Allocareproctus unangas, James Wilder Orr & Morgan Scott Busby, 2006

James Wilder Orr & Morgan Scott Busby, 2006, Revision of the snailfish genus Allocareproctus Pitruk & Fedorov (Teleostei: Liparidae), with descriptions of four new species from the Aleutian Islands., Zootaxa 1173, pp. 1-37 : 27-30

Allocareproctus unangas new species

Goldeneye Snailfish

(Figures 1-2, 6, 10, 13; Tables 1-4)

Holotype: UW 112308 , 82.5 mm, 53.1274°N, 169.9643°W, 387 m depth, 1 June 2002, F/V Morning Star, cruise 2002-01, haul 35 , J.W. Orr/D.E. Stevenson .

Paratypes: UW 112300 , 1(129.7 mm), female, 53.2067°N, 169.8452°W, 399 m depth, 4 June 2002, F/V Morning Star, cruise 2002-01, haul 52 , J.W. Orr ; UW 112313 , 1(115.2 mm), 53.0363°N, 170.2986°W, 210 m depth, 27 May 2000, F/V Vesteraalen, cruise 2000- 01, haul 39 , W.C. Flerx ; UW 112303 , 2(79-105.8 mm), 51.5636°N, 178.3331°E, 465 m depth, 30 June 2000, M/V Dominator, cruise 2000-01, haul 159 , K.P. Maslenikov ; UW 112306 , 2(40.3-64.4 mm), 53.1899°N, 169.8622°W, 398 m depth, 19 July 2002, F/V Vesteraalen, cruise 2002-01, haul 195 , R.N. Clark ; UW 112305 , 1(104.2 mm), 52.2762°N, 170.5968°W, 231 m depth, 30 May 2000, M/V Dominator, cruise 2000-01, haul 49 , J.W. Orr ; UW 112304 , 1(126.2 mm), 52.40236°N, 171.8333°W, 270 m depth, 8 August 2002, F/ V Sea Storm, cruise 2002-01, haul 213 , R.C. Harrison ; UW 112087 , 1(83 mm), 53.1303°N, 169.9617°W, 433 m depth, 26 May 2000, F/V Vesteraalen, cruise 2000-01, haul 35 , W.C. Flerx ; UW 112089 , 2(73.5-78.6 mm), 52.4212°N, 170.2785°W, 211 m depth, 29 May 2000, M/V Dominator, cruise 2000-01, haul 43 , benthic bag, J.W. Orr ; UW 112301 , 1(117.7 mm), 52.3896°N, 171.36°W, 234 m depth, 11 June 2000, M/V Dominator, cruise 2000-01, haul 82 , K.P. Maslenikov ; UW 112302 , 2(76.7-98.2 mm), 52.3675°N, 171.3377°W, 318 m depth, 11 June 2000, M/V Dominator, cruise 2000-01, haul 83 , benthic bag, K.P. Maslenikov ; UW 112085 , 1(78 mm), 51.9056°N, 176.6003°E, 264 m depth, 5 July 2000, F/V Vesteraalen, cruise 2000- 01, haul 173 , E.S. Brown ; UW 112086 , 1(101.6 mm), 52.3679°N, 171.2465°W, 316 m depth, 18 June 1997, F/V Vesteraalen, cruise 1997-01, haul 42 , W.C. Flerx ; UW 112088 , 2(84.2-102 mm; 84.2 mm cleared and stained), 52.5303°N, 172.1104°W, 364 m depth, 26 June 1997, F/V Vesteraalen, cruise 1997-01, haul 78 , R.C. Harrison ; UW 112307 , 1(101.7 mm), 52.2383°N, 172.1247°W, 357 m depth, 29 July 2002, F/V Sea Storm, cruise 2002-01, haul 167 , R.C. Harrison ; USNM 385685 , 4(68.3-96.1 mm), 52.3687°N, 171.2406°W, 323 m depth, 5 May 2000, M/V Dominator, cruise 2000-01, haul 51 , benthic bag, J.W. Orr ; USNM 385686 , 1(118 mm), 52.5080 ºN, 172.2650ºW, 215 m depth, 21 June 2004, F/V Sea Storm, cruise 2004-01, haul 65 , J.W. Orr ; USNM 385687 , 2(95-115 mm), 52.9580ºN, 169.4346ºW, 429 m depth, 12 June 2004, F/V Gladiator, cruise 2004-01, haul 26 , K.P. Maslenikov ; CAS 223483 , 1(92 mm), 52.8965ºN, 169.4597ºW, 341 m depth, 13 June 2004, F/V Gladiator, cruise 2004-01, haul 29 , benthic bag, K.P. Maslenikov ; CAS 223484 , 1(113 mm), 53.2200ºN, 169.7387ºW, 323 m depth, 13 June 2004, F/V Gladiator, cruise 2004-01, haul 27 , K.P. Maslenikov ; CAS 223485 , 1(105 mm), 53.0341ºN, 170.2061ºW, 176 m depth, 14 June 2004, F/V Gladiator, cruise 2004-01, haul 32 , benthic bag, K.P. Maslenikov ; UW 28351 , 2(82.2-128.7 mm), no data .

Diagnosis

Teeth strongly trilobed (Fig. 2D); nasal papillae absent; papillae associated with few pores, invariably present only on maxillary pore 6 and suprabranchial pores 1-2; peritoneum dark; orobuccal valve with 1 finger-like projection; orobuccal cavity pale; gill rakers 8-12, short, blunt; interorbital papilla present; pyloric caeca on left side, short; body color light red; iris golden.

