Careproctus lerikimae, Orr, James Wilder, Kai, Yoshiaki & Nakabo, Tetsuji, 2015

Orr, James Wilder, Kai, Yoshiaki & Nakabo, Tetsuji, 2015, Snailfishes of the Careproctus rastrinus complex (Liparidae): redescriptions of seven species in the North Pacific Ocean region, with the description of a new species from the Beaufort Sea, Zootaxa 4018 (3), pp. 301-348 : 331-334

Careproctus lerikimae new species

Dusty Snailfish

Figure 3 C, 5G, 6; Tables 2–3

Careproctus sp. cf. rastrinus (Orr et al.) .— Rand & Logerwell 2011:480 (Beaufort Sea, checklist).— Mecklenburg et al. 2013:21 (Arctic–boreal Pacific?, checklist).

Holotype. UW 118033, 132.3 mm, ripe male, Alaska, Beaufort Sea, 71.5131ºN, 152.2033ºW, 178 m depth, E. Acuña, 15 August 2008, FV Ocean Explorer, cruise 200801, haul 22 ( Fig. 3 C).

Paratypes. UW 154841 (out of UW 118033), 3 (74.0– 132.3 mm), same data as holotype; UW 117918, 2 (97.6–117.4 mm), 71.52ºN, 152.25ºW, 175 m depth, E. Acuña, 11 August 2008, FV Ocean Explorer, cruise 200801, haul 10; UW 119072, 63.0 mm, 71.6601ºN, 152.4944ºW, 302 m depth, E. Acuña, FV Ocean Explorer, cruise 200801, haul 9; UW 119073, 2 (149.0– 153.5 mm), 71.7415ºN, 154.9833ºW, 198 m depth, E. Acuña, 7 August 2008, FV Ocean Explorer, cruise 200801, haul 3; UW 119200, 1 (116.3 mm), 71.7457ºN, 153.9435ºW, E. Acuña, 12 August 2008, FV Ocean Explorer, cruise 200801, haul 11; UW 119201, 87.8 mm, 71.9004ºN, 153.9072ºW, 347 m depth, E. Acuña, 7 August 2008, FV Ocean Explorer, cruise 200801, haul 4; UW 119202, 5 (70.7–159 mm), 71.8907ºN, 154.9465ºW, 470 m depth, E. Acuña, 6 August 2008, FV Ocean Explorer, cruise 200801, haul 2; UAM 47840, 2 (79.8–91.3 mm), 70.5397ºN, 141.9993ºW, sta. A2-350, 19 August 2013; UAM 47797, 2 (111.0 mm), 69.8306ºN, 138.4046ºW, 26 August 2013; UAM 47938, 1 (69.0 mm), 70.9297ºN, 146.0694ºW, L. Edenfield, 15 August 2013; UAM 47861, 2 (65.0– 117.9 mm), 70.2685ºN, 140.2974ºW, L. Edenfield, sta. TBS-200, 25 August 2013; UAM 3707, 2 (65.0 mm, 1 disintegrated), 71.2526ºN, 150.1ºW, 500 m depth, L. Edenfield & K. Walker, 24 September 2012, Sta. B1-500, otter trawl, haul 8, PSR 2385; UAM 3710, 5 (50.5–123.0 mm), 71.4297ºN, 151.1ºW, 497 m depth, L. Edenfield & K. Walker, 27 September 2011, sta. B2-500, haul 10, otter trawl, PSR 2388; UAM 6317, 2 (81.9 mm), 71.6546ºN, 152.6617ºW, 184 m depth, L. Edenfield, 27 August 2011, Norseman II, Sta. WB08, haul 26, PSR 2000, DSFIB 092-11, 093-11; UAM 2973, 1 (136.2 mm), 71.3609ºN, 151.3092ºW, L. Edenfield, 25 August 2011, Norseman II, Beau 2011-71, PSR 1956, DSFIB 768-11.

