Monocentris japonica ( Houttuyn, 1782 )

Su, Yo, Lin, Hsiu-Chin & Ho, Hsuan-Ching, 2022, A new cryptic species of the pineapple fish genus Monocentris (Family Monocentridae) from the western Pacific Ocean, with redescription of M. japonica (Houttuyn, 1782), Zootaxa 5189 (1), pp. 180-203 : 183-190

Monocentris japonica ( Houttuyn, 1782)

Figs. 3–4 , 5A , 6 , 10 , 12A , 13–14 . Tables 2–4

Gasterosteus japonicus Houttuyn, 1782:329

(Type locality: Nagasaki, Japan; no types known).

Sciaena cataphracta Thunberg, 1790:108 , pl. 3

(Type locality: Nagasaki, Japan).

Monocentris carinata Bloch & Schneider, 1801:100 , pl. 24

(Type locality: Japan; no types known).

Monocentris japonica ( Houttuyn, 1782) : Yamakawa in Okamura et al. 1985:431, 651; Yamada & Okamura 1986:116; Masuda & Allen 1987:87; Shen et al. 1993:210; Masuda & Kobayashi 1994:61; Kotlyar 1996:202; Okamura & Amaoka 1997:158; Paxton in Carpenter & Niem 1999:2214; Hayashi in Nakabo 2002:502; Shao & Chen 2003:148; Heemstra & Heemstra 2004:133; Shen & Wu 2011:290; Shao et al. 2013:41; Jawad et al. 2014:1; Iwatsubo & Motomura 2017; Ali et al. 2018:315; Jawad et al. 2018:102; Eagderi et al. 2019:24; Psomadakis et al. 2020:347.

Monocentris japonicus ( Houttuyn, 1782) : Siebold et al. 1883:50; Kotlyar 1985:534; Sainsbury et al. 1985:84; Smith 1986:413; Konishi 1999:50.

Neotype (herein designated). KAUM –I.73145 (138.8 mm SL), 4 miles off Rocket Center , Kimotsuki, Kimotsukigun, Kagoshima, Japan, 31°12'35.4"N, 131°09'03.6"E, 95 m, 27 May 2015, rolling net, coll. K. Koeda & H. Hata. COI: ON025552 .

