Trachyscorpia (Mesoscorpia) carnomagula, Hiroyuki Motomura, Peter R. Last & Gordon K. Yearsley, 2007

Hiroyuki Motomura, Peter R. Last & Gordon K. Yearsley, 2007, Two new species of the scorpionfish genus Trachyscorpia (Sebastidae: Sebastolobinae) from the southern Indo-West Pacific, with comments on the distribution of T. eschmeyeri., Zootaxa 1466, pp. 19-34 : 22-28

Trachyscorpia (Mesoscorpia) carnomagula , new species

English name: Deepsea Scorpionfish

Figures 1A-B, 2A, 3; Table 1

Material examined. Holotype. CSIRO H 4234-01 , 224.2 mm SL, east of St Patricks Head , Tasmania, Australia, 41°30’S, 148°44’E, 900 m depth , B. Kellaher, FV Adriatic Pearl, 5 July 1996.

Paratypes. Eighteen specimens, 137.5-368.8 mm SL. Tasman Sea: AMS I. 42737-007 , 241.7 mm SL, Lord Howe Plateau , 34°02’S, 162°36’E, 780-818 m depth , NORFANZ team, RV Tangaroa, 25 May 2003 ; AMS I. 42742-002 (2 specimens), 208.3-248.8 mm SL, Lord Howe Plateau , 34°12’S, 162°41’E, 748-772 m depth , NORFANZ team, RV Tangaroa, 26 May 2003 ; AMS I. 42770-001 , 184.3 mm SL, Western Norfolk Ridge , 34°18’S, 168°23’E, 809-857 m depth , NORFANZ team, RV Tangaroa, 3 June 2003 ; CSIRO H 6084- 02 , 212.7 mm SL, West Norfolk Ridge , 34°18-19’S, 168°23-25’E, 825-850 m depth , P. Last et al., RV Tangaroa, 3 June 2003 ; CSIRO H 6084-03 , 197.8 mm SL, same data as CSIRO H 6084-02 ; CSIRO H 6044-02 , 276.5 mm SL, Lord Howe Rise , 33°59'-34°01’S, 162°35’E, 812-818 m depth , P. Last et al., RV Tangaroa, 25 May 2003 ; CSIRO H 6044-03 , 238.3 mm SL, same data as CSIRO H 6044-02 ; CSIRO H 6044-04 , 245.8 mm SL, same data as CSIRO H 6044-02 ; CSIRO H 6044-05 , 237.9 mm SL, same data as CSIRO H 6044-02 ; CSIRO H 6050-17 , 176.9 mm SL, Lord Howe Rise , 34°11-12’S, 162°37-41’E, 748-763 m depth , P. Last et al., RV Tangaroa, 26 May 2003 ; CSIRO H 6050-18 , 151.2 mm SL, same data as CSIRO H 6050-17 ; CSIRO H 4403-03 , 355.6 mm SL, Cascade Plateau , 43°57’S, 150°23’E, 800-1020 m depth , B. Kellaher, FV Adriatic Pearl, 25 Oct. 1996 ; KAUM-I. 150 , 187.2 mm SL, same data as AMS I. 42770-001 . New Zealand: NMNZ P. 23060 , 368.8 mm SL, Hikurangi Trough , 40°01’S, 178°05’E, 731-840 m depth , RV James Cook, 28 Aug. 1986 ; NMNZ P. 35364 , 194.4 mm SL, outer northern Bay of Plenty , 36°10’S, 176°47’E, 920-1039 m depth , FV Seamount Explorer, 19 July 1998 ; NMNZ P. 36975 , 137.5 mm SL, east of Coromandel , 36°31’S, 176°30’E, 915-980 m depth , FV Seamount Explorer, 21 June 1998 ; NMNZ P. 38277 , 239.7 mm SL, north of Chatham Island , 42°50’S, 176°56’E, 750-919 m depth , C. Petyt, 15 June 2002 .

