Neoscorpaena nielseni
Creators: name: Matsumoto, Tatsuya
name: Motomura, Hiroyuki
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Scorpaeniformes
Scorpaenidae
Neoscorpaena
Neoscorpaena nielseni

description: Neoscorpaena nielseni (Smith 1964)
[Standard English name: Spotfin Scorpionfish]
Figures 1–4; Table 2
Sebastapistes nielseni Smith 1964: 298, pl. 30 (fig. C) (type locality: off Durban, South Africa, 29°56′S, 31°19′E).
Neomerinthe nielseni: Eschmeyer 1986: 469, fig. 149.14 (South Africa); Poss & Motomura 2022: 522, unnumbered fig. (northern Mozambique).
Neoscorpaena nielseni: Motomura et al. 2011: 62, fig. 3 (Madagascar, Seychelles, and Réunion).
Material examined. 35 specimens, 78.6–175.4 mm SL. Mauritius: CAS 236690, 175.4 mm SL, J. B. Baissac. Australia: AMS I.31289-001, 148.4 mm SL, AMS I.31289-002, 106.0 mm SL, AMS I.31289-003, 147.8 mm SL, AMS I.31289-004, 121.1 mm SL, AMS I.31289-005, 8 specimens, 118.7–142.6 mm SL, off Green head, Western Australia, 30°00′06″S, 114°27′48″E –29°58′06″S, 114°27′06″E, 380 m, trawl, FRV Southern Surveyor, 8 Feb. 1991; CSIRO H2587-01, 127.0 mm SL, southwest of Shark Bay, Western Australia, 27°08′48″S, 112°44′48″E – 27°06′24″S, 112°44′06″E, 370–438 m, trawl, FRV Southern Surveyor, 2 Feb. 1991; CSIRO H2598-05, 6, 108.2– 137.6 mm SL, west of Green Head, Western Australia, 30°00′06″S, 114°27′48″E –29°58′06″S, 114°27′06″E, 380 m, trawl, FRV Southern Surveyor, 8 Feb. 1991; CSIRO H2608-13, 3, 132.6– 137.2 mm SL, Rottnest Canyon, Western Australia, 31°55′12″S, 115°10′12″E –31°57′24″S, 115°08′30″E, 320–850 m, trawl, FRV Southern Surveyor, 11 Feb. 1991; CSIRO H3084-01, 2, 106.4 and 110.0 mm SL, west of Geraldton, Western Australia, 28°40′56.4″S, 113°33′05.4″E, 340 m, scampi pot, Flinders, 29 Apr. 1990; CSIRO H6366- 16, 124.2 mm SL, southwest of Geraldton, Western Australia, 29°52′03.6″S, 114°23′13.2″E –29°52′25.8″S, 114°28′52.8″E, 401–414 m, trawl, FRV Southern Surveyor, 2 Dec. 2005; CSIRO H6368-27, 84.6 mm SL, southwest of Shark Bay, Western Australia, 27°08′00.6″S, 112°45′03.6″E –27°08′48″S, 112°45′43.2″E, 405–414 m, trawl, FRV Southern Surveyor, 5 Dec. 2005; CSIRO H6369-02, 1 of 4, 95.6 mm SL, west of Gantheaume Bay, Western Australia, 27°56′06.6″S, 113°04′51.6″E – 27°56′39″S, 113°05′16.8″E, 417–428 m, trawl, FRV Southern Surveyor, 4 Dec. 2005; CSIRO H6371-05, 3, 81.3– 114.7 mm SL, west of Geraldton, Western Australia, 28°59′24″S, 113°45′54″E –28°59′48″S, 113°46′08.4″E, 389– 407 m, trawl, FRV Southern Surveyor, 3 Dec. 2005; CSIRO H6372-02, 129.4 mm SL, west of Lancelin, Western Australia, 31°00′45″S, 114°49′30″E –31°00′16.8″S, 114°49′22.8″E, 393–394 m, trawl, FRV Southern Surveyor, 1 Dec. 2005; CSIRO H6375-01, 126.7 mm SL, west of Shark Bay, Western Australia, 25°55′39.6″S, 112°14′34.8″E – 25°56′17.4″S, 112°14′45.6″E, 404–407 m, trawl, FRV Southern Surveyor, 6 Dec. 2005; CSIRO H6377-01, 100.8 mm SL, northwest of Geraldton, Western Australia, 28°29′22.2″S, 113°25′08.4″E –28°30′03.6″S, 113°25′30″E, 416–431 m, sherman benthic sled, FRV Southern Surveyor, 4 Dec. 2005; CSIRO H6460-10, 78.6 mm SL, west of Parth, Western Australia, 31°37′04.8″S, 114°58′19.2″E –31°37′23.1″S, 114°57′57.6″E, 364–404 m, trawl, FRV Southern Surveyor, 19 Nov. 2005.
