Parascombrops glossodon Schwarzhans & Prokofiev

Schwarzhans, Werner W. & Prokofiev, Artem M., 2017, Reappraisal of Synagrops Günther, 1887 with rehabilitation and revision of Parascombrops Alcock, 1889 including description of seven new species and two new genera (Perciformes: Acropomatidae), Zootaxa 4260 (1), pp. 1-74 : 33-36

Parascombrops glossodon Schwarzhans & Prokofiev , new species

Fig. 7C , 8F , 9C , 12A, D , 13C , 14J–N , 18 , 35 , Tables 2–7

Material examined (46 specimens). Holotype USNM 436687, 70 mm SL, Philippines, Mindanao , Zamboango del Norte, Point Tagalo Light, 08°45’N, 123°33’E, 309 m, Albatross Philippines Expedition, 0 9. Aug. 1909 . Paratypes: AMS I.21835-026, 5 specimens, 54.5–72 mm SL, off Northern Territory, Australia, 09°37’S, 133°17’E, 156–164 m, CSIRO Soela , 15. Nov. 1980 ; BMNH 1986.10.9.79-85, 7 specimens, 41.5–72.5 mm SL, off Bali ; CAS 214605, 2 specimens, 68.5–70 mm SL, off Daxi , northeastern Taiwan, 24°56’N, 121°54’E, Iwamoto party, 19. Jul.2001 ; NMMB-P22001, 3 specimens, 76–84 mm SL, off Dong-gang , southwestern Taiwan ; NMMB-P23098, 86 mm SL, Dong-gang, southwestern Taiwan; NMMB-P23095, 5 specimens, Dong-gang , southwestern Taiwan ; NMMB- P11355, 85 mm SL, Dong-gang , southwestern Taiwan ; NMMB-P23101, 2 specimens, 56–64 mm SL, Dong-gang , southwestern Taiwan ; USNM 99335, 64.5 mm SL, off Mindoro , Philippines, 13°27’N, 121°17’E, 198 m, Albatross Philippines Expedition, 0 2. Feb. 1908 ; USNM 382250, 63 mm SL, off Myanmar, 10°39’N, 97°06’E, 290 m, International Indian Ocean Expedition , 24 Mar. 1963 ; USNM 436684, 73 mm SL, off Luzon , Philippines, 13°52’N, 120°46’E, 216 m, Albatross Philippines Expedition, 21. Jan. 1908 ; USNM 436685, 7 specimens, 55.5–64 mm SL, off Luzon , Philippines, 13°58’N, 120°21’E, 208 m, Albatross Philippines Expedition, 14. Jul. 1908 ; USNM 436686, 3 specimens, 69.5–77 mm SL, off Minadanao , Philippines, 08°46’N, 123°32’E, 320 m, Albatross Philippines Expedition, 0 9. Aug. 1909 ; USNM 438230, 2 specimens, 61.5–64.5 mm SL, same data as holotype ; ZMMGU 23812, 4 specimens, 67–80 mm SL, Arafura Sea , 09˚12΄0 S, 133˚29΄5 E, 197 m, “ Akademik Berg ”, 11.07.1967 .

Diagnosis. Moderately deep-bodied species with convex dorsal head profile. Anal fin II + 7. Pectoral fin with 14–16 rays, pectoral length 24–28.5% SL. Gill rakers 16–20. Pseudobranchial filaments broad 15–25, increasing with size. First anal-fin pterygiophore long, straight, slender, with narrow, hollow tip. Vomer broad, triangular, rounded posteriorly, with many granular teeth. Palatine and ectopterygoid with 2 to 4 rows granular teeth. Tongue with long central band of densely packed granular teeth. Orbital diameter 11.7–13.3% SL. No longitudinal ridges on preopercular lobe. Otolith compact (OL:OH = 1.6–1.7).

