryukyu Islands, purchased at Iyumachi fish market, Tomari, Naha, Okinawajima island , 4 February 2020, Y. Sakurai ; KAUM–I. 144671, 196.7 mm SL, KAUM–I. 144672, 189.8 mm SL, KAUM–I. 144673, 194.6 mm SL, southern Ryukyu Islands, purchased at Iyumachi fish market, Tomari, Naha, Okinawa-jima island , 25 June 2020, Y. Sakurai . TAIWAN: KAUM–I. 113361, 184.7 mm SL, off Dong-gang , Pingtung, 22°39′N, 120°24′E, 10 March 2018, line-fishing, K. Koeda and H. Hata GoogleMaps . PHILIPPINES: UPVMI. 2410, 149.0 mm SL, purchased at Miagao Fish Market , Miagao, Iloilo, Visayas, 4 July 2018, J. Okamoto . FIJI: KAUM–I. 14938, 182.7 mm SL, off Suva, Viti Levu Island , 18°17′S, 178°21′E, 2–4 January 1982 GoogleMaps .

Revised diagnosis. A species of Pristipomoides , characterized by the following characters: pored lateral-line scales 59–63; body moderately deep 32.1–36.5% of SL; lower gill rakers 9–11 (mode 10), including 8–10 (9) rod-shaped rakers; body color pale pink dorsally, silvery-white ventrally, with five yellow saddles, usually not extending below lateral line; a few small silvery-blue blotches inside yellow saddles; small silvery-blue blotches below lateral line on trunk absent or indistinct; distinct line formed by small silvery-blue blotches absent on lower caudal peduncle; a large silveryblue blotch on upper opercle extending anteriorly beyond preopercular margin; a line formed by small silvery-blue blotches on upper caudal peduncle ending at upper caudalfin base; a pair of lines formed by small silvery-blue blotches along dorsal-fin base (dorsal view); a larger pair of elliptical silvery-blue blotches on occipital region (all silvery-blue blotches retained as dark-brown blotches after preservation); no distinct white margins on dorsal and anal fins.

Description. Counts and measurements, expressed as percentages of SL, are given in Table 1 View Table 1 . Morphological and color characters given in Diagnosis not repeated here. Body laterally compressed. Upper profile of head slightly convex; dorsal outline rather more strongly curved than ventral; ventral outline evenly curved. Nostrils close together; anterior nostril opening elliptical, with flap; posterior nostril opening elliptical, located on anterior of orbit. Interorbital space moderately wide, flattened. Occipital region convex. Mouth terminal, oblique; posterior tip of maxilla extending beyond level of anterior margin of pupil, but not below middle of eye; maxilla mostly covered by cheek. Enlarged conical teeth anteriorly on upper jaw; small conical teeth in outer row on mid-lateral part of upper jaw; 3 or 4 pairs of conical teeth on lower jaw; villiform teeth on inner row of upper and lower jaws, vomer and palatines. Tongue naked. Opercle and subopercle scaled, flattened without spines. Interopercle naked; posterior margin of lower interopercle serrated. Eight enlarged scales from occipital region to above opercle. Body scales ctenoid; scales absent on snout, interorbital space and maxilla; dorsal, anal, pelvic and pectoral fins naked; small dense scales on caudal-fin rays. Lateral line complete.

Origin of dorsal fin above posterior tip of opercle; dorsal fin continuous, not deeply incised near junction of spinous and rayed portions; fourth dorsal-fin spine longest, last dorsal-fin soft ray elongate; end of dorsal-fin base slightly posterior to end of anal-fin base. Origin of anal fin below second or third dorsal-fin soft ray; first anal-fin spine half height of second spine; third anal-fin spine longer than second; anal-fin soft rays longer than anal-fin spines; last analfin soft ray elongate. Caudal fin homocercal, deeply forked. Pectoral fin pointed, fifth ray longest, reaching to vertical through anus. Origin of pelvic fin slightly posterior to dorsal fin origin; depressed pelvic fin not reaching anus.

Coloration when fresh ( Fig. 1A–C View Fig ). Body pinkish, with yellow saddles and small silvery-blue blotches dorsally. Snout pink; interorbital space slightly yellowish. Small elliptical silvery-blue blotch behind dorsoposterior margin of orbit. Pectoral, pelvic, and anal fins semi-transparent pink to yellowish-white. Spinous portion of dorsal fin yellow dorsally, remaining portions of dorsal fin semi-transparent yellowish-white. Caudal fin yellow, with pinkish margin on lower lobe.

Coloration of preserved specimens ( Fig. 2A–D View Fig ). Body yellowish pale-brown, with numerous small dark brown blotches dorsally. Fins semi-transparent white.

Distribution. Widely distributed in the western Pacific Ocean; recorded from Japan (Amami-oshima, Okinawajima, and Ishigaki-jima islands), Taiwan (Dong-Gang, Pingtung), the Philippines (Iloilo, Panay Island), and Fiji (Viti Levu Island) ( Snyder 1911; Shimose et al. 2020; Shimose 2021; this study; Fig. 4 View Fig ).

