PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON 
114(l):51-57. 200L 
Prognatholiparis ptychomandibularis, a new genus and species of the 
fish family Liparidae (Teleostei: Scorpaeniformes) from the Aleutian 
Islands, Alaska 
James Wilder Orr and Morgan S. Busby 
NOAA/National Marine Fisheries Service, Alaska Fisheries Science Center, 
Resource Assessment and Conservation Engineering Division, 7600 Sand Point Way NE, 
Seattle, Washington 98115, U.S.A. 
Abstract. — A new species representing a monotypic genus of liparid fishes 
is described from the central Aleutian Islands. The new genus differs from all 
known liparid genera by its strongly protruding lower jaw and prominent folds 
and flaps of skin on the jaws and snout. It is similar to Allocareproctus jordani 
and Careproctus pycnosoma, which are also moderately slender liparids with 
large pelvic disks, but it is further distinguished from these species by its lower 
meristics, more slender body, and absence of pyloric caeca. Ptychomandibu- 
laris also differs from Allocareproctus in its possession of an eighth preoper- 
culomandibular pore, absence of coronal and post-coronal pores, two epurals, 
and autogenous hypural plates. 
A single specimen of a new liparid (Fig. 
1) was collected during the 1997 triennial 
groundfish survey of the Aleutian Islands, 
conducted by the Alaska Fisheries Science 
Center of the U.S. National Marine Fish- 
eries Service. The specimen was captured 
in Seguam Pass in the central Aleutians at 
455 m depth (Fig. 2). The new species pos- 
sesses unique morphological features that 
indicate its distinctiveness as the only 
known member of a new genus. 
Methods 
The holotype was fixed at sea in 10% 
formalin-seawater solution and later trans- 
ferred to 70% ethanol. Counts and mea- 
surements follow Burke (1930) and Pitruk 
(1991), with the exception of pore and pec- 
toral-fin ray counts. Pore counts follow 
Stein and Andriashev (1990). In pectoral- 
fin ray counts, the upper lobe includes the 
dorsalmost ray to the ray dorsal to the 
shortest ray; the lower lobe includes the 
shortest ray in the notch to the ventralmost 
ray. Caudal-fin morphology and counts of 
dorsal- and anal-fin rays, branchiostegals, 
epipleural and pleural ribs, and vertebrae 
were obtained by examining radiographs. 
Osteology of the pectoral fin was not visible 
in radiographs. The holotype was deposited 
in the University of Washington Fish Col- 
lection (UW). 
Prognatholiparis, new genus 
Type species. — Prognatholiparis pty- 
chomandibularis, new species, by monoty- 
py- 
Diagnosis. — Lower jaw projecting ante- 
rior to upper jaw (Fig. 3); prominent flaps 
and folds of skin on snout, upper jaw, and 
ventral portion of mandible; pelvic disk 
large, 37.4% head length (Fig. 4); body 
slender, depth at pectoral-fin base 20.5% 
SL, depth at anal-fin origin 19.0% SL; ce- 
phalic lateralis pores in 2-6-8- 1 pattern, cor- 
onal and post-coronal pores absent (Fig. 5); 
epurals two, fused at base; hypural plates 
autogenous (Fig. 6); pleural ribs present; 
pseudobranchiae absent; subcutaneous ge- 
52 
PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON 
Fig. I. 
Vinter. 
Prognatholiparis ptychomandibularis, holotype, UW 042341, 88.0 mm SL, male. Illustration by B. 
latinous layer absent; pyloric caeca absent 
(Table 1). 
Description. — See species account. 
Etymology. — Prognatholiparis from the 
Greek pro (irpo) = in front of + gnathos 
("/vaBoQ = jaw + Liparis, a genus of snail- 
fishes, applied in reference to the protruding 
lower jaw, which distinguishes this genus 
from all other known liparid genera. 
Prognatholiparis ptychomandibularis, new 
species 
Wrinkle-jaw snailfish 
Figs. 1-6, Table 1 
Holotype.— \J^ 042431, 88 mm SL, 
male, Seguam Pass, east of Seguam Island, 
52.31836°N, 172.7453°W, 455 m depth, W. 
Flerx, collector, RA'^ Vesteraalen, Cruise 
ns'oo' 
-180°00' 
-175°00' 
-170°00' 
-165°00' 
-160°00' 
55°00' 
ALASKA 
N 
'X' 
>-,"5;>' 
Seguam Is. 
100 200 km 
55°00' 
50°00' 
175°00' 
-ISO-OO' 
-175°00' 
-170°00' 
-165°00' 
Fig. 2. Collection locality of Prognathalipahs ptychtmuindihularis, holotype. UW 042341, 
male, Seguam Pass, central Aleutian Islands, Alaska. 
