Parascombrops ohei 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 : 41-43

Parascombrops ohei Schwarzhans & Prokofiev , new species

Figs. 2C , 6G , 7G , 9H , 13G , 14S – U , 22 , 37 , Tables 2–7

Material examined (8 specimens). Holotype BSKU 72614, 75 mm SL, Japan, Tosa Bay, 33°14’N, 133°38’E, 172– 215 m . Paratypes: BSKU 9951, 53.5 mm SL, no data; BSKU 63370-71, 2 specimens, 82.5–87 mm SL, Japan, Tosa Bay, Mimase fish market near Kochi ; BSKU 87909, 74.5 mm SL, Japan, Tosa Bay Kuroshio Town, 200 m ; BSKU 116497-98, 2 specimens, 64–77.5 mm SL, Japan, Tosa Bay, Mimase fish market near Kochi ; NSMT P59841, 70.5 mm SL, Japan, Tosa Bay, Mimase fish market near Kochi .

Diagnosis. Moderately slender species with convex dorsal head profile and bluntly rounded snout. Anal fin with 2 spines and 7 soft rays, first ray being segmented, but not branched ( Fig. 6G ). Pectoral fin with 14–15 rays, pectoral length 23.1–26.6% SL. Gill rakers 13–16. Pseudobranchial filaments 19–25. First anal-fin pterygiophore long, straight, with sharply pointed tip, not hollow. Vomer triangular, broad, with many granular teeth. Palatine and ectopterygoid broad, with 2–4 granular teeth rows. Orbital diameter 10.7–12.3% SL. One or two longitudinal ridges on preopercular lobe. Otolith very slender (OL:OH = 1.9–2.1).

Description. Counts and measurements (see also summary Tables 2–7). Counts: D1: VIII–IX; D2: I + 9; A: II + 7; V: I + 5; P: 14 (14–15); developed gill rakers 14 (13–16); pseudobranchial filaments 24 (19–25). Morphometrics (% of SL): orbit 12.0 (10.7–12.3); snout 7.7 (7.0–9.8); head length 36.9 (34.1–37.7); pectoral length 24.6 (23.1–26.6); maximal body depth 27.7 (21.5–27.7); predorsal length 37.4 (35.5–40.3); preventral length 31.3 (31.3–36.4); preanal length 65.8 (65.0–66.7). Snout short, rounded; interorbital space convex. Posterior edge of maxillary concave with postero-dorsal and postero-ventral angles broadly rounded and postero-ventral angle extended downward and slightly backward, resulting in slightly oblique posterior rim of maxillary. Preopercular lobe with one or two longitudinal ridges, hind margin serrations not extending into crests on preopercular lobe; inner edge of preopercle with 3–5 denticles. First soft anal fin-ray segmented, but not branched. Proximal-middle radial of first anal-fin pterygiophore long, straight, with sharply pointed tip, not hollow, ending in space between last abdominal and first caudal vertebrae. First haemal spine with a very slight posterior expansion. Pelvic fin spine serrated along its outer edge; all other fin spines smooth.

Dentition. Premaxillary with a pair of strong canines near symphysis, followed posteriorly by a wide band of minute granular teeth. Dentary with a pair of strong canines, and a band of small conical teeth near symphysis, followed by a row of small conical teeth and 2–4 enlarged canine-like teeth on each side. Vomer triangular, broad, with many granular teeth, few or no longer teeth at rear margin. Palatine and ectopterygoid broad, with 2–4 granular tooth rows. Tongue without teeth.

Otolith morphology (n = 7). Otolith very elongate, thin, up to about 8 mm length. OL:OH = 1.9–2.1; OL:OT about 8–9. Dorsal rim shallow, nearly horizontal except for very feeble mediodorsal bulge; postdorsal angle rounded, positioned far backwards very close to posterior rim. Ventral rim shallow, deepest slightly in front of its middle, below collum of sulcus. Rostrum well developed, moderately sharply pointed; weak excisura and antirostrum. Posterior rim blunt, short, with angle at junction with ventral rim at tip of cauda. Dorsal and posterior rims smooth or slightly crenulated; ventral rim smooth. Inner face slightly convex with slightly supramedian positioned sulcus. Sulcus shallow, with long cauda and moderately wide, shallow ostium. Ostium distinctly less than twice as wide as cauda, with distinct colliculum. Cauda with rounded, distinctly downward bent tip, terminating close to posterior tip of otolith. CaL:OsL = 1.1–1.25. Dorsal depression long, narrow. Ventral furrow distinct, close to ventral rim of otolith anteriorly and slightly turning upwards posteriorly towards tip of cauda. Outer face slightly concave, smooth, with few short radial furrows near dorsal rim.

