Careproctus maslenikovae, Orr, 2021

Orr, James Wilder, 2021, Three New Small Snailfishes of the Genus Careproctus (Teleostei: Cottiformes: Liparidae) from the Aleutian Islands, Alaska, Ichthyology & Herpetology 109 (2), pp. 456-466 : 462-463

Careproctus maslenikovae , new species

urn:lsid:zoobank.org:act:6D0043CE-B8C6-4F26-9FCE-AB993CFD0D63

Blushing Snailfish

Figures 1B , 2B , 3B , 4 ; Table 1

Holotype.— UW 155708 *, 36.9 mm, ripe female, Aleutian Islands , west of the Islands of Four Mountains, 52.64668N, 170.20278W, 234 m depth, F/ V Gladiator , cruise 2006-01, haul 35, benthic bag, J. W. Orr, 15 June 2006.

Paratypes.— 3 specimens, 29.4–40.3 mm. SIO 20-13 (ex UW 200023 ), 37.0 mm, ripe female, 51.60848N, 178.85988W, 322 m depth, F/ V Sea Storm, cruise 2002-01, haul 76, benthic bag, K. P. Maslenikov, 28 June 2002 ; UW 154503 *, 29.4 mm, male, 51.67168N, 178.31118W, 261 m depth, F/ V Gladiator , cruise 2006-01, haul 91, W. C. Flerx, 2 July 2006 ; UW 200022 , 40.3 mm, ripe female, 51.45648N, 178.44598W, 280 m depth, F/ V Sea Storm, cruise 2002-01, haul 72, K. P. Maslenikov, 26 June 2002 .

Diagnosis.— Careproctus maslenikovae is distinguished from all other described North Pacific species of Careproctus by having a robust body covered with small bumps and anterior dorsal-fin rays forming a lobe with deeply exserted rays. Careproctus spiraki shares these characters but C. maslenikovae differs in its more robust, shorter body reflected in having a greater body depth at pelvic disc (24.1–30.9 % vs. 17.3–24.6 % in C. spiraki ), greater head width (15.1–20.1 % vs. 11.1–14.9 %); more anteriorly placed anus, with snout to anus length 34.4– 37.2 % (vs. 24.9–33.1 %); anus placed farther from the posterior edge of the pelvic disc (5.8–7.0 % vs. 1.6–5.6 %); longer pre-anal-fin length (43.9–47.7 % vs. 34.4–43.2 %); and shorter length posterior to anal-fin origin (52.3–56.1 vs. 56.8–65.6 %). The following meristic characters are also less in C. maslenikovae than in C. spiraki : vertebrae 42–43 (vs. 42– 46 in C. spiraki ), dorsal-fin rays 38–40 (vs. 38–43), and pectoral-fin rays 26–29 (vs. 28–32). Careproctus maslenikovae is also similar to C. lacrima , new species, but is further and readily distinguished from it in its more slender body with its tight skin (vs. more robust body with loose skin in C. lacrima ), two suprabranchial pores (vs. one pore), two separate chin pores (vs. one chin pore), and far lower meristic counts (dorsal-fin rays 38–40 vs. 47–52 in C. lacrima , new species; anal-fin rays 32–33 vs. 43–45; pectoral-fin rays 26–29 vs. 32–38; and total vertebrae 42–43 vs. 53–57).

