Parascorpaena poseidon Chou and Liao, 2022

Mochizuki, Kentaro & Motomura, Hiroyuki, 2024, Distributional Range Extension of the Shallow Water Scorpionfish Parascorpaena poseidon (Perciformes: Scorpaenidae), with a Revised Diagnosis of the Species, Species Diversity 29 (1), pp. 91-98 : 91-97

Parascorpaena poseidon Chou and Liao, 2022

[English name: Poseidon’s scorpionfish; new standard Japanese name: Mitsumata-nettaifusakasago] ( Figs 1–5 ; Tables 1, 2)

Parascorpaena poseidon Chou and Liao, 2022: 2 , figs 1–4 (type locality: Sizihwan, Kaohsiung, Taiwan).

Parascorpaena mossambica (not of Peters): Naranji et al. 2017: 106, fig. 1 (Visakhapatnam, Andhra Pradesh, India).

Material examined. Fifty-two specimens, 35.3–123.3 mm SL. Japan: NSMT-P 17865 , 97.8 mm SL, Kusugawa, Yaku-shima Island, Kagoshima Prefecture, 28 September 1974; URM-P 4237, 37.6 mm SL, off Naha, Okinawa-jima island ,

© 2024 The Japanese Society of Systematic Zoology.

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Okinawa Prefecture, 10 December 1976, T . Yamamoto. Philippines: ANSP 51367 , 95.9 mm SL, Vigan , Ilocos Sur, Luzon, J . Clemens, 1923; CAS 54005 , 56.2 mm SL, 2 km north of Sibulan , Negros Oriental, ca . 0.3 m depth, 09°29′N, 123°17′E, D. Empeso, 31 October 1958; CAS 64929 , 83.1 mm SL, Mahatao, southwest of Mabatui Point , Batanes Province, 20°24′32″N, 121°55′40″E, A . Ross, 31 May 1986. Thailand: CAS 54004 , 2 specimens, 85.4–89.3 mm SL, Paton Bay , Phuket, Andaman Sea, N . Tyler et al., 22 March 1963; URM-P 14719, 92.5 mm SL, near Phuket Marine Biological Center , Phuket, Andaman Sea, 12 April 1984 . Indonesia: FMNH 52475, 102.2 mm SL, Gunungsitoli, Nias Island, M . Weber. Sri Lanka: CAS 54002, 113.2 mm SL, ca . 45 m off shore from harbor, Trincomalee, 0.6–4.5 m depth, W. F. Smith-Vaniz, 26 June 1969; CAS 54003 , 94.0 mm SL, Weligama, Matara , 0.6–3.0 m, C . C. Koenig, 14 February 1970; CAS 227042 , 92.3 mm SL, same data as CAS 54002; FMNH 75818 , 27 specimens, 35.3–123.3 mm SL, Galle, Southern Province, 5 March 1964; FMNH 75821 , 79.0 mm SL, Galle , Southern Province, L . P. Woods et al., 6 March 1964; KAUM –I . 10317 (formally CAS 54002 ), 106.3 mm SL, same data as CAS 54002; KAUM –I . 184183, 114.9 mm SL, KAUM –I. 184184, 99.9 mm SL, KAUM –I. 184185, 106.5 mm SL, KAUM –I. 184186, 104.4 mm SL, KAUM –I. 184187, 113.9 mm SL, KAUM –I. 184188, 116.1 mm SL, KAUM –I. 184189, 111.9 mm SL, KAUM –I. 184190, 99.7 mm SL, Chapel Island, Trincomalee , 0.3–0.9 m depth, W . F. Smith-Vaniz, 30 June 1969. India: ANSP 145967 , 97.9 mm SL, north of Thiruvananthapuram , Kerala, 0–3 m depth, J . E. Randall and W. F. Smith-Vaniz, 12 February 1980; BPBM 27680 , 2 specimens, 87.3–115.4 mm SL, Kovalam , Kerala, 0–2 m depth, J . E Randall and W. F. Smith-Vaniz, 12 February 1980.