^.0 mm SL, 
VOLUME 1 14. NUMBER 1 
53 
iol-4 
pml 
Fig. 3. PrognathoUparis ptychomandibularis, holotype, UW 042341, 88.0 mm SL, male. Left lateral view 
199701, T. Cosgrove, Captain, haul 58, 22 
Jun 1997. 
Diagnosis. — Same as for genus. 
Counts. — See Table 1. 
Description of holotype. — Body slender, 
depth at pectoral-fin base 20.5% SL, depth 
at anal-fin origin 19.0% SL; predorsal 
length 28.2% SL; preanal length 35.7% SL; 
head shghdy depressed; maxilla 18.5% HL, 
ending well anterior to orbit; mandible 
25.6% HL, articulation with quadrate ante- 
rior to orbit; fleshy lip originating well pos- 
terior to the tip of the mandible leaving a 
narrow anterior edge on lower jaw; snout 
and mandible with longitudinal folds of 
skin bracketing pores of the cephalic later- 
alis, folds on snout broadened distally with 
slighdy constricted base, folds on mandible 
formed as strong ridges (Fig. 3); mandible 
projecting anterior to snout, with 4 rows of 
weakly trilobate teeth tapering to a single 
row posteriorly; teeth in 4 rows at tip of 
Fig. 4. PrognathoUparis ptychomandibularis. holotype, UW 042341, 88.0 mm SL, male Ventral view of 
TTZu7Z :'''7''''''''' '^r ^^" ^"'^ P^'^'^ '''''■ '""'-' - P-opercu.omand.bu.ar pore? -7 (Po^e 
4 of right side IS not visib.e; see text for discussion). I.lustration by B. Vinter. 
54 
PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON 
Table I. — Meristics and morphometries of the holotype of Prognatholiparis ptychomandihularis n. sp., UW 
042431. Pectoral-fin ray counts are presented with upper + lower lobe in parentheses; caudal-fin ray counts are 
presented as dorsal procurrent, dorsal principle -I- ventral principle, ventral procurrent rays. Vertebral counts are 
presented with precaudal + caudal in parentheses. 
Measurement (mm) 
Dorsal-fin rays 
Anal-fin rays 
Pectoral-fin rays 
Branchiostegal rays 
Caudal-fin rays 
Vertebrae 
Pyloric caeca 
Cephalic pores 
Standard length 
Head length 
Caudal-fin length 
% SL 
Head length 
Predorsal length 
Preanal length 
Snout-to-anus length 
Snout-to-disk length 
Disk-to-anus length 
Body depth at pectoral-fin base 
Body depth at anal-fin origin 
Pectoral-fin upper lobe length 
Pectoral-fin lower lobe length 
Disk diameter 
Caudal-fin length 
% HL 
Maxilla length 
Mandible length 
Snout length 
Orbit diameter 
Gill slit length 
Disk diameter 
% CL 
Dorsal fin overlap on caudal fin 
Anal fin overlap on caudal fin 
37 
30 
30(2H-9) 
6 
3,5+7,2 
41 (10+31) 
2-6-7-1 
88.0 
19.5 
17.9 
22.2 
19.5 
28.2 
24.8 
35.7 
31.4 
23.9 
21.0 
11.6 
10.2 
4.1 
3.6 
20.5 
18.0 
19.0 
16.7 
15.1 
13.3 
13.1 
11.5 
8.3 
7.3 
20.3 
17.9 
18.5 
3.6 
25.6 
5.0 
33.8 
6.6 
22.1 
4.3 
20.0 
3.9 
37.4 
7.3 
33.0 
5.9 
25.1 
4.5 
upper jaw tapering to a single row posteri- 
orly. Eye small, orbit diameter 22.1% HL. 
Pyloric caeca absent. 
Cephalic lateralis in 2-6-8-1 pattern on 
left side, preoperculomandibular pore 4 not 
opened on right side (Figs. 3-5). Nasal 
pores small, without tubes. Infraorbital 
pores small, only pore 6 on short tube. 
Mandibular canal from opposing sides unit- 
ed on dental symphysis at a single pore. 
Preoperculomandibular pores 1-5 large. 
without projecting tube; pores 6-8 small, on 
short tubes. Supratemporal pore one, on 
short tube. 
Gill opening small, 20% HL, slit extend- 
ing to above first pectoral-fin ray. Bran- 
chiostegal rays six. 