Remarks. The present specimens were identified as Pristipomoides amoenus due to the moderately deep body (33.9–36.5% of SL), X, 11 dorsal-fin rays, III, 8 anal-fin rays, 15 or 16 pectoral-fin rays, 60–63 pored lateral line scales, and 9–11 lower gill rakers (including 7–9 rod-shaped rakers), thereby agreeing with characters given for the species by Shimose et al. (2020). Morphometrics of the present specimens were also generally consistent with those given by Shimose et al. (2020) ( Table 1 View Table 1 ).

Among its congeners, P. amoenus is most similar to P. argyrogrammicus ( Figs 1D–F View Fig , 2E–H View Fig , 5 View Fig ), from which it can be distinguished by having 9–11 lower gill rakers, including 8–10 rod-shaped rakers (vs. 11–14 lower gill rakers, including 9–11 rod-shaped rakers in the latter). In addition, a pairwise nucleotide difference of 2.6–3.5% between the two species has been established, based on a dataset of 575 bp sequences from the mitochondrial COI region ( Shimose et al. 2020). Shimose et al. (2020) also suggested that P. amoenus was distinguishable from P. argyrogrammicus in lacking a white margin on the dorsal, anal, and caudal fins (vs. white margin present in the latter), and having small blue blotches (usually retained as brown blotches in preserved specimens) within the yellow body saddles (vs. blue blotches absent). However, the tip and/or margin of the caudal fin’s lower lobe and anal fin of P. amoenus are sometimes white ( Fig. 1A–C View Fig ), whereas the posterior margin of the caudal fin yellowish individuals of P. argyrogrammicus is not ( Fig. 1F View Fig ), suggesting that the fin color feature may be unreliable for separating the two species. The presence of small blue blotches within the yellow body saddles in Shimose et al. (2020) is confirmed here as a valid character for separating P. amoenu s from P. argyrogrammicus ( Figs 1–3 View Fig View Fig View Fig , 5 View Fig ).

Our examinations of specimens and photographs of the two species revealed that they could be distinguished from one another by the following newly recognized color features: small silvery-blue blotches below the lateral line on the trunk absent or indistinct in P. amoenu s ( Figs 1A–C View Fig , 2A–C View Fig , 3A View Fig ) vs. distinctly present in P. argyrogrammicus ( Figs 1D–F View Fig , 2E–G View Fig , 5A, C View Fig ); a distinct line formed by small silveryblue blotches absent on the lower caudal peduncle ( Figs 1A–C View Fig , 2A–C View Fig , 3A View Fig ) vs. distinct line present ( Figs 1D–F View Fig , 2E–G View Fig , 5A, C View Fig ); a large silvery-blue blotch on the upper opercle extending anteriorly beyond the preopercular margin ( Figs 1A–C View Fig , 2A–C View Fig , 3A View Fig ) vs. a small blotch not reaching to the preopercular margin ( Figs 1D–F View Fig , 2E–G View Fig , 5A, C View Fig ); a line formed by small silvery-blue blotches on the upper caudal peduncle ending at the upper caudal-fin base ( Figs 1A–C View Fig , 2A–C View Fig , 3A View Fig ) vs. extending onto the upper margin of the caudal-fin upper lobe ( Figs 1D–F View Fig , 2E–G View Fig , 5A, C View Fig ); a pair of lines formed by small silvery-blue blotches along the dorsal-fin base (dorsal view) ( Figs 2D View Fig , 3B View Fig ) vs. usually 3 clusters of silvery-blue blotches ( Figs 2H View Fig , 5B View Fig ), distinctly retained as dark-brown blotches in preserved specimens ( Fig. 2 View Fig ). In addition, a pair of small elliptical silvery-blue blotches on the occipital region of P. amoenu s ( Figs 2D View Fig , 3B View Fig ) were larger than those of P. argyrogrammicus ( Figs 2H View Fig , 5B View Fig ).

Although Shimose et al. (2020) noted that a greater eye diameter, deeper caudal peduncle, and shorter pelvic and anal fins may also distinguish between P. amoenus and P.argyrogrammicus , an analysis of those morphometrics in this study showed no significant differences between the two species ( Table 1 View Table 1 ).

An Amami-oshima specimen (KAUM–I. 108165, 212.2 mm SL), previously identified as P. argyrogrammicus by Nakae et al. (2018) and Hata (2019; erroneously referred to as KAUM–I. 10865), and two Taiwanese specimens (KAUM–I. 113361, 184.7 mm SL; NMMB-P 11951, 91 mm SL), previously identified as P. argyrogrammicus by Tanaka (2019), were all identified here as P. amoenus , which has previously been recorded only from Okinawa-jima and Ishigaki-jima islands (both Okinawa Prefecture), southern Ryukyu Islands, Japan ( Snyder 1911; Shimose et al. 2020; Shimose 2021). The present specimens from Amami-oshima island (Kagoshima Prefecture, Japan), Dong-gang (Taiwan), Iloilo ( Philippines) and Viti Levu Island ( Fiji) represent the first records of P. amoenus from outside Okinawa Prefecture, the Amami-oshima specimens being the northernmost record for the species and the Fijian specimen, the first record from the Southern Hemisphere.