Two new species of snailfishes of the genus Careproctus (Cottoidei: Liparidae) from the western North Pacific Ocean with a range extension of Careproctus brevipectoralis Kai, Yoshiaki Endo, Hiromitsu Tashiro, Fumihito Nakayama, Naohide Zootaxa 2021 2021-04-06 4951 2 361 371 Kai, Endo & Nakayama Kai, Endo & Nakayama 2021 [151,775,1014,1041] Actinopterygii Liparidae Careproctus Animalia Scorpaeniformes 1 362 Chordata species cyanogladius sp. nov.   Figs. 1A, 1B, 2A, 2D, 3A; Table 1  urn:lsid:zoobank.org:act: 8106F681-65CE-46F9-A7A6-A633F3B731E7     Holotype. BSKU 96466, 303.6 mmSL, male, 38.4647ºN, 143.5283ºE, off Kinkazan, Miyagi, Japan,  3,137–3,223 mdepth( KT08-27, St. K-3), R/ V  Tansei-maru,  23 Oct. 2008, coll. by Hiromitsu Endo and Naohide Nakayama.    Paratypes. BSKU  96458, 161.9 mmSL, male, 39.5342ºN, 143.6835ºE, off Miyako, Iwate, Japan,  3,150–3,201 mdepth( KT08-27, St.M-4),  R/ V  Tansei-maru,  22 Oct. 2008, coll. by Hiromitsu Endoand Naohide Nakayama;  BSKU 96474, 203.0 mm SL, female, 38.4748ºN, 143.3470ºE, off Kinkazan, Miyagi, Japan,  2,698–2,814 mdepth( KT08-27, St.K-3),  R/ V  Tansei-maru,  23 Oct. 2008, coll. by Hiromitsu Endoand Naohide Nakayama.   Diagnosis.A species of  Careproctuswith the following combination of characters: vertebrae 63; dorsal-fin rays 57–58; anal-fin rays 50; principal caudal rays 7; pectoral-fin rays 29–31; pectoral fin without notch; uppermost pectoral-fin base below a horizontal through posterior margin of maxillary; pelvic disk oval; cephalic pores 2-6-7-?, chin pores well separated; teeth simple; pyloric caeca 6–10; anus anterior to middle point between posterior rim of pelvic disk and anal-fin origin, slightly closer to pelvic disk than to anal-fin origin; body color pale blue or gray when fresh.   Description.Counts and measurements are shown in Table 1. Paratypedata are given in parentheses if different from the holotype. Body slender, compressed, tapering posteriorly, deepest at anus ( Fig. 1A, B). Skin thin, fragile, lacking prickles. Head compressed, dorsal profile steep from nape to snout. Snout deep, rounded, slightly projecting anterior to lower jaw. Mouth large, subterminal; maxilla extending to posterior rim of orbit; oral cleft extending to anterior rim of orbit. Premaxillary teeth simple, canine ( Fig. 2A), in 7 (6–10) oblique rows. Mandibular teeth simple, canine, in 5 (6–7) oblique rows; inner teeth larger. Diastema absent at symphysis of upper and lower jaws. Orbit rounded, relatively small. Nostril single, with short tube slightly below level of mid-orbit. Cephalic sensory pores small: nasal pores 2, maxillary pores 6, preoperculomandibular pores 7, suprabranchial pores damaged in holotypeand all paratypes; cephalic pore pattern 2-6-7-?. Chin pores paired, opening well separately ( Fig. 3A). Upper margin of gill slit at level with middle of orbit, lower margin broken in holotypeand all paratypes. Gill rakers 11 (10), short. Opercular flap broad, square. Pyloric caeca 10 (6), on center-left side of visceral cavity.   TABLE 1Counts and measurements of  Careproctus cyanogladius  sp. nov.,  C. orri  sp. nov., and  C. brevipectoralis.      Careproctus cyanogladius   Careproctus orri   Careproctus brevipectoralis  Holotype Paratypes Holotype Paratype Non-type Chernova al.(2020)  et  BSKU BSKU NSMT-P HUMZ BSKU ZMH  96466 96458, 96474 53657 201730 96445 26370  Standard length (mm) 303.6 161.9–203.0 121.0 143.4 194.6 150.0  Counts  Dorsal-fin rays 58 57 53 52 51 49  Anal-fin rays 50 50 49 47 44 43  Pectoral-fin rays 31 29–30 35 34 28 26  Caudal-fin rays 1+3/4+1 1+3–4/3–4+1 1+5/5+0 0+5/5+0 1+5/4+1 1+5/4+1  Precaudal vertebrae 11 11 11 11 9 10  Caudal vertebrae 52 52 49 47 47 45  Total vertebrae 63 63 60 58 56 55  Pyloric caeca 10 6 21 >15 14 -  Gill rakers 11 10 - - - -  In % of standard length  Head length 21.1 18.4–20.1 26.3 25.5 19.9 17.7  Snout