Dorsal fin with 37 soft rays gradually in- 
creasing in length from anterior to posterior, 
membrane of posteriormost ray connected 
to dorsalmost ray of caudal fin for about 
33.0% of caudal-fin length. Anal fin with 
VOLUME 114, NUMBER 1 
nl 
55 
tc sp 
pml-8 
Fig. 5. Prognatholiparis ptychomandibularis, holotype, UW 042341, 88.0 mm SL, male. Diagrammatic view 
of cephalic pores. Abbreviations from anterior to posterior: nl and n2 = nasal pores 1 and 2; soc = supraorbital 
canal; ioc = infraorbital canal; iol-6 = infraorbital pores 1-6; pml-8 = preopercularmandibular pores 1-8; 
pmc = preoperculomandibular canal; tc = temporal canal; sp = suprabranchial pore. Illustration by B. Vinter. 
30 rays gradually increasing in length from 
anterior to posterior, membrane of posteri- 
ormost ray connected to ventralmost ray of 
caudal fin for 25.1% of caudal-fin length. 
Pectoral fin with 30 rays in two lobes, 
lobes separated by shallow notch with 21 
rays in upper lobe and 9 rays in lower lobe. 
Pectoral-fin rays in notch spaced as in rays 
of lobes. Upper lobe rounded, extending to 
anal-fin origin, length 15.1% SL, with rays 
3—10 longest; length of rays gradually 
shortening from ray 10 to ray 22; lower 
lobe pointed, extending beyond anus, 
length 75% of upper lobe length, 13.1% SL, 
with ray 24 longest; rays 25-30 shortening 
ventrally; tips of lower rays of dorsal lobe 
and all rays of lower lobe exserted. 
Pelvic disk large, 37.4% HL and 8.3% 
SL, length about equal to width, fleshy cov- 
ering obscuring internal structure (Fig. 4). 
Anus located midway between pelvic disk 
and origin of anal fin; distance from disk to 
anus 49.4% disk length (4.1% SL). 
Caudal fin 20.3% SL, with 12 principal 
and 5 procurrent rays (3 -I- 5/7 -I- 2). Neural 
and haemal spines of preural centrum 2 
complete and fused to centrum. Epurals 2, 
partially fused together at base. Hypural 
plates autogenous; parhypural fused to ven- 
tral hypural (Fig. 6). Vertebrae 41, precau- 
dal vertebrae 10, caudal vertebrae 31. Pleu- 
ral ribs present on vertebrae 8-10, epipleur- 
als on vertebrae 1-20, epineurals on verte- 
brae 1-19. 
Color in alcohol pale brown, with scat- 
tered melanophores over body beneath 
translucent cutaneous layer, darker on nape 
and at anterior base of dorsal fin. Orobran- 
chial cavity, stomach, peritoneum, and in- 
testines pale. 
Ecology. — The single known specimen 
of Prognatholiparis ptychomandibularis 
was captured at 455 m depth with species 
typical of moderately deep waters of the 
Aleutian Islands. The haul was dominated 
by Reinhardtius hippoglossoides and Bath- 
yraja maculata. The holotype had a full 
stomach that contained ostracods and rocks. 
Etymology. — ptychomandibularis from 
the Greek ptyx, ptychos (tttu^, tttuxoO — a 
fold -I- Latin mandibula = jaw, in reference 
to the skin folds on the snout and along the 
ventral margin of the mandible. 
Comparisons. — Some 25 genera of lipar- 
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PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASfflNGTON 
ns 
Fig. 6. Prognatholiparis ptychomandibularis, holotype, UW 042341, 88.0 mm SL, male. Caudal skeleton 
as illustrated from radiograph, pul and pu2 = preural centrum 1 and 2; u = urostyle; dhp = dorsal hypural 
plate; vhp = ventral hypural plate; ph = parhypural; ns = neural spine; hs = haemal spine; ep = epural. 
Illustration by B. Vinter. 
ids are recognized worldwide, and the phy- 
logenetics of the Liparidae are poorly un- 
derstood (Kido 1988, Balushkin 1996, An- 
driashev & Stein 1998). However, Prog- 
natholiparis is easily distinguished from all 
other liparid genera on the basis of its 
strongly projecting lower jaw and the folds 
of skin on the upper and lower jaws. Gen- 
erally, among species of the North Pacific, 
it is phenetically most similar to the species 
Allocareproctus jordani and C. pycnosoma, 
which are also characterized by a moder- 
ately slender body, pale coloration, large 
disk, and small gill slit. Both species pos- 
sess either trilobed teeth as in Prognatho- 
liparis or both simple and trilobed teeth 
(Burke 1930, Kido 1985, 1988; Pitruk & 
Fedorov 1993). 
Prognatholiparis differs from both these 
species in its lower meristics, including dor- 
sal-, anal-, and pectoral-fin rays, and ver- 
tebrae. Both A. jordani and C pycnosoma 
have at least 41 dorsal-fin rays, 33 anal-fin 
rays, 36 pectoral-fin rays, and 46 vertebrae. 