Diagnosis and description. The diagnosis and description of this species are the same as for the genus. Meristics and morphometrics of N. nielseni examined in this study given in Table 2.
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a between 6th dorsal-fin spine base and lateral line, b between last dorsal-fin spine base and lateral line, c at vertical midline of eye, d at posterior end of preocular spine base
Distribution. Neoscorpaena nielseni is widely distributed in the southern Indian Ocean, having been recorded from South Africa, north of Mozambique, Madagascar, Seychelles, Réunion, Mauritius, and Western Australia (Smith 1964; Eschmeyer 1986; Motomura et al. 2011; Poss & Motomura 2022; this study) (Fig. 4).
Remarks. All of the present specimens of N. nielseni from the southeastern Indian Ocean conformed to the following characteristics of the species given by Motomura et al. (2011): usually 10 dorsal-fin soft rays; usually 18 pectoral-fin rays; usually 25 pored lateral-line scales; 5–7 gill rakers on upper limb, 12 or 13 on lower limb, total 17– 20; usually five scale rows above lateral line; usually 10 scale rows below lateral line; usually 6 scale rows between sixth dorsal-fin spine base and lateral line; usually 5 scale rows between last dorsal-fin spine base and lateral line; 4–12 suborbital spines; second preopercular spine present; parietal spine absent; anterior lacrimal spine rounded (not spinous); and pectoral fin bilobed. The number of scale rows of the examined specimens differed slightly from those given by Motomura et al. (2011): scale rows in longitudinal series 34–40 (32–37 in the latter); and predorsal scales 5–7, usually 6 (6–8). However, these differences were here considered to represent intraspecific variations. Although Motomura et al. (2011) redescribed N. nielseni based on 12 specimens, many of them had lost scales, with only three having complete countable scale rows, and thus hiding possible intraspecific variation. Similarly in the present study, only 4 of 35 specimens examined had complete countable scale rows. Accordingly, the full extent of intraspecific variation in the number of scale rows in this species remains unknown.
Motomura et al. (2011) reported that larger specimens of N. nielseni had a greater number of scale rows in the longitudinal series (35–37 in specimens of 159.5–216.1 mm SL vs. 33–35 in specimens of 65.7–135.8 mm SL), and concluded that differences were due to individual and ontogenetic variation, although further examination of large specimens was needed. Nonetheless, a wide range in number of scale rows in the longitudinal series (34–40) was noted here in 10 specimens of medium size (100.8–147.8 mm SL), suggesting that individual variation in the number of scale rows exists, regardless of body size. Motomura et al. (2011) also noted that larger specimens had a longer snout, which was confirmed here (12.2% of SL, CAS 236690, 175.4 mm SL, cf. 10.8–12.1% of SL, 34 specimens, 78.6–148.4 mm SL) (Table 2).
The present study extended the distribution range of N. nielseni to Mauritius (southwestern Indian Ocean) and Western Australia (southeastern Indian Ocean). Although Hutchins (2001) listed Neoscorpaena nielseni (as Neomerinthe nielseni) on his checklist of the fishes of Western Australia, based on WAM P. 31801-001 (124 mm SL), that specimen was later identified as an example of genus Phenacoscorpius by Motomura et al. (2011). Therefore, the present study is the first to record N. nielseni from waters off Australia, based on bona fide specimens. Incidentally, WAM P. 31801-001 was examined here and identified as a species of Neomerinthe, having three suborbital spines, branched pectoral-fin rays and lacking an occipital pit.
The species has been collected from depths of 40–507 m (Motomura et al. 2011), the Australian specimens examined here having been collected in depths between ca. 320–431 m (excluding CSIRO H2608-13, coll. betw. 320–850 m).
