Parascolopsis akatamae n. sp.

[English name: Rosy dwarf monocle bream; Standard Japanese name: Aka-tamagashira]

(Figs. 1A, 2 A–D, 3, 4A–C, 5, 6; Table 1)

urn:lsid:zoobank.org:act: 6A75C237-9692-4539-B577-C2E4B3D492B8

Scolopsis eriomma (not of Jordan & Richardson 1909); Akazaki 1984: 169, Pl. 164-D (southern Japan).

Parascolopsis eriomma: Russell 1990: 69, Pl. IV-c (Okinawa, Japan); Russell 2001: 3081, Pl. XXII, 166 (Okinawa, Japan); Nalk et al. 2002: 73, fig. 1 (Goa, India); Shibukawa et al. 2003: 102, unnumbered color photograph (Sulawesi, Indonesia); Motomura & Matsuura 2010: 124, fig. 228 (Yaku-shima Island, Japan); White et al. 2013: 226, fig 75.15 (south eastern Indonesia); Kannan et al. 2013: fig. 1 (Tuticorin, India); Jawad & Al-Badri 2014: 186, fig. 2 (Iraqi); Hung et al. 2017: 11, fig. S3H (Taiwan); Fujiwara 2017: 148, color photograph of UPVMI 182 (Panay Island, Philippines).

Holotype. OCF-P 4098, 160 mm SL, off Motobu, Okinawa-jima Island, southern Japan (26º38′27′′N, 127º45′39′′E), 200 m depth, 31 May 2019, fishing, coll. A. Kaneko, Y. Oshiro and K. Miyamoto.

Paratypes (10 specimens, 150.1–270.8 mm SL). KAUM–I. 55567–55569, 3 specimens, 260.0– 270.8 mm SL, off Tokara Islands, southern Japan (29º34′N, 129º38′E),> 100 m depth, 19 July 2013, line-fishing, coll. M. Mat- sunuma; FMNH 120979, 189.0 mm SL, Hengchun fish market, Pingtung, southern Taiwan, coll. H. C. Ho, W. L. Smith, C. C. Jones and H. J. Walker; FRLM 26347, 153.1 mm SL, Bitung fish market, North Sulawesi, Indonesia, 22 Oct. 2000, coll. S. Kimura and T. Peristiwady; FRLM 26423, 150.1 mm SL, Bitung fish market, North Sulawesi, Indonesia, 22 Oct. 2000, coll. S. Kimura and T. Peristiwady; MUFS 12090, 223.0 mm SL, Meitsu, Miyazaki, Japan, 24 Apr. 1996; OCF-P3726, 166.0 mm SL, off Motobu, Okinawa-jima Island, southern Japan (26º38′32′′N, 127º45′40′′E), 200 m depth, 28 Sep. 2017, fishing, coll. A. Kaneko, Y. Oshiro and K. Miyamoto; OCF-P 3875, 218.5 mm SL, off Ishigaki-jima Island, southern Japan, 16 Jan. 2018, coll. T. Shimose; OCF-P 4211, 152.4 mm SL, off Motobu, Okinawa-jima Island, southern Japan, 26 Sep. 2019, coll. A. Kaneko and H. Hirose.

Non-type specimens (33 specimens, 98.3–278.8 mm SL). KAUM–I. 55852, 245.0 mm SL, off Amami-oshima Island, Japan; KAUM–I. 99341, 252.1 mm SL, southern Ryukyu Islands from the Amami to Yaeyama islands, Japan; KAUM–I. 108195, 225.9 mm SL, off Amami-oshima Island, Japan; FRLM 53348, 260.0 mm SL, off Kuchinoerabu-jima Island, Japan; MUFS 4406, 231.6 mm SL, Naha, Okinawa, Japan; MUFS 11800–11802, 3 specimens, 181.2–186.2 mm SL, Yakushima Island, Japan; MUFS 20220 and 20221, 2 specimens, 262.6 and 278.8 mm SL, Kagoshima, Japan; OCF-P20140418- 8, 212.2 mm SL, female, off Okinawa-jima Island, Japan; OCF-P2982, 121.0 mm SL, male, off Motobu, Okinawa-jima Island, Japan; OCF-P3723–3725, 3 specimens, 2 males and 1 female, 113.8–172.6 mm SL, off Motobu, Okinawa-jima Island, Japan; OCF-P4071 and 4072, 2 specimens, 140.1 and 159.0 mm SL, off Okinawa-jima Island, Japan; OCF-P4088 and 4089, 2 specimens, 227.0 and 252.7 mm SL, near Ishigaki-jima Island, Japan; OCF-P4119–4127, 9 specimens, 98.3–202.2 mm SL, off Motobu, Okinawa-jima Island, Japan; URM-P 29321, 146.7 mm SL, Phuket fish market, Thailand; URM-P 35549, 219.6 mm SL, Okinawa-jima Island, Japan; URM-P 42478, 240.5 mm SL, Yoron-jima Island, Japan; URM-P 43747, Kagoshima, Japan; URM-P 44587, Nakagusuku Bay, Okinawa-jima Island, Japan.

Diagnosis. Distinguished from congeners by the following combination of characters: gill rakers on first arch 16–19; caudal fin lightly forked, length of forked part of caudal fin 5.8–6.5 times in SL (Figs. 1A, 2 A–D, 3A); eye diameter 1.3–1.8 times in length of longest dorsal-fin spine (Fig. 3B); pale yellow stripe present from lower edge of the eye to posterior edge of the preopercle (Figs. 1A, 2 A–D); strong biofluorescence emission observed on isthmus and branchiostegal membrane (Fig. 4 A–C) (see paragraph of biofluorescence emission patterns).