Description. Counts and measurements (see also summary Tables 2–7). Counts: D1: IX; D2: I + 9; A: II + 7; V: I + 5; P: 14 (14–16); developed gill rakers 20 (16–20); pseudobranchial filaments 23 (15–25). Morphometrics (% of SL): orbit 12.2 (10.3–13.3); snout 10.5 (8.8–11.4); head length 40.6 (37.6–43.6); pectoral length 24.7 (23.7–28.5); maximal body depth 27.7 (25.2–30.8); predorsal length 38.3 (37.2–43.1); preventral length 36.7 (34.2–39.9); preanal length 67.7 (62.8–69.9). Snout bluntly pointed; interorbital space convex. Posterior edge of maxillary straight to weakly concave with postero-dorsal and postero-ventral angles rounded and postero-ventral angle not expanded; posterior margin of the maxillary vertical. Hind margin of lower part of subopercle and of interopercle moderately to weakly serrated, rarely almost smooth. Preopercular lobe without longitudinal ridges, but denticles of hind margin serration extending into crests onto preopercular lobe; inner edge of preopercle with 3–6 small denticles not extending along ventral branch. Proximal-middle radial of first anal fin pterygiophore very long, almost straight, with narrow hollow tip, reaching last pair of parapophyses. First haemal spine with narrow to moderate posterior expansion. Pelvic-fin spine serrated along its outer edge; all other fin spines smooth. About 22–29 scales along lateral line.

Dentition. Premaxillary with a pair of canines near symphysis, followed posteriorly by a wide band of minute granular teeth. Dentary with a pair of canines and a band of minute conical to granular teeth in anterior half, broadened at symphysis, narrowed to a single row posteriad, and a row of 2–4 conical to caniniform teeth on sides, with 1 or 2 medial teeth distinctly enlarged; behind these 1–2 rows of minute teeth (sometimes absent at least from one side). Vomer with broad, almost round patch of granular teeth, slightly enlarged and conical near sides of base. Palatines and ectopterygoids with bands of 3 to 4, rarely 2 granular teeth. Tongue with a long and broad central band of densely packed granular teeth ( Fig. 8F ).

Otolith morphology (n = 14). Otolith compressed, thin, up to about 6 mm length. OL:OH = 1.6–1.7; OL:OT about 7. Dorsal rim with broadly rounded medio-dorsal angle and rounded postdorsal angle close to posterior rim. Ventral rim deepest slightly in front of its middle, below collum of sulcus. Rostrum well developed, sharply pointed; no or only weak excisura and antirostrum. Posterior rim bluntly rounded. Dorsal rim smooth or crenulated to various degrees; ventral rim smooth. Inner face slightly convex with slightly supramedian positioned sulcus. Sulcus shallow, with posteriorly slightly widened, long cauda and moderately wide, shallow ostium. Ostium less than twice as wide as cauda, with distinct colliculum. Cauda with rounded, slightly bent tip, terminating close to posterior tip of otolith. CaL:OsL = 1.05–1.15. Dorsal depression wide. Ventral furrow moderately distinct, close to ventral rim of otolith anteriorly and bending away from it backwards towards tip of cauda. Outer face slightly concave, rather smooth.

Coloration (in alcohol). Preserved fishes pale overall. Dorsal surface and sides of head, lower jaw and scale pockets on upper two-thirds of body with numerous diffuse small dotted melanophores, strongly concentrated along margins of scale pockets. Fins pale with numerous minute diffuse melanophores on both dorsal and caudal fins and base of pectoral fin, sometimes few sparse minute melanophores on anal fin. Some specimens with a small black mark on upper lip at level of anteroventral angle of lachrymal. Mouth pale, sometimes with narrow triangular patch of minute melanophores in front of vomer. Branchial cavity dark; peritoneum black.

Size. Small species, attaining a maximum size between 80 and 90 mm SL.

Discussion. Parascombrops glossodon differs from all other species of the genus Parascombrops as well as other acropomatid genera by the presence of a long patch of densely packed granular teeth on the tongue, and the large, almost round teeth patch on the vomer. It is a small species with large eyes (orbit diameter 11.7–13.3% SL) and a bluntly pointed snout.

Geographic and bathymetric distribution. Parascombrops glossodon is a holotropic species caught at relatively shallow depth from 156 to 320 m. It is distributed throughout the Western Pacific from the Philippines and the seas around Indonesia to Taiwan and northern Australia and westwards into the eastern Indian Ocean, where a single specimen was identified from offshore Myanmar ( USNM 382250 ).