Coloration. Preserved fishes a uniform pale coloration, with few small melanophores scattered over body. Snout, occiput and tip of first dorsal fin over first 4 spines dark. Patches of small melanophores on dorsal fins, caudal fin, upper part of opercle, rear part of maxillary and tip of lower jaw. Scale pockets of upper half of body with intensely dark colored rims. Mouth pale. Branchial cavity dark anteriorly and with small patch of melanophores behind pseudobranchial filaments; peritoneum dark.

Size. Fishes reaching sizes up to about 90 mm SL.

Discussion. Parascombrops ohei is a slender species (maximum body depth 21.5–25.7% SL) with a rounded head profile and snout. The species is best identified by the unique characters of very slender otoliths (OL:OH = 1.9–2.1), and the presence of a segmented, unbranched first soft anal-fin ray at all sizes. It is distinguished from P. nakayamai in the short, rounded snout (vs. long and pointed), the presence of longitudinal ridges on the preopercular lobe (vs. absent), the slender, sharply pointed and not hollow first anal-fin pterygiophore (vs. slightly curved distally, with moderately broad hollow tip), the broad vomer with many granular teeth (vs reduced with only few long teeth along the rear margin), and the broad palatine with 2–3 rows of granular teeth (vs 1 row). It differs from P. philippinensis in the more rounded head profile, the presence of longitudinal ridges on the preopercular lobe (vs. absent), the slender, sharply pointed and not hollow first anal-fin pterygiophore (vs. broad, with hollow tip), the slender otolith (OL:OH = 1.9–2.1 vs. 1.6–1.85), and the broad palatine and ectopterygoid. It resembles P. argyreus in the morphology of the first anal-fin pterygiophore, shape of the maxillary plate and the presence of longitudinal ridges on the preopercular lobe, but differs in the lower number of pseudobranchial filaments in specimens of similar size, 19–25 (vs 26–38), the strongly convex head profile, the slender otolith and the broader palatine tooth band. The presence of an unbranched segmented first soft anal-fin ray in P. ohei n. sp. is reminiscent of the emergent 3rd anal-fin spine of P. analis . However, there is an abundance of differentiating characters between these species (see diagnoses and key), and we therefore regard the development of the weak third anal spine as homoplastic.

Geographic and bathymetric distribution. Parascombrops ohei appears to be endemic to southern Japan, and so far has only been caught in Tosa Bay at about 200 m depth. Fossil otoliths of P. ohei are known from the Late Pliocene Dainichi Sand of Kakegawa, Shizuoka Prefecture, further to the North-East of the Tosa Bay.

Etymology. Named in honor of Fumio Ohe, Seto (near Nagoya, Japan), the otolith specialist who first recognized the presence of a hitherto unrecorded species of Parascombrops in the Pliocene record of Japan.

Figures

FIGURE 2 A – F. Examples of cranial crests: A, Kaperangus microlepis n. gen., CAS 222834, SL 78.5 mm; B, Caraibops trispinosus n. gen., CAS 61040, 97.5 mm SL; C, Parascombrops ohei n. sp., BSKU 72614, holotype, 75 mm SL; D, Parascombrops argyreus, BPBM 23839, 118 mm SL; E, Parascombrops spinosus, USNM 395230, 95.5 mm SL; F, Parascombrops philippinensis, BMNH 1879.5. 14.167, lectotype, 70 mm SL. Lower images with crests highlighted.

FIGURE 6 A – H. Spine serrations in Parascombrops: A, C, serrated first dorsal fin spine (6 A = Parascombrops serratospinosus, AMS I. 22822 - 017, 72 mm SL; 6 C = Parascombrops spinosus, USNM 395230, 95.5 mm SL); B, serrated second dorsal fin spine (Parascombrops serratospinosus, AMS I. 22822 - 017, 72 mm SL); D, second dorsal fin spines smooth (Parascombrops spinosus, USNM 395230, 95.5 mm SL); E, serrated spine in pelvic fin (Parascombrops madagascariensis n. sp., MNHN 2008 - 1769, holotype, 68.5 mm SL); F, in anal fin spine serrated (Parascombrops serratospinosus, AMS I. 22822 - 0 17, 72 mm SL); G, anal fin with two spines, one unbranched soft ray and six branched soft rays (Parascombrops ohei n. sp., BSKU 72614, holotype, 75 mm SL); H, anal fin with three spines and six soft rays (Parascombrops analis, MNHN 1998 - 1056, 82 mm SL).

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 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 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 22 A – B. Parascombrops ohei n. sp.; holotype, BSKU 72614, 75 mm SL.

FIGURE 37. Geographic distribution of Parascombrops mochizukii, P. nakayamai, P. ohei, P. parvidens, and P. serratospinosus. Large symbols indicate location of holotypes. One symbol may represent several samples.