Description. Counts and proportional measurements are presented in Table 1. Body moderately deep, deepest at pelvic-fin base, depth 2.5–3.2 times in SL; head moderate, 3.0–3.5 times in SL; snout short, length less than diameter of eye, 3.6–5.2 times in HL; nostrils small, anterior and posterior nostrils closely aligned, located in front of eye; anterior nostril with small nasal flap; eyes large, round, located in upper portion of anteroposterior axis, diameter 2.5–3.5 times in HL; interorbital width 0.9–1.6 times in eye diameter; suborbital shallow, depth 2.7–6.3 times in eye diameter; mouth moderate, terminal, and slightly oblique; upper jaw nearly reaching to about level of anterior margin of pupil, 2.8–3.6 times in HL; 3–5 pairs of enlarged canines on front of both jaws, single row of small conical teeth follows with canines, villiform teeth present inside of canines and small conical teeth; posterior edge of suborbital finely denticulate, with a small spine at upper corner; posterior margin of preopercle finely denticulate; posterior corner of opercle with a small spine.

Origin of dorsal fin above pectoral-fin base, predorsal-fin length 0.9–1.0 times in HL; dorsal fin without notch; longest dorsal-fin spine falls within 4th to 6th dorsal-fin spine, longest dorsal-fin spine 1.9–2.3 times in HL; origin of anal fin about level with 1st soft dorsal-fin ray, preanal-fin length 1.4–1.6 in SL; 3rd anal-fin spine longest or almost equal to 2nd anal-fin spine, 3rd anal-fin spine 2.2–2.7 times in HL; posterior tips of dorsal and anal-fin rays falling well short of caudal-fin base; pectoral fins moderately long, tip of fins just reaching level of anus or slightly short, their length 1.0–1.2 times in HL; origin of pelvic fins about level with 3rd dorsal-fin spine, tip of fins just reaching anus or slightly short; length of 1st pelvic-fin ray 1.1–1.6 times in HL; caudal fin lightly forked, upper lobe slightly longer than lower lobe; length of upper lobe and forked part of caudal fin 3.2–3.8 and 5.8–6.5 times in SL, respectively.

Scales cycloid; scales on top of head extending forward between eyes to about level of posterior margin of pupil; snout, suborbital, lips, maxilla and isthmus naked; preopercle with 3–5 transverse scale rows, its lower limb naked; opercle with 3–6 transverse scale rows; dorsal fin and anal fin scaleless; axilla of pectoral fin naked; pelvic fin with axillary scales; anterior half of caudal fin covered with small scales.

Color of fresh specimens (Figs. 1A, 2 A–D). Generally reddish body, darker dorsally and paler ventrally; iris red or orange; three pale yellow stripes on head, 1) tip of jaws to lower part of cheek, 2) lower edge of eye to posterior edge of preopercle, 3) posterior edge of eye to pectoral-fin base; pale yellow stripe on mid-lateral line of trunk and tail; dark red saddle larger than eye present on dorsal-fin origin (unclear or absent in large specimen); small black spot on upper portion of pectoral-fin base; dorsal fin mainly yellow (small specimen) or red (large specimen), red vermiculate patterns present on membrane in small specimens; pectoral, pelvic and anal fins pale yellow; caudal fin mainly yellow, unclear red vermiculate patterns present on forked part.

Color of preserved specimens. Generally brownish, darker dorsally and paler ventrally; eyes blackish; yellow and red marks present in the fresh condition completely lost with preservation; all fins translucent white.

Biofluorescence emission patterns (Fig. 4 A–C). Yellow lateral stripe across pupil on iris; weak green stripe on mid-lateral line of trunk and tail; green vermiculated patterns present on dorsal fin; base of pectoral fin green, pelvic and anal fins green; caudal fin mainly green, dark vermiculated patterns present on caudal fin; isthmus and branchiostegal membrane strongly green.

Distribution (Fig. 5). Parascolopsis akatamae n. sp. has been recorded based on specimens or identifiable photographs from southern Japan (Akazaki 1984; Russell 1990; 2002; Motomura et al. 2010; this study), Taiwan (Hung et al. 2016; this study), Philippines (Fujiwara 2017), Indonesia (Shibukawa et al. 2003; White et al. 2013; this study), Thailand (this study), India (Nalk et al. 2002; Kannan et al. 2013) and Iraq (Jawad & Al-Badri 2014).

It is possible that P. akatamae is widely distributed in the Indo-West Pacific. The following records identified as “ Parascolopsis eriomma ” may actually be P. akatamae: South China Sea (Randall & Lim 2000), Myanmar (Psomadakis et al. 2020), Timor and Arafura Seas (Larson et al. 2013), Arabian Sea (Manilo & Bogorodsky 2003; Psomadakis et al. 2015), Red Sea (Khalaf 2004; Golani & Fricke 2018) and Madagascar (Fricke et al. 2018).

Etymology. Parascolopsis akatamae n. sp. has long been confused with P. eriomma. P. akatamae is more widely distributed than P. eriomma (Fig. 5), and more common at least in Japan and Taiwan (Hung et al. 2016; this study). Therefore, the English name “Rosy dwarf monocle bream” and Japanese name “Aka-tamagashira” previously used for P. eriomma more appropriately applies to the new species to avoid unnecessary confusion. The specific epithet “ akatamae ” is derived from the local name in Japan of the type locality.

Remarks. Parascolopsis akatamae n. sp. was collected from a depth of 100–200 m on a sand-rubble bottom. No sexual dimorphism is observed in morphology, coloration, or fluorescence patterns.