Non-type specimen. Southeastern Indian Ocean: CSIRO H 2625-02 , 263.3 mm SL, west of Point D’Entrecasteaux , Western Australia, Australia, 34°59'-35°00’S, 114°42-43’E, 738-750 m depth , P. Last, FRV Southern Surveyor, 18 Feb. 1991.

Diagnosis. A species of Trachyscorpia with the following combination of characters: dorsal-fin spines 13; vertebrae 26; tympanic spines present; upper-jaw lip well developed, covering most of premaxillary tooth band laterally; no scales on lateral surface of maxilla; 57-63 scale rows in longitudinal series; second pelvicfin soft ray short (17.9-24.9% SL, mean 20.3%), shorter than upper-jaw length; body deep (depth 34.3-42.5% of SL, mean 38.0%); orbit diameter large (14.1-18.0% of SL, mean 16.1%); pelvic-fin spine short (9.4-15.9% of SL, mean 12.4%); first anal-fin spine short (5.1-7.7% of SL, mean 6.4%); head profile convex; swimbladder present; head and trunk whitish with two blackish bands from eye on head and 4 blackish saddles on body in preserved specimens.

Description. Proportional measurements of the specimens of T. (M.) carnomagula sp. nov. are given as percentages of SL in Table 1. In this description below, data for the holotype are presented first, followed by data for paratypes and non-type material (if different) in parentheses.

Dorsal fin with 13 spines and 9 soft rays; all soft rays branched; length of first spine 1.9 (1.7-2.2; mean 1.9) in second spine; third spine longest (fourth spine in five paratypes), its length slightly less than orbit diameter; fourth to twelfth spines progressively shorter; length of twelfth spine 1.4 (1.2-1.7; mean 1.5) in last spine; membrane of spinous portion of dorsal fin moderately notched; soft rays damaged in holotype (first or second soft ray longest, its length longer than that of longest dorsal-fin spine); posterior branch of last soft ray joined by membrane to caudal-fin peduncle for less than one-third its length (approximately half in CSIRO H 6050-17). Anal fin with 3 spines and 5 soft rays; all soft rays branched; second and third spines damaged in holotype (first spine 1.9-2.6, mean 2.2 in second spine, 1.6-2.2, mean 1.8 in third spine); first soft ray (second ray in CSIRO H 4403-03 and NMNZ P. 23060) longest, its length longer than that of second anal-fin spine; posterior branch of last soft ray joined by membrane to caudal-fin peduncle for less than one-fifth its length (for approximately one-third its length in CSIRO H 6050-17). Pectoral fins with 21 rays on each side of body (19-21), the uppermost ray unbranched, remaining rays branched; sixth ray longest (fourth ray in two paratypes and a non-type specimen; fourteenth ray in NMNZ P. 38277; sixteenth ray in CSIRO H 4403-03), its length slightly longer than upper-jaw length; posterior margin of fin bilobed, thirteenth (fourteenth in 10 paratypes; fifteenth in CSIRO H 2625-02) to fifteenth (seventeenth in CSIRO H 6050-17, H 2625-02) rays progressively longer; rays in lower lobe thickened, fleshy. Pelvic fin with 1 spine and 5 soft rays, all soft rays branched; entire first to third rays and base of fourth and fifth rays covered with thick fleshy skin; second soft ray longest, its length slightly shorter than upper-jaw length; last soft ray joined by membrane to abdomen for more than one-third its length. Caudal fin with 15 (15-17) segmented rays, 12 (13) rays branched, 3 (1 or 2) remaining rays unbranched; dorsal procurrent rays 6, ventral rays 7 (6 or 7); posterior margin of fin nearly straight or slightly rounded. Caudal-peduncle depth 1.9 (1.5-2.3; mean 1.8) in caudal-peduncle length.