Revised diagnosis. A species of Parascorpaena distinguished from all congeners by the following combination of characters: pectoral-fin rays usually 16 or 17 (rarely 15); scale rows in longitudinal series 43–49; pored lateral-line scales 22–26; scale rows below lateral-line 12–17; scale rows between 6th dorsal-fin spine base and lateral line 6–8 (usually 7); scale rows between last dorsal-fin spine base and lateral line 6–8 (usually 7); gill rakers 4–6 + 7–9 + 1–3 = 14– 17; penultimate dorsal-fin spine relatively long, its length 60.0%–83.3% of last dorsal-fin spine length; occipital pit fairly deep; suborbital bone with two ridges, origin of first posterior to origin of second, first with a single spine, second with two - all spines of equal size ( Fig. 3 ); supraocular tentacle absent or very short; base of dorsal-fin soft ray covered with small scales; head and body uniformly brown when fresh ( Fig. 1 ); all fins with randomly distributed blackish spots ( Figs 1 , 2 ); membranes of spinous portion of dorsal fin without a distinct black blotch in males ( Figs 1 , 2 ); body size relatively large, maximum recorded size 128.8 mm SL [based on Chou and Liao (2022), and present study].

Description. Counts and measurements shown in Table 1. Diagnostic characters given above not repeated. Head to base of pectoral fin moderately compressed, body progressively more compressed posteriorly. Dorsal profile of snout strongly elevated, forming angle of about 50–65 degrees to horizontal axis of head and body, dorsum elevated from nape to 4–6th dorsal-fin spine base, thereafter gradually lowering to end of dorsal-fin base. Maximum body depth at upper margin of pelvic-fin base, gradually becoming shallower thereafter. Anterior nostril with short membranous tube, located before preocular spine. Posterior nostril locat- ed anterior to margin at mid-eye level, round.

Nasal spine simple, sharp, directed dorsally, its length less than pupil diameter. Median interorbital ridge absent. Interorbital ridge located between base of preocular and tympanic spines in dorsal view, conjoined level with and between origins of tympanic spines, forming a distinct ridge to anterior angular edge of occipital pit. Interorbital space deep. Preocular spine extending along anterior contour of orbit, directed dorsally, its base well developed. Supraocular spine extending along upper contour of orbit, directed posterodorsally or posteriorly. Postocular spine located behind base of supraocular spine, directed dorsally or posterodorsally. Sphenotic with 1–3 (usually 2) spines, located behind eye. Tympanic spine located above sphenotic spine, directed dorsally or posterodorsally, longer than preocular spine. Interorbital, coronal and pretympanic spines absent. Parietal spine located behind tip of tympanic spine, directed posterodorsally. Nuchal spine located behind parietal spine, directed posterodorsally or posteriorly, joining posterior margin of parietal spine, its length usually equal to that of parietal spine (longer than parietal spine in small specimens). Pterotic spine located below nuchal spine, directed posterodorsally, included in head profile (except for spine tip). Upper posttemporal spine located below tip of nuchal spine, directed posterodorsally. Lower posttemporal spine located directly below upper posttemporal spine, directed posterodorsally, longer than upper posttemporal spine. Supracleithral spine located directly behind lateral line, direct- ed posterodorsally or posteriorly. Lacrimal ridge extending from base of preocular spine to posterior lacrimal spine, directed posteriorly. Lacrimal bone with two spines, anterior lacrimal spine directed anteriorly, posterior lacrimal spine directed anteriorly or anteroventrally. Anterodorsal and lateral lacrimal spines absent. Preopercle with five spines; uppermost spine largest, simple, sharp, its base with supplemental preopercular spine; second spine simple, sharp; third to fifth spines flat, with broad base. Upper opercular spine extending from ventral margin of nuchal spine to base of lateral line, directed posterodorsally. Lower opercular spine extending from ventral margin of nuchal spine to base of cleithral spine, directed posteriorly. Weak ridge extending between tips of upper and lower posttemporal spines. Cleithral spine above base of pectoral fin, directed posterodorsally, length greater than pupil diameter.

Three to five small tentacles above eye. Anterior and posterior lacrimal tentacles linked posteriorly to head by skin. One to four small tentacles on lateral surface of maxilla. Preopercular flaps usually occurring on tips of fourth and fifth preopercular spines (rarely tips of third and fifth spines). Lateral-line scales and lateral surface of body scales with randomly distributed tentacles. Interorbital, occiput, and postorbital spaces with small papillae. Upper and lower jaws, vomer, and palatine each with band of villiform teeth (large specimens with teeth patches on tip of upper jaw).

