Three New Small Snailfishes of the Genus Careproctus (Teleostei: Cottiformes: Liparidae) from the Aleutian Islands, Alaska

Three new species of small snailfishes, with maximum lengths up to only 60 mm, are described from collections in the Aleutian Islands taken during fisheries resource assessment surveys conducted by the U.S. National Marine Fisheries Service. Previous molecular analyses demonstrated that two of the species are closely related; the third species was found among material thought to consist only of one of these two species. Two of the new species are distinguished from all other species of Careproctus on the basis of an anterior dorsal-fin lobe with exserted rays and bodies with widespread small rounded bumps covered with tiny prickles. They are distinguished from each other on the basis of fin ray and vertebral counts, as well as differences in body shape. The third new species is diagnosed from all other species of Careproctus by having a small teardrop-shaped body, with loose thin skin and without an anterior dorsal-fin lobe, as well as by high counts of meristic characters, especially pectoral-fin rays. Each species is found widely within the Aleutian Islands from west of Kiska Island in the west to north of Umnak Island in the east at depths of 90 to 447 m.

T HE snailfish family Liparidae encompasses over 430 species in about 32 genera worldwide (Chernova et al., 2004;Orr et al., 2019). Its most species-rich genus, Careproctus, comprises about 140 species (Chernova et al., 2004;Fricke et al., 2020), some 50 of which are known from the North Pacific, where they are found mainly on the edge of the continental shelf to the deeper waters of the continental slope. Although paraphyletic, as demonstrated in molecular analyses , the genus is characterized by having a pelvic disk, single nostril, pectoral-fin rays typically fewer than anal-fin rays, pseudobranchs absent, and body color that is not variegated except in a few species (Orr and Maslenikov, 2007).
Fisheries resource assessment surveys conducted by the U.S. National Marine Fisheries Service, Alaska Fisheries Science Center (AFSC), have provided material leading to the descriptions of several new liparids from Alaska Busby, 2001, 2006;Orr, 2004Orr, , 2012Orr, , 2016Orr and Maslenikov, 2007), as well as extensive material for molecular phylogenetic analyses (Knudsen et al., 2007;Orr et al., 2019). The three new species described herein were collected during these periodic surveys from 1997 to 2018 in the Aleutian Islands from nearly the entire length of the island chain (e.g., von Szalay et al., 2017). All are small pale species, easily missed in the catches of the large benthic otter trawls used in these surveys. Two of the species, originally identified as Careproctus sp. A and Careproctus sp. J, were included in a recent molecular phylogenetic analysis and were recovered together with C. canus in the C. canus species group clade . A third similar species was later discovered among material previously identified as Careproctus sp. A. Herein, I provide diagnoses, descriptions, and distributions of the three new species, as well as comparative remarks on C. canus, the fourth member of the clade.

MATERIALS AND METHODS
All material examined was obtained from benthic otter trawls (Stauffer, 2004) conducted in the Aleutian Islands, Alaska, USA. Where indicated, some material was collected in a small ''benthic bag'' attached near the footrope of the otter trawl as described by Orr (2004). All material was fixed in 10% formalin at sea, unless otherwise noted as fixed in 95% ethanol. Specimens with tissues preserved in 95% ethanol are indicated with an asterisk in lists of material examined.
Counts, measurements, and descriptive terminology follow Orr and Busby (2006), based on previous studies of Andriashev and Stein (1998) and Stein et al. (2001), except for pectoral girdle morphology, which follows Orr and Maslenikov (2007). Counts of median-fin rays and vertebrae were taken from radiographs. Counts of gill rakers were taken from the first gill arch on the right side. The right gill membrane and abdomen in most specimens were cut to examine the branchial and visceral cavities; right pectoral girdles were dissected, cleared, and counter stained following Potthoff (1984). Lengths are presented as standard length (SL) and proportions as percent SL, unless otherwise indicated as percent head length (HL), orbit length (OL), or caudal length (CL). Fleshy interorbital width is taken at the greatest width including tissue extending dorsally over the eye; bony interorbital width is the narrowest bony width. Suborbital depth to lower jaw is measured from the ventral rim of the orbit to the mandibular articulation. Measurements and counts are presented in species accounts as the range for all material examined followed by the value for the holotype in parentheses when intraspecific variation is indicated. Comparative counts and measurements for C. canus of Kido (1985) are augmented by new data from material examined. Institutional abbreviations are those provided by Sabaj (2020 .9-23.5 (11.9) % OL.
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 (1þ1þ1þ1), 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.
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.
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 (1þ1þ1þ1), 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.
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.  Table 1 Diagnosis.-Careproctus lacrima is distinguished from all other described North Pacific species of Careproctus by having a small teardrop-shaped body, with loose thin skin, and anterior dorsal-fin rays buried in tissue. Among species of the C. canus species group , Careproctus lacrima is most similar to small C. canus, differing in having seven preoperculomandibular pores (vs. six in C. canus), lower counts of dorsal-fin rays (47-52 vs. 51-55) and vertebrae (53-57 vs. 55-60), and a smaller maximum size (60 mm vs. 198 mm). Careproctus lacrima is also similar to C. spiraki and C. maslenikovae but is further and readily distinguished from them in lacking small, rounded bumps on its body and in having a single chin pore (vs. two chin pores), higher counts of pectoral-fin rays (32-38 vs. 28-32 in C. spiraki and 26-29 in C. maslenikovae), vertebrae (53-57 vs. 42-46 and 42-43), dorsal-fin rays (47-52 vs. 38-43 and 38-40), and anal-fin rays (43-45 vs. 32-37 and 32-33).
Gill opening small, 16.3-30.3 (21.0) % HL, upper margin at level of mid-orbit or dorsal part of orbit, extending to just above pectoral fin. Opercular flap rounded. Branchiostegal rays six.
Pectoral fin moderately notched, with 32-38 (35) rays (Table 1). Upper lobe of 25-32 (29) rays extending to anal-fin origin or beyond to anal-fin ray three, dorsalmost rays lengthening to rays 6-7, more ventral rays gradually shortening to shortest ray of notch. Lower lobe short, with 6-8 (6) rays, extending just past anus; dorsal rays gradually lengthening to thick and fleshy rays 2-3, ventral rays more slender and gradually shortening to ventralmost ray near pectoral symphysis. Tips of rays 5-50 % free of membrane, lower rays more strongly exserted. Rays in notch slightly more widely spaced than rays of lobes. Uppermost pectoralfin ray level with lower part of orbit. Lowermost pectoral-fin ray below posterior rim of orbit.
Proximal pectoral radials four (1þ1þ1þ1), robust; all radials round, unnotched, radial four not widely spaced from radial three (Fig. 3C). All fenestrae absent. Scapula small, with strong helve and rounded base, lacking distinct posterior arm; coracoid broadly triangular with broad lamina. Distal radials present at base of all but first pectoral-fin ray, more ventral distal radials smaller.
Pelvic disk moderate in size, 24.7-37.9 (30.4) % HL, round, slightly longer than wide, anterior lobe moderately developed, flat with margins often turned slightly down or up. Anus much closer to pelvic disk than to anal-fin origin.
The largest specimen examined was a 60.0 mm ripe female (UW 200025). The smallest female with yolked eggs was 43.5 mm (UW 200033). The largest male examined was 47.5 mm (UW 49434); no males examined had enlarged, swollen testes.
Coloration.-In life, body pale, mostly translucent, small white spots over head to nape, faint darker pigment scattered internally over posterior part of body (Fig. 1C). Flash of white covering belly from pectoral fin base to near anal-fin origin. Pectoral fins unpigmented, translucent; pelvic disc white; median fins translucent, rays with faint pigment. Iris brassy. Peritoneum and orobranchial cavity pale; stomach, intestines, pyloric caeca, and urogenital papilla pale. When preserved, body uniformly pale with scattered fine dark speckling (Fig. 2C).
Etymology.-The specific epithet refers to the translucent and tear-drop shaped body. It is derived from the Latin lacrima for tear or teardrop to be treated as a noun in apposition.