Non-types. Eighty specimens, 16.4–147.0 mm SL. Taiwan (58 specimens): CSIRO H 7398-16 (1 specimen, 92.1 mm SL), off Dong-gang fishing port (ca. 22°22'22"N, 120°27'34"E), Pingtung, southwestern Taiwan , 18 Mar. 2012 . NMMB-P03656 (1, 104.9), NMMB-P03678 (2, 94.3–101.6), off Dong-gang , 28 May 2002 , coll. J.- H. Wu. NMMB-P04146 (2, 100.4–100.9), 14 Aug. 1997 . NMMB-P06200 (1, 82.4), off Daxi (ca. 24°53'37"N, 121°55'26"E), Yilan, northeastern Taiwan , 8 May 2003 , bottom trawl, coll. Y.-M. Ju. NMMB-P09063 (1, 100.3), off Dong-gang , 13 Jun 2008 , coll. C.-W. Chang. NMMB-P24055 (1, 61.9), off Ke-Tzu-Liao (ca. 22°42'53"N, 120°13'12"E), Kaohsiung, southwestern Taiwan , 11 March 2015 , bottom trawl, coll. H.-C. Ho. NMMB-P30547 (1, 73.6), off Dong-gang , 6 Dec. 2018 , bottom trawl, coll. H.-C. Ho. NMMB-P33774 (1, 51.1) Ke-Tzu-Liao, 23 May 2019 , coll. H.-C. Ho. NMMB-P36037 (3, 94.6–116.7), Keelung, northeastern Taiwan, COI: ON025557 – ON025559 . NMMB-P36195 (20, 102.6‒144.0), NMMB-P36196 (20, 84.5‒130.3), NMMB-P36197 (3, 94.2‒ 101.8), black individuals, all collected from outside Tainan , western Taiwan , 150‒200 m, 2021. NMMB-P36198 (1, 120.0), 23°10'N, 119°31'E, off Chimei Island , south of Penghu , 27 Jan. 2022 . NMMB-P36199 (1, 104.0), 22°50'N, 119°54'E, off Chiehdin, Kaohsiung, 12 Feb. 2021 . Japan (11): KAUM –I.71509 (1, 99.8), East China Sea, COI: ON025550 . KAUM –I.73146 (1, 130.4), collected with neotype, COI: ON025551 . KAUM –I.127912 (1, 103.8), off Tanabe , Wakayama, 33°39'24.0"N, 135°12'07.2"E, 13 July 2018 , COI: ON025553 . KAUM –I.131687 (1, 54.7), off Uchinoura Bay, Kimotsuki , Kagoshima, 31°16'54.5"N, 131°04'56.7"E, 30–35 m, 9 Jul. 2019 , set net, coll. M. Yamada, COI: ON025554 . KAUM –I.149072 (1, juvenile, 16.4), off Bandokorobana National Park, Beppu, Ei , Minami-kyushu , Kagoshima, 31°14'29.4"N, 130°25'33.0"E, 0.3 m, 16 Dec. 2020 , hand net, coll. R. Furuhashi, COI: ON025555 . KAUM –I.153257 (1, juvenile, 24.6), east of Sakinoyama, Kataura , Kasasa , Minami-satsuma , Kagoshima, 31°25'26.4"N, 130°11'29.4"E, 4 Jan. 2021 , set net, coll. M. Itou, COI: ON025556 . MNHN 0000-5116 (1, 90.4), 1868. MNHN 0000-7355 (1, 91.1), Japan , no other data. MNHN A-0448 (1, 97.4), dry specimen. MNHN 1889-0015 (1, ca. 102), dry specimen. MNHN 1904-0292 (1, ca. 122), dry specimen . China (2): MNHN 0000- 7354 (1, 104.7), no other data. MNHN 0000-8375 (1, 101.5), no other data . Australia (1): NMMB-P00593 (1, 147.0), 1 May 1985 , bottom trawl, no other data. New Caledonia (4): MNHN 1996-0967 (1, 140.2), 20°00'00.0"S, 158°46'01.2"E, Chesterfield Islands , Coral Sea, 225 m, 22 Jul. 1984 . MNHN 1996-0969 (1, 133.2+, tail broken), 23°40'58.8"S, 167°58'58.8"E, 280 m, 23 May 1987 . MNHN 1996-0970 (1, 130.4), 19°46'22.8"S, 158°25'04.8"E, Chesterfield Islands , Coral Sea, 203–208 m, 1 Aug. 1988 . MNHN 2014-2709 (1, 109.4+, tail broken), 20°30'6.5''S, 158°42'2.1''E, Chesterfield Islands , Coral Sea, 196‒213 m, 13 Oct. 2005 . Reunion (2): MNHN 1966-0849 (1, 137.4), 20°58'01.2"S, 54°34'58.8"E, west of Reunion , 180 m, Jun. 1966 . MNHN 1966-0731 (1, 134.6), 20°45'S, 53°15'E, northwest of Reunion , 80 m, 1964 . Madagascar (1): MNHN 1996-0968 (1, 141.6), 23°19'58.8"S, 43°34'01.2"E, off Tulear, 300 m, 17 Mar. 1969 .

Diagnosis. A species of Monocentris differing from its congeners in having following combination of characters: LLS 13–17; LLB1 11–14, modally 11–12; LLB3 8; total gill rakers 16–20; scales between LLB4 and AS small, its posterior tip not reaching second postpelvic scute; vomer without teeth; and mouth large, reaching vertical through posterior margin of eye.

Description. Meristic and morphometric values are provided in Tables 2 and 3 . Data below are for the neotype, followed by range in other specimens in parentheses, except where indicated.