Dorsal-fin origin above upper posttemporal spine; fourth or fifth spine longest; progressively shorter until eleventh spine; twelfth spine length equal to that of eighth or ninth spine; membrane of spinous portion moderately notched; all soft rays branched; second or third soft ray longest; progressively shorter to posteriormost ray; posterior branch of posteriormost soft ray joined by membrane to caudal peduncle for approximately half its length. Anal-fin origin below 11th dorsal-fin spine to first dorsal-fin soft ray; first spine shortest; second spine longest; all soft rays branched; first soft ray longest, its length greater than longest dorsal-fin soft ray; progressively shorter until last soft ray; posterior branch of last soft ray joined by membrane to caudal peduncle for less than one-tenth its length. Origin of pectoral fin below cleithral spine; its tip reaching level with upper margin of anus; fifth to eighth soft rays longest; uppermost 0 or 1 and lowermost 9–12 rays unbranched, middle 3–6 rays branched. Pelvic-fin soft rays branched; second soft ray longest, its length slightly greater than third dorsal-fin spine length; last soft ray joined by membrane to abdomen for about half its length. Posterior margin of caudal fin slightly rounded.

Postorbital and posterior tip of opercular margins with embedded cycloid scales. Body (except for anterior dorsal margin) covered with well-exposed cycloid scales; anterior dorsal margin covered with ctenoid scales, usually with 2–5 small spines, spines progressively developed anteriorly (1 or 2 small spines in small specimens). Lateral line usually complete (interrupted anteriorly on caudal peduncle in small specimens), sloping weakly downward posteriorly. Sensory pores of lateral-line scales tubular.

Coloration of fresh specimen (based on Fig. 1 ). Snout and suborbital areas brown, postorbital area yellowish-brown. Ventral margin of head pale brownish-red. Body uniformly brown, dorsal margin mottled with poorly defined white blotches, ventral margin pale brownish-red. A broad white band on caudal peduncle area, extended vertically. Dorsal fin brown with some irregular white bands. Anal fin brownish-red with some irregular white bands. Pectoral fin brownish-red with some irregular white and brown bands. Pelvic fin brownish-red with some pale white blotches. Caudal fin brown with some irregular white and brown bands.

Coloration of preserved specimens (based on Fig. 2 ). Head and body ground color brown, mottled with poorly defined dark-brown blotches. A broad white band on caudal peduncle area retained. A broad dark-brown band on base of caudal fin. Dorsal and anal fins pale brown, mottled with poorly defined dark-brown blotches. Pectoral fin brown, with retained brown bands. Pelvic fin brown. Caudal fin pale brown, with retained brown bands. All fins with retained black spots.

Distribution. Widely distributed in the eastern Indian and western Pacific oceans, being recorded from Japan (Yaku-shima and Okinawa-jima islands), Taiwan (Penghu Islands, Kaohsiung, and Pingtung), Philippines (Batanes, Luzon, and Negros islands), Thailand (Phuket), Indonesia (Nias Island), Sri Lanka (Trincomalee, Galle, and Matara), and India (Kerala and Andhra Pradesh) ( Naranji et al. 2017; Chou and Liao 2022; this study) ( Fig. 5 ).

Although Naranji et al. (2017) recorded P. mossambica (Peters, 1855) from India on the basis of 10 specimens, these specimens were re-identified here as P. poseidon on the basis of the number of gill rakers.

Remarks. The specimens examined here generally conformed to the genus Parascorpaena , as defined by Motomura et al. (2005a, 2009) and Poss and Motomura (2022): usually XII, 9 dorsal-fin rays; III, 5 anal-fin rays; lacrimal bone with two lacrimal spines, posterior lacrimal spine directed anteriorly or anteroventrally; suborbital bone with two ridges, one located above the other; and most of the body covered with cycloid scales. One specimen included in a series collected off Galle, Sri Lanka (FMNH 75818, 1 of 27, 35.3 mm SL) had XIII dorsal-fin spines, a second (FMNH 75818, 1 of 27, 123.3 mm SL), 10 dorsal-fin soft rays, and a third (FMNH 75818, 1 of 27, 88.9 mm SL), XIII dorsal-fin spines and 8 dorsal-fin soft rays. In other respects, these specimens agreed with the diagnostic characters for the genus.

