Careproctus spectrum Bean 1890

Careproctus spectrum Bean 1890

English common name: Stippled Snailfish Figures 4 B, 6; Tables 2–3

Careproctus spectrum Bean 1890:40. Type locality: Gulf of Alaska, 55.167°N, 160.3°W.— Gilbert 1896:443 (comparison, in part).— Jordan & Evermann 1898:2133 (description).— Jordan & Gilbert 1899:478 (Unga Island).— Evermann & Goldsborough 1907:333 (Alaska).—Burke 1912:570 (description of C. gilberti).—Gilbert & Burke 1912a:78 (misidentification, = C. gilberti ?).— Burke 1930:123 (description, key).— Soldatov & Lindberg 1930:31 (Attu Island, keys).— Taranetz 1937:137 (Alaska, in key).— Schmidt 1950:195 (comparison).— Bhlke 1953:136 (type catalog).— Wilimovsky 1954:286 (Alaska).— Wilimovsky 1958:79 (Alaska, in key).— Quast & Hall 1972:29 (Alaska).— Fedorov 1973:66 (Bering Sea).— Allen & Smith 1988:67 (Alaska, “pink snailfish”, in part).—Robins et al. 1991:44 (list).— Mecklenburg et al. 2002:617 (Alaska, in key, in part).— Chernova et al. 2004:16 (checklist).— Chernova 2005b:S7 (comparisons).— Nelson et al. 2004:124 (list), Love et al. 2005:103 (checklist).— Kai et al. 2011a:153 (listed).—Page et al. 2013:128 (list).

Lectotype. SU 48, 91 mm, Alaska, north of the Shumagin Islands, between Unga and Nagai islands; 55.167°N, 160.3°W, depth 201 m, Albatross station 2848, 31 July 1888, herein designated (Fig. 4 B).

Paralectotypes. USNM 45363, 2 (68.2–73.1 mm), both in poor condition, same locality data as lectotype.

Diagnosis. Careproctus spectrum can be distinguished from other members of the C. rastrinus species complex by the combination of a large orbit, large pelvic disc, and counts of vertebrae, and dorsal- and anal-fin rays. Its larger orbit (33.9–34.4 % HL) distinguishes it from C. scottae (16.4–32.1 % HL), C. phasma (17.3–31.6 % HL), C. acanthodes (24.0–33.9 % HL), C. trachysoma (16.7–28.3 % HL), and the new species C. lerikimae (21.1– 33.0 % HL). Its larger pelvic disc (22.5–23.1 % HL) distinguishes it from C. trachysoma (11.1–18.1 % HL), C. pellucidus (10.0–17.0 % HL), and most individuals of C. rastrinus and C. scottae (9.9–26.7 % HL). It is further distinguished from C. rastrinus, C. scottae, C. trachysoma, and C. lerikimae n. sp. by its lower counts of dorsal- (52–54 vs. ≥ 54 in C. scottae, C. rastrinus, C. trachysoma, and C. lerikimae n. sp.) and anal-fin rays (47 vs. ≥ 47 in C. scottae, C. rastrinus, C. trachysoma, and C. lerikimae n. sp.).

Description. Body moderately robust, gently tapering posteriorly, moderately compressed; depth at anal-fin origin 84.5–86.4 (86.4) % HL. Head large, robust, dorsal profile gently rounded from nape to snout. Snout rounded, slightly shorter than orbit 82.9–93.0 (82.9) % OL, 28.1–32.0 (28.1) % HL, slightly projecting anterior to lower jaw. Mouth subterminal, horizontal; upper jaw 44.7 % HL, maxilla extending to mid-orbit, oral cleft extending to anterior rim of orbit; mandible 54.1 % HL. Premaxillary tooth plates matching mandibular tooth plates. Premaxillary and mandibular teeth simple or with slightly developed lobes in 10 or 12 oblique rows.

Diastema absent at symphysis of upper and lower jaws. Orbit large, 33.9–34.4 (33.9) % HL, dorsal margin below dorsal contour of head, suborbital depth to upper jaw 28.1 % OL; pupil round. Interorbital space moderately broad, bony distance 20.7% HL, fleshy distance 25.7–45.9 (45.9) % HL, convex.