Comparative material examined. Neomerinthe amplisquamiceps (Fowler 1938) (8 specimens, 45.2–130.5 mm SL): all specimens listed in Matsumoto & Motomura (2023). Neomerinthe bauchotae Poss & Duhamel 1991 (2 specimens, 74.2 and 79.8 mm SL): MNHN 1989-0273, holotype, 74.2 mm SL, Amsterdam Island, 38°48′S, 77°34′E, 350–412 m, 18 July 1976; CAS 70095, paratype, same data as holotype. Neomerinthe beanorum (Evermann & Marsh 1900) (3 specimens, 103.5–111.4 mm SL): CAS 24384, 2 specimens, 103.5 and 111.4 mm SL, Belize, 17°28′30″N, 87°57′30″W, ca. 274.3–329.2 m, 23 Jan. 1967; USNM 438712, 107.7 mm SL, Prince Rupert Bay, Portsmouth, Dominica, 15°33′33.5″N, 61°28′17.0″W, 99–304 m, D. Felder, A. Schrier, B. Van Bebber, & M. G. Harasewych, 8 Mar. 2016. Neomerinthe bucephalus (Alcock 1896) (60 specimens, 43.2–140.4 mm SL): 55 specimens listed in Matsumoto & Motomura (2023) and 5 specimens listed in Matsumoto & Motomura (2024a). Neomerinthe costata Matsumoto & Motomura 2024b (11 specimens, 32.2–86.9 mm SL): all specimens listed in Matsumoto & Motomura (2024b). Neomerinthe erostris (Alcock 1896) (57 specimens, 22.8–89.3 mm SL): all specimens listed in Matsumoto et al. (2023). Neomerinthe folgori (Postel & Roux 1964) (1 specimen, 279.5 mm SL): MNHN 1963-0600, holotype, 279.5 mm SL, Brava Island, Cabo Verde, 14°45′00.0″N, 24°40′01.0″W, 200 m, Dec. 1963. Neomerinthe harenartis Matsumoto & Motomura 2023 (4 specimens, 97.4–123.4 mm SL): all specimens listed in Matsumoto & Motomura (2023). Neomerinthe hemingwayi Fowler 1935 (4 specimens, 100.7–386.6 mm SL): KAUM –I. 181061, 383.6 mm SL, KAUM –I. 181062, 378.4 mm SL, off North Caroline, USA, 34°49′45.6″N, 75°26′54.6″W – 34°48′47.6″N, 75°27′06.6″W, 192–230 m, 11 Mar. 2020; TCWC 7446.06, 2 specimens,100.7 and 121.8 mm SL, Mustang Island, Gulf of Mexico, USA, 27°43′40″N, 96°11′26″W, 76 m, 6, Aug. 1993. Neomerinthe kaufmani (Herre 1952) (51 specimens, 49.4–91.5 mm SL): all specimens listed in Matsumoto & Motomura (2023). Neomerinthe megalepis (Fowler 1938) (59 specimens, 36.7–89.6 mm SL): all specimens listed in Matsumoto & Motomura (2023). Neomerinthe naevosa Motomura, Béarez & Causse 2011 (1 specimen, 52.2 mm SL): listed in Matsumoto & Motomura (2024a). Neomerinthe ornithoptera Matsumoto & Motomura 2024a (3 specimens, 67.0– 70.2 mm SL): all specimens listed in Matsumoto & Motomura (2024a). Neomerinthe parallelaspina Matsumoto & Motomura 2024b (53 specimens, 34.2–96.4 mm SL): all specimens listed in Matsumoto & Motomura (2024b). Neomerinthe rufescens (Gilbert 1905) (29 specimens, 26.9–82.7 mm SL): all specimens listed in Matsumoto & Motomura (2024a). Neomerinthe sp. (1 specimen): WAM P. 31801-001, 124 mm SL, North West Cape, Western Australia, Australia, 21°26′25″S, 114°08′17″W, AIMS, 13 Mar. 2001.
description: Published as part of Matsumoto, Tatsuya & Motomura, Hiroyuki, 2025, Re-establishment of the monotypic genus Neoscorpaena Mandrytsa 2001 (Teleostei: Scorpaenidae), with a range extension of N. nielseni (Smith 1964) to the eastern Indian Ocean, pp. 173-185 in Zootaxa 5633 (1) on pages 179-182, DOI: 10.11646/zootaxa.5633.1.10, http://zenodo.org/record/15372683