Scale rows in longitudinal series 61 (57-64 in 10 paratypes and a non-type specimen; uncountable in remaining paratypes). Pored lateral-line scales 28 (27-28 in two paratypes and a non-type specimen; uncountable in remaining paratypes). Scales below lateral line 18 (17-19 in three paratypes and a non-type specimen; uncountable in remaining paratypes). Scale rows between base of sixth dorsal-fin spine and lateral line 8 (8 or 9 in seven paratypes and a non-type specimen; uncountable in remaining paratypes). Predorsal scale rows 10 (9-11). Gill rakers on upper limb 5 (4 in CSIRO H 6044-02 and NMNZ P. 36975; 6 in CSIRO H 6044-05), lower limb 13 (12 in AMS I. 42742-002, I. 42770-001; 14 in CSIRO H 6044-04), including 4 (3 in five paratypes and a non-type specimen) rakers on hypobranchial; total gill rakers 18 (17 in four paratypes; 19 in CSIRO H 6044-04, H 6044-05). Gill rakers relatively short and spinous with numerous serrae, longest raker on first gill arch subequal length with gill filaments around angle of gill arch; fourth gill slit closed by membrane(a small slit present in some paratypes). Swimbladder present. Vertebrae 26.

Body moderately compressed anteriorly, progressively more compressed posteriorly. Nape and anterior body not strongly arched. Body relatively deep, depth less than head length. No distinct small papillae on head. Several short, slender tentacles on dorsal margin of eye membrane. No distinct tentacles on posterior ends of preocular, supraocular and postocular spine bases. A short tentacle on posterodorsal edge of low membranous tube associated with anterior nostril; length of tentacle greater than anterior nostril diameter. No tentacles on occiput, mid-interorbital space, snout, maxilla, lips, underside of lower jaw, preopercle, opercle, fins and lateral surface of body. Pectoral-fin axil without skin flaps.

Exposed ctenoid scales covering interorbital space, occiput, opercle and an area surrounded by tympanic, pterotic, parietal, nuchal and lower posttemporal spines. Cycloid scales covering cheek and an area surrounded by posterior margin of orbit, pterotic spine, preopercular margin and suborbital ridge (some scales ctenoid). Other parts of head not covered with exposed or embedded scales. Well-exposed ctenoid scales on lateral surface of body, scales becoming cycloid on ventral surface. Body scales extending on to basal rays and membranes of all fins, except pelvic fins; scales on fins cycloid. Exposed cycloid scales covering pectoral-fin base and anteroventral surface of body; some scales embedded in thin skin. Lateral line strongly sloping downward at tip of opercle. Sensory pores of cephalic lateralis system prominent; 3 large pores on cheek just below suborbital ridge, first pore just below posterior end of lacrimal bone, second pore below posterior margin of orbit, third below end of suborbital ridge. Underside of dentary with 3 sensory pores on each side, first pore below anterior to tip of anterior lacrimal spine, second pore below and between tips of anterior and posterior lacrimal spines, third pore located on posterior margin of dentary; second pore not covered with skin (covered with thin skin in left pore in holotype; in right pore in AMS I. 42742-002; in both pores in three paratypes). A small pore behind symphysial knob of lower jaw on each side; an indistinct pore on each side of symphysial knob.

Mouth large, slightly oblique, forming an angle of about 20 (20-30) degrees to horizontal axis of head and body. Posterior margin of maxilla not reaching a vertical through posterior margin of orbit (just reaching in six paratypes). Upper edge of posterior maxilla slightly swollen laterally; central part of maxilla flat. Lower jaw with a symphysial knob. Width of symphysial gap separating premaxillary teeth bands greater than width of each band. Tooth band of upper jaw wider than that of lower jaw. Upper jaw with a band of villiform teeth; tooth band narrowing posteriorly. Lower jaw with a band of villiform teeth; lengths of most teeth subequal to those of upper jaw. Vomer V-shaped, covered entirely with teeth; usually no distinct naked areas on vomerine tooth patch. Width of vomerine plate less than length of palatine plate. Palatines covered with teeth. Underside of lower jaw smooth without ridges.

