Minous trachycephalus ( Bleeker 1855 )

Matsunuma, Mizuki & Motomura, Hiroyuki, 2018, Three new species of the Indo-Pacific stingfish genus Minous (Synanceiidae: Minoinae) with redescriptions of M. trachycephalus (Bleeker 1855) and M. pictus Günther 1880, Zootaxa 4455 (2), pp. 201-257 : 225-236

Minous trachycephalus ( Bleeker 1855)

English name: Striped Stingfish

Figures 9D–F , 10 , 13D, E , 14–18 , 19G–K , 20E , 24B ; Tables 1–5, 7

Aploactis trachycephalus Bleeker 1855: 451 (original description; type locality: Manado, Sulawesi, Indonesia; holotype: RMNH.PISC. 5901).

Corythobatus trachycephalus: Bleeker 1865: 282 (listed).

Minous trachycephalus: Eschmeyer et al. 1979: 465 , figs. 1, 6 (northeastern Indian Ocean and northwestern Pacific oceans; description, synonymy, nomenclatural remarks on holotype); Allen & Erdmann 2012: 243, unnumbered fig. (East Indies; short description); Motomura 2013: 85, unnumbered fig. (Thailand, Gulf of Thailand; short description; specimen: KAUM–I. 23829); Matsunuma et al. 2017: 1289, figs. 1b, 2a (Red Sea; description).

Minous pictus not of Günther: Günther 1880: 41, pl. 18, fig. D (Arafura Sea, south of New Guinea; in part); Allen et al. 2003: 380, unnumbered fig. (Pacific Ocean; ecological and identification notes); Naranji et al. 2017: 1, fig. 1 (Visakhapatnam, India, Bay of Bengal; in part; description).

Holotype. RMNH. PISC. 5901, 55.9 mm SL, Manado , Sulawesi, Indonesia.

Paralectotype of M. pictus . BMNH 1879.5 .14.372, 36.6 mm SL, Arafura Sea , south of New Guinea, 09°59′S, 139°42′E, 28 fm. (ca. 51 m) depth, Challenger station 188, 10 Sep. 1874.

Non-type Bleeker specimens: 5 specimens, 33.1–43.8 mm SL: BMNH 1880.4. 21.110, 43.8 mm SL, Manado, Sulawesi, Indonesia; RMNH .PISC. 38554, 53.9 mm SL, RMNH.PISC. 38555, 52.0 mm SL, RMNH.PISC. 38556, 45.9 mm SL, RMNH. PISC. 38557, 33.1 mm SL, Manado , Sulawesi, Indonesia.

