Parascombrops glossodon

description

Description. Counts and measurements (see also summary Tables 2 – 7). Counts: D 1: IX; D 2: 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 l

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)

description

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.

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)

diagnosis

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).

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)

discussion

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).

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)