DISCUSSION
The three new species are more similar to one another than to all other species of Careproctus in the North Pacific. Two of the new species were recovered in a moderately well-supported clade in the recent molecular phylogenetic analysis of Orr et al. (2019: fig. 10) designated as the C. canus species group. Careproctus spiraki (as ' 'Careproctus sp. A'') was placed as the sister species of C. lacrima (as ''Careproctus sp. J'') and C. canus. Although not included in the molecular analysis, C. maslenikovae is similar in size and coloration to C. spiraki, and the two species are clearly closely related.
Careproctus spiraki and C. maslenikovae are distinguished from each other by several significant differences in body shape, particularly body depth and posterior body length, and meristic characters, and both are easily distinguished from C. lacrima by their possession of small bumps on the body, an anterior dorsal-fin lobe, two chin pores, and lower meristic counts of vertebrae and median fins.
Among other small liparids with a distinct disc are C. abbreviatus, which reaches a maximum size of 100 mm, and Lopholiparis flerxi obtaining 38 mm (Maslenikov et al., 2013). Careproctus abbreviatus, known certainly from only three specimens (Burke, 1930;Chernova et al., 2004;Maslenikov et al., 2013), can be easily distinguished from all by its low count of pectoral-fin rays (21-24); small, deeply cupped pelvic disc; and absence of an anterior dorsal-fin lobe. Lopholiparis flerxi, another rare species known from only five specimens (Orr, 2004;Maslenikov et al., 2013;UW 159752), is readily identified by its heavily ossified superficial head bones, distinct rounded anterior dorsal-fin lobe, and low vertebral and dorsal-and anal-fin ray counts (Orr, 2004). In life, C. lacrima has small white spots covering the head and nape, similar to Lopholiparis (Maslenikov et al., 2013: fig. 2E), but lacks the anterior dorsal-fin lobe and superficial ossified bones of the head, and it has much higher meristic counts. Other similarly small liparids in the region are among the pelagic or semi-pelagic species of Paraliparis and the monotypic Lipariscus and Nectoliparis. These small species all reach maximum lengths of 70-100 mm (Kido, 1988(Kido, , 1993Mecklenburg et al., 2002), similar to the new species, but are easily distinguished from them by the absence of a pelvic disc.
Other North Pacific species with a distinct anterior dorsalfin lobe include C. (Temnocora) candidus and related undescribed species (Orr, unpubl. data; J. Gardner, pers. comm., January 2020). All are larger species, variegated in body color, with an elliptical pupil and typically higher meristic counts than either C. spiraki or C. maslenikovae, the two new species with an anterior dorsal-fin lobe.
The geographic ranges of all three new species overlap across the Aleutian Islands, although none of the species were collected together in the same haul. Careproctus lacrima was collected in shallower depths, while C. maslenikovae and C. spiraki were collected deeper. Among the three, Careproctus spiraki was collected at the deepest depths of about 450 m, near the deepest trawling depths attempted in surveys of the Aleutian Islands since the 1980s.
I have tentatively identified one specimen (UW 158306) as C. sp. cf. spiraki from the eastern Aleutian Islands that has a pectoral-fin ray count of 41, nine rays more than any other specimen of C. spiraki. It is similar in having an anterior dorsal-fin lobe with exserted rays and similar vertebral and median fin counts, as well as being similar in general body morphology, but it was fixed in 95% ethanol at sea and is distorted. It likely is an undescribed species, but I postpone its description until additional material in good condition is available.
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