Other non-type specimens: 51 specimens, 16.5–70.4 mm SL: Thailand (Gulf of Thailand): KAUM –I. 23829, 43.5 mm SL, KAUM –I. 23830, 49.7 mm SL, KAUM –I. 24086, 51.2 mm SL, KAUM –I. 24087, 56.8 mm SL, Gulf of Thailand , trawl ; KAUM –I. 47803, 47.6 mm SL, Fish landing bridge at Klong Wan, Prachuab Khirikhan Province , 11°44′33″N, 99°47′26″E, trawl; URM-P 9 0 22, 54.6 mm SL, Songkhla fish market, trawl, 9 Apr. 1984 ; URM-P12 155, 35.8 mm SL, Songkhla fish market, trawl, 21 Oct. 1983 . Thailand (Andaman Sea): KAUM –I. 33284, 70.4 mm SL, KAUM –I. 33285, 61.2 mm SL, KAUM –I. 33286, 59.6 mm SL, KAUM –I. 33287, 56.5 mm SL, KAUM –I. 33288, 55.7 mm SL, KAUM –I. 33289, 44.3 mm SL, Pak Nam Ranong fishing port , Ranong, 09°56′N, 98°35′E, trawl. Malaysia (Borneo): KAUM –I. 49280, 55.2 mm SL, KAUM –I. 49281, 44.5 mm SL, KAUM –I. 49282, 50.8 mm SL, off Kota Kinabalu , Sabah, 06°00′N, 116°07′E, 12 Aug. 2012 . Philippines: CAS 29371, 39.4 mm SL, Buenavista, Mindanao, F. B. Steiner, 14 Apr. 1973 ; USNM 272154 , 39.7 mm SL, east of Sicogon Island, Visayan Sea between Northern Negross and Masbate, 11°27′45″N, 123°23′45″E, 47.6 m depth, L. Alcala et al., RV Sting Ray, 4 June 1978 . Vanuatu: USNM 350129 , 26.0 mm SL, Ranon Bay, Ambrym Island , Vanuatu Islands , 17°51′34″S, 168°07′01″E, 9–16 m depth, J. T. Williams and D. G. Smith, 26 May 1997 . New Caledonia: MNHN 2005-2618, 49.6 mm SL, Belep Island , 19°45′00′′S, 163°45′00′′E, RV Vauban, 16 June 1985 . Australia (Arafura Sea): AMS I.21842-007, 53.2 mm SL , Northern Territory , Arafura Sea, 10°37′11′′S, 133°46′48′′E, RV Soela, 16 Nov. 1980; NTM S.12970-001, 53.7 mm SL , Arafura Sea , Northern Territory, 09°53′S, 136°18′E, 54–55 m depth, H. Larson, 29 Oct. 1990 ; NTM S.13270-003, 2 specimens, 45.6–58.1 mm SL, Gulf of Carpentaria , Queensland, 11°04′S, 139°56′E, 57 m depth, R. Williams, 29 Nov. 1991 . Australia (Western Australia): CSIRO H1477-2, 43.2 mm SL, north of Dampier Archipelago , Western Australia, 20°06′–09′S, 116°39′–40′E, 49–50 m depth, FRV Soela, demersal trawl, 24 Sept. 1988 ; NMV A29708 -007, 22.7 mm SL, northwestern Australia , 16°44′25″–07″S, 121°01′54″E, 109–112 m depth, Broome L 25 transect, RV Southern Surveyor, 30 June 2007 ; NTM S.11673-005, 52.2 mm SL, south of Rowley Shoals, Northeast Shelf , Western Australia, 19°12′S, 118°41′E, 76–80 m depth, NT Fisheries, 1 June 1985 . Coral Sea: CSIRO H3442-02, 47.1 mm SL, east of Cape York Peninsula , Queensland, 11°34′S, 143°30′E, 40 m depth, 30 May 1993 ; CSIRO H4151-03, 54.6 mm SL, east of Cape York Peninsula , Queensland, 11°42′S, 143°27′E, FRV Gwendoline May, trawl, 14 Mar. 1995 . Maldives: BMNH 1901.12.31.21-23, 3 specimens, 16.5–24.4 mm SL, Maldives. Yemen: CAS 227832 , 44.8 mm SL, Aden . Egypt (Red Sea): MNHN 1966-0437 , 47.4 mm SL, El-bahr El-ahmar , 28°52′12′′N, 32°45′00′′E, RV Al Sayad, 8 Dec. 1928 . Israel (Red Sea): HUJ 1633 , 55.0 mm SL, Eilat, May 1951 ; HUJ 14005, 32.6 mm SL, Eilat, 8 Sept. 1986; HUJ 14681, 55.2 mm SL, Eilat, 23 June 1965; HUJ 14682, 52.8 mm SL, Eilat, 14 July 1965; SAIAB 4152 , 56.0 mm SL, Eilat , 29°32′59′′N, 34°57′00′′E, M. Dor, 1 June 1965 . Eritrea: HUJ 20655, 25.3 mm SL, Horgigo Bay , 3 Apr. 1961 . Saudi Arabia: KAUMM 422 , 35.0 mm SL, off Jizan, 16°34′N, 42°33′E, 30–32 m depth, 4 Nov. 2014 ; SMF 35844, 38.0 mm SL, off Jizan, 16°45′N, 42°29′E, 28–30 m depth, 5 Nov. 2014 . Madagascar: SAIAB 53292 , 3 specimens, 48.9–60.9 mm SL, east of Nosy Komba , 13°23′59′′S, 48°16′59′′E, H. Phillip, bottom trawl, 2 Sept. 1995 .

Diagnosis. A species of Minous distinguished from other congeners by the following combination of characters: 1st dorsal-fin spine much shorter than 2nd dorsal-fin spine, their bases close together; dorsal-fin rays X or XI, 9–11 (modally XI, 10), total rays 20–23 (21); anal-fin rays I–III, 7–9 (II, 8), total rays 9–11 (10); anterior and posterior lacrimal spines sharp, anterior spine tip canted anteroventrally, posterior spine tip usually canted ventrally to posteroventrally (angle to horizontal axil of head and body variable) but never curved anteroventrally as in M. roseus ; body grayish dorsally ( Figs. 14 , 15 ), without oblique alternating dark and light stripes; pectoral fin inner surface with many dark bordered bright yellow (whitish in preserved specimens) blotches basally, forming somewhat hexagonal pattern when fresh, distal portion largely yellow (whitish) when fresh ( Figs. 13E , 16 ); pore above pectoral-fin base with or without short blunt rounded skin flap.

