Careproctus spiraki, 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 : 456-462

Careproctus spiraki , new species

urn:lsid:zoobank.org:act:DC4BF5BC-63BC-44F4-A8FA-226E1ED8C1D3

Pimpled Snailfish

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

Careproctus sp. A : Orr et al., 2019: 33, table 3 (molecular phylogenetics).

Holotype.— UW 159753 , 52.5 mm, Aleutian Islands , Seguam Pass, 52.32558N, 172.74668W, 457 m depth, F/ V Sea Storm, cruise 2004-01, haul 60, J. W. Orr, 19 June 2004.

Paratypes.— 19 specimens, 38.7–54.6 mm. SIO 20-11 (ex UW 200019 ), 44.7 mm, 51.80438N, 174.57758W, 323 m depth , F/ V Ocean Explorer, cruise 2018-01, haul 84, N. E. Roberson, 30 June 2018; SIO 20-12 (ex UW 200099 ), 45.3 mm, 52.24408N, 171.69988W, 394 m depth , F/ V Sea Storm, cruise 2002-01, haul 211, R. C. Harrison, 6 August 2002; UW 155710 *, 41.9 mm, 53.04118N, 169.09978W, 193 m depth , F/ V Gladiator , cruise 2006-01, haul 19, J. W. Orr, 12 June 2006; UW 155713 *, 3, 38.7–47.9 mm, 52.36758N, 171.24638W, 328 m depth , F/ V Gladiator , cruise 2006-01, haul 39, benthic bag, J. W. Orr, 16 June 2006; UW 155809 , 41.2 mm, 52.36758N, 171.33778W, 325 m depth , F/ V Dominator, cruise 2000-01, haul 83, benthic bag, K. P. Maslenikov, 11 June 2000; UW 200012 (ex UW 159753 ), 43.8 mm, same locality as holotype; UW 200013 , 2 , 40.5–45.3 mm, 51.80488N, 174.56538W, 320 m depth , F/ V Dominator, cruise 2000-01, haul 92, K. P. Maslenikov, 13 June 2000; UW 200014 , 45 mm, 51.5418N, 176.62198W, 373 m depth , F/ V Dominator, cruise 2000-01, haul 109, benthic bag, K. P. Maslenikov, 17 June 2000; UW 200015 , 50.8 mm, 51.78178N, 177.48518E, 261 m depth, F/ V Vesteraalen , cruise 2000-01, haul 139, benthic bag, 24 June 2000 ; UW 200016 , 44.3 mm, 52.3318N, 172.7478W, 447 m depth, F / V Sea Storm , cruise 2002-01, haul 156, J. W. Orr, 23 July 2002 ; UW 200017 , 48.2 mm, 51.45168N, 178.62798W, 453 m depth, F / V Sea Storm , cruise 2016-01, haul 103, W. A. Palsson, 2 July 2016 ; UW 200018 , 39.7 mm, 52.33348N, 172.74598W, 439 m depth, F / V Ocean Explorer , cruise 2018-01, haul 52, 22 June 2018 ; UW 200020 , 47.8 mm, 51.80668N, 174.55658W, 323 m depth, F / V Ocean Explorer , cruise 201801, haul 85, N. E. Roberson, 30 June 2018 ; UW 200021 , 40 mm, 51.55088N, 177.66118W, 328 m depth, F / V Ocean Explorer , cruise 2018-01, haul 99, N. E. Roberson, 3 July 2018 .

Diagnosis.— Careproctus spiraki is distinguished from all other described North Pacific species of Careproctus by having a slender body covered with small bumps and anterior dorsal-fin rays forming a lobe with deeply exserted rays. Careproctus maslenikovae , new species, shares these characters, but C. spiraki differs in its more slender, longer body reflected in the following morphometric characters: body depth at pelvic disc less (17.3–24.6 % vs. 24.1–31.0 % in C. maslenikovae , new species); head width less (11.1–14.9 % vs. 15.1–20.1 %); anus placed more anteriorly, snout to anus length less (24.9– 33.1 % vs. 34.4–37.2 %), anus closer to the posterior edge of the pelvic disc (1.6–5.6 % vs. 5.8–7.0 %); pre-anal-fin length shorter (34.4–43.2 % vs. 43.9–47.7 %); and length posterior to anal-fin origin longer (56.8–65.6 vs. 52.3–56.1 %). The following meristic characters are also different between the two species: vertebrae 42–46 in C. spiraki (vs. 42–43 in C. maslenikovae , new species), dorsal-fin rays 38–43 (vs. 38–40), and pectoral-fin rays 28–32 (vs. 26–29). Careproctus spiraki 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 thin skin in C. lacrima , new species), two suprabranchial pores (vs. one pore), two separate chin pores (vs. one chin pore), and lower meristic counts (dorsal-fin rays 38–43 vs. 47–52 in C. lacrima , new species; anal-fin rays 32–37 vs. 43–45; pectoral-fin rays 28–32 vs. 32–38; and total vertebrae 42–46 vs. 53–57).