Suprabranchial pores 2 (Burke 1930).

Gill opening small, 17.8 % HL, upper margin at level of mid-orbit, extending ventrally to dorsalmost pectoralfin ray.

Dorsal-fin rays 52–54 (Tables 2–3), anterior dorsal lobe absent; anteriormost pterygiophore bearing a single ray, inserted between neural spines 3 and 4. Predorsal length 24.7 % SL. Anal-fin rays 47 (Tables 2–3), one anal-fin pterygiophore anterior to first haemal spine. Preanal length 39.1 % SL.

Pectoral fin deeply notched, with 32 rays (Tables 2–3). Upper lobe 65.3 % HL, with 24 rays extending beyond anus to anal-fin origin. Lower lobe moderately elongate,>34.3 % SL, with 8 rays, extending to anus (Burke 1930). Uppermost pectoral-fin ray level with oral cleft. Insertion of lowermost pectoral-fin ray below mid-orbit.

Pelvic disc large, length 22.5–23.1 % HL, round, slightly longer than wide, width 20.6–22.7% HL, flat, distance from tip of snout to pelvic disc 13.7 % SL. Anus posterior to gill slit, close behind pelvic disc.

Principal caudal-fin rays 9, dorsal procurrent rays 1, ventral procurrent rays 0, (1+4+5+0).

Prickles absent. Pyloric caeca 21 (Burke 1930).

Vertebrae 59, precaudal 10, caudal 49 (Tables 2–3). Pleural ribs 2, present on vertebrae 8–9.

Coloration. The lectotype is now uniform light brown in preservation, with a pale orobranchial cavity, peritoneum, and viscera. The type material was described by Bean (1890) as having “Color along back of some examples light brown, elsewhere uniformly pale.” This description is almost certainly of preserved material and likely includes type material of C. gilberti, subsequently described by Burke (1912). Burke (1930) later described a few aspects of coloration in the remaining types of C. spectrum: “Skin transparent, lax; muscles flesh colored; mouth, gill cavity, and internal organs pale; peritoneum silvery, without dots; abdomen silvery.”

Life history. The largest specimen examined was the lectotype, a 91 mm male (SU 48).

Distribution. Careproctus spectrum is known only from the type series taken in the northwestern Gulf of Alaska (Fig. 6). The collection depth was 201 m at the type locality.

Etymology. The specific epithet is derived from the Latin spectrum, meaning “specter” or “ghostly apparition.”

Remarks. Careproctus spectrum was described by Bean (1890) from the western Gulf of Alaska in the Shumagin Islands, based on at least 26 specimens, apparently split into at least two lots: USNM 45363 and SU 48 (Böhlke 1953; Chernova et al. 2004). Burke (1912) recognized that two species were among the syntypes and subsequently described C. gilberti based on the much smaller disc of many of the specimens. He described C. gilberti on the basis of 25 of the syntypes of C. spectrum, including three specimens of SU 48. A fourth specimen (Fig. 4 B) is part of SU 48, labeled with the same tin tag, but was not noted by Burke (1912) and has not been mentioned in later publications. We identified it as likely to be one of the three remaining syntypes of C. spectrum. Unlike the two syntypes of USNM 45363, which are both disintegrating, the condition of this specimen, while poor, is adequate to collect additional morphological data. The apparent designation of USNM 45363 as the lectotype by Burke (1930) is invalid as the lot contains two specimens (Böhlke 1953). Because both of these specimens are in very poor condition, we herein designate SU 48 as the lectoype of C. spectrum and the two specimens of USNM 45363 as paralectotypes. The three specimens of C. gilberti remaining in SU 48 were recataloged as SU 69904.

An original illustration of one syntype is problematic (USNM 45363, view P02535, illustrated by S. F. Denton, provided by L. Palmer, USNM), as it shows an individual with an anus near the anal-fin origin and a dark line along the body. This illustration was published by Mecklenburg et al. (2002) and appropriately modified to place the anus near the pelvic disc following the description of Burke (1930) and to remove the dark line.