Distribution. Minous trachycephalus is widely distributed throughout the Indo-West Pacific region, from the Red Sea and Madagascar east to Vanuatu and New Caledonia, and northern Australia north to the Gulf of Thailand (based on examined specimens) ( Fig. 10 ). Although the species has actually been recorded from a more widespread area, including Taiwan, Vietnam, Sumatra ( Indonesia), India and Sri Lanka ( Eschmeyer et al. 1979; Mishra et al. 1999; Poss 1999), confirmation of this extended range based on voucher specimens is necessary, owing to previous taxonomic confusion of the species with congeners (see synonym lists). Underwater photographs of the species from the East Indies, also reported by Allen & Erdmann (2012), are shown here as Fig. 13D, E (from Lembeh Strait, North Sulawesi, Indonesia). Sampling data for eight specimen lots recorded their collection mostly by bottom trawl at depths of 9–112 m (mostly> 50 m depth).

Remarks. Meristic and morphometric values taken from examined specimens are given in Tables 1–5, 7. The other meristic values without individual variations are as follows: pectoral-fin rays 12; pelvic fin rays I, 5; vertebrae 11 + 14 = 25.

An underwater photograph reported by Allen et al. (2003) as M. pictus was identified here as M. trachycephalus , lacking oblique alternating dark and light stripes on the body and a longitudinal yellow band on the dorsal fin (see Species comparisons). Although Naranji et al. (2017) recorded M. pictus from India, their photograph is also identical with M. trachycephalus , based on the diagnostic coloration of the dorsal fin and pectoral fin inner surface. However, Naranji et al.’s (2017) description of highly variable coloration on the pectoral fin inner surface and broad range of dorsal-fin ray meristics (IX–XII, 9–13) suggests that their materials included several species of Minous .

Variations in diagnostic characters. Individual or geographical variations in several morphological features were apparent in the examined specimens of M. trachycephalus . Specimens from Sabah, Malaysia (Borneo) differed from those from the Andaman Sea by having a paler caudal fin ( Fig. 15D, F ) [vs dusky and scattered with numerous minute melanophores in the latter ( Fig. 15A, B )] and relatively pale dorsum, with a distinct dark blotch below the middle of the dorsal-fin base in small specimens (ca. 40–50 mm SL) ( Fig. 13F ) (vs darker dorsum without a distinct blotch). The coloration of specimens from the Gulf of Thailand (geographically between the Andaman Sea and Borneo) and Australia ( Fig. 15C, E, G, H ) appeared to be intermediate between those of the Andaman Sea and Bornean specimens. Moreover, the Bornean specimens also had the posterior lacrimal spine tip tending to be more ventrally canted ( Fig. 19I ) than in the Andaman Sea specimens ( Fig. 19J ) in a range of comparable growth stages. Further morphological and genetic analyses based on a greater number of specimens of M. trachycephalus from throughout its distributional range are necessary to determine the trends in such variations.