length 7.7 6.7–7.3 8.1 7.7 7.2 -  Orbit length 3.1 3.7–4.2 5.5 5.2 4.0 4.7  Interorbital width 5.9 5.6–6.7 7.8 6.8 6.8 9.9  Maxilla length 10.1 9.9–11.1 10.9 11.0 8.8 -  Gill slit length - - 8.6 8.6 4.0 -  Body depth at pelvic disk 19.2 15.9–16.2 21.8 23.8 20.3 20.0  Body width 12.5 8.7–11.0 10.1 8.9 11.7 -  Pectoral-fin length 20.1 20.1–21.5 14.4 17.9 13.5 11.3  Pectoral-fin lower lobe length - - 18.2 19.9 13.3 13.3  Pectoral-fin notch-ray length - - 3.7 3.5 4.7 4.6  Predorsal length 19.2 20.1–22.8 28.8 28.4 26.3 -  Preanal length 34.2 34.0–34.1 38.0 40.7 37.5 34.0  Snout to anus length 25.7 22.5–22.8 23.5 23.4 25.6 -  Pelvic disk length 3.9 4.4–4.9 7.1 7.3 6.5 7.3  Caudal-fin length - 17.0–19.5 12.3 - 13.8 -  In % of caudal-fin length  Dorsal-fin connection caudal fin to - 31.7–41.9 52.9 - 47.3 -  Anal-fin connection caudal fin to - 42.3–45.1 57.6 - 58.3 -   FIGURE 1.  Careproctus cyanogladius  sp. nov., BSKU 96466, holotype, 303.6 mm SL, in preserved condition (A), in fresh condition (B);  Careproctus orri  sp. nov., NSMT-P 53657, holotype, 121.0 mm SL, in preserved condition (C);  Careproctus brevipectoralis, BSKU96445, 194.6 mm SL, in preserved condition (D), in fresh condition (E). Vertebrae 63 (11+52). Pleural ribs on abdominal vertebrae 9 and 10 (or 8 and 9). Dorsal-fin rays 58 (57), gradually increasing in height posteriorly. Anteriormost dorsal-fin pterygiophore without ray, inserted between 3 rdand 4 thneural spines; dorsal-fin origin above anus. Anal-fin rays 50, gradually increasing in height posteriorly; anal-fin origin below 9 thdorsal-fin ray. One anal-fin pterygiophore anterior to first haemal spine bearing a single ray (no anal-fin pterygiophore anterior to first haemal spine in paratypes). Membrane of posterior dorsal- and anal-fin rays attached about equidistant on caudal fin. Caudal fin truncate (damaged in holotype). Principal caudal-fin rays 7 (upper 3 and lower 4 inall specimens), single dorsal and anal procurrent rays present. Hypural plates fused with terminal vertebral centrum, slit absent. Pectoral fin rounded, with 31 (29–30) rays, 2 ndray from uppermost longest, just reaching to anal-fin origin (to 2 ndor 3 rdanal-fin ray); rays of lower lobe exserted, tip of longest ray one-third free of membrane; notch absent; uppermost pectoral-fin base below a horizontal through posterior margin of maxillary ( Fig. 1A, B); symphysis of pectoral fins below anterior rim of orbit. Pectoral-fin base concave between 20 thand 21 st(21 stand 22 ndor 22 ndand 23 rd) rays from uppermost. Proximal pectoral radials 4, relatively small and rounded, equally spaced ( Fig. 2D). No interradial fenestrae between proximal radials. Scapula broad with robust helve. Coracoid rounded dorsally with short thin helve. Distal radials present at base of all pectoral-fin rays, except for uppermost and lowermost rays. Pelvic disk oval, length 1.5 (1.5–1.8) times longer than its width. Anus anterior to middle point between posterior rim of pelvic disk and anal-fin origin, slightly closer to pelvic disk than to anal-fin origin. Coloration: Head and body pale blue or gray with dark peritoneum visible through thin skin when fresh ( Fig. 1B). Dorsal, anal and pectoral fins pale blue; edges of posterior dorsal and anal fins dark brown; pectoral fin dark brown. Eye black. Body uniformly gray when preserved, and fins pale. Distal margins of dorsal and anal fins dark brown; pectoral fin dark brown. Peritoneum and orobranchial cavity dark brown; stomach and pyloric caeca white.   Distribution.Western Pacific Ocean, off the Pacific coast of Tohoku District, northern Honshu Is., Japan, in depths of  2,698 –3,223m.   Etymology.The specific name “  cyanogladius” derived from Latin “cyaneus” (blue) and “gladius” (sword), refers to the pale blue coloration and the compressed and elongated sword-like body shape.   Remarks.  