Careproctus klisi Gardner & Orr & Tornabene 2023, new species

Careproctus klisi, new species

urn:lsid:zoobank.org:act: A2BD6236-2323-48C7-969C-79F06C6C46FD

Ramped Snailfish

Figures 3C, 4C, 4D, 5, 6, 7; Tables 1, 2; Supplemental Table A

Holotype.— UW 200421 (out of UW 154881), 105.3 mm, male, Aleutian Islands, Petrel Bank, northeast of Semisopochnoi Island, 52.0360 8 N, 179.3053 8 E, 277 m depth, F/ V Sea Storm, cruise 2012-01, haul 137, W. C. Flerx, 12 July 2012.

Paratypes.— 12 specimens, 72.4–106.0 mm. SIO 22-1 (ex UW 155519), 92.3 mm, 52.0756 8 N, 176.3549 8 E, 149 m depth, F/ V Vesteraalen, cruise 2000-01, haul 177, 6 July 2000; UAM 4013 (ex UW 155516), 97.7 mm, 52.0874 8 N, 176.3232 8 E, 145 m depth, F/ V Vesteraalen, cruise 2000-01, haul 175, 5 July 2000; USNM 439017 (ex UW 159773), 80.0 mm, 52.3688 8 N, 179.9117 8 W, 182 m depth, F/ V Sea Storm, cruise 2014-01, haul 118, G. R. Hoff, 8 July 2014; UW 117553, 106.0 mm, 52.0340 8 N, 176.4665 8 E, 152 m depth, F/ V Sea Storm, cruise 2006-01, haul 191, 24 July 2006; UW 117556, 103.5 mm, 52.5192 8 N, 179.5092 8 W, 135 m depth, F/ V Sea Storm, cruise 2006-01, haul 86, B. Knoth, 29 June 2006; UW 117559, 89.7 mm, 52.0537 8 N, 176.4118 8 E, 142 m depth, F/ V Sea Storm, cruise 2006-01, haul 195, 25 July 2006; UW 155354, 86.5 mm, 51.9269 8 N, 176.6285 8 E, 149 m depth, F/ V Ocean Explorer, cruise 2010-01, haul 124, 15 July 2010; UW 155411, 95.5 mm, 52.2281 8 N, 175.2933 8 E, 173 m depth, F/ V Sea Storm, cruise 2004-01, haul 197, P. Von Szalay, 25 July 2004; UW 155491, 88.7 mm, 52.5150 8 N, 179.5188 8 W, 134 m depth, F/ V Vesteraalen, cruise 2002-01, haul 181, benthic bag, 14 July 2002; UW 155518, 72.4 mm, 51.8447 8 N, 173.9294 8 W, 257 m depth, F/ V Vesteraalen, cruise 2000-01, haul 88, W. C. Flerx, 14 June 2000; UW 158344, 90.3 mm, 52.0381 8 N, 179.3166 8 E, 280 m depth, F/ V Ocean Explorer, cruise 2018-01, haul 121, N. E. Roberson, 11 July 2018; UW 159772, 103.6 mm, 52.5150 8 N, 179.5188 8 W, 134 m depth, F/ V Vesteraalen, cruise 2002-01, haul 181, A. A. Abookire, 14 July 2002.

Diagnosis.— Careproctus klisi is distinguished from described species of Careproctus by having the following combination of characters: coloration variegated; anterior dorsal-fin lobe absent; pupil a horizontal ellipse to horizontal slit; prickles absent; body deep at dorsal-fin origin, anal-fin origin, and the midpoint of anal fin; and anus close to pelvic disk. It is most similar to C. candidus, with which it shares variegated coloring, pupil a horizontal ellipse to horizontal slit, and counts of dorsal-fin rays, anal-fin rays, and vertebrae. It can be distinguished from C. candidus in having a unique anterior dorsal-fin configuration in which the dorsal fin is composed of two contiguous sections: the anterior section of six to seven short rays of approximately equal lengths, followed by a long posterior section of rays that are longer than the anterior section and of approximately equal lengths. It also has a deeper body than C. candidus: depth at anal-fin origin 75.6– 100.0 (mean 87.3) % HL (vs. 58.2–92.3 [mean 71.2] % HL in C. candidus), depth at midpoint of anal fin 36.1–53.1 (mean 42.2) % HL (vs. 23.6–42.9 [mean 30.8] % HL in C. candidus).