Note on the holotype. Minous trachycephalus was originally described by Bleeker (1855) (as Aploactis trachycephalus ) based only the holotype from Manado, Sulawesi, Indonesia, stating “Longitudo speciminis unici 75′′′. [Length (= total length) of the single specimen 75 mm]”. Subsequently, Hubrecht (1879) reported a total of eight Bleeker specimens of M. trachycephalus (group A, 5 specimens; group B, 2 specimens; group C, 1 specimen). Five group A specimens were originally registered as RMNH.PISC. 5901 [55.9 mm SL (caudal fin broken), 53.9 mm SL (caudal fin broken), 52.0 mm SL (65.7 mm TL), 45.9 mm SL (caudal fin broken) and 33.1 mm SL (44.4 mm TL)] ( Fig. 17A–E ). Another Bleeker specimen of A. trachycephalus is registered as BMNH 1880.4.21.110 [43.8 mm SL (59.5 mm TL)] ( Fig. 17F ). According to Hubrecht (1879), the primary type specimen was included within group A, Eschmeyer et al. (1979) also pointing out that the holotype of A. trachycephalus was included in RMNH.PISC. 5901 (mixed up with four non-type specimens). Among the original five specimens of RMNH.PISC. 5901, the total lengths (65.7 mm TL and 44.4 mm TL) of 52.0 mm-SL and 33.1 mm-SL specimens are inconsistent with that of the holotype of A. trachycephalus . Although the caudal fins of the remaining three specimens (55.9 mm SL, 53.9 mm SL and 45.9 mm SL) are damaged, the total lengths of the specimens could be estimated as 75.4 mm TL, 72.8 mm TL and 62.3 m TL, respectively, based on measurements of 26 undamaged specimens of M. trachycephalus (TL = 1.3043*SL + 2.4503). The total length (estimated) of the largest Bleeker Group A specimen (55.9 mm SL, 75.4 mm TL), being closest and similar to that of the holotype of A. trachycephalus given by Bleeker (1855), is therefore regarded here as the holotype of the species ( Fig. 17A ), the remaining four specimens (reregistered as RMNH.PISC. 38554–38557) having no type status ( Fig. 17B–E ).

Species comparisons. M. roseus , M. groeneveldi and M. trachycephalus vs other congeners. Minous roseus sp. nov., M. groeneveldi sp. nov. and M. trachycephalus all have the pectoral fin inner surface broadly yellow distally, with dark radial stripes along the rays ( M. roseus and M. groeneveldi ) or a dark hexagonal or nearly hexagonal pattern ( M. trachycephalus ). Although M. pusillus possesses similar pectoral fin markings ( Fig. 4F–H ), such markings form radial stripes in small specimens (<ca. 40 mm SL) ( Fig. 4H ), becoming a minute hexagonal or nearly hexagonal pattern in larger specimens ( Fig. 4G, H ), whereas the dark markings in M. roseus and M. trachycephalus (no information for M. groeneveldi ) do not change with growth. Minous pusillus is also readily distinguished from M. trachycephalus and M. groeneveldi by the absence of a yellow or light-colored band on the dorsal fin (vs present in M. trachycephalus and M. groeneveldi ) and a largely grayish dorsum [vs almost entirely pinkish or reddish when fresh (entirely creamy-white in preserved specimens) in M. roseus ].

Moreover, M. pusillus possesses relatively long, hair-like dorsal-fin spines (thinner than soft rays) ( Fig. 3G, H ) [first dorsal-fin spine length 8.1–15.7% (mean 11.3%) of SL], compared with relatively short strong (inflexible) dorsal-fin spines in M. roseus , M. groeneveldi and M. trachycephalus [first dorsal-fin length 3.9–7.7% (6.0%) of SL in M. roseus , 5.8% of SL in M. groeneveldi and 3.2–9.3% (6.3%) of SL in M. trachycephalus ] ( Fig. 18D ). Minous pusillus also has a relatively smaller head [length 38.3–45.6% (mean 42.0%) of SL in M. pusillus vs 41.9– 47.6% (45.8%) of SL in M. roseus , 45.1% of SL in M. groeneveldi and 42.4–48.3% (45.1%) of SL in M. trachycephalus ], shorter snout [length 11.1–15.6% (13.6%) of SL vs 16.2–18.6% (17.4%) of SL, 17.0% of SL and 14.9–17.1% (16.1%) of SL] and narrower interorbital space [width at mid-orbit 5.9–9.9% (7.3%) of SL vs. 10.1– 12.5% (11.4%) of SL, 11.0% of SL and 8.4–12.1% (10.2%) of SL] ( Fig. 18A–C ). Minous pusillus further differs from M. roseus , M. groeneveldi and M. trachycephalus in having modally 21 total dorsal-fin rays (vs 22 in M. roseus and M. groeneveldi ), modally 10 total anal-fin rays (vs 11 in M. roseus and M. groeneveldi ), modally 11 lower gill-rakers (vs 8 in M. roseus and M. groeneveldi ; 9 in M. trachycephalus ), modally 13 total gill rakers (10 in M. roseus and M. groeneveldi ; 11 in M. trachycephalus ) and 11 + 14 = 25 vertebrae (11 + 15 = 26 in M. roseus and M. groeneveldi ) (see Tables 1, 2, 4, 5).