Dorsal profile of snout steep, forming an angle of about 55 (50-60) degrees to horizontal axis of head and body. Nasal spine simple, small; embedded in skin, except for spine tip (spine well exposed in AMS I. 42737- 007 and CSIRO H 2625-02); directed posterodorsally, its length greater than posterior nostril diameter. Ascending process of premaxilla slightly intruding into interorbital space, its posterior margin extending well beyond level with posterior margin of posterior nostril and not reaching level with middle of preocular spine base in dorsal view. Median interorbital ridge absent. Interorbital ridges separated by a shallow channel, beginning posterior to nasal spines and joining at origin of tympanic spines; interorbital ridges unbranched, diverging anteriorly and posteriorly in dorsal view, distance between interorbital ridges narrowest at a vertical through anterior margin of pupil. Interorbital space moderately deep, about one-eighth of orbit extending above dorsal profile of head. Preocular spine simple, directed dorsally; tip of spine extending beyond level with upper margin of pupil in lateral view. Supraocular spine simple (spine absent in CSIRO H 2625-02; with 2 points on left side of head in NMNZ P. 23060), its length shorter than those of preocular, postocular and tympanic spines. Postocular spines simple (serrated in NMNZ P. 23060), strongly canted laterally. Tympanic spine simple (serrated in NMNZ P. 23060), strongly pointed, directed dorsally, its length subequal to that of postocular spine. Interorbital, coronal and pretympanic spines absent. Occiput nearly flat, lacking pit; longitudinal length of pit greater than width; occiput surrounded laterally by tympanic spines, parietal spines, and indistinct low ridges between tympanic and parietal spines. Parietal spine simple (3 points on right side of head in holotype; 2 points on one side in four paratypes; 2 points on each side in CSIRO H 4403-03; serrated in NMNZ P. 23060), smaller than nuchal spine. Nuchal spine simple (2 points on right side of head in holotype and CSIRO H 4403-03; serrated in NMNZ P. 23060); nuchal and parietal spines joined at base. Sphenotic with several small spines. Postorbital with several small spines. Pterotic spine simple (with 2 points on left side of head in holotype and CSIRO H 4403-03; serrated in NMNZ P. 23060), located below parietal and nuchal spines. No ridges in an area surrounded by parietal, nuchal, pterotic and lower posttemporal spines. Upper posttemporal spine absent. Lower posttemporal spine simple, its base length less than that of pterotic spine. Supracleithral spine simple, not strongly pointed. Cleithral spine flattened, with a point.

Lateral lacrimal spine simple, strongly pointed (2 spines on right side in CSIRO H 6050-17; 2 spines on left side in CSIRO H 6050-18; lateral lacrimal spine serrated in CSIRO H 4403-03). Lateral surface of lacrimal with 6 elements radiating from center; a backward ridge with a distinct median ridge, other ridges with a low median ridges; 2 downward ridges forming anterior and posterior lacrimal spines; anterior ends of 2 forward ridges and dorsal end of an upward ridge embedded in skin. Anterior lacrimal spine pointed, directed ventrally (ventroposteriorly), its tip not reaching (just reaching) dorsal margin of upper lip; no additional spine occurring at base of anterior lacrimal spine. Posterior lacrimal spine simple, directed ventroposteriorly, its tip not reaching upper lip; posterior lacrimal spine greater than anterior spine. Suborbital ridge with 5 spines (5-7 spines in paratypes, usually 5 spines; ridge serrated in CSIRO H 4403-03 and NMNZ P. 23060), first and second spines below pupil, third spine below posterior margin of orbit, fourth and fifth spines between posterior margin of orbit and preopercular margin (based on right side of head in holotype and smaller paratypes). Space between ventral margin of eye and suborbital ridge remarkably narrow. Suborbital pit absent. Preopercle with 5 spines; uppermost spine largest with a supplemental preopercular spine on its base; second to fifth spines without a distinct median ridge. Preopercle, between uppermost preopercular spine and upper end of preopercle, smooth without serrae or spines. Upper opercular spine simple without a median ridge. Lower opercular spine simple with a low median ridge. Space between upper and lower opercular spines without ridges. Posterior tips of upper and lower opercular spines not reaching opercular margin.

