Allocareproctus kallaion

Orr, James Wilder & Busby, Morgan Scott, 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: 23-27

publication ID 10.5281/zenodo.2645716

publication LSID

persistent identifier

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scientific name

Allocareproctus kallaion

new species

Allocareproctus kallaion  new species

Combed Snailfish

( Figures 1–6View FIGURE 1View FIGURE 2View FIGURE 3View FIGURE 6, 9View FIGURE 9, 12–13View FIGURE 12View FIGURE 13; Tables 1–4)

Holotype: UW 112244View Materials, 157.0 mm, female, 52.3405ºN, 172.7455ºW, 441 m depth, 31 May 2002, F/ V Morning Star, cruise 2002­01, haul 32, J.W. Orr.GoogleMaps 

Paratypes: UW 112243View Materials, 3 (145.0–190.0 mm), 52.3732ºN, 171.3548ºW, 324 m depth, 10 August 2002, F/V Sea Storm, cruise 2002­01, haul 225, R.C. HarrisonGoogleMaps  ; UW 112235View Materials, 1 (162.0 mm), 52.3796ºN, 170.6611ºW, 278 m depth, 31 May 2000, F/V Vesteraalen, cruise 2000­01, haul 51, W.C. FlerxGoogleMaps  ; UW 112241View Materials, 3 (108.0–167.0 mm), 52.331ºN, 172.7470ºW, 441 m depth, 23 July 2002, F/V Sea Storm, cruise 2002­01, haul 156, J.W. OrrGoogleMaps  ; UW 112237View Materials, 1 (152.9 mm), 52.2383ºN, 172.1247ºW, 357 m depth, 29 July 2002, F/V Sea Storm, cruise 2002­01, haul 167, benthic bag, R.C. HarrisonGoogleMaps  ; UW 112236View Materials, 2 (129.0–133.0 mm; 129.0 mm cleared and stained), 52.4877ºN, 172.5677ºW, 419 m depth, 26 June 1997, M/V Dominator, cruise 1997­01, haul 71, R.C. HarrisonGoogleMaps  ; UW 112242View Materials, 3 (139.5–176.0 mm), 52.3217ºN, 172.7447ºW, 458 m depth, 16 June 1994, F/V Pacific Knight, cruise 1994­01, haul 54GoogleMaps  ; UW 112278View Materials, 8 (109.8–157.0 mm), 52.3405ºN, 172.7455ºW, 441 m depth, 31 May 2002, F/V Morning Star, cruise 2002­01, haul 32, J.W. OrrGoogleMaps  ; UW 112239View Materials, 1 (161.0 mm), 52.3282ºN, 172.7468ºW, 444 m depth, F/V Vesteraalen, cruise 2000­01, haul 67, W.C. FlerxGoogleMaps  ; UW 112238View Materials, 2 (110.8–119.5 mm), 52.3282ºN, 172.7468ºW, 444 m depth, 4 June 2000, F/V Vesteraalen, cruise 2000­01, haul 67, benthic bag, W.C. FlerxGoogleMaps  ; UW 113691View Materials, 16 (72.0–170.0 mm), 52.3255ºN, 172.7466ºW, 450 m depth, 19 June 2004, F/V Sea Storm, cruise 2004­01, haul 60, J.W. Orr; USNMGoogleMaps  385683, 2View Materials (113.0–165.0 mm), 52.3255ºN, 172.7466ºW, 450 m depth, 19 June 2004, F/V Sea Storm, cruise 2004­01, haul 60, benthic bag, J.W. Orr; USNMGoogleMaps  385684, 1View Materials (156.0 mm), 52.4888ºN, 172.5564ºW, 397 m depth, 20 June 2004, F/V Sea Storm, cruise 2004­01, haul 61, J.W. Orr; CASGoogleMaps  223481, 1View Materials (146.0 mm), 52.5251ºN, 172.0747ºW, 364 m depth, 21 June 2004, F/V Sea Storm, cruise 2004­01, haul 66, J.W. Orr; CASGoogleMaps  223482, 1View Materials (195.0 mm), 52.2102ºN, 172.2060ºW, 341 m depth, 23 June 2004, F/V Sea Storm, cruise 2004­01, haul 73, J.W. OrrGoogleMaps  .


Teeth simple ( Fig. 2CView FIGURE 2); nasal pore 1 with pigmented papilla; peritoneum black; orobuccal valve with 4–6 finger­like projections; orobuccal cavity dark; gill rakers 14–18, stout, with strong spines at tip; interorbital papilla absent; body blotchy red, darker gray anteriorly; iris silver gray.


Body depth at pectoral­fin base 11.8–18.6 (15.4)%, at center of pelvic disk 13.8–21.2 (18.0)%, at anal­fin origin 14.0–22.0 (18.8)%. Predorsal length 22.7–28.6 (25.2)%. Preanal length 38.8–47.0 (43.4)%.

Head large, width 12.4–19.6 (18.4)%, length 21.7–24.3 (22.4)%. Interorbital width 4.3–7.7 (5.1)%. Snout 5.5–8.8 (6.9)%. Mouth small, maxilla 7.5–11.3 (11.3)%, extending to anterior portion of orbit. Teeth simple, recurved, rarely with weak shoulders ( Fig. 2CView FIGURE 2), in a narrow band of 4–12 oblique rows of 5–10 teeth per row in all except the posterior outer row; outer row of 34 teeth forming comb­like series. In all except outer row, middle teeth of each row largest; in outer row, first 20 teeth equally sized, succeeding teeth gradually smaller posteriorly. Orbit large, diameter 5.3–7.3 (6.1)%.