In addition to the differences in pectoral fin inner surface coloration, M. roseus , M. groeneveldi and M. trachycephalus can be readily distinguished from M. andriashevi , M. monodactylus , M. quincarinatus , M. usachevi and M. versicolor ( Fig. 3A–F ) by the first dorsal-fin spine being much shorter than the second spine (first dorsal-fin spine length 29–37%, 36% and 19–61% of second spine length in M. roseus , M. groeneveldi and M. trachycephalus , respectively), with bases close together, whereas both spines are of similar length (first dorsal-fin spine length 91–152% of second spine length) with well separated bases in the other five species. Moreover, M. inermis and M. longimanus ( Fig. 3I, J ) differ from M. roseus , M. groeneveldi and M. trachycephalus in having a longer pectoral fin, its length 45.2–59.3% (mean 51.2%) of SL and 51.7–63.6% (57.9%) of SL in M. inermis and M. longimanus , respectively, with the tip almost reaching to or extending beyond the end of the anal-fin base [pectoral-fin length 34.8–44.4% (39.8%) of SL, 38.0% of SL and 38.0–49.6% (43.3%) of SL in M. roseus , M. groeneveldi and M. trachycephalus , respectively: tip never reaching to the end of anal-fin base]. The remaining congeners, including M. coccineus , M. dempsterae , M. pictus and M. radiatus sp. nov. ( Figs. 3K, L , 23 , 24 ), can be also readily distinguished from M. roseus , M. groeneveldi and M. trachycephalus by their oblique alternating dark and light stripes on the body (absent in the latter three species).

Minous trachycephalus vs M. roseus and M. groeneveldi . Minous trachycephalus differs from M. roseus and M. groeneveldi in having fewer dorsal-fin soft rays [9–11 (modally 10) in M. trachycephalus vs 10–12 (11) in M. roseus and 11 in M. groeneveldi ], total dorsal-fin rays [20–22 (21) vs 21 or 22 (22) and 22], anal-fin soft rays [7–9 (8) vs 8–10 (9) and 9], total anal-fin rays [9–11 (10) vs 10–12 (11) and 11], lateral-line tubes [13–18 (15) vs 15–19 (17) and 16] and vertebrae (11 + 14 = 25 vs 11 + 15 = 26 in M. roseus and M. groeneveldi ) (Tables 1–3), in addition to morphometric differences: narrower interorbital width at preocular spine base [6.4–9.4% (mean 7.7%) of SL in M. trachycephalus vs 7.8–10.8% (9.1%) in M. roseus and 9.2% in M. groeneveldi ] and shorter second dorsal-fin spine [11.1–18.1% (14.1%) of SL vs 15.3–21.0% (18.3%) and 15.9%] ( Fig. 19B, C ). Moreover, the pectoral fin inner surface in M. trachycephalus has darkly margined bright yellow (lighter in preserved specimens) blotches, forming a hexagonal or nearly hexagonal pattern ( Figs. 9D–F , 13E 16 ), whereas dark stripes along the rays on a bright yellow background characterize the other two species ( Figs. 7B , 9A–C , 11D , 13B ). The body of M. trachycephalus is primarily grayish dorsally in large specimens> 50 mm SL ( Figs. 14A, B , 15 ), but broadly pinkish or yellowish (lighter in preserved specimens), except for dark blotches below the middle and posterior portions of the dorsal-fin base, in M. roseus and M. groeneveldi ( Fig. 6B, C , 7 , 11B, C , 12 ).

Minous roseus vs M. groeneveldi and M. trachycephalus . Minous roseus sp. nov. is clearly distinguished from M. groeneveldi and M. trachycephalus in having sharp anterior and posterior lacrimal spines, the tip of the former canted anteroventrally and that of the latter canted anteroventrally or ventrally in large specimens> 60 mm SL ( Fig. 20D–F ), whereas both lacrimal spines are relatively bunt with ventrally canted tips in M. groeneveldi ( Fig. 20B ); sharp, with the anterior spine tip canted anteroventrally and that of the posterior spine usually canted ventrally or posteroventrally (angle to horizontal axis of head and body variable) but never curved anteroventrally in M. trachycephalus ( Fig. 20H–K ). Moreover, M. roseus differs from M. groeneveldi and M. trachycephalus in having an elongate tentacle-like skin flap [blunt and short or absent in 3 of 13 examined specimens] on a pore above the pectoral-fin base in specimens> 40 mm SL, the tentacle length much greater than the pore diameter ( Fig. 21B–D ), whereas a blunt, thick skin flap (absent in 3 of 18 examined specimens of M. trachycephalus ) occurred in the latter two species ( Fig. 21E, F ).

