Parascombrops argyreus

description

Description. Counts and measurements are summarized in Tables 2 – 7. Snout bluntly rounded; interorbital space slightly convex. Posterior edge of maxillary deeply concave with postero-dorsal and postero-ventral angles sharp and postero-ventral angle expanded backward and downward resulting in an obliquely truncated posterior expansion of the maxillary. Preopercular lobe with 2 – 3 longitudinal ridges; denticles of hind margin serration not extending onto crests on preopercular lobe; inner edge of preopercle with 2 – 6 small denticles not extending along ventral branch. Two anal-fin spines. First anal fin pterygiophore slender and almost straight, pointed, wedgeshaped, lacking a groove at anterior edge, reaching anterior margin of first haemal spine. First haemal spine narrow. Pelvic fin spine serrated along its outer edge; all other fin spines smooth. About 28 – 30 scales along lateral line. Dentition. Premaxilla with a pair of canines near symphysis and additional, much smaller canine-like teeth inside the main canine tooth on each side (sometimes absent), followed posteriorly by a wide band of tiny conical teeth. Dentary with a pair of canines and a band of minute conical teeth n

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. Large slender-bodied species with slightly convex dorsal head profile. Anal fin II + 7. Pectoral fin with 13 – 16 rays, pectoral length 21.5 – 26 % SL. Gill rakers 12 – 16, decreasing with size. Pseudobranchial filaments broad, (22) 26 – 38, increasing in number with growth. First anal-fin pterygiophore long, straight, slender, with sharp tip and not hollow. Ectopterygoid broad with 2 – 4 rows of denticles. Orbit diameter 9.3 – 12.0 % SL. Posterior edge of maxillary plate distinctly concave with a lobate ventral expansion; 2 – 3 longitudinal ridges on preopercular lobe. Otolith moderately elongate (OL: OH = 1.65 – 1.9).

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. Statistic ontogenetical correlation found that the number of gill rakers decreases with growth, while the number of pseudobranchial filaments increases. Parascombrops argyreus closely resembles P. philippinensis. Differences observed in the number of gill rakers and pseudobranchial filaments require comparison of specimens of about the same size (Fig. 27). The most reliable characters for distinguishing these two species are the oblique truncated posterior edge and the ventro-posterior expansion of the maxillary plate (Fig. 8 E) (vs straight or very weakly concave, without expansion in P. philippinensis; Fig. 8 A), the presence of 2 – 3 longitudinal ridges on the preopercular lobe (vs absence), the broad ectopterygoid with 2 – 4 rows of denticles (vs narrow with 1 – 2 rows of denticles) and the pointed tip of the first anal-fin pterygiophore without groove (vs broad tip and with groove). All these characters appear to be stable with ontogeny. Geographic and bathymetric distribution. The distribution of P. argyreus is patchy, disjunctive and antitropical in the Indo-West-Pacific off Hawaii, in the Tasman Sea to northeastern New Zealand, and off southeast Africa, which wa

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)

materials_examined

Material examined (69 specimens). AMS I. 24449 - 008, 3 specimens, 87 – 90 mm SL, northwestern shelf, Australia, 18 ° 53 ’ S, 116 ° 10 ’ E, 450 m; AMS I. 42758 - 006, 120 mm SL, Norfolk Ridge, 32 ° 35 ’ S, 167 ° 38 ’ E, 348 – 362 m; BPBM 23839, 4 specimens, 97 – 119 mm SL, off Hawaii, 21 ° 10 ’ N, 157 ° 25 ’ W, 172 m; BPBM 23852, 2 specimens, 120 – 122 mm SL, off Hawaii, 21 ° 11 ’ N, 157 ° 25 ’ W, 168 – 194 m; BPBM 25884, 53 mm SL, off Hawaii, 21 ° 06 ’ N, 156 ° 45 ’ W; CAS 90647, 138 mm SL, off Tonga, 24 ° 54 ’ S, 168 ° 21 ’ W; CAS 90755, 4 specimens, 96 – 135 mm SL, off Tonga, 23 ° 40 ’ S, 168 ° 00 ’ W; IOM 1774, 2 specimens, 120 – 130 mm, 33 ° 07´– 33 ° 12´S, 43 ° 51´– 43 ° 46´E, between 180 and 700 m; LACM 32242 - 33, 3 specimens, 90 – 118 mm SL, off Hawaii; LACM 32668 - 37, 3 specimens, 102 – 119 mm SL, off Hawaii; LACM 44728 - 6, 110 mm SL, off Madagascar, 12 ° 28 ’ S, 48 ° 09 ’ E; LACM 56351 - 1, 3 specimens, 64 – 70 mm SL, off Hawaii; LACM uncatalogued, TC 35 - 8, 13 specimens, 59 – 102 mm SL, off Hawaii; MNHN 1994 - 0014 (otolith only), off New Caledonia, 24 ° 55 ’ S, 168 ° 22 ’ E, 500 – 580 m; MNHN 1998 - 0993, 2 specimens, 99 – 100 mm SL, off Vanuatu, 16 ° 33 ’ S, 167 °

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)