Diagnosis. Careproctus lerikimae is distinguished from all other species of Careproctus by the combination of cytb and 16S rRNA sequences (“ARC1”, in part, of Kai et al. 2011a; Table 1), an anteriorly robust body uniformly covered by widely spaced cactus-like prickles, the absence of the postorbital pore, a moderate-sized pelvic disc, elongate lower pectoral-fin rays, a light peritoneum, a round pupil, and 1–3 pterygiophores anterior to first haemal spine. It is most similar to C. phasma of the Bering Sea and Gulf of Alaska, from which it can be distinguished by its dusky coloration (vs. body entirely pale in C. phasma ), higher number of vertebrae (59–64 in C. lerikimae vs. 55–60 in C. phasma ) and median fin rays (dorsal 56–59 and anal 48–51 in C. lerikimae vs. 50–56 and 43–49 in C. phasma ), as well as its longer maxilla, shorter lower pectoral-fin lobe, and shorter nasal tube. Among other species of Careproctus reported from the Arctic, C. lerikimae differs from C. reinhardti in having a much smaller gill slit extending only to the upper most pectoral-fin rays rather than to the lower pectoral-fin lobe, a larger orbit (3–4.5 times in head vs. 5–6 in C. reinhardti ; Burke, 1930), a horizontally rather than an obliquely oriented mouth, a nearly round rather than a long pear-shaped pelvic disc, a normally positioned pectoral-fin rather than a lowinserted pectoral fin ( Chernova, 2005b), and higher counts of median fin rays (D 56–60, A 48–51 vs. D 54–55, A 45–46 in C. reinhardti ). It is also similar to members of the C. dubius group ( Chernova 2014b), particularly C. solidus Chernova and C. dubius Chernova but differs from both in its higher number of vertebrae (59–64 in C. lerikimae vs. 60 in C. solidus and C. dubius ), a higher number of dorsal-fin rays (56–60 vs. 54–55), and its horizontal mouth position (vs. oblique mouth in C. solidus ). Careproctus longipinnis Burke is also similar but differs in its higher number of dorsal-fin rays (56–60 vs. 55 in C. longipinnis ), presence of prickles (vs. absent in C. longipinnis ), shorter pectoral-fin lower lobe (0.8–1.5 times the length of the upper lobe in C. lerikimae vs. 1.6 times in C. longipinnis ), and lower position of the pectoral fin (even with oral cleft in C. lerikimae vs. middle of suborbital space in C. longipinnis ). It is also similar to C. karaensis Chernova but differs in its round pupil (longitudinally oval in C. karaensis ), the presence of 1–3 pterygiophores anterior to the first haemal spine (absent in C. karaensis ), an arcuate vertebral column (gently curved in C. karaensis ), the absence of dark pigment on upper pectoral-fin rays (blackish upper margin in C. karaensis ), and a shorter urogenital papilla (1.3–2.4 vs. 5 % SL) in males.

Description. Body rounded and deep anteriorly, tapering moderately posteriorly, moderately compressed; depth at pectoral-fin base 82.8–126.9 (93.5) % HL. Head large, 22.9–29.8 (28.0) % SL, robust, dorsal profile rounded from nape to snout. Snout rounded, slightly projecting anterior to lower jaw, longer than orbit, 103.2– 167.2 (159.1) % OL, 27.1–40.1 (36.6) % HL. Mouth terminal, small, horizontal; upper jaw 38.1–51.7 (44.8) % HL, maxilla extending to mid-orbit, oral cleft extending to anterior part of orbit; mandible 46.9–63.8 (47.0) % HL. Premaxillary tooth plates matching mandibular tooth plates. Premaxillary and mandibular teeth simple in 21–29 oblique rows of 8–10 teeth forming narrow bands. Diastema absent at symphysis of upper and lower jaws. Orbit 21.1–33.0 (23.0) % HL, dorsal margin at or just below dorsal contour of head, suborbital depth to upper jaw 11.4– 21.4 (14.6) % HL, to lower jaw 25.7–37.9 (30.0) % HL; pupil round. Interorbital space broad, fleshy distance 29.2– 54.8 (42.3) % HL, bony distance 15.6–30.8 (22.7) % HL, strongly convex. Nostril single, with short tube at level with mid-orbit; nostril tube length 1.7–16.0 (11.8) % OL.

Pores of cephalic lateralis system of moderate size, pore pattern 2-5-7-2, chin pores paired. Interorbital pore absent.

Gill opening small, 16.9–35.8 (26.5) % HL, upper margin at or just above level of mid-orbit, extending ventrally to just above the upper pectoral-fin ray to pectoral-fin ray 1–4 (above upper ray). Opercular flap rounded. Gill rakers 6–10 (9) (Tables 2–3), short, blunt.