Papillae present on many pores: present on nasal pore 1, absent from nasal pore 2; present on maxillary pores 2–6, rarely present on pore 1 (2–6); present on preoperculomandibular pores 5–7, often present also on pore 4 (5–7); present on suprabranchial pores 1–2 (Fig. 4D). Papillae with slight pigment or unpigmented. Interorbital papilla absent. Cephalic free neuromasts large and profuse to nearly indiscernible over the interorbit and nape.

Gill opening small, 4.6–6.7 (5.6)%, entirely above pectoral fin. Gill rakers on anterior arch 14–18 (16), stout with strong spines at tip. Orobuccal valve with 4–6 (4) finger­like lobes, central lobe largest, other lobes successively smaller ( Fig. 12BView FIGURE 12).

Dorsal­fin 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 caudal­fin ray for 2.0–4.4 (2.7)%. Anal fin with 33–37 (36) rays, posteriormost ray membranously attached to ventralmost caudal­fin ray for 2.6–5.1 (3.4)%. One to three (2) anal­fin pterygiophores and associated rays anterior to first haemal spine.

Pectoral­fin rays 36–40 (37) in two lobes separated by shallow notch, 9–12 (10) rays in lower lobe. Dorsalmost ray at level just below ventral rim of orbit. Upper lobe rounded, extending to anal­fin origin, length 15.8–20.1 (17.6)%, with rays 6–7 (6) longest; length of shortest notch ray 4.3–9.5 (6.7)%; length of lower lobe 13.3–20.2 (15.0)%, extending between posterior margin of pelvic disk and anus, with ray 3 longest, rays 9–12 shortening ventrally.

Pelvic disk large, length 8.0–9.7 (8.5)%, width 7.1–8.8 (7.8)%. Distance from disk to anus 2.7–9.4 (6.2)%, about 28–105 (73.7)% DL, distance from anus to anal­fin origin 11.6–18.9 (16.6)%, about 125–225 (196)% DL. Urogenital papilla conical, short, about 10–25 (11.2)% DL when protruded, unpigmented. Pyloric caeca about 22–27 (22), on right side of body, finger­like, long, 25–50 (48.4)% HL.

Caudal fin slightly rounded, 12.8–17.1 (14.3)%, depth at hypural plate 2.7–4.6 (2.9)%, with principal rays 11–14 (12), dorsal principal rays 5–7 (5), ventral principal rays 6–7 (7). Dorsal procurrent rays 2–3 (2), borne on epural and posteriormost neural spine; ventral procurrent ray 1–2 (1), borne on expanded posteriormost haemal spine. Vertebrae 45–49 (49), abdominal vertebrae 12, caudal vertebrae 33–37 (37).

Color in life light red, with darker red blotches scattered over body, dark speckling at origin of dorsal fin, anterior part of body blue­gray, posterior part of body blotchy red; iris silver gray. Color in alcohol dark gray anteriorly, becoming pale posteriorly, with pigment on cephalic papillae and at origin of dorsal fin. Peritoneum black; orobranchial cavity dark.

Largest specimen examined a 195 mm male (CAS 223482). Smallest female with yolked eggs 162 mm; smallest male with enlarged, swollen testes 124 mm.

Range Allocareproctus kallaion  has been collected only in the east­central Aleutian Islands, from Seguam Pass to Yunaska Island at depths of 278–458 m ( Fig. 9View FIGURE 9).


The specific epithet is derived from the Greek “ ” for “comb”, an allusion to the multiple projections on the orobuccal valve and the single row of teeth on the posterior part of the dentary.


Unlike other species of Allocareproctus  , larger specimens of A. kallaion  were often collected with greatly distended stomachs filled with water. This mechanism of inflation in A. kallaion  is similar to that of puffer fishes (Tetraodontiformes; Brainerd 1994, Wainwright & Turingan 1997) and frogfishes ( Antennariidae  ; Pietsch & Grobecker 1987). Members of the putative sister family of the Liparidae  , the Cyclopteridae  , are well known for their ability to expand when disturbed, although the mechanism of inflation has not been examined ( Mecklenburg et al. 2002).


Allocareproctus kallaion  is easily distinguished from all other species of Allocareproctus  by the following characters. Its body in life is a blotchy red unlike the uniform red to peach coloration of other species. Both in life and when preserved, the anterior part of the body and orobuccal cavity are darker, unlike the pale color of other species. It differs from all other species in having multiple lobes on the orobuccal valve ( Fig. 12BView FIGURE 12), high numbers (14–18 vs. 7–12 in all other species) of larger gill rakers with stronger spines on the tips, invariably 12 abdominal vertebrae, and a comb­like uniserial row of teeth on the dentary. Its simple teeth further distinguish it from A. tanix  , A. unangas  , and A. ungak  , which all possess moderately to strongly trilobed teeth ( Fig. 2View FIGURE 2).

Several morphometric characters differ significantly between A. kallaion  and all other species of Allocareproctus  . Head length, body depth, snout length, suborbital depths to oral cleft and mandible, predorsal length, snout to anus length, pelvic­disk length and width, and lengths of dorsal­ and anal­fin connections to the caudal fin are less, while pelvic disk to anus length is greater than in all other species.


University of Washington Fish Collection


Smithsonian Institution, National Museum of Natural History


California Academy of Sciences