Careproctus cyanogladius  sp. nov.is most similar to  Careproctus gelatinosus( Pallas, 1769), which was redescribed as valid by Chernova (2005)who considered it a senior synonym of  Careproctus furcellus Gilbert & Burke, 1912, in having simple teeth, a pectoral fin without a notch, chin pores well separated, and the uppermost pectoral-fin base below a horizontal through the posterior margin of the maxillary ( Kido 1988; Chernova 2005). However,  C. cyanogladius  sp. nov.has fewer vertebrae (63 vs. 67–71), dorsal- (57–58 vs. 61–65) and anal-fin rays (50 vs. 54–59), and pyloric caeca (6–10 vs. 29–49) ( Kido 1988; Chernova 2005; this study). The anus of  C. cyanogladius  sp. nov.is slightly anterior to the middle point between the posterior rim of the pelvic disk and the anal-fin origin, but that of  C. gelatinosusis just behind the posterior rim of the pelvic disk. In addition, the fresh coloration readily distinguishes the two species:  C. cyanogladius  sp. nov.has a pale blue body with dark peritoneum visible through thin skin;  C. gelatinosushas a typically pale pink body ( Kido 1985; this study) (Fig. 4).   Careproctus laperousei Chernova, Thiel & Eidus, 2020is only known from the holotypecollected from the northern slope of Kuril-Kamchatka Trench at depth of  4,796 –4,803m. It is also similar to the present new species in having simple teeth, a pectoral fin without a notch, and chin pores in separated pits ( Chernova et al. 2020). The count of pectoral-fin rays in  C. laperousei(26) is near the lower end of the range of  C. cyanogladius  sp. nov.(29–31), but the counts of dorsal- and anal-fin rays and vertebrae of the former are different from the latter (53 vs. 57–58, 45 vs. 50, and 57 vs. 63, respectively).  Careproctus laperouseican also be distinguished from the new species by several other characters, including the position of the pectoral fin (uppermost pectoral-fin base at the level of maxillary pores of infraorbital region) and the anteriormost dorsal-fin pterygiophore with a ray ( Chernova et al. 2020). Among species of  Careproctusknown from the North Pacific,  C. cyanogladius  sp. nov.shares a gray or dark body coloration and simple teeth with  Careproctus bathycoetus Gilbert & Burke, 1912,  Careproctus cypselurus( Jordan& Gilbert in  Jordan& Evermann, 1898),  Careproctus homopterus Gilbert & Burke, 1912, and  Careproctus nigricans Schmidt, 1950. However, the new species can be readily distinguished from  C. bathycoetesby having more pectoral-fin rays (29–31 vs. 22), from  C. cypselurusby having a truncated caudal fin (vs. deeply forked), and  C. nigricansby the anus position (slightly anterior to the middle point between the posterior rim of the pelvic disk and the anal-fin origin vs. just behind the posterior rim of the pelvic disk) and fewer principal caudal-fin rays (7 vs. 8–10) (  Jordan& Evermann 1898; Gilbert & Burke 1912; Schmidt 1950; this study). Gilbert & Burke (1912)described  C. homopterus, but apparently were mistaken in describing the holotypeas having 32 pectoral-fin rays. The holotypehas 21 pectoral-fin rays with a distinct notch, being clearly different from  C. cyanogladius  sp. nov.(29–31 pectoral-fin rays without a notch). 3071261307 2008-10-23 BSKU, R, V Japan 3180 38.4647 Kinkazan 6 143.5283 Tansei-maru 1 362 KT08-27 1 Miyagi holotype 3071261302 [199,407,1297,1323] BSKU 1 362 1 paratype 3071261310 KT Japan 3176 3.15 Miyako 78 -3.201 St. 1 362 KT08-27 1 Iwate paratype 3071261308 [494,1432,1333,1360] 2008-10-22 R, V Hiromitsu Endo & Naohide Nakayama Japan Tansei-maru 1 362 1 Iwate paratype 3071261309 [151,307,1369,1395] BSKU Japan 1 362 BSKU 96474 1 Iwate paratype 3071261304 KT Japan 2756 2.698 Kinkazan 78 -2.814 St. 1 362 KT08-27 1 Miyagi paratype 3071261301 [381,1298,1405,1432] 2008-10-23 R, V Hiromitsu Endo & Naohide Nakayama Japan Tansei-maru 1 362 1 Miyagi paratype