Description

Body depth at pectoral-fin base 14.2-22.6 (20.1)%, at center of pelvic disk 18.9-24.6 (20.4)%, at anal-fin origin 18.8-26.5 (25.5)%. Predorsal length 26.5-33.3 (29.7)%. Preanal length 37.4-46.4 (41.9)%.

Head large, width 12.7-18.8 (15.3)%, length 25.1-28.2 (25.7)%. Interorbital width 5.1-8.2 (5.1)%, about equal to orbit length. Snout 6.5-9.2 (8.8)%. Mouth small, maxilla 8.4-12.0 (11.1)%, extending to anterior portion of orbit. Teeth strongly trilobed (Fig. 2D), in a band of 8-12 oblique rows of 5-9 teeth per row. Orbit large, diameter 5.0-7.8 (5.0)%.

Papillae small, present on few pores: absent from nasal pores 1-2; present on maxillary pore 6, often present on pore 5 (5-6); often present on preoperculomandibular pores 6-7, rarely absent (6-7); present on suprabranchial pores 1-2 (Fig. 4E). Interorbital papilla present. Papillae unpigmented. Cephalic free neuromasts reduced or nearly indiscernible over the interorbit and nape.

Gill opening small, 4.7-7.1 (5.9)%, entirely above pectoral fin or extending to pectoral-fin ray 3 (entirely above in the holotype). Gill rakers on anterior arch 8-12 (9), blunt and stout. Central projection of orobuccal valve a moderately elongate single lobe.

Dorsal-fin rays 42-45 (44), tips of anterior 4-6 rays projecting from fin membrane, anteriormost rays about 30% free from membrane, succeeding rays less so; posteriormost ray attached membranously to dorsalmost caudal-fin ray for 2.5-5.0 (3.6)%. Anal fin with 36-39 (38) rays, posteriormost ray membranously attached to ventralmost caudal-fin ray for 3.0-5.3 (3.6)%. One to three (2) anal-fin pterygiophores and associated rays anterior to first haemal spine.

Pectoral-fin rays 38-42 (39) in two lobes separated by shallow notch, 9-10 (10) rays in lower lobe. Dorsalmost ray at level of ventral rim of orbit. Upper lobe rounded, extending to or just past anal-fin origin, length 15.4-20.1 (17.0)%, with ray 6 longest; length of shortest notch ray 4.9-10.9 (10.9)%; length of lower lobe 13.4-19.5 (15.7)%, extending to anus, with ray 2 longest, rays 3-10 shortening ventrally. Pelvic disk large, length 7.8-11.4 (10.3)%, width 7.4-10.7 (9.9)%. Distance from disk to anus 1.7-8.3 (5.6)%, about 20-90 (54.5)% DL, distance from anus to anal-fin origin 5.7-15.8 (13.5)%, about 50-150 (130.6)% DL. Urogenital papilla conical, short, 9.2-30.5 (30.5)% DL, unpigmented. Pyloric caeca about 22, on left side of body, fingerlike, short, 17.2-28.5 (24.0)% HL.

Caudal fin slightly rounded, 11.7-17.0 (13.5)%, depth at hypural plate 2.4-5.2 (3.4)%, with principal rays 11-12 (12), dorsal principal rays 5, ventral principal rays 6-7 (7). Dorsal procurrent rays 1-3 (2), borne on epural and posteriormost neural spine; ventral procurrent ray 1-2 (1), borne on expanded posteriormost haemal spine. Vertebrae 46-50 (48), abdominal vertebrae 10-11 (10), caudal vertebrae 36-40 (38).

Body color in life uniform light red; iris golden. Color in alcohol pale, with pigment absent from cephalic papillae and absent from origin of dorsal fin. Peritoneum black; orobranchial cavity pale.

Largest specimen examined a 129.7 mm female (UW 112300). Smallest female with yolked eggs 91 mm; smallest male with enlarged, swollen testes 76.7 mm.

Range

Allocareproctus unangas has been collected only in the Aleutian Islands, from Buldir Pass to the Islands of Four Mountains, at depths of 210 to 465 m (Fig. 10).

Etymology

Named in honor of the people of the Aleutian Islands, the specific epithet “unangas” is the autonym of the Aleuts of Atka Island, a major island near the center of the species distribution. It is to be treated as a noun in apposition.

Remarks

Eggs of A. unangas were collected from the octocoral Primnoa sp. from Seguam Pass, with eggs of another liparid (Busby et al., in press). These are the first records of spawning in nature outside of lithodid crabs for liparids other than species of Liparis . See description and discussion of Busby et al. (in press).

Comparisons

Allocareproctus unangas is most similar to A. ungak , which also has trilobed teeth (Fig. 2D -E) and a uniform red body. It is distinguished from A. ungak by its golden iris (vs. silver gray in A. ungak ), papilla on nasal pore 1, fewer pores with associated papillae (Fig. 4), and pyloric caeca shorter and on the left side of the body. The two species also exhibit significant modal differences in several meristic characters (Tables 1-3), including dorsal-fin rays (39-42 in A. ungak vs. 42-45 in A. unangas ), anal-fin rays (33-35 vs. 36-39), pectoral-fin rays (35-40 vs. 38-42), and caudal vertebrae (34-36 vs. 36-40). Morphometric differences include a greater head length, body depths at anal-fin origin and pelvic disk, predorsal length, and snout to anus length in A. unangas than in A. ungak . See other comparisons under species accounts above.