All of the present specimens from the eastern Indian and western Pacific oceans conformed to the following diagnostic characters of P. poseidon given by Chou and Liao (2022): 22–24 pored lateral-line scales; three equally-sized suborbital spines; supraocular tentacle absent or very short; all fins with randomly distributed blackish spots; spinous portion of dorsal fin without a distinct black blotch (males).

Some meristic and measurement values of the examined specimens differed slightly from those given by Chou and Liao (2022): 15–17 pectoral-fin rays in this study (15 or 16 in the latter); 43–49 scale rows in longitudinal series (43–47); 3–6 pre-dorsal scale rows (2 or 3); 4–6 + 7–9 + 1–3 = 14–17 gill rakers (5 + 8 or 9 + 2 or 3 = 15 or 16); and penultimate dorsal-fin spine length 62.7%– 83.3% of last dorsal-fin spine length (60%–81%). However, these small differences were regarded as intraspecific variations only, particularly in view of those characters given in Chou and Liao (2022) having been based on only 10 specimens, representing a limited distribution. Nevertheless, two diagnostic characters of the former differed significantly from those given by Chou and Liao (2022): 6–8 scale rows between 6th dorsal-fin spine base and lateral line (10–12 in the latter); 6–8 scale rows between last dorsal-fin spine base and lateral line (10–12). Apparently Chou and Liao (2022) miscounted these meristics, due to photographs of type specimens ( Chou and Liao 2022: figs 1, 2) showing ca. 6 or 7 scale rows between the 6th dorsal-fin spine base and lateral line, and 7 scale rows between the last dorsal-fin spine base and lateral line, respectively. Similarly, six morphometric values for the presently-examined specimens differed significantly from those given by Chou and Liao (2022): head length 42.2%–47.0% of SL (36.4%–39.7% in the latter); snout length 11.5%–16.4% of SL (4.1%–7.9%); interorbital width at vertical midline of eye 7.6%–10.9% of SL (5.4%– 7.7%); upper-jaw length 20.2%–24.0% of SL (14.9%–19.6%); pre-dorsal-fin length 34.1%–39.5% of SL (21.5%–28.7%); and pre-pelvic-fin length 37.3%–44.1% of SL (33.6%– 36.3%). These differences may be due to different measurement methods having been used by Chou and Liao (2022).

Parascorpaena poseidon is similar to the congeners P.mc-

Pearson’s correlation coefficient (r) Body depth at pelvic-fin spine base 0.136

Body depth at first anal-fin spine base 0.216

Body width 0.666

Head length 0.386

Head width 0.493

Snout length 0.693

Orbit diameter −0.485 Interorbital width at vertical midline of eye 0.463 Interorbital width at posterior end of 0.330 preocular spine base

Upper-jaw length 0.478

Maxilla depth 0.446 Postorbital length 0.431 Separation between opercular spine tips −0.535 Pre-dorsal-fin length −0.058 Pre-anal-fin length 0.194 Pre-pelvic-fin length 0.376

1st dorsal-fin spine length 0.175

2nd dorsal-fin spine length −0.202

3rd dorsal-fin spine length −0.190

4th dorsal-fin spine length −0.062

5th dorsal-fin spine length 0.075 Penultimate dorsal-fin spine length 0.296

Last dorsal-fin spine length 0.011

Longest dorsal-fin soft ray length 0.051 Dorsal-fin soft ray base length 0.105

1st anal-fin spine length 0.248

2nd anal-fin spine length 0.146

3rd anal-fin spine length 0.110

Longest anal-fin soft ray length −0.063 Pectoral-fin ray length −0.027 Pelvic-fin spine length −0.129