Dorsal-fin rays V, i+10=11 (V–VII, i–ii+9–11=10–12); anal-fin rays i+9=10 (i+8–10=9–11); principal caudalfin rays 10+9=19 (9–10+8–9=17–19), uppermost and lowermost rays unbranched; procurrent caudal-fin rays 5 (3–5) dorsally and 4 (3–5) ventrally; pectoral-fin rays ii+12+0=14 (ii+9–12+0–ii=13–15); pelvic-fin rays I, 3; gill rakers 6+1+12=19 (5–7+1+10–13=16–20); LLA1 15/15 (13–17/13–16); LLA2 6/6 (2–6/2–6); LLS 15/14 (13– 17/13–16); LLB1 12/12 (11–14/11–13); LLB2 8/8 (8–9/7–9); LLB3 8/8; LLB4 3 (prepelvic)+4 (postpelvic)/3+4; scales surrounding dorsal-fin base 23 (19–23); scales surrounding anal-fin base 6 (6–8); medium predorsal scales 3 (2–4, mode 3); abdominal scutes 2 (rudimentary)+3 (prepelvic)+4 (postpelvic) (rarely 2+3+5); vertebrae 12+14=26 (12+13–14=25–26, n=25); pyloric caeca 6–8 (based on NMMB-P36037, n=3); pseudobranchial filaments 19 (14– 21, n=16); branchiostegal rays 8.

Body oblong, longer than deep, depth at dorsal-fin origin 1.9 (1.4–2.0) in SL. Head large, its length 2.3 (2.1– 2.4) in SL, and subequal to its height, 1.0 (0.8–1.0) in HL; upper profile in front of dorsal fin roundly convex, with forehead region gently concave; forehead narrow, its width 4.1 (3.6–5.1) in HL; eyes moderately small, 3.9 (2.6– 3.7) in HL; snout broadly rounded, extending clearly before maxilla, its length 3.3 (3.2–4.0) or 3.6 (3.5–4.8) in HL; space between eyes convex and broad, interorbital width 2.5 (3.3–3.7) in HL; crests on head bones well-developed, connected by thin membranes with numerous tiny pores.

Mouth large, posterior end of maxilla (lower corner) extending clearly beyond vertical thorugh posterior margin of eye. Nostrils nearly connected to each other but separated by narrow membranes, both immediately in front of anterior margin of eye and above horizontal through of eye; posterior nostril much larger than anterior one. Long groove extending from symphysis of premaxillae to tip of snout. Small blunt dentigerous knob at each side of symphysis of dentaries, with a concavity right behind the knob where the light organ is housed. Supramaxilla elongate, rectangular posteriorly, covering most of posterior portion of maxilla with long needle-like process at anterodorsal corner; posteroventral corner of maxilla exposed.

Most portions of lateral and medial surfaces of premaxilla covered with villiform teeth; anterior third and inner portion of posterior two-thirds of dentary covered with villiform teeth, a long fleshy patch of papillae on outer portion of dentary; symphyseal notch of premaxilla naked and knob at symphysis of dentaries with villiform teeth. Palatine with narrow band of teeth; vomer toothless. Gill rakers rod-shaped, somewhat laterally compressed, with villiform teeth on their tips and inner surfaces; those in outer row of first arch longest; rakers on inner row of first arch and both inner and outer rows of second to third arches short; small tooth patches forming bumps, present on midline of all four outer arches. Villiform teeth present on fifth ceratobranchial. Small villiform tooth patch on second pharyngeal arch forming oval patch. Large teardrop-like tooth patch on third pharyngeal arch.

Body covered with enlarged firmly-attached bony scales, scales slightly overlapping; spines on anterior scales rudimentary, and eventually developed as central spine pointing backward; pectoral-fin base covered with 3 rows of cycloid scales; caudal-fin base covered with several small scales with a central spine; abdominal margin with single row of serrated scutes, the last forming a strong posterior spine; 2 scales present between LLB4 and AS on inner surface of pelvic-fin base ( Fig. 5A ), second scale large, reaching anterior margin of second post-pelvic scute; isthmus with 1 or 2 enlarged scales; gular region naked, without scales.