Description.— Body stout, tapering posteriorly, slightly compressed, depth at dorsal-fin origin 92.7–111.5 (109.6) % HL. Body posterior to anal-fin origin short, about 52.3–56.1 (52.3) % SL. Head moderately large, 26.0–28.5 (28.2) % SL, dorsal profile rounded from nape to snout. Snout rounded, slightly projecting beyond upper jaw, slightly longer than orbit, 26.1–36.5 (32.7) % HL. Mouth small, maxilla 38.3–46.9 (45.2) % HL, extending to mid-orbit, oral cleft extending anterior to orbit. Lower jaw slightly inferior, premaxillary tooth plates matching mandibular tooth plates. Premaxillary and mandibular teeth trilobed in 8 or 9 oblique rows, increasing from four to six teeth in anteromedial rows to nine teeth in posterolateral rows. Diastema absent at symphysis of upper and lower jaws. Orbit large, 24.0–29.8 (29.8) % HL, dorsal margin below dorsal contour of head, suborbital depth to oral cleft 54.6–78.3 (61.3) % OL; pupil round. Interorbital space broad, fleshy width 47.9–56.7 (56.7) % HL, bony width 23.5–30.1 (29.8) % HL, slightly convex. Nostril single, with base of well-developed tube at level with upper part of orbit; nostril tube length 6.1–7.7 (7.7) % HL, 22.6–30.4 (27.3) % OL.

Pores of cephalic lateralis of moderate size: nasal pores two, maxillary pores six, preoperculomandibular pores seven, suprabranchial pores two (pore pattern 2-6-7-2); chin pores paired in separate pits. Interorbital pore absent. Free neuromasts not observed.

Gill rakers 6–9 (8), short, rounded with tiny spines. Gill opening small, 14.6–22.9 (19.2) % HL, upper margin at level of mid-orbit or dorsal part of orbit, extending to just above pectoral fin. Opercular flap narrowly rounded. Branchiostegal rays six.

Dorsal-fin rays 38–40 (39; Table 1 ), anterior 5–6 rays exserted, deeply emarginate, forming slight lobe, anterior uniserial and unsegmented, more posterior rays biserial and segmented; all rays simple. Predorsal inserted between neural spines two and three, anteriormost dorsal-fin pterygiophore inserted between neural spines three and four, together bearing a single ray.

Anal-fin rays 32–33 (32; Table 1 ), all rays biserial, segmented, and simple. One or two anal-fin pterygiophores each bearing a single ray anterior to first haemal spine. Anal-fin origin below vertebrae 11–12 (caudal vertebrae 1–2).

Pectoral fin moderately notched, with 26–29 (29) rays ( Table 1 ). Upper lobe of 20–22 (22) rays extending to anal-fin origin or beyond to anal-fin ray two, dorsalmost rays lengthening to rays 5–6, more ventral rays gradually shortening to shortest ray of notch. Lower lobe short, with 7–8 (7) rays, extending to anus; dorsal rays gradually lengthening to thick and fleshy rays 3–4, ventral rays gradually shortening to ventralmost ray near pectoral symphysis. Tips of rays 5–40 % free of membrane, lower rays more strongly exserted. Rays in notch slightly more widely spaced than rays of lobes. Uppermost pectoral-fin ray level with ventral rim of orbit. Lowermost pectoral-fin ray below posterior rim of orbit.

Proximal pectoral radials four (1 þ 1 þ 1 þ 1), robust, unnotched, radial four not widely spaced from radial three, radial 2 larger than all others ( Fig. 3B ). Scapular fenestra small, other fenestrae absent. Scapula with slender strong helve; coracoid narrowly triangular with broad lamina. Distal radials present at base of all except the first pectoral-fin ray, more ventral distal radials reduced.

Pelvic disk large, 40.4–44.6 (42.7) % HL, flat, round, about equal in length to width, anterior lobe moderately developed, flat with margins often slightly upturned. Anus closer to pelvic disk than to anal-fin origin.

Principal caudal-fin rays 10–11 (11; Table 1 ), dorsal procurrent rays 1, ventral procurrent rays 1. Membrane of posterior dorsal-fin rays attached to caudal fin 14.0–27.9 (20.0) % CL; posterior anal-fin rays, 14.0–30.8 (20.0) % CL.

Skin thin, small rounded bumps covered with tiny prickles widespread over body. Pyloric caeca 16–18, thick, length about 43% HL.

Vertebrae 42–43 (43), 9 precaudal, 33–34 (34) caudal ( Table 1 ). Pleural ribs absent or one reduced pair on penultimate precaudal vertebra. Hypural plate composed of dorsal and ventral plates divided by deep split about 50–75 % length of plate. Single epural present.