Origin of first dorsal-fin spine above posterior end of supracleithral spine (above first pored lateral-line scale in 11 paratypes). Posterior margin of opercular membrane extending beyond a vertical through third dorsal-fin spine base. Posterior tip of pectoral fin reaching (not reaching in CSIRO H 4403-03; extending beyond in 12 paratypes and a non-type specimen) a vertical through tenth dorsal-fin spine and not reaching anal-fin origin. Origin of pelvic-fin spine slightly posterior to origin of pectoral fin. Posterior tip of depressed pelvic fin not extending beyond anus and a vertical through posterior tip of pectoral fin (extending slightly beyond pectoral-fin tip in NMNZ P. 36975, P. 38277). Origin of first anal-fin spine slightly posterior to origin of last dorsal-fin spine.

Color when fresh. Head and body mainly reddish, with blackish markings on posterior half of head, dorsal half of trunk, and fins, especially central pectoral fin (Figs. 1A-B). Color when alive is unknown.

Color of preserved specimens. Head and body yellowish-white dorsally, whitish ventrally. Two blackish broad bands on head; one running from middle of ventral margin of eye to fifth preopercular spine through dorsal angle of posterior margin of maxilla; the other running from posterior margin of eye to dorsal end of opercle (an additional black band from posterior margin of eye to posteroventral margin of opercle in two largest paratypes). Poorly defined blotches on maxilla and lips (blotches absent in three smaller paratypes). Anterior nostril tentacle black distally. Inside of opercle black. Four blackish saddles (each saddle fused, forming blackish body in two largest paratypes); first saddle above opercle, including membranes between first and third dorsal-fin spines; second saddle broadest, extending from basal half of membranes between fifth and twelfth (or eleventh) dorsal-fin spines to below lateral line; third saddle extending from basal membranes of dorsal-fin soft rays to above lateral line; fourth saddle on posterior caudal-fin peduncle, reaching ventral surface of caudal-fin peduncle. Distal half of membranes between fourth (or fifth) and eleventh (or tenth) dorsal-fin spines dense black, forming an elongate black blotch. A poorly defined blackish blotch on middle of soft rayed portion of dorsal fin. Two poorly defined blackish blotches on base and middle (or submargin) of pectoral fin (middle blotch dense black in NMNZ P. 35364). Pelvic fin yellowish with poorly defined blackish blotches. Anal fin yellowish with a few melanophores (lack of melanophores in CSIRO H 6050-18). Caudal fin yellowish with a few scattered melanophores. Abdominal cavity lining dense black.

Distribution. Currently known only from the southwestern Pacific Ocean (Tasman Sea and northern New Zealand) at depths of 731-1020 m. One specimen (CSIRO H 2625-02, 263.3 mm SL, non-type), tentatively identified as T. carnomagula in this study (see Remarks), was collected from southwest of Western Australia, Indian Ocean, at a depth of 738-750 m. Trachyscorpia carnomagula co-occurs with T. eschmeyeri .

Etymology. The specific name carnomagula is derived from the Latin carnosus meaning fleshy, and magulum meaning jaw or mouth, in reference to the fleshy lip on the upper jaw, compared with the poorly developed lip of T. eschmeyeri . The English name, Deepsea Scorpionfish, was first proposed for this species (as Trachyscorpia sp.) by Daley et al. (1997) and we follow it as the standard name for T. carnomagula .

Remarks. A specimen (CSIRO H 2625-02), tentatively identified here as T. carnomagula , lacks supraocular spines on either side of the head, although all other specimens of T. carnomagula have the well-developed spines on both sides. In addition, it is the only specimen collected from off southwestern Western Australia. Further specimens from the region are required to assess the taxonomic status of this specimen, so we have excluded the specimen from the type series.