Ecology. This species was collected off Dong-gang, Taiwan during the Sakura shrimp (Lucensosergia lucens (Hansen, 1922)) fishing season (December – May) in mid-water trawls together with Parascombrops yamanouei n. sp. and other pelagic fishes like bregmacerotids and surface-migrating myctophids (H.-C. Ho, pers. comm. 2016). However, in the Arafura Sea (ZMMGU 23812) it was collected in association with demersal fishes like Acropoma japonicum Günther, 1859 , Malakichthys levis Yamanoue & Matsuura, 2001 , Owstonia aff. pectinifer (Myers, 1939) and Bembrops spp. at depth close to sea bottom but not far from a major drop-off.

Etymology. From the Greek glossa (= tongue) and odous (= teeth), referring to the teeth on the tongue, the main diagnostic character.

Figures

FIGURE 7 A – Q. Head profiles of Parascombrops, Caraibops, Kaperangus, Synagrops and Ƒerilus pseudomicrolepis. A, Parascombrops analis, MNHN 1998 - 1056, 82 mm SL; B, Parascombrops argyreus, ZMUC P 44272, 122 mm SL; C, Parascombrops glossodon n. sp., BMNH 1986.10. 9.79. 85, paratype, 4 mm SL; D, Parascombrops madagascariensis n. sp., MNHN 2008 - 1769, holotype, 68.5 mm SL; E, Parascombrops mochizukii n. sp., NMMBA-P 782, holotype, 166 mm SL; F, Parascombrops nakayamai n. sp., BSKU 102255, holotype, SL 97 mm; G, Parascombrops ohei n. sp., BSKU 72614, holotype, 75 mm SL; H, Parascombrops parvidens n. sp., BSKU 98886, holotype, 57.5 mm SL; I, Parascombrops pellucidus, USNM 44428, 64.5 mm SL; J, Parascombrops philippinensis, ZMA 112.453 (paralectotype of P. malyanus), 52 mm SL; K, Parascombrops serratospinosus, CAS 238016, 67.5 mm SL; L, Parascombrops spinosus, USNM 395230, 95.5 mm SL; M, Parascombrops yamanouei n. sp., NMMB-P 23097, paratype, 70 mm SL; N, Caraibops trispinosus, CAS 61040, 97.5 mm SL; O, Kaperangus microlepis, CAS 222834, 78.5 mm SL; P, Synagrops japonicus, ZMUC P 44324, 159 mm SL; 7 Q, Ƒerilus pseudomicrolpis, CAS 61164, 91 mm SL.

FIGURE 8 A – F. Dentition and shape of maxillary: A, long, fang-like teeth on symphyses and laterally on dentary, maxillary with straight posterior edge (Parascombrops philippinensis, BMNH 1879.5. 14.167, lectotype, 70 mm SL); B, no long teeth on premaxillary or dentary, maxillary with straight posterior edge (Parascombrops parvidens n. sp., BSKU 98888, paratype, 62 mm SL); C, D, mouth cavity with teeth patches on vomer, palatine and ectopterygoid (8 c = Parascombrops nakayamai n. sp., CAS 34870, 81.5 mm SL; 8 D = Parascombrops serratospinosus, AMS I. 22822 - 017, 72 mm SL); E, maxillary with ventroposterior extension and concave posterior edge (Parascombrops argyreus, BPBM 23839, 118 mm SL); F, teeth patch on tongue (Parascombrops glossodon n. sp., ZMMGU 23812, paratype, 80 mm SL).

FIGURE 9 A – H. Dentition on vomer, palatines and ectopterygoids: A, Parascombrops analis, AMS I. 20919 - 038, 107.5 mm SL; B, Parascombrops argyreus (B 1 = view of mouth roof, BPBM 23829, 119 mm SL; B 2 = lateral close-up view of left palatine and ectopterygoid, MNHN 1998 - 1041, 92 mm SL); C, Parascombrops glossodon n. sp., AMS I. 21835 - 026, paratype, 72 mm SL; D, Parascombrops madagascariensis n. sp., MNHN 1988 - 1443, paratype, 62 mm SL; E, Parascombrops mochizukii n. sp., NMMB-P 3887, paratype, 98 mm SL; F, Parascombrops nakayamai n. sp., AMS I. 2449 - 008, paratype, 93.5 mm SL; G, Parascombrops parvidens n. sp., BSKU 99887, paratype, 58 mm SL; H, Parascombrops ohei n. sp., BSKU 0 63370, paratype, 87 mm SL.