Dorsal-fin rays 56–60 (59; Tables 2–3), anterior dorsal lobe absent, anterior rays buried in tissue, tips of more posterior rays not exserted. Anteriormost dorsal-fin pterygiophore inserted between neural spines 2 and 3 or 3 and 4, rayless or bearing a single small ray (2 and 3, rayless). Predorsal length 25.2–32.2 (27.8) % SL. Anal-fin rays 48–51 (51; Tables 2–3), one to three anal-fin pterygiophores anterior to first haemal spine (two), each bearing a single ray, tips of rays not exserted. Anal-fin origin below vertebrae 12–13 (caudal vertebrae 1–2), preanal length 36.2–48.2 (38.3) % SL.

Pectoral fin deeply notched, with 28–36 rays (32; Tables 2–3). Upper lobe 47.8–82.4 (50.6) % HL, with 20–27 (22) rays, extending beyond anus to near anal-fin origin, shorter than lower lobe, dorsalmost rays lengthening to rays 5–7, more ventral rays gradually shortening to shortest ray of notch. Lower lobe moderately elongate, 59.0– 105.6 (76.5) % HL, with 7–10 rays (10), extending beyond anus midway to anal-fin origin; dorsal rays gradually lengthening to elongate rays 3–4, ventral rays gradually shortening to ventralmost ray near pectoral symphysis. Tips of rays of dorsal lobe 5–15% free of membrane, rays of lower lobe more strongly exserted, up to 65% free. Notch strong, rays in notch slightly more widely spaced than rays of lobes, more widely spaced ventrally. Uppermost pectoral-fin ray level with oral cleft or slightly more dorsal (cleft). Insertion of lowermost pectoral-fin ray anteriorly placed, below area between snout and anterior rim of orbit. Proximal pectoral radials four (3+1), robust: radial 1 hour-glass shaped, radial 2 notched and distinctly hour-glass shaped, radial 3 crescent shaped, radial 4 round ( Fig. 5 G). Interradial fenestrae three, extending between scapula and proximal radials 1–3: oval between scapula and radial 1 and radials 1 and 2; dorsoventrally elongate between radials 2 and 3. Scapula broadly T-shaped with large robust dorsoposterior arm and helve and smaller ventroanterior arm; coracoid with broad triangular head, small foramen, and short robust helve. Distal radials present at base of rays 2–13, ventralmost at level of proximal radial 2, more ventral rays articulating directly with pectoral cartilage.

Pelvic disc large, length 18.8–29.1 (21.6) % HL, round, slightly longer than wide, width 14.8–24.1 (19.9) % HL, anterior lobe moderately developed, slightly to moderately cupped, distance from tip of snout to pelvic disc 11.0–16.0 (12.6) % SL. Anus at a level just posterior to orbit, close behind pelvic disc; distance from snout to anus 14.7–25.2 (17.5) % SL, 57.8–105.6 (62.6) % HL.

Principal caudal-fin rays 9, dorsal procurrent rays 1, ventral procurrent rays 1 (1 + 4/5 + 1). Caudal fin 30.9– 49.6 % HL. Membrane of posterior dorsal-fin rays attached to caudal fin at shorter distance than anal-fin rays: dorsal-fin rays attached to caudal fin 27.5–56.4 % CL; anal-fin rays, 35.9–57.6 % CL. Depth at base of caudal fin 9.1–20.0 % CL.

Skin relatively thin, loose gelatinous layer beneath skin, short cactus-like prickles uniformly covering body, widely spaced, in most dense region about 10 prickles in orbit length. Pyloric caeca 17–23, length about 33–51 % HL, left side of visceral cavity.

Vertebrae 59–64 (63), precaudal 10–12 (11), caudal 50–52 (52; Tables 2–3). Pleural ribs 2 or 3 (2), present on vertebrae 9–10 or 9–11 (9–10), when 2 each long and slender, when 3 anteriormost small.

Coloration. Body orangish pink and white to grayish, fins orangish pink in life, with speckling scattered over body and fins ( Fig. 3 C); head, dorsum from nape to caudal fin, and ventrum at anal-fin origin to caudal fin pink to marginally orange; isthmus, base of pectoral fin, and body posterior of gill slit to anal-fin origin white; belly silvery white (crystalline guanine) to anal-fin origin, black speckling increasing dorsally; dark line internally at base of dorsal fin rays, extending from nape to caudal fin base, and at base of rays in the posterior half of the anal fin; base and lower lobe of pectoral fin white to faintly orange; dorsal margin and distal portion of fin dusky orange; eye with dark dorsal margin, becoming brassy and whiter ventrally. Body and fins pale with speckling in preservation; base of dorsal and anal fins beneath skin with pigment, showing faint line between fins and body; eye entirely black. Peritoneum pale, with occasional scattered speckles dorsally; orobranchial cavity pale; stomach, intestines, and pyloric caeca pale; urogenital papilla pale.

