Eumicrotremus gyrinops ( Garman 1892 )

Stevenson, Duane E., Mecklenburg, Catherine W. & Kai, Yoshiaki, 2017, Taxonomic clarification of the Eumicrotremus asperrimus species complex (Teleostei: Cyclopteridae) in the eastern North Pacific, Zootaxa 4294 (4), pp. 419-435 : 430-434

Eumicrotremus gyrinops ( Garman 1892)

Alaskan Lumpsucker

Figs. 3 , 5 ; Table 1

Cyclopteroides gyrinops Garman 1892:37 . [Type locality: St. Paul Island , Alaska. Holotype: MCZ 16026.]

Lethotremus muticus Gilbert 1896:449 . [Type locality: Albatross station 2844, near Unimak Pass, 54 fathoms. Lectotype: USNM 53806 ; Paralectotypes: CAS-SU 774 , CAS-SU 3093 , USNM 48614 , USNM 59376 .]

Eumicrotremus phrynoides Gilbert & Burke 1912:69 . [Type locality: Albatross station 4779, Petrel Bank, Bering Sea, 54–56 fathoms. Holotype: USNM 74378 .]

Cyclopteropsis phrynoides: Soldatov & Lindberg 1930:325 . [New combination].

Cyclopterocottus phrynoides: Popov 1930:74 . [New combination].

Eumicrotremus gyrinops: Lindberg & Legeza, 1955:423 . [New combination].

Eumicrotremus muticus: Oku et al., 2017:55 . [New combination].

Holotype. MCZ 16026, 38.5 mm, St. Paul Island , Alaska, 56.9°N, 170.4°W.

Diagnosis. A species of Eumicrotremus distinguished from all other ENP species of Eumicrotremus by the following combination of characters: tubercles, when present, irregularly arranged in interorbital space (vs. four distinct interorbital rows in E. orbis ); enlarged pair of tubercles absent at origin of second dorsal and anal fin (vs. present in E. andriashevi ); thick dermal papillae absent (present in E. barbatus ). Eumicrotremus gyrinops is distinguished from members of the WNP E. asperrimus species complex (including E. asperrimus , Cyclopteropsis bergi , and C. lindbergi ) by higher modal counts of dorsal-fin spines (usually VII vs. usually VI) and lower modal counts of pectoral-fin rays (24–28 vs. 25–30).

Counts and proportions. First dorsal-fin spines VI–VIII; second dorsal-fin rays 10–12 (10.6); anal-fin rays 9– 12 (10.1); pectoral-fin rays 24–28 (26.1); vertebrae 10–12 + 15–19 = 26–30 (27.9). Following proportions as percent SL: head length 28.9–45.1 (36.9); body depth 28.7–57.7 (45.6); first dorsal-fin base 16.1–29.9 (23.5); second dorsal-fin base 15.4–26.2 (21.5); anal-fin base 13.7–25.4 (18.0); pectoral-fin base 24.8–35.8 (29.3); interdorsal distance 2.1–7–19.7 (7.9); predorsal length 29.1–47.2 (38.9); snout to vent 57.3–76.6 (64.6); vent to anal-fin origin 9.7–23.6 (16.3); caudal peduncle length 8.5–14.7 (11.6); caudal peduncle depth 8.0–13.0 (9.9); pectoral-fin length 15.6–26.8 (21.3); snout to disc 17.5–35.1 (24.4); disc length (outer) 20.2–30.3 (23.7); disc length (inner) 9.9–16.2 (12.1); disc width (outer) 18.5–29.3 (24.1); disc width (inner) 9.7–17.0 (13.3); disc to vent (outer) 8.5–31.1 (21.1); disc to vent (inner) 11.6–35.6 (25.6); caudal-fin length 22.5–31.9 (26.7). Following proportions as percent HL: orbit length 31.5–50.8 (40.4); snout length 7.4–25 (15.9); postorbital head length 32.7– 54.1 (41.2); interorbital width 40.9–78.5 (55.4); mouth width 50.4–93.9 (73.2); anterior internasal width 20.4–36.1 (28.9).