Description.— Body slender, tapering posteriorly, rounded anteriorly, moderately compressed posteriorly; greatest depth at dorsal-fin origin 72.3–115.3 (109.6) % HL. Body posterior to anal-fin origin long, about 56.8–65.6 (57.0) % SL. Head moderately large 23.4–26.7 (25.1) % SL, dorsal profile narrowly rounded from nape to snout. Snout rounded, slightly projecting beyond upper jaw, length about equal to orbit length, 22.0–33.3 (33.3) % HL, jaws terminal. Mouth small, maxilla 35.6–43.0 (37.1) % HL, extending anterior to mid-orbit, oral cleft extending anterior to orbit. Premaxillary tooth plates matching mandibular tooth plates. Premaxillary and mandibular teeth trilobed in 7–14 oblique rows, increasing from three to five teeth in anteromedial rows to nine teeth in posterolateral rows. Diastema absent at symphysis of upper and lower jaws. Orbit large, 21.2–35.0 (31.8) % HL, dorsal margin below dorsal contour of head, suborbital depth to oral cleft 29.0–76.0 (38.1) % OL; pupil large, round. Interorbital space broad, fleshy distance 26.8– 46.1 (37.1) % HL, bony distance 16.1–23.5 (17.4) % HL, slightly convex. Nostril single, with base of well-developed tube at level with middle to upper part of orbit; nostril tube length 3.4–7.2 (3.8) % HL, 11.9–23.5 (11.9) % 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 ( Andriashev and Stein, 1998) not observed.

Gill rakers 4–8 (5), short, rounded with tiny spines. Gill opening small, 15.5–29.4 (15.9) % HL, upper margin at level of dorsal part of orbit, extending to just above pectoral fin. Opercular flap angular. Branchiostegal rays six.

Dorsal-fin rays 38–43 (40; 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 32–37 (33; 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 10–11 or 11–12 (caudal vertebrae 1–2).

Pectoral fin moderately notched, with 28–32 (29) rays ( Table 1 ). Upper lobe of 20–24 (23) rays extending to anal-fin origin or beyond to anal-fin ray four, dorsalmost rays lengthening to rays 5–7, more ventral rays gradually shortening to shortest ray of notch. Lower lobe short, with 6–9 (8) rays, extending to about anus; dorsal rays slightly and gradually lengthening to thicker and slightly fleshy rays 5–6, ventral rays more slender and gradually shortening to ventralmost ray near pectoral symphysis. Tips of rays 5– 30 % free of membrane, lower 5–6 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 part of orbit.

Proximal pectoral radials four (1 þ 1 þ 1 þ 1), robust; radial one slightly notched at scapular fenestra, radials two through four round, unnotched, radial four not widely spaced from radial three ( Fig. 3A ). Scapular fenestra small, other fenestrae absent. Scapula with strong helve; coracoid narrowly triangular with broad lamina. Distal radials present at base of pectoral-fin rays two to 23, more ventral distal radials reduced, absent from base of ventralmost 6 rays, which articulate with non-staining fibrocartilage.

Pelvic disk large, 35.7–47.3 (37.1) % HL, flat, round, slightly longer than wide, anterior lobe moderately developed. Anus much closer to pelvic disk than to anal-fin origin.

Principal caudal-fin rays 10–12 (11; Table 1 ), dorsal procurrent rays 1, ventral procurrent rays 0–1 (1). Membrane of posterior dorsal-fin rays attached to caudal fin for 18.9– 29.1 (22.6) % CL; posterior anal-fin rays, 22.6–47.0 (29.0) % CL.

Skin thin, small rounded bumps covered with tiny prickles widespread over body. Pyloric caeca 16–18, thick, length about 37% HL.