Dorsal-fin spines thickened, second spine longest, and subsequent spines progressively shorter; first four spines connected with membranes at base, and alternating side to side; bases of spinous dorsal fin concave, forming groove to receive spines; outer margin of soft rays rounded. Pectoral fin short, 1.5 (1.4–1.7) in HL, its tip reaching lateral line, but not reaching vertical through anal-fin origin. Pelvic-fin spine enlarged, its length 1.3 (1.0–1.8) in HL; abdominal scutes and LLB4 forming a large groove to receive pelvic spine. Caudal-fin margin slightly concave, tips rounded. Pyloric caeca pale, unbranched.

Size. Moderately small species, the largest specimen examined by us is 147.0 mm SL; reported up to 170 mm SL in Australia ( Sainsbury et al. 1985).

Coloration. When fresh, body yellowish, body scales with distinct black margin ( Figs. 3A , 4 ). Mouth cavity, including underside of the tongue, peritoneum, and stomach whitish. Vomer, palatine, outer margin of premaxilla, and dentary black. Preserved specimens with a darker yellowish body ( Fig. 3B ). In some moderately large individuals, the body is darker than normal (NMMB-P36197, 94.2‒101.8 mm SL, Fig. 4B ), but never found in larger individuals.

Otolith morphology. Two sagittal otoliths taken from NMMB-P36199 (117.0 mm SL) measured 9.7 and 9.8 mm in length ( Fig. 6 ). Otolith square to rhomboidal, 8.3–8.4 % SL, length/depth ratio 1.15. Dorsal margin irregular crenate, roughly divided into 3 lobes; ventral margin smoothly curved; posterior margin entire, slightly convex, no pseudo-excisura or pseudo-rostrum; distal surface flat to slightly convex with some shallow grooves associated with the lobes on dorsal margin; proximal surface slightly concave; sulcus groove deep and wide, heterosulcoid, ostium clearly larger and wider than cauda, ostium not open anteriorly; colliculum heteromorph; crista superior welldeveloped to ridge-like, crista inferior not developed; rostrum steep, its margin nearly straight; antirostrum poorly developed; no notch on excisura; dorsal depression deep and broad, extending from antirostrum nearly to posterior end of cauda; ventral depression absent.

Distribution. Widely distributed in the Indo-West Pacific, including Japan, Taiwan, China, New Caledonia (including Chesterfield Islands), Australia, Red Sea, Reunion, Madagascar, and South Africa. Inhabits from shallow waters to ca. 300 m depth. Records from New Zealand belong to a distinct species (Su et al. in preparation).

Figures

FIGURE 3. Monocentris japonica (Houttuyn, 1782). A. KAUM–I.73146, non-type, 130.4 mm SL, fresh, photo by KAUM. B. KAUM–I.73145, neotype, 138.8 mm SL, preserved.

FIGURE 4. Monocentris japonica (Houttuyn, 1782). A. KAUM–I.149072, 16.4 mm SL, juvenile, fresh, photo by KAUM. B. NMMB-36197, 1 of 3, 96.5 mm SL, a black individual, previously frozen.

FIGURE 5. Ventral view of Monocentris species showing scales between AS and LLB4 (outlined by red dots). A. M. japonica, KAUM–I.71509, non-type, 99.8 mm SL, preserved. B. M. chrysadamas sp. nov., DOS 08609, paratype, 82.1 mm SL, preserved. Anterior to left.

FIGURE 6. Sagittal otoliths taken from Monocentris japonica, NMMB-P36199, non-type, 117.0 mm SL. Showing outer (A, C) and inner face (B, D). A–B. right-side otolith, 9.8 mm otolith length. C–D. left-side otolith, 9.7 mm otolith length.