Description. Head and body short, firm, and globose; snout short; cheeks tumid. Interorbital space broad, slightly concave. Eye large, placed high on head, entering dorsal profile. Nostrils with tubes, the anterior short and wide, posterior relatively narrow, approximately same length as anterior. Mouth wide, slightly oblique, posterior margin of maxilla terminating anterior to margin of orbit. Teeth in jaws blunt, conical, arranged in three to five distinct diagonal rows on both premaxilla and dentary, approximately 25–35 teeth in each jaw. Upper and lower pharyngeal teeth present, similar in size and shape to jaw teeth.

Cephalic sensory system consisting of supraorbital, interorbital, postorbital, suborbital, and operculomandibular canals. Supraorbital canal opening through two pores, one anterior to nostrils and one medial to internarial space. Interorbital canal opening through single median pore. Postorbital canal opening anteriorly through a supraorbital pore and posteriorly through a postbranchial pore. Suborbital canal with two pores, anteriormost pore ventral to orbit, posterior pore posteroventral to orbit. Operculomandibular canal with single opercular pore on cheek and four mandibular pores closely spaced along lower jaw. All sensory pores opening through short thick tubes.

Development and distribution of bony tubercles on head and body highly variable. In holotype (38.5 mm SL), tubercles small, low, rounded, embedded in skin, each with several prominent spines; tubercles few and sparsely spaced, forming an indistinct row on either side of spinous dorsal fin, several additional tubercles dispersed along anterior portion of body; head naked. Tubercles generally smaller and fewer in smaller specimens and in males; larger males (45–55 mm SL) with tubercles completely covered by skin, producing wart-like protrusions on body; males and smaller females often without tubercles on head or body; all specimens examined over 58 mm SL (n = 13) completely covered with large tubercles, and all female.

First dorsal fin high, usually not covered with thick skin or tubercles in smaller specimens (including holotype); becoming increasingly embedded in skin and covered with spiny tubercles in larger specimens, particularly in females; fin membranes moderately to heavily pigmented. Second dorsal and anal fins directly opposite each other, nearly equal in length and height, usually without bony tubercles or fleshy papillae; fin membranes translucent, without pigment. Caudal fin truncate; fin membranes translucent, without pigment; rays in some specimens with several faint dark blotches suggesting bands running perpendicular to body axis. Pectoral fins translucent, their bases densely covered with small melanophores; larger specimens usually with several rounded tubercles covering pectoral base. Pelvic disc large, ovate, slightly constricted anteriorly; its length usually slightly greater than its width. Anus approximately midway between posterior margin of pelvic disc and origin of anal fin.

Coloration. Holotype with small melanophores relatively evenly spaced over entire head and body, without conspicuous bands, stripes, or blotches. Additional material in life yellowish-brown to medium brown, generally darker on head and dorsum, often with dark brown to black blotches and vermiculations, particularly on dorsal surface of head and body; becoming lighter posteriorly and generally white or nearly white on ventral surface. Some degree of faint banding usually present on pectoral and all median fins.

Distribution. Specimens examined are from the eastern Bering Sea, Aleutian Islands, and western and central Gulf of Alaska ( Fig. 6 ).

Remarks. The holotype of E. gyrinops (MCZ 16026) is in poor condition. It has apparently been desiccated and rehydrated at least once. Thus, the tubes associated with the mandibular pores, and to a lesser extent the other pores as well, appear longer and more prominent than in most other specimens. In addition, its fins are badly damaged, and its internal organs have been removed through a very large incision on the left side of the body.