FIGURE 12 A – E. Gills and pseudobranchial filaments: A, gill arch showing many developed rakers (Parascombrops glossodon n. sp., USNM 436685, paratype, 64 mm SL); B, gill arch with a low number of developed rakers and atrophied remnants of rakers at each end of the arch (Parascombrops nakayamai n. sp., MNHN 1998 - 0993, paratype, 100 mm SL); C – D, pseudobranch with low number of filaments (C = Kaperangus microlepis, CAS 222834, 78.5 mm SL; D = Parascombrops glossodon n. sp., USNM 436685, paratype, 64 mm SL); E, pseudobranch with many filaments (Parascombrops argyreus, BPBM 23839, 119 mm SL).

FIGURE 13 A – Q. Anal-fin pterygiophores and shape of large first anal-fin pterygiophore of genera Parascombrops, Caraibops, Kaperangus, Synagrops and of Ƒerilus pseudomicrolepis. A, Parascombrops analis, BSKU 94343, 74.5 mm SL; B, Parascombrops argyreus, AMS I. 42758 - 006, 120 mm SL; C, Parascombrops glossodon n. sp., USNM 436684, paratype, 73 mm SL; D, Parascombrops madagascariensis n. sp., MNHN 2008 - 1769, holotype, 68.5 mm SL; E, Parascombrops mochizukii n. sp., NMMBA-P 3887, paratype, 98 mm SL; F, Parascombrops nakayamai n. sp., BSKU 102255, holotype, 97 mm SL; G, Parascombrops ohei n. sp., BSKU 72614, holotype, 75 mm SL; H, Parascombrops parvidens n. sp., BSKU 15219, paratype, 70 mm SL; I, Parascombrops pellucidus, USNM 44428, 65.5 mm SL; J, Parascombrops philippinensis, BMNH 2016.9. 14.1, paralectotype, 64 mm SL; K, Parascombrops serratospinosus, CAS 238016, 67.5 mm SL; L, Parascombrops spinosus, MNHN 1989 - 0411, 82 mm SL; M, Parascombrops yamanouei n. sp., NMMB-P 15571, paratype, 102 mm SL; N, Caraibops trispinosus, CAS 61040, 97.5 mm SL; O, Kaperangus microlepis, CAS 222834, 78.5 mm SL; P, Synagrops japonicus, MNHN 1998 - 0993, 84 mm SL; Q, Ƒerilus pseudomicrolpis, CAS 61164, 91 mm SL.

FIGURE 14 A – Y. Otoliths (inner faces and representative ventral views): A – E, Parascombrops argyreus (14 A – B = MNHN 1998 - 1041, 14 C = ZMUC P 44272, 14 D – E = CAS 90647); F – G, Parascombrops analis (MNHN 1998 - 1056); H – I, Parascombrops mochizukii n. sp. (NMMB-P 3887); J – N, Parascombrops glossodon n. sp. (14 J – K = NMMB-P 23095, 14 L = USNM 436684, 14 M – N = BMNH 1986.10.9.79); O – R, Parascombrops nakayamai n. sp. (14 O = MNHN 1998 - 0993, 14 P = BSKU 102255, 14 Q – R = NMMB-P 23092); S – U, Parascombrops ohei n. sp. (14 S = BSKU 72614, 14 T – U = BSKU 116498); V – Y, Parascombrops parvidens n. sp. (14 V – W = BSKU 98883, 14 X – Y = BSKU 98886).

FIGURE 18 A – B. Parascombrops glossodon n. sp.; paratype, BMNH 1986.10. 9.79, 72.5 mm SL.

FIGURE 35. Geographic distribution of Parascombrops analis, P. glossodon, P. madagascariensis and P. yamanouei. Large symbols indicate location of holotypes. One symbol may represent several samples.