Minous groeneveldi vs M. roseus . Minous groeneveldi sp. nov. is closely related to M. roseus , sharing a similar color pattern on the pectoral fin inner surface. However, M. groeneveldi differs in having lesser head depth [17.6% of SL in the former vs 18.8–21.6% (20.0%) of SL in M. roseus ] ( Fig. 19A ), a horizontal line parallel to the head and body axis through the top of the snout bulge meeting the ventral margin of pupil in the 77.7 mm SLholotype ( Fig. 20A ) (compared with well below the ventral margin of pupil in> 60 mm SL-specimens of M. roseus ; Fig. 20C ). Minous groeneveldi also has the body yellowish dorsally, with a relatively broad dark stripe centrally, in the fresh holotype (77.7 mm SL) ( Fig. 12 ), compared with largely pale pink or yellow, with a narrow dusky stripe centrally, in large specimens of M. roseus .

TABLE 7. Selected meristic and morphometric values (expressed as percentages of standard length) recorded from specimens of Minous trachycephalus (including holotype of Aploactis trachycephalus

and paralectotype of M. pictus ).

……continued on the next page

TABLE 7. (Continued)

Gill raker counts include upper + lower = total gill rakers. Modes and means include all specimens.

Figures

FIGURE 3. Specimens of Minous andriashevi (A–B), M. quincarinatus (C), M. usachevi (D), M. versicolor (E), M. monodactylus (F), M. pusillus (G, H), M. longimanus (I), M. inermis (J), M. coccineus (K) and M. dempsterae (L). (A) ZIN 49334, holotype, 56.8 mm SL, western Indian Ocean; (B) CAS 64623, 25.4 mm SL, Somalia; (C) BSKU 117662, 92.4 mm SL, Japan; (D) ZIN 50132, paratype, 112.7 mm SL, Gulf of Aden; (E) WAM P.31888.002, 71.4 mm SL, Australia; (F) KAUM–I. 29961, 63 mm SL, Japan; (G) KAUM–I. 24581, 35.9 mm SL, Japan; (H) KAUM–I. 31342, 57.2 mm SL, Japan; (I) SAIAB 84308, 1 of 17 specimens, 82.5 mm SL, Saya de Malha Bank; (J) BMNH 1939.5.24.1661-1670, 1 of 11, 70.8 mm SL, Gulf of Aden; (K) KAUM–I. 33291, 103.0 mm SL, Thailand; (L) USNM 218419, 1 of 4, 78.2 mm SL, India. A, B, D, E, I, J and L specimens preserved; C, F–H and K specimens fresh. Photos: Gota Ogihara (A and D).

FIGURE 4. Inner surfaces of pectoral fins in Minous andriashevi (A), M. quincarinatus (B), M. usachevi (C), M. versicolor (D), M. monodactylus (E) and M. pusillus (F–H). (A) ZIN 49334, holotype, 56.8 mm SL, western Indian Ocean; (B) KAUM–I. 9941, 107.0 mm SL, Taiwan; (C) ZIN 50132, paratype, 112.7 mm SL, Gulf of Aden; (D) HUMZ 64248, 71.3 mm SL, Australia; (E) KAUM–I. 31082, 71.5 mm SL, Japan; (F) KAUM–I. 31342, 57.2 mm SL, Japan; (G) KAUM–I. 24425, 50.6 mm SL, Japan; (H) KAUM–I. 24581, 35.9 mm SL, Japan. A, C and D specimens preserved; B and E–H specimens fresh. Photos: Gota Ogihara (A, C and D).

FIGURE 6. Preserved specimens of Minous roseus sp. nov. at different growth stages. (A) CSIRO CA1844, holotype, 72.1 mm SL, Western Australia; (B–C) NTM S.13974-005, paratype, 63.9 mm SL, Western Australia; (D) CSIRO CA1576, paratype, 53.2 mm SL, Western Australia; (E) CSIRO CA1576, paratype, 53.2 mm SL, Western Australia; (F) CAS 60400, 40.2 mm SL, Maldives; (G) AMS I.22832-012, paratype, 32.8 mm SL, Western Australia.