Vertebrae 42–46 (43), 9 or 10 (10) precaudal, 33–37 (33) caudal ( Table 1 ). Pleural ribs 2–3, present on vertebrae 9 and 10 when 2, present on vertebrae 7–9 or 8–10 when 3, anteriormost shorter and more slender, those more posterior longer and thicker. Hypural plate composed of dorsal and ventral plates divided by a small to large split up to 75% length of plate. Single epural present.

The largest specimen examined was a ripe 52.5 mm female with yolked eggs (UW 159753). The smallest female with yolked eggs was 39.7 mm (UW 111834). The largest male examined was 41.9 mm (UW 155710); no males examined had enlarged, swollen testes.

Coloration.— In life, body overall red to pink, darkening slightly posteriorly with darker speckling ( Fig. 1A ). Anterior pores of head surrounded by unpigmented areas, lips unpigmented. Bright white blotch behind pectoral fin over abdomen. All fins with red rays, membranes unpigmented. Peritoneum and orobranchial cavity pale; stomach, intestines, pyloric caeca, and urogenital papilla pale. When preserved, body pale with faint dark pigment posteriorly at base of dorsal and anal fins and on sides of body ( Fig. 2A ).

Distribution.— Careproctus spiraki has been collected only in the Aleutian Islands, from Kiska Island in the west (177.58E) to north of Umnak Island in the east (169.18W) at depths of 193–447 m ( Fig. 4 ).

Life history.— One partially digested specimen (discarded) was found in the stomach of a Malacocottus zonurus taken in the central Aleutian Islands.

Etymology.— The species epithet spiraki , to be treated as a noun in apposition, is derived from the Greek RPTQIa ´, meaning small rice-like bumps, and refers to the small bumps covering the body.

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.

Tables

Table 1. Proportional morphometric and meristic characters of Careproctus spiraki, new species, Careproctus maslenikovae, new species, and Careproctus lacrima, new species. Morphometric data are given in percent standard length and presented as the range, followed by the mean 6 standard deviation (SD).