Material examined. Eumicrotremus asperrimus (18 specimens): Sea of Japan : FAKU 131263 (GenBank AB 917623, 917693), 102 mm female, Kyoto, 36°N, 134.75°E, 320 m ; FAKU 131983 (GenBank AB917614 , 917684), 40 mm male, 35.881°N, 132.474°E, 240 m; FAKU 132544 (GenBank AB917600 , 917670), 59 mm male, 37.758°N, 136.294°E, 342 m; FAKU 132564 (GenBank AB917601 , 917671), 58 mm male, 38.026°N, 136.916°E, 330 m; FAKU 132598 (GenBank AB917621 , 917691), 34 mm male, Ishikawa, 37.7°N, 136.308°E, 260 m ; FAKU 133204 (GenBank AB 917615, 917685), 61 mm male, Kyoto, 38.03°N, 135.413°E, 300 m. Sea of Okhotsk : FAKU 133231 (GenBank AB917616 , 917686), 98 mm female, 45.062°N, 143.068°E ; FAKU 133235 (GenBank AB917620 , 917690), 52 mm, 44.99°N, 144.115°E, 220 m; FAKU 133279 (GenBank AB917604 , 917674), 56 mm female, 44.382°N, 144.341°E, 350 m; FAKU 133280 (GenBank AB917605 , 917675), 54 mm female, 44.382°N, 144.341°E, 350 m; FAKU 133281 (GenBank AB917606 , 917676), 59 mm female, 44.382°N, 144.342°E; FAKU 133282 (GenBank AB917607 , 917677), 60 mm male, 44.382°N, 144.342°E; FAKU 133283 (GenBank AB917608 , 917678), 60 mm female, 44.382°N, 144.342°E; FAKU 133284 (GenBank AB917609 , 917679), 49 mm male, 44.382°N, 144.341°E, 350 m; FAKU 133285 (GenBank AB917610 , 917680), 91 mm female, 44.382°N, 144.342°E; FAKU 133286 (GenBank AB917611 , 917681), 56 mm female, 44.382°N, 144.341°E, 350 m; FAKU 134958 (GenBank AB917639 , 917709), 59 mm female, 44.78°N, 143.928°E, 170 m; FAKU 134985 (GenBank AB917643 , 917713), 56 mm male, 45.46°N, 142.967°E, 117 m.

Eumicrotremus awae : FAKU 134183, 18 mm, Japan, Sagami Bay; FAKU 134725, 18 mm, Japan, Sagami Bay; FAKU 135824, 24 mm, Japan, Sagami Bay; UW 42938, 16 mm, Japan, Sagami Bay, 35.15°N, 139.17°E.

Eumicrotremus bergi (2 specimens): FAKU 132552 (GenBank AB917597 , 917667), 59 mm male, Sea of Japan , 38.031°N, 136.778°E, 419 m; FAKU 132557 (GenBank AB917596 , 917666), 62 mm male, Sea of Japan, 37.959°N, 137.31°E, 320 m.

Eumicrotremus gyrinops (235 specimens): Type material: MCZ 16026, holotype of Cyclopteroides gyrinops , 38.5 mm, St. Paul Island , Alaska ; USNM 74378 , holotype of Eumicrotremus phrynoides, Albatross station 4779, Petrel Bank , Bering Sea , 54–56 fm; USNM 53806, lectotype of Lethotremus muticus, Albatross station 2844, near Unimak Pass , 54 fm; CAS-SU 774, paralectotype of Lethotremus muticus, Albatross station 2844, near Unimak Pass, 54 fm; CAS-SU 3093, USNM 48614, USNM 59376, paralectotypes of Lethotremus muticus, Albatross station 3223, Unimak Pass, 39 fm. Bering Sea (31 specimens): UW 28373, 85 mm female, 57°0'N, 171°25.02'W, 59 fm; UW 28384, 69 mm female, 60°59.1'N, 177°19.02'W, 130 m ; UW 28390, 65 mm female, 60°28.14'N, 177°W, 143 m; UW 119071, 16(29–47 mm males, 27–40 mm females), 56°53'N, 169°39'W, 75 m; UW 119538 (GenBank AB917661 , 917731), 92 mm female, 57°59.23'N, 170°20.09'W, 74 m; UW 150056, 82 mm female, 59°19.98'N, 172°28.26'W, 87 m; UW 150057, 51 mm male, 56°50.08'N, 170°26.76'W, 98 m; UW 150071 (GenBank AB917626 , 917696), 75 mm female, 54°50.25'N, 169°57.12'W, 71 m; UW 150072, 88 mm female, 60°20.28'N, 174°3.36'W, 90 m; UW 151282, 3(41 mm male, 33–77 mm females), 56°49.57'N, 170°28.07'W, 101 m; UW 151285, 80 mm female, 58°20.58'N, 170°22.32'W, 74 m; UW 151415, 46 mm male, 56°40.32'N, 170°4.44'W, 95 m; UW 152368, 36 mm male, 60°8.88'N, 172°57.12'W, 59 m; UW 155892, 81 mm female, 56°35.22'N, 170°38.22'W, 108 m.