FIGURE 7. Fresh specimens of Minous roseus sp. nov.—lateral views (A, C);—pectoral fin inner surface (B). (A–B) CSIRO CA1844, holotype, 72.1 mm SL, Western Australia; (C) CSIRO CA1576, paratype, 53.2 mm SL, Western Australia. Photos: CSIRO.

FIGURE 9. Inner surfaces of pectoral fins in preserved specimens of Minous roseus sp. nov. (A–C) and M. trachycephalus (D–F). (A) CSIRO CA1844, holotype, 72.1 mm SL, Western Australia (right side, reversed); (B) KAUM–I. 113069, paratype, 52.8 mm SL, Western Australia; (C) NMV A29722-006, paratype, 44.2 mm SL, Western Australia; (D) RMNH.PISC. 5901, holotype, 55.9 mm SL, Indonesia; (E) KAUM–I. 33284, 70.4 mm SL, Gulf of Thailand; (F) BMNH 1879.5.14.372, paralectotype of M. pictus, 36.6 mm SL, Arafura Sea. Photos: Gota Ogihara (A, C and D).

FIGURE 10. Distributional maps of Minous trachycephalus (purple squares); M. groeneveldi sp. nov. (yellow stars); M. roseus sp. nov. (blue circles); M. andriashevi (gray downward triangles); M. pictus (yellow upward triangles); and M. radiatus sp. nov. (green diamonds). White arrowheads indicate type localities. Black arrowheads indicate photographic records (Lembeh Strait, North Sulawesi, Indonesia).

FIGURE 11. Preserved holotype of Minous groeneveldi sp. nov. (NTM S.11031-002, 77.7 mm SL, Indonesia)—Lateral views (A, B); dorsal view (C);—magnifications of pectoral fin inner surface (right side, reversed) (D) and pelvic fin (E).

FIGURE 12. Fresh holotype of Minous groeneveldi sp. nov. [NTM S.11031-002, 77.7 mm SL, Indonesia (right side, reversed)]. Photo: Thomas Gloerfelt-Tarp.

FIGURE 13. Underwater photographs of Minous groeneveldi sp. nov. (A–C) and M. trachycephalus (D, E) from Lembeh Strait, North Sulawesi, Indonesia. Photos: Rokus Groeneveld.

FIGURE 14. Preserved specimens of Minous trachycephalus. (A, B) KAUM–I. 33284, 70.4 mm SL, Gulf of Thailand; (C) NTM S.13270-003, 1 of 2 specimens, 58.1 mm SL, Australia; (D) SAIAB 53292, 1 of 3, 48.9 mm SL, Madagascar; (E) MNHN 2005-2618, 49.6 mm SL, New Caledonia; (F) USNM 272154, 39.7 mm SL, Philippines.

FIGURE 15. Fresh specimens of Minous trachycephalus. (A) KAUM–I. 33284, 70.4 mm SL, Thailand (Andaman Sea); (B) KAUM–I. 33285, 61.2 mm SL, Thailand (Andaman Sea); (C) KAUM–I. 24087, 56.8 mm SL, Thailand (Gulf of Thailand); (D) KAUM–I. 49280, 55.2 mm SL, Malaysia (Borneo); (E) KAUM–I. 23830, 49.7 mm SL, Thailand (Gulf of Thailand); (F) KAUM–I. 49281, 44.5 mm SL, Malaysia (Borneo); (G) CSIRO H4151-03, 54.6 mm SL, Australia (Queensland); (H) CSIRO H1477-2, 43.2 mm SL, Australia (Western Australia). Photos: Thor Carter (G and H).

FIGURE 16. Pectoral fin inner surface in fresh specimens of Minous trachycephalus. (A) KAUM–I. 33285, 61.2 mm SL, Thailand (Andaman Sea); (B) KAUM–I. 49280, 55.2 mm SL, Malaysia (Borneo); (C) KAUM–I. 49281, 44.5 mm SL, Malaysia (Borneo); (D) KAUM–I. 23829, 43.5 mm SL, Thailand (Gulf of Thailand).