Prognatholiparis also differs in several oth- 
er characters, including the absence of 
fleshy flaps on the rim of the cephalic pores 
(present in Allocareproctus and C. pycno- 
soma), and a longer lower pectoral-fin lobe 
that extends beyond the anus (does not 
reach the anus in Allocareproctus and C. 
pycnosoma). 
VOLUME 114, NUMBER 1 
57 
In addition to characters of the lower jaw 
and snout, these species may differ from 
Prognatholiparis in the configuration of the 
anterior dorsal-fin rays, which project 
above the fin membrane. In the holotype of 
Prognatholiparis, the anterior rays appear 
to have been connected by membrane to 
their tips but were damaged during the 
specimen's collection. 
Prognatholiparis differs from most lipar- 
ids (Kido 1988, Balushkin 1996), including 
Allocareproctus jordani (Pitruk & Federov 
1993), in the structure of its caudal skele- 
ton, which includes hypural plates autoge- 
nous from the preural centrum and two 
epurals. Most liparids, especially those con- 
sidered more derived, possess a relatively 
consolidated caudal skeleton, with fused 
hypural plates and a single epural (Kido 
1988; Balushkin 1996). 
Kido (1985, 1988) and Burke (1930) also 
considered C. curilanus and C. ectenes sim- 
ilar to C. pycnosoma, and therefore possibly 
similar to Prognatholiparis. Careproctus 
ectenes is a very slender and elongate spe- 
cies with exerted anterior dorsal rays and is 
similar to C. curilianus in its possession of 
an elongate protruding snout, a character 
that distinguishes both species from Prog- 
natholiparis. 
With the exception of Allocareproctus 
jordani, which was recently redescribed by 
Pitruk & Fedorov (1993) on the basis of 15 
additional specimens, each of these species 
is known from less than five individuals. 
For each of these, the cephalic pore mor- 
phology, caudal skeleton, and features of 
the axial skeleton are not known. Recent 
surveys and collections of additional lipar- 
ids from the Aleutian Islands may serve to 
shed light on these similar species and their 
relationships. 
Acknowledgments 
We thank W C. Flerx for collecting and 
preserving the holotype and B. Vinter for 
providing all illustrations. For discussions 
of liparid morphology and systematics, we 
thank A. P. Andriashev, N. V. Chemova, 
and D. L. Stein. For critical reviews, we 
thank A. C. Matarese, T. W. Pietsch, and G. 
R. Hoff. We thank T. W. Pietsch and B. K. 
Urbain for access to the University of 
Washington Fish Collection and curation of 
the holotype, R. L. Cartwright for providing 
radiographs, C. T. Baier for identifying gut 
contents, and R. C. Harrison for transla- 
tions. 
Literature Cited 
Andriashev, A. P., & D. L. Stein. 1998. A review of 
the snailfish genus Careproctus (Liparidae, 
Scorpaeniformes) in Antarctic and adjacent wa- 
ters. — Contributions in Science, Natural History 
Museum of Los Angeles County 470:1—63. 
Balushkin, A. V. 1996. A new genus and species of 
liparid fish Palmoliparis beckeri from the north- 
ern Kurile Islands (Scorpaeniformes, Liparidae) 
with consideration of phylogeny of the fami- 
ly.— Voporsy Ikhtiologii 36(4):28 1-299. [In 
Russian; English translation as Journal of Ich- 
thyology 36(4):28 1-287.] 
Burke, C. V. 1930. Revision of the fishes of the family 
Liparidae. — Bulletin of the U.S. National Mu- 
seum 150:i-xii -I- 1-204. 
Kido, K. 1985. New and rare species of the genus Car- 
eproctus (Liparididae) from the Bering Sea. — 
Japanese Journal of Ichthyology 32(1):6— 17. 
. 1988. Phylogeny of the family Liparididae, 
with the taxonomy of the species found around 
Japan. — Memoirs of the Faculty of Fisheries, 
Hokkaido University 35(2): 125-256. 
Pitruk, D. L. 1991. Some structural characteristics of 
the seismosensory system in fishes of the family 
Liparididae (Scorpaeniformes). — Investigations 
on taxonomy and morphology of fishes. Pro- 
ceedings of the Zoological Institute of the 
U.S.S.R. Academy of Sciences 235:37-49. [In 
Russian.] 
, & V. V. Fedorov. 1993. Allocareproctus gen. 
novum (Scorpaeniformes, Liparidae) — a new 
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Ocean. — Voporsy Ikhtiologii 33(1): 16-20. [In 
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thyology 33(5):99-107.] 
Stein, D. L., & A. R Andriashev. 1990. Liparididae, 
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