Aleutian Islands (160 specimens): UW 22199, 69 mm, 53°43.98'N, 164°49.98'W, 209 m ; UW 28389, 42 mm, 54°24'N, 165°24'W; UW 46659, 32 mm, 51°54.6'N, 176°52.2'W, 211 m; UW 46660, 45 mm, 52°51.53'N, 172°27.52'E, 146 m; UW 46662, 45 mm, 53°1.68'N, 173°12.36'E, 133 m; UW 46664, 5(43–51 mm females), 52°11.04'N, 179°39.84'W, 115 m; UW 46665, 5(44–49 mm females), 51°58.98'N, 179°23.52'E, 139 m; UW 49401, 2(40 mm male, 45 mm female), 52°7.8'N, 179°54.6'W, 112 m; UW 49409, 41 mm male, 52°4.92'N, 179°21.54'E, 306 m; UW 49412, 45 mm male, 52°25.86'N, 179°56.52'E, 163 m; UW 49418, 49 mm male, 52°31.27'N, 174°26.96'E, 182 m; UW 49423, 50 mm female, 52°2.82'N, 179°25.26'E, 143 m; UW 49436 ( GenBank AB917625 , 917629, 917695, 917699), 2(36–38 mm, males), 52°08.14'N, 179°53.41'W, 121 m ; UW 49467, 34 mm male, 52°29.96'N, 170°40.65'W, 208 m; UW 49470, 4(37–52 mm females, 36 mm male), 52°10.86'N, 179°37.02'E, 124 m; UW 49471, 4(41–44 mm males), 52°22.62'N, 179°38.82'E, 245 m; UW 49474, 18(34–38 mm males, 30–40 mm females), 51°39.23'N, 176°22.56'W, 143 m; UW 49504, 61 mm female, 52°2.34'N, 179°24.96'E, 145 m; UW 49577, 5(40–42 mm females), 52°59.42'N, 172°21.95'E, 146 m; UW 49580, 49 mm female, 52°28.15'N, 173°11.34'E, 116 m; UW 49587, 45 mm female, 52°35.6'N, 172°55.38'E, 154 m; UW 111260, 39 mm male, 52°27.91'N, 174°12.6'E, 110 m; UW 111265, 35 mm female, 52°23.82'N, 173°58.72'E, 112 m; UW 111267, 2(34– 41 mm females), 51°39.23'N, 176°22.2'W, 145 m; UW 111280, 52 mm female, 52°52.7'N, 175°12.5'W, 151 m; UW 111288, 62 mm female, 52°25.27'N, 170°16.74'W, 211 m; UW 111300, 47 mm female, 52°21.71'N, 171°16.14'W, 134 m; UW 111309, 40 mm male, 52°21.96'N, 179°54.84'W, 168 m; UW 111310, 35 mm female, 52°29.56'N, 174°22.08'W, 177 m; UW 111311, 7(32–42 mm males, 38–51 mm females), 52°57.72'N, 170°23.82'W, 221 m; UW 111314, 2(49–50 mm females), 52°18.38'N, 175°48.91'E, 235 m; UW 111335, 35 mm male, 52°30.19'N, 174°15.22'W, 102 m; UW 111451, 2(36–44 mm males), 52°29.46'N, 170°8.82'W, 183 m; UW 112040, 35 mm male, 52°22.97'N, 174°8.62'E, 148 m; UW 112041, 41 mm female, 52°26.26'N, 174°17.57'E, 220 m; UW 112272 ( GenBank AB917663 , 917664, 917733, 917734), 2(32 mm male, 45 mm female), 52°31.20'N, 170°39.25'W, 124 m ; UW 117593, 43 mm female, 52°39.45'N, 173°50.48'E, 79 m; UW 151458, 3(35–38 mm males, 33 mm female), 51°2.50'N, 172°15.1'W, 162 m; UW 151803 ( GenBank AB917644 , 917714), 36 mm male, 51°53.15'N, 173°55.29'W, 136 m ; UW 151804 ( GenBank AB917645 , 917715), 45 mm female, 52°02.56'N, 179°48.44'W, 250 m ; UW 151810 ( GenBank AB917646 , 917716), 43 mm female, 52°49.40'N, 173°41.17'W, 109 m ; UW 151811 ( GenBank AB917647 , 917717), 44 mm female, 52°24.33'N, 170°16.57'W, 213 m ; UW 151814 ( GenBank AB917648 , 917718), 46 mm male, 52°49.42'N, 170°27.32'W, 99 m ; UW 152131 ( GenBank LC209624 , 209640), 49 mm female, 52°35.48'N, 172°55.48'E, 145 m ; UW 152132 ( GenBank LC209625 , 209641), 40 mm male, 52°28.32'N, 173°11.4'E ; UW 152138, 2(31 mm male, 33 mm female), 54°22.2'N, 165°32.94'W, 83 m; UW 152355, 3(39–60 mm male, 41 mm female), 52°55.94'N, 170°24.61'W, 222 m; UW 152358 ( GenBank LC209626 , 209642), 35 mm female, 51°45.04'N, 177°51.7'E, 157 m ; UW 152359 ( GenBank LC209627 , 209643), 3(38 mm male, 37–41 mm females), 51°54.64'N, 173°47.03'W, 118 m ; UW 152360 ( GenBank LC209628 , 209644), 33 mm male, 51°39.08'N, 178°20.06'E, 206 m ; UW 152361, 4(36–42 mm males, 33 mm female), 52°29.62'N, 170°23.63'W, 216 m; UW 152362 ( GenBank LC209629 , 209645), 32 mm male, 52°2.16'N, 179°24.84'E, 150 m ; UW 152363 ( GenBank LC209630 , 209646), 29 mm female, 51°36.96'N, 178°11.28'W, 134 m ; UW 152364, 38 mm female, 52°17.28'N, 170°47.58'W, 226 m; UW 152365 ( GenBank LC209631 , 209647), 35 mm male, 52°49.68'N, 173°41.28'E, 115 m ; UW 152366 ( GenBank LC209632 , 209648), 36 mm male, 51°52.92'N, 173°55.38'W ; UW 152367 ( GenBank LC209633 , 209634, 209649, 209650), 2(37–41 mm males), 52°52.02'N, 171°18.06'W, 204 m ; UW 152369 ( GenBank LC209635 , 209651), 33 mm female, 51°47.28'N, 177°43.56'E, 155 m ; UW 152370 ( GenBank LC209636 , 209652), 3(40–41 mm females), 51°37.98'N, 177°9.96'W, 172 m ; UW 152371 ( GenBank LC209637 , 209653), 2(35–37 mm males), 52°26.88'N, 174°18.66'E, 228 m ; UW 152428, 53 mm female, 52°52.28'N, 171°19.06'W, 202 m; UW 152431 ( LC209833 , 209845), 40 mm female, 52°22.92'N, 174°8.46'E, 155 m; UW 152432, 43 mm female, 52°26.88'N, 174°18.66'E, 228 m; UW 152433 ( GenBank LC209638 , 209639, 209654, 209655), 2(35–42 mm males), 52°58.62'N, 170°3.72'W, 122 m ; UW 152434 ( LC209834 , 209846), 41 mm male, 52°28.33'N, 173°11.37'E; UW 152438, 2(27–43 mm males), 52°28.59'N, 170°8.7'W, 183 m; UW 152444, 39 mm male, 54°20.65'N, 165°32.94'W, 104 m; UW 152460, 2(38 mm male, 31 mm female), 52°23.18'N, 174°W, 85 m; UW 152466, 2(36 mm male, 46 mm female), 52°48.65'N, 171°31.38'W, 201 m; UW 152469 ( LC209835 –209843, 209847–209855), 9(37–48 mm females), 52°48.95'N, 173°44.35'E, 111 m; UW 152490 ( LC209844 , 209856), 42 mm female, 52°24.22'N, 174°15.53'E, 255 m; UW 154964, 9(41 mm male, 36–57 mm females), 52°10.84'N, 179°36.97'E, 127 m; UW 156510, 4(32–38 mm females), 51°47.46'N, 177°40.74'E, 171 m; UW 156512, 37 mm female, 52°28.5'N, 170°44.94'W, 260 m; UW 156511, 2(41–42 mm females), 52°35.28'N, 172°55.72'E, 127 m.