Of four specimens examined, three, including the holotype, were females 36.9–40.3 mm with ripe eggs. The smallest specimen was a 29.4 mm immature male (UW 154503).

Coloration.— In life, body overall light red-orange ( Fig. 1B ). Top of head from nape to snout pale, unpigmented. Red slash extending from nares posteriorly over eyes and joining pigmented red-orange cheeks. Anterior pores of head surrounded by unpigmented areas, lips unpigmented. Bright white flash behind pectoral fin over side of abdomen; pale, unpigmented area posterior to white flash above anal-fin origin extending to dorsal-fin base posterior to anterior lobe. All fins with red rays, membranes unpigmented. Eye black. Peritoneum and orobranchial cavity pale; stomach, intestines, pyloric caeca, and urogenital papilla pale. When preserved, body uniformly pale with scattered fine dark speckling ( Fig. 2B ).

Distribution.— Careproctus maslenikovae has been collected only in the Aleutian Islands at depths of 234–322 m ( Fig. 4 ). The holotype was collected just west of the Islands of Four Mountains (170.28W), while all paratypes were collected about 600 km to the west in the vicinity of Tanaga Island (178.38W to 178.98W).

Etymology.— Named for the diligent collector of many snailfish types and other specimens, Katherine P. Maslenikov, Collections Manager of the Burke Museum’s Fish Collection at the University of Washington, and for her contributions to and cheerful support of ichthyology in the Pacific Northwest.

Figures

FIG. 1. (A) Careproctus spiraki, new species, UW 159753, 52.5 mm, holotype, Aleutian Islands, Seguam Pass, 52.32558N, 172.74668W, 457 m depth; (B) Careproctus maslenikovae, new species, UW 155708, 36.9 mm, holotype, ripe female, Aleutian Islands, west of the Islands of Four Mountains, 52.64668N, 170.20278W, 234 m depth; (C) Careproctus lacrima, new species, UW 200024 (out of UW 49434), 50.2 mm, ripe female, holotype, Aleutian Islands, north of Tanaga Island, 52.00388N, 177.82788W, 111 m depth; (D) Careproctus canus, UW 156561, 198 mm, southeast of Buldir Island, 52.10178N, 176.0048E, 174 m depth. All photographed before preservation.

FIG. 2. (A) Careproctus spiraki, new species, UW 159753, 52.5 mm, holotype, Aleutian Islands, Seguam Pass, 52.32558N, 172.74668W, 457 m depth; (B) Careproctus maslenikovae, new species, UW 155708, 36.9 mm, holotype, ripe female, Aleutian Islands, west of the Islands of Four Mountains, 52.64668N, 170.20278W, 234 m depth; (C) Careproctus lacrima, new species, UW 200024 (out of UW 49434), 50.2 mm, ripe female, holotype, Aleutian Islands, north of Tanaga Island, 52.00388N, 177.82788W, 111 m depth; (D) Careproctus canus, UW 47852, 170 mm, southeast of Buldir Island, 52.10178N, 176.0048E, 174 m depth. All photographed after preservation.

FIG. 3. Right medial views of pectoral girdles. (A) Careproctus spiraki, new species, paratype, UW 155713, 42.6 mm; (B) Careproctus maslenikovae, new species, paratype, UW 200022, 40.3 mm; (C) Careproctus lacrima, new species, paratype, UW 200046, 50.4 mm; (D) Careproctus canus, UW 47852, ca. 170 mm with regenerated caudal fin. Shaded areas represent cartilage.

FIG. 4. Distribution of three new species of Careproctus from the Aleutian Islands based on all known material: Careproctus spiraki, new species (white circle), Careproctus maslenikovae, new species (gray triangle), and Careproctus lacrima, new species (black circle). Each symbol may represent more than one capture. Holotype localities are represented by stars. Bottom contour illustrated is 200 m.