FIGURE 17. Preserved holotype (A) and Bleeker non-type specimens (B–F) of Minous trachycephalus from Manado, Indonesia. (A) RMNH.PISC. 5901, holotype, 55.9 mm SL; (B) RMNH.PISC. 38554, 53.9 mm SL; (C) RMNH.PISC. 38555, 52.0 mm SL; (D) RMNH.PISC. 38556, 45.9 mm SL; (E) RMNH.PISC. 38557, 33.1 m SL; (F) BMNH 1880.4.21.110, 43.8 mm SL. Photos: Gota Ogihara.

FIGURE 18. Relationships of (A) head length; (B) snout length; (C) interorbital width at mid-orbit; and (D) 1st dorsal-fin spine length (all as % of standard length) to standard length (mm) in Minous roseus sp. nov. (blue circles), M. groeneveldi sp. nov. (yellow star, holotype), M. trachycephalus (purple squares) and M. pusillus (black crosses). Open arrowhead indicates paralectotype of M. pictus (= M. trachycephalus). Closed arrowheads indicate holotypes of M. roseus and M. trachycephalus, and lectotype of M. pusillus.

FIGURE 19. Relationships of (A) head depth; (B) interorbital width at preocular spine base; and (C) 2nd dorsal-fin spine length (all as % of standard length) to standard length (mm) in Minous roseus sp. nov. (blue circles), M. groeneveldi sp. nov. (yellow star, holotype) and M. trachycephalus (purple squares). Open and closed arrowheads indicate paralectotype of M. pictus (= M. trachycephalus) and holotype of M. roseus, respectively.

FIGURE 20. Lateral view of head (A, C, G) and lacrimal spines (semi-schematic) in Minous groeneveldi sp. nov. (A, B), M. roseus sp. nov. (C–F) and M. trachycephalus (G–K). (A, B) NTM S.11031-002, holotype, 77.7 mm SL, Indonesia; (C, D) CSIRO CA1844, holotype, 72.1 mm SL, Western Australia; (E) CSIRO CA1589, paratype, 53.9 mm SL, Western Australia; (F) NMV A29660-012, paratype, 33.5 mm SL, Western Australia; (G) RMNH.PISC. 5901, holotype, 55.9 mm SL, Indonesia; (H) KAUM–I. 33284, 70.4 mm SL, Thailand (Gulf of Thailand); (I) KAUM–I. 49280, 55.2 mm SL, Malaysia (Borneo); (J) KAUM–I. 33288, 55.7 mm SL, Thailand (Andaman Sea); (K) BMNH 1879.5.14.372, paralectotype of M. pictus, 36.6 mm SL, Arafura Sea. Red dotted lines (in A and C) indicate horizontal line through top of snout bulge. Red and blue arrowheads indicate anterior and posterior lacrimal spines, respectively. Bars indicate 1 mm.

FIGURE 21. Pores above pectoral-fin base and associated skin flap in Minous roseus sp. nov. (A–D), M. trachycephalus (E) and M. groeneveldi sp. nov. (F). (A) NTM S.13974-005, paratype, 63.9 mm SL, Western Australia; (B) CSIRO CA1844, holotype, 72.1 mm SL, Western Australia; (C) NMV A29712-004, paratype, 40.6 mm SL, Western Australia; (D) NMV A29660-012, paratype, 33.5 mm SL, Western Australia; (E) KAUM–I. 33284, 70.4 mm SL, Gulf of Thailand; (F) NTM S.11031-002, holotype, 77.7 mm SL, Indonesia. Red arrowhead (in A) indicates pore location. Blue arrowheads indicate skin flaps (absent in M. trachycephalus). Right side, reversed in A–C. Bars indicate 0.5 mm.

FIGURE 23. Fresh specimens of Minous radiatus sp. nov.—lateral view (A, C, E);—pectoral fin inner surface (magnified) (B, D, F). (A, B) KAUM–I. 39286, holotype, 89.6 mm SL, Taiwan; (C, D) KAUM–I. 23222, paratype, 89.0 mm SL, Gulf of Thailand; (E, F) KAUM–I. 24084, paratype, 67.4 mm SL, Gulf of Thailand. Right side, reversed in D and F.

FIGURE 24. Fresh specimens of Minous pictus—lateral view (A, C);—pectoral fin inner surface (magnified) (B, D). (A, B) CSIRO H1489-4, 101.8 mm SL, Australia; (C, D) CSIRO CA1679, 82.0 mm SL, Australia. Right side, reversed in A. Photos: Thor Carter (A and B) and Richard Martin (C and D).