Gulf of Alaska (42 specimens): UW 28386, 2(52–54 mm), 56°N, 157°W, 50 fm; UW 47916, 38 mm female, 58°7.47'N, 151°30.6'W, 157 m ; UW 47923, 9(34–39 mm females, 37 mm male), 58°56.46'N, 150°19.02'W, 146 m; UW 47935, 2(39 mm female, 39 mm male), 56°43'N, 152°36.72'W, 97 m; UW 47948, 3(32 mm female, 37–40 mm males), 54°53.85'N, 158°42.48'W, 98 m; UW 116417, 40 mm female, 58°46.32'N, 150°23.58'W, 151 m; UW 117047, 4(34–38 mm males, 36–38 mm females), 54°44.1'N, 158°37.26'W, 104 m; UW 117609 ( GenBank AB917634 , 917704), 3(41–43 mm females, 38 mm male), 58°15.17'N, 151°24.51'W, 157 m ; UW 119222 ( GenBank AB917627 , 917628, 917697, 917698), 2(32–38 mm females), 57°36.33'N, 150°20.16'W, 130 m ; UW 119548, 39 mm male, 55°16.88'N, 157°6.48'W, 94 m; UW 119596, 40 mm male, 57°53.28'N, 150°16.47'W, 158 m; UW 119690, 4(38–41 mm females), 58°53.03'N, 150°52.08'W, 164 m; UW 119706, 60 mm female, 58°54.29'N, 150°36.3'W, 119 m; UW 119779 ( GenBank AB917631 , 917701), 35 mm male, 58°38.59'N, 150°08.45'W, 121 m ; UW 119782 ( GenBank AB917632 , 917702), 39 mm male, 58°30.48'N, 150°17.52'W, 90 m ; UW 151260 ( GenBank AB917657 , 917658, 917659, 917727, 917728, 917729), 5(31–37 mm males, 35 mm female), 58°54'N, 151°24.96'W, 153 m ; UW 154590, 39 mm male, 55°29.21'N, 157°2.82'W, 90 m.