FIGURE 10. Maximum-likelihood tree based on COI sequences of Monocentris spp. generated by Kimura-2-parameter model (Kimura, 1980) with 1000 bootstrap pseudoreplicates, with Cleidopus gloriamaris chosen as the outgroup. Numbers beside each node represent bootstrap values, with values <75% omitted. Scale bar on bottom-left corner denotes the number of substitutions per unit length on tree.

FIGURE 12. Lateral view of pectoral-fin region, showing (A) an extra scale (red arrow) below pectoral-fin base in neotype of M. japonica, and (B) absent in paratype, DOS 08609, 82.1 mm SL, of M. chrysadamas. Anterior to left.

FIGURE 13. Allometric growth in M. chrysadamas sp. nov. (red circle) and M. japonica (blue triangle). A. Head depth (% SL vs. SL). B. Body depth (% SL vs. SL). C. Postorbital length (% SL vs. SL). D. Dorsal-fin–pelvic-fin length (% SL vs. SL). E. Dorsal-fin–pectoral-fin length (% SL vs. SL).

FIGURE 14. Frequency of standard length in M.chrysadamas sp. nov. (n=71) and M. japonica (n=66). Color of bars correspond with species' colors in key.

Tables

TABLE 2. Meristic characters of Monocentris chrysadamas sp. nov. and M. japonica. Values presented as left/right when available. Abbreviations: NT, Non-type; PT, Paratype.

	M. chrysadamas sp. nov.			M. japonica
	Holotype	PT+NT (n=23)	Neotype	NT (n=24)
Dorsal-fin elements	VI, i+9=10	V–VII, i–ii+8–10=10–12	V, i+10=11	V–VII, i–ii+9–11=10–12
Pectoral-fin elements	ii+11+i=14	ii+10–12+0–i=13–15	ii+12+0=14	ii+9–12+0–ii=13–15
Anal-fin elements	i+9=10	i+9–10=10–11	i+9=10	i+8–10=9–11
Gill rakers	6+1+12=19	5–7+1+10–12=16‒20	6+1+12=19	5–7+1+10–13=16‒20
Pseudobranchial filaments	16	14–21 (n=16)	19	14–21 (n=17)
Pyloric caeca	8	7 (n=2)	N/A	6–8 (n=3)
Vertebrae	12+14	12+14	12+14	12+13–14
LLA1	14/13	12–15/12–15	15/15	13–17/13–16
LLA2	5/5	2–7/2–6	6/6	2–7/2–6
LLS	14/13	12–15/12–15	15/14	13–17/13–16
LLB1	10/10	9–12/9–11	12/12	11–14/11–13
LLB2	7/7	7–9/7–8	8/8	8–9/7–9
LLB3	7/6	6–7/6–7	8/8	8/8
LLB4	3+4/3+4	3+4/3+4	3+4/3+4	3+4/3+4
Predorsal scales	4	1–4	3	2–4
Scales surrounding dorsal-fin base	22	18–21	23	19–23
Scales surrounding anal-fin base	6	6–8	6	6–8

TABLE 3. Morphometric data for specimens of Monocentris chrysadamas sp. nov. and M. japonica. Abbreviations: A, Anal-fin; C, Caudal-fin; CPD, Caudal-peduncle; D, Dorsal-fin; NT, Non-type; P, Pectoral-fin; PT, Paratype; SD, Standard deviation; SNL, Snout length; V, Pelvic-fin.