Longest pelvic-fin soft ray length −0.148 Caudal-fin length −0.358 Caudal-peduncle length −0.400 Caudal-peduncle depth 0.004

adamsi (Fowler, 1938) and P. mossambica in having three suborbital spines ( Fig. 3 ). However, the former differs from P. mcadamsi in having 6–8 (usually 7) scale rows between the 6th dorsal-fin spine base and lateral line [5–7 (usually 6) in P. mcadamsi ], 6–8 (usually 7) scale rows between the last dorsal-fin spine base and lateral line [4–6 (usually 5)], 4–6 + 7–9 + 1–3 = 14–17 gill rakers (3–5 + 6–8 + 0 or 1 = 10–13), a fairly deep occipital pit (shallow), the supraocular tentacle absent or very short (absent to longer than pupil diameter), base of the dorsal-fin soft ray covered with small scales (without small scales), head and body uniformly brownish when fresh (uniformly red), all fins with randomly distributed blackish spots (no blackish spots), spinous portion of the dorsal fin without a distinct black blotch in males (a distinct black blotch present in males), and a relatively large body [largest specimen recorded 128.8 mm SL (relatively small, largest recorded specimen 65.4 mm)] ( Poss 1999; Chou and Liao 2022; Poss and Motomura 2022; Mochizuki et al. 2023; this study). It differs from P.mossambica in having 14–17 (usually 14–16) gill rakers [9–15 (usually 11–14) in P. mossambica ], the suborbital bone with two ridges, the origin of the first posterior to the origin of the second, first with a single spine, second with two spines - all spines equally sized ( Fig. 3 ) (origin of first ridge anterior to origin of second, first with a spine, second with two larger spines), and supraocular tentacle absent or very short (absent to longer than pupil diameter) ( Poss 1999; Chou and Liao 2022; Poss and Motomura 2022; this study; K. Mochizuki and H. Motomura, unpublished data).

Several body proportions (% of SL) of P. poseidon change with growth ( Table 2), including body width, head width, snout length, interorbital width at vertical midline of eye, upper-jaw length, maxilla depth, and postorbital length increasing ( Fig. 4A–G ), and orbit diameter, and separation between opercular spine tips decreasing ( Fig. 4H–J ).

Since P. poseidon has been recorded previously only from Taiwan, the present specimens represent a considerably wider distribution of the species, in the eastern Indian and western Pacific oceans. There being no current Japanese name for P. poseidon , the new Japanese name “Mitsumata-nettaifusakasago”, is proposed here, on the basis of NSMTP 17865, “Mitsumata” in reference to the three suborbital spines, and “nettaifusakasago” being the common Japanese name for Parascorpaena .

Comparative material examined. Parascorpaena poseidon (2 specimens, 67.3–128.8 mm SL, both from Taiwan): ASIZP 69359, 128.8 mm SL, Wanlitong, Pingtung, L.-C. Chen, 18 June 1970; KAUM–I. 39262, 67.3 mm SL, Wanlitong, Pingtung, 29°59′52″N, 120°42′03″E, 0.5 m, 3 July 2011.

Figures

Fig. 1. Fresh specimen of Parascorpaena poseidon from Kovalam, Kerala, India (BPBM 27680, 1 of 2 specimens, 115.4mm SL). Photo by J. E. Randall (BPBM).

Fig. 2. Variously-sized preserved specimens of Parascorpaena poseidon. A, FMNH 75818, 1 of 27 specimens, 35.3mm SL, Galle, Sri Lanka; B, FMNH 75818, 1 of 27 specimens, 65.3mm SL, Galle, Sri Lanka; C, NSMT-P 17865, 97.8mm SL, Yaku-shima Island, Osumi Islands, Kagoshima, Japan; D, BPBM 27680, 1 of 2 specimens, 115.4mm SL, Kovalam, Kerala India.

Fig. 3. Lateral (A) and dorsal (B) views of head of Parascorpaena poseidon (NSMT-P 17865, 97.8mm SL). Bars indicate 5mm.

Fig. 4. Relationships between body width (A); head width (B); snout length (C); interorbital width at vertical midline of eye (D); upper-jaw length (E); maxilla depth (F); postorbital length (G); orbit diameter (H); and separation between opercular spine tips (I) (all as % of SL) and standard length (mm) in Parascorpaena poseidon, showing ontogenetic changes. Star indicates holotype [except for snout length, interorbital width at vertical midline of eye, and upper-jaw length—see text regarding measurements by Chou and Liao (2022)].

Fig. 5. Distributional records of Parascorpaena poseidon, based on original description (triangles and star), literature record as P. mossambica (closed circle), and present study (open circles). Star indicates type locality.