Description.— Body robust, deepest at dorsal-fin origin, tapering gradually posteriorly, rounded in cross section anteriorly, compressed posteriorly; depth at dorsal-fin origin 91.8–113.4 (102.0) % HL; depth at anal-fin origin 75.6–100.0 (100.0) % HL; depth at midpoint of anal fin 36.1–53.1 (53.1) % HL. Head large and robust, its length 27.5–29.4 (29.0) % SL, dorsal profile rounded from nape to snout. Snout blunt, slightly projecting anterior to lower jaw. Mouth subterminal, maxilla 33.5–39.8 (36.7) % HL, extending to anterior edge of pupil or to mid-orbit, oral cleft extending to anterior rim of orbit. Lower jaw slightly inferior, premaxillary tooth plates matching mandibular tooth plates. Both premaxillary and mandibular teeth trilobed in 8–13 oblique rows of 5–10 teeth. Diastemata absent at symphysis of upper and lower jaws. Orbit large, 30.4–40.5 (31.5) % HL, dorsal margin below dorsal contour of head, suborbital depth to maxilla 23.5–47.1 (43.8) % OL; pupil a horizontal ellipse to a horizontal slit. Interorbital space moderate, fleshy distance 24.1–32.2 (28.2) % HL, bony distance 10.4–14.4 (10.8) % HL. Snout about equal to orbit length, 74.3–112.8 (112.5) % OL, 29.0–36.2 (35.4) % HL. Nostril single, in well-developed tube level with mid-orbit; nostril tube length 1.2–4.4 (3.0) % HL.

Pores of cephalic lateralis of moderate size; pore pattern 2- 6-7-2; chin pores two in a single pit. Free neuromasts about 4–5, small and difficult to discern, originating above gill slit and extending to a level at mid-body to a distance about level with anus.

Gill opening small, 14.1–25.9 (25.9) % HL, upper margin level with upper rim of orbit or mid-orbit, extending ventrally to just above pectoral fin or to pectoral-fin ray one or two (entirely above). Opercular flap angular. Gill rakers 7–10, short, blunt.

Dorsal-fin rays 43–48 (47; Table 1), all rays simple. Anterior dorsal-fin lobe absent, dorsal fin composed of two contiguous sections: the anterior with ray one shorter than rays two through five to seven, which are nearly equal in length, rays either not exserted or tips barely exserted from fin membrane; the posterior section starting at rays six to eight with rays longer than those of anterior section and approximately equal in length (Fig. 3C). Anterior part of dorsal fin often bent in fresh specimens (Fig. 6A, C) resulting in the appearance of a notch when one is not present. Anteriormost dorsal-fin pterygiophore inserted between neural spines two and three, bearing a single small ray. Anterior rayless pterygiophore present. Predorsal length 24.8–28.5 (27.1) % SL.

Anal-fin rays 37–41 (40; Table 1), anal-fin pterygiophores anterior to first haemal spine one or two (two), each bearing a single ray. All rays simple. Anal-fin origin below vertebrae 10– 11 (caudal vertebra 1), preanal length 38.0–46.0 (38.0) % SL.