	M. chrysadamas sp. nov.				M. japonica
	Holotype	Selected PT+NT (n=23)		Neotype	NT (n=20)
SL (mm)	115.5	97.2 (38.8–127.6)		138.8	93.9 (16.4–147.0)
%SL		Mean (range)	SD		Mean (range)	SD
Head length	46.0	46.5 (43.8–50.1)	1.6	42.7	45.3 (41.2–48.6)	2.0
Head depth	47.7	49.3 (45.8–57.0)	2.8	42.0	47.8 (42.0–56.5)	3.7
Body depth	59.5	62.4 (57.9–71.3)	3.4	52.0	59.5 (50.9–69.5)	4.5
Body width	20.6	19.9 (17.9–21.4)	1.0	18.8	20.1 (16.7–23.1)	1.7
SNL 1	13.7	13.5 (12.0–15.5)	1.0	13.1	12.8 (10.8–15.3)	1.1
SNL 2	12.2	12.3 (11.3–13.3)	0.5	11.9	11.5 (9.4–12.9)	1.0
Eye diameter	13.4	13.7 (12.0–16.7)	1.2	11.0	14.1 (11.5–17.9)	1.9
Forehead height	10.6	11.3 (9.9–14.0)	1.1	10.3	11.0 (8.4–13.2)	1.3
Interorbital width	17.1	18.2 (16.9–21.2)	1.2	17.1	18.5 (14.0–24.8)	2.4
Suborbital width	10.6	10.8 (9.6–11.8)	0.6	10.1	10.0 (8.2–12.1)	0.9
Upper-jaw length	26.2	25.6 (23.2–29.0)	1.5	21.9	23.1 (18.3–27.8)	2.3
Lower-jaw length	26.3	25.2 (23.2–26.9)	1.0	22.2	24.0 (22.2–28.1)	1.8
Postorbital length	23.1	24.3 (22.6–26.1)	0.9	21.7	22.5 (20.7–24.2)	1.0
Predorsal length	55.2	58.1 (53.6–62.9)	2.5	49.3	54.9 (49.1–60.7)	3.5
Prepectoral length	43.7	43.9 (40.5–49.0)	2.2	43.1	43.4 (39.3–46.9)	2.0
Prepelvic length	53.1	52.5 (47.3–59.6)	2.9	50.7	52.5 (46.1–60.5)	3.5
Preanal length	83.8	83.3 (78.8–87.9)	2.2	84.4	84.4 (82.0–87.4)	1.5
D–P length	42.6	43.9 (40.6–50.7)	2.9	35.7	42.2 (35.8–53.1)	4.1
D–V length	59.6	61.9 (56.7–70.8)	4.3	50.8	58.3 (48.7–67.0)	4.4
P–V length	12.8	14.5 (12.7–18.0)	1.6	12.3	13.7 (11.7–17.2)	1.3
V–A length	39.6	38.8 (35.0–40.7)	1.6	38.5	39.3 (37.0–42.8)	1.8
D–A length	62.0	65.4 (61.1–72.2)	3.3	58.8	63.6 (67.7–57.8)	2.8
1st D spine	10.2	12.1 (5.9–17.5)	2.7	11.7	14.7 (8.1–21.7)	3.8
2nd D spine	N/A	31.5 (25.8–39.9)	3.5	N /A	27.5 (12.8–35.4)	6.2
3rd D spine	30.6	29.0 (22.7–39.7)	3.8	23.3	25.0 (12.5–33.5)	5.7
4th D spine	14.2	11.8 (5.8–22.1)	4.1	10.4	11.9 (6.9–22.1)	4.1
D length	47.1	48.8 (44.6–55.6)	2.5	48.1	49.4 (46.1–52.0)	1.7
D height	14.7	17.9 (10.5–25.4)	3.1	17.8	16.6 (14.2–20.1)	1.4
P length	29.1	31.0 (27.2–35.8)	2.3	27.7	29.1 (24.7–32.5)	2.0
V spine	34.0	35.4 (30.3–41.2)	2.8	33.2	35.7 (25.5–43.9)	4.1
A length	13.7	15.4 (12.8–21.1)	1.8	13.3	14.5 (12.6–16.1)	1.1
A height	18.2	19.0 (16.0–22.9)	1.8	14.9	18.1 (14.2–21.2)	1.6
CPD height	10.5	11.0 (9.9–16.6)	1.3	10.0	10.9 (9.4–19.3)	2.1
CPD length	14.7	15.6 (13.1–20.9)	1.9	15.3	14.2 (11.5–17.2)	1.4
C length	25.6	26.6 (23.7–32.8)	2.7	24.3	27.6 (24.1–30.4)	1.7