		C. spiraki			C. maslenikovae			C. lacrima
	n	Range	Mean 6 SD	n	Range	Mean 6 SD	n	Range	Mean 6 SD
Standard length (mm)	18	38.7–52.5		4	29.4–40.3		19	31.4–58.5
%SL
Head length	18	23.4–26.7	25.160.9	4	25.9–28.5	27.761.2	19	27.7–33.5	30.861.7
Head width	18	11.1–14.9	13.061.2	4	15.1–20.1	17.962.0	19	9.6–16.2	12.462.0
Greatest body depth	18	19.0–30.2	24.462.7	4	24.1–30.9	27.763.2	19	24.5–31.2	27.762.1
Body depth at anal-fin origin	18	14.2–19.7	17.161.3	4	18.4–19.5	18.760.5	19	16.2–23.5	19.662.3
Body depth from anal-fin origin to	18	21.2–28.2	25.762.1	4	27.6–31.3	29.561.7	19	23.8–30.0	26.161.5
dorsal-fin origin
Body depth at pelvic fin	18	17.3–24.6	20.762.1	4	24.1–30.9	25.963.4	19	23.0–28.1	25.961.4
Body depth at dorsal-fin origin	18	19.0–30.2	24.462.8	4	26.2–30.9	28.962.0	19	23.6–31.2	27.662.2
Snout length	18	5.5–8.4	7.060.7	4	7.4–9.5	8.660.9	19	7.6–10.0	8.760.6
Orbit length	18	5.6–8.8	7.260.8	4	6.2–8.4	7.460.9	19	6.0–8.2	7.060.7
Post orbit length	18	8.8–13.8	10.861.3	4	10.3–13.4	11.761.5	19	12.5–17.1	15.161.3
Interorbital width (bony)	18	3.9–5.8	4.760.6	4	6.7–8.5	7.760.9	19	3.6–6.9	5.260.9
Interorbital width (fleshy)	18	6.7–11.3	9.461.4	4	12.4–16.0	14.561.5	19	6.5–11.5	9.061.4
Suborbital depth to upper jaw	18	2.2–4.2	3.460.6	4	4.1–5.1	4.660.5	19	3.6–6.4	4.860.9
Suborbital depth to lower jaw	18	5.5–8.5	7.060.8	4	7.5–9.5	8.360.9	19	6.7–11.3	9.061.2
Mouth width	18	8.1–13.7	10.761.4	4	12.7–14.3	13.560.8	19	8.0–16.4	10.762.2
Maxilla length	18	8.7–10.9	9.660.7	4	10.9–12.7	11.860.8	19	10.9–13.6	12.260.8
Mandible length	18	9.1–11.1	10.260.7	4	11.1–14.4	12.361.4	19	12.2–14.9	13.660.7
Gill slit length	18	3.9–6.9	5.461.0	4	3.8–6.5	5.561.2	19	5.3–8.7	7.161.2
Pectoral-fin length	18	14.6–19.6	17.261.5	4	18.6–19.7	19.360.5	19	15.5–23.1	20.662.2
Lower lobe of pectoral-fin length	18	11.2–15.9	13.961.3	4	13.6–16.0	14.861.0	19	11.8–19.0	14.862.2
Notch ray of pectoral-fin length	17	7.1–12.4	9.661.1	4	8.4–11.2	9.761.4	19	4.5–10.5	8.161.5
Predorsal length	18	25.7–30.5	27.961.3	4	26.6–30.8	28.861.8	19	30.5–38.7	34.762.2
Pre-anal-fin length	18	34.4–43.2	40.462.3	4	43.9–47.7	46.661.8	19	40.8–50.6	45.562.5
Snout to pelvic-disc length	18	10.9–17.1	15.161.6	4	16.1–20.3	18.562.0	19	15.6–22.8	19.562.0
Snout to anus length	18	24.9–33.1	28.762.0	4	34.4–37.2	35.661.2	19	24.8–31.6	29.061.9
Pelvic disc length	18	8.6–12.4	9.960.9	4	11.1–12.6	11.760.7	19	8.0–11.5	9.361.0
Pelvic disc width (flattened)	18	7.8–10.3	8.860.7	4	9.9–12.4	11.261.0	19	6.3–11.0	8.961.2
Pelvic disc to anus length	18	1.6–5.6	3.961.2	4	5.8–6.9	6.460.6	19	0.2–1.9	0.960.4
Anus to anal-fin length	18	10.4–16.1	13.761.6	4	8.8–15.9	12.563.0	19	14.5–29.8	20.464.1
Post anal-fin origin length	18	56.8–65.6	59.662.3	4	52.3–56.1	53.461.8	19	49.4–59.2	54.562.5
Caudal-fin length	18	11.5–14.4	12.860.8	4	11.7–14.6	12.861.3	18	10.3–16.1	13.561.5
Dorsal-fin attachment to caudal-fin	18	2.3–4.0	3.060.5	4	2.0–3.3	2.760.6	18	4.6–8.5	6.161.1
length
Anal-fin attachment to caudal-fin	18	2.7–5.3	3.560.6	4	2.0–4.0	2.960.9	18	5.1–9.0	6.961.3
length
Caudal-fin base depth	18	2.1–3.0	2.560.3	4	2.4–3.0	2.760.3	19	1.5–2.9	2.260.3
Nasal tube length	18	0.8–1.8	1.360.3	4	1.7–2.2	2.060.2	18	0.6–2.4	1.460.5
Meristics
Dorsal-fin rays	18	38–43	40.461.3	4	38–40	38.861.0	19	47–52	50.261.3
Anal-fin rays	18	32–37	33.961.3	4	32–33	32.560.6	19	43–45	43.760.7
Pectoral-fin rays	18	28–32	29.461.2	4	26–29	27.561.3	19	32–38	34.761.6
Pectoral-fin lower lobe rays	18	6–10	8.060.8	4	6–8	7.060.8	19	6–8	6.660.8
Principal caudal-fin rays	17	10–12	10.860.5	3	10–11	10.760.6	13	11–13	11.260.6
Precaudal vertebrae	18	9–10	9.260.4	4	9–9	9.060	19	10–11	10.160.2
Caudal vertebrae	18	33–37	34.861.2	4	33–34	33.560.6	19	43–47	45.160.8
Total vertebrae	18	42–46	44.061.3	4	42–43	42.560.6	19	53–57	55.160.8
Pterygiophores anterior to haemal	17	1–2	1.560.5	4	1–2	1.560.6	18	1–2	1.160.3
spine I
Gill rakers	14	4–8	5.661.2	3	6–9	7.761.5	11	4–6	4.860.8