Eumicrotremus lindbergi (4 specimens): FAKU 132535 ( GenBank AB917599 , 917669), 55 mm male, Sea of Japan, 36.845°N, 136.317°E, 261 m ; FAKU 132563 ( GenBank AB917598 , 917668), 59 mm male, Sea of Japan, 38.026°N, 136.916°E, 330 m ; FAKU 134222 (GenBank AB917624 , 917694), 53 mm male, Sea of Japan, Shimane, west of Oki I. ; FAKU 134862 ( GenBank AB917638 , 917708), 54 mm male, Sea of Japan, Shimane, 35.6°N, 131.033°E, 180 m.

Eumicrotremus orbis : UW 119821 (GenBank AB917655 , 917725), 2(17 mm male, 31 mm female), Salish Sea , San Juan Island, Jackson Beach, 48°31.2'N, 123°W, 2 m.

Figures

FIGURE 3. Type specimens for nominal species of the eastern North Pacific Eumicrotremus asperrimus species complex: (A) Lethotremus muticus, lectotype, USNM 53806; (B) Cyclopteroides gyrinops, holotype, MCZ 16026; and (C) Eumicrotremus phrynoides, holotype, USNM 74378.

FIGURE 5. Osteological variation in Eumicrotremus gyrinops: lateral view of the prootic in (A) UW 49474 and (B) UW 47923; lateral view of the urohyal in (C) UW 49474 and (D) UW 47923; first dorsal fin in (E) UW 49474 and (F) UW 47923; and caudal skeleton in (G) UW 49474 and (H) UW 47923. HS, haemal spine of second preural centrum; L, laminar structure of urohyal; NF, nerve foramen; PR, proximal radial of first dorsal spine.

FIGURE 6. Distribution of material examined for Eumicrotremus gyrinops. Open circles represent specimens with no evidence of tubercles on the head or body.