Parascombrops glossodon Schwarzhans & Prokofiev, new species
Creators: name: Schwarzhans, Werner W.
name: Prokofiev, Artem M.
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Perciformes
Acropomatidae
Parascombrops
Parascombrops glossodon

description: 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.
description: Published as part of 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), pp. 1-74 in Zootaxa 4260 (1) on pages 33-36, DOI: 10.5281/zenodo.571305