Life history. The largest specimen examined was a 136.2 mm maturing female (UAM 2973). The only ripe female with yolked eggs was 159.0 mm, with eggs about 4.1 mm in diameter. Ripe males ranged from 93 to 132.3 mm.

Distribution. Careproctus lerikimae has been collected only from the Beaufort Sea off northern Alaska ( Fig. 6 ). Collection depths range from 175 to 500 m. One lot in poor condition collected from a haul at a depth of 66 m ( Rand & Logerwell 2011) was likely left in the net and washed down from a previous haul conducted at 175 m or deeper (K. Rand, pers. comm., 2014).

Etymology. The new species is named in honor of Erika Acuña, Kim Rand, and Libby Logerwell of the Alaska Fisheries Science Center for collecting or coordinating in 2008 the collection of the first representatives of the new species at sea. The specific epithet is an amalgamation of the collectors’ names to be treated as a noun in apposition.

Remarks. Kai et al. (2011a) recovered a clade they identified as “ARC1” that included both Arctic ( C. lerikimae ; UW 117918) and Gulf of Alaska specimens ( C. phasma ; UW 154442 as “UW uncataloged”) as the sister clade of “BER3” ( C. phasma ) of the Bering Sea. Within ARC1, C. lerikimae formed the sister group of the single Gulf of Alaska representative of C. phasma , differing from it by 1 bp within cyt b data only. New16s and cyt b sequence data from C. phasma (UW 151271, 151272, 151291 – 151296; Table 1) placed the Gulf of Alaska C. phasma well within the C. phasma clade, to the exclusion of C. lerikimae , with 0.2% sequence divergence within C. phasma (Kai, unpublished data, 2014).

Careproctus lerikimae is similar to species of the C. dubius species group of Chernova (2014b) in lacking the postorbital pore and having a long lower pectoral-fin lobe and cactus-like prickles. In contrast, C. lerikimae has a round pupil, unlike the slit pupil of all species in the C. dubius group, and males have a short urogenital papillae (1- 2 % SL), unlike the long urogenital papilla (2–6 % SL) in species of C. dubius ( Chernova 2005a; Chernova 2014b). In addition, cactus-like prickles are widely spaced over the body in C. lerikimae ; all members of the C. dubius species group densely covered by prickles (Chernova 2014ab; Chernova, pers. comm., 2015). Meristic characters are similar, although C. lerikimae has a higher range of vertebral and dorsal-fin ray counts than nearly all species ( Chernova 2014b, table 1). However, all but four of the 11 species of the C. dubius group are described from single specimens and thus more complete ranges of morphometric and meristic data are unknown.

Figures

FIGURE 3. Eastern Pacific and Arctic species of the Careproctus rastrinus species complex: A) C. scottae, UW 151322, 195.0 mm; B) C. phasma, UW 154447, 72.3 mm; C) Careproctus lerikimae n. sp., UW 118033, holotype, 132.3 mm.

FIGURE 5. Pectoral girdles of species of the Careproctus rastrinus species complex: A) C. rastrinus, HUMZ 60772, 149.2 mm; B) C. trachysoma, FAKU 131179, 229.2 mm; C) C. scottae, UW 155110, 165 mm; D) C. acanthodes, FAKU 135569, 79.2 mm; E) C. pellucidus, FAKU 135317, 210.0 mm; F) C. phasma, UW 117934, 191 mm; G) C. lerikimae n. sp., paratype, UW 154841. Scale bar = 5 mm. c = coracoid, f = interradial fenestra, pr = proximal radial, dr = distal radial, s = scapula. Shaded areas represent cartilage.

FIGURE 6. Distribution of species of the Careproctus rastrinus species complex: C. rastrinus (□), C. trachysoma (●), C. scottae (○), C. acanthodes (◊), C. pellucidus (▲), C. phasma (■), C. spectrum (∆), and C. lerikimae n. sp. (♦), based on material examined. Each symbol may represent more than one capture.