Pectoral fin moderately notched, with 36–39 rays (39; Table 1). Upper lobe of 27–30 (30) rays extending to anal-fin ray two to four, dorsalmost rays lengthening to rays 6–8, more ventral rays gradually shortening to shortest ray of notch. Dorsal margin crenulate, fin margins more emarginate ventrally. Lower lobe with 7–9 (9) rays, extending to just past anus or beyond to halfway between anus and anal-fin origin; dorsal rays of lower lobe gradually lengthening to thicker and fleshy rays 2–3, ventral rays gradually shortening to ventralmost ray near pectoral symphysis. Tips of rays 10–70 % free of membrane, rays of lower lobe more strongly exserted. Rays in notch slightly more widely spaced than rays of lobes. Uppermost pectoral-fin ray level with region between mid-orbit and ventral rim of orbit.

Proximal pectoral radials four (3 þ 1), robust; proximal radials one through three round, radial four a rounded square (Fig. 4C, D). Interradial fenestrae one (1 specimen, Fig. 4C) or two (1 specimen, Fig. 4D), scapular fenestra always ovular, extending between scapula and proximal radial one; when two fenestrae present, second is very small, slender, extending between proximal radials two and three but not reaching either. Scapula broadly Y-shaped with robust helve; coracoid with triangular head and long helve. Anterodorsal hook small, rounded. Distal radials present at base of all but the first pectoral-fin ray and ventral 7–8 rays, which articulate directly with fibrocartilage pad.

Pelvic disk moderately large, length 29.5–37.1 (31.2) % HL, round, typically slightly longer than wide, width 26.2–35.9 (33.4) % HL, anterior lobe moderately developed, flat with margins often slightly upturned, distance from tip of upper jaw to pelvic disk 12.6–19.9 (17.2) % SL. Anus closer to pelvic disk than to anal-fin origin, 4.7–14.8 (14.8) % HL from pelvic disk, distance from tip of upper jaw to anus 22.9–28.6 (22.9) % SL.

Principal caudal-fin rays 10–11 (11; Table 1), dorsal procurrent rays 1 to 3 (2), ventral procurrent rays 0 to 2 (1). Membrane of posterior dorsal-fin rays attached for shorter distance to caudal fin than anal-fin rays: dorsal-fin rays attached to caudal fin 19.8–36.4 (28.4) % CL; anal-fin rays 35.7–54.8 (45.2) % CL. Depth at base of caudal fin 11.9–17.8 (15.5) % CL.

Skin thin and somewhat loose in preservation, prickles absent. Pyloric caeca 17–21, long with rounded tips, about 25% HL.

Vertebrae 47–51 (49), precaudal 9–10 (10), caudal 37–42 (39; Table 1). Pleural ribs 1–2 (1), present on vertebrae eight to nine, anteriormost small when two present, other long and slender. Hypural plate composed of dorsal and ventral plates divided by slight notch in plate. Single epural present.

Coloration.— Body variegated pinkish and pale in life, head with white blotch on cheek, white spots often scattered over body and with darker reddish to brownish along distal margins of median fins posteriorly (Fig. 6). Eye greenish dorsally to goldish ventrally in life with pupil a horizontal ellipse to a horizontal slit. Body pale and vaguely mottled in preservation, eye black (Fig. 7A). Peritoneum, orobranchial cavity, stomach, intestines, pyloric caeca, and urogenital papilla pale.

Life history.— Largest specimen examined was an immature female 106.0 mm (UW 117553), with immature eggs 0.4 mm in diameter. All females were maturing or immature; none were ripe with yolked eggs. In maturing females, only opaque, developed but unyolked eggs, and translucent, immature eggs less than 1 mm were present. In immature females, only very small, translucent immature eggs were present. Ten females were maturing or immature, the smallest being 72.4 mm (UW 155518). One male 103.5 mm (UW 117556) was ripe and two males, 92.3–105 mm, were mature.

Distribution.— Careproctus klisi has been collected in the western and central Aleutian Islands from west of Buldir Island and on Petrel Bank to south of Amlia Island in the east (Fig. 5). Collection depths ranged from 134 to 280 m.

Etymology.— The species epithet is derived from the Greek JK´IRG, meaning ‘‘incline’’ or ‘‘ramp,’’ to signify the unique anterior dorsal-fin morphology present in the species. It is to be treated as a noun in apposition.