Deep-sea Fauna of the Sea of Japan, edited by T. Fujita, National Museum of Nature and Science Monographs, No. 44,
pp. 157–176, 2014

Deep-sea Cumacean Crustacea from the Sea of Japan, Based on theSpecimens Collected by R/V Tansei-maru (Cruise KT-11-9).
Tadashi Akiyama
Ushimado Marine Laboratory, Okayama University, Ushimado, Okayama, 701–4303 Japan
E-mail: akiyama@uml.okayama-u.ac.jp

Abstract: Deep-sea cumaceans from Japanese coast of the Sea of Japan, collected by R/V Tanseimaru (cruise KT-11-9) were examined. Twenty-six species of 11 genera, 5 families were recognized.
Among them, Campylaspis brevirostris (Nannastacidae) and Cumella tanseiae (Nannastacidae) were
new to science. Adult males of Petalosarsia declivis (Sars, 1865) are redescribed.
Key words:

Crustacea, Cumacea, deep-sea, the Sea of Japan, new species.

Introduction
Fifteen species of deep-sea cumaceans (Crustacea, Peracarida) have been known from the
Sea of Japan (Vassilenko and Tzareva, 2004); Hemilamprops gracilis Hart, 1930, Eudorellaemarginata Kröyer, 1846, Eudorella paciﬁca hart, 1930 Eudorella bathyalis Vassilenko and Tzareva, 2004, Leucon acutirostris Sars, 1864, Leucon kobjakovae, Lomakina, 1955, Campylaspis
clavata, Lomakina, 1952, C. glabra Sars, 1879, C. pisum Vassilenko and Tzareva, 2004, Diastylis paraspinulata Zimmer, 1926, D. moskalevi Vassilenko and Tzareva, 2004, Leptostylis villosa
Sars, 1869, Paraleptostyls vityazi Vassilenko and Tzareva, 2004. Lomakina (1955, 1958)
reported some cumacean species from Okhotsk Sea, adjacent to the Sea of Japan, including shallow water species. In 2011, deep-sea cumacean specimens were collected by R/V Tansei-maru of
the Japan Agency for Marine-Earth Science and Technology (JAMSTEC, cruise KT-11-9). In thepresent study, these specimens were examined. Among them, two new nannastacid species aredescribed herein. In addition, adult male specimens of Petalosarsia declivis (Sars, 1865) areredescribed.
Materials and Methods
Cumacean specimens examined in the present study were collected during R/V Tansei-maru
cruise KT-11-9 by the National Museum of Nature and Science (NSMT). The sampling sites are
summarized in Table 1. Gear used for the collections was a beam trawl of 3 m span, with tworing nets (30 cm in diameter, 130 cm in length) equipped with nylon mesh of 0.5 mm opening.
The collected sediment samples, including cumaceans and other tiny benthic organisms, were
preserved in 70–80% ethanol or 5–10% borate buffered formalin sea water. In the Laboratory,
cumacean specimens were sorted under a stereo microscope (Leica MZ6), and preserved in
70–80% ethanol. Type specimens and other specimens designated are deposited in NSMT.

Tadashi Akiyama

158
Table 1.

List of the sampling sites. Gear for all collections was a ORE beam trawl of 3 m span.

Haul No.

Date

Position in

Position out

Depth (m)KT-11-9-M1
KT-11-9-M2
KT-11-9-M3
KT-11-9-M4
KT-11-9-M5
KT-11-9-M6
KT-11-9-E1
KT-11-9-E2
KT-11-9-E3
KT-11-9-E4
KT-11-9-T1
KT-11-9-T2
KT-11-9-T3
KT-11-9-T4
KT-11-9-T5
KT-11-9-T6
KT-11-9-N1
KT-11-9-N2
KT-11-9-N3
KT-11-9-N4
KT-11-9-K1–1
KT-11-9-K1–2
KT-11-9-K2
KT-11-9-K3
KT-11-9-K4
KT-11-9-K5

27 May 2011
28 May 2011
28 May 2011
28 May 2011
28 May 2011
28 may 2011
29 May 2011
29 May 2011
29 May 2011
29 May 2011
31 May 2011
31 May 2011
31 May 2011
1 Jun. 2011
1 Jun. 2011
1 Jun. 2011
1 Jun. 2011
1 Jun. 2011
1 Jun. 2011
1 Jun. 2011
3 Jun. 2011
3 Jun. 2011
3 Jun. 2011
2 Jun. 2011
2 Jun. 2011
2 jun. 2011

44°43.7′N, 140°05.79′E
44°40.48′N, 140°02.38′E
44°37.21′N, 139°56.68′E
44°35.38′N, 139°52.93′E
44°31.41′N, 139°47.13′E
41°16.68′N, 139°36.85′E
41°52.01′N, 139°33.90′E
41°50.26′N, 139°34.03′E
41°47.46′N, 139°34.49′E
42°03.91′N, 139°40.11′E
37°28.45′N, 137°28.15′E
37°28.77′N, 137°29.07′E
37°29.18′N, 137°33.25′E
37°19.80′N, 137°33.38′E
37°18.45′N, 137°31.77′E
37°29.18′N, 137°45.89′E
37°54.59′N, 136°56.92′E
37°57.06′N, 136°56.60′E
38°03.25′N, 136°53.39′E
38°08.04′N, 136°49.64′E
35°43.26′N, 134°27.11′E
35°42.89′N, 134°28.04′E
35°46.11′N, 134°30.94′E
35°54.85′N, 134°18.60′E
35°59.92′N, 134°20.58′E
36°22.25′N, 134°23.61′E

44°43.12′N, 140°05.44 E
44°39.53′N, 140°02.83 E
44°36.29′N, 139°57.82′E
44°34.32′N, 139°53.70′E
44°29.35′N, 139 °7.96′E
44°14.25′N, 139°37.25′E
41°52.94′N, 139°34.33′E
41°48.70′N, 139°34.18′E
41°48.96′N, 139°34.88′E
42°03.38′N, 139°39.98′E
37°29.18′N, 137°27.86′E
37°29.53′N, 137°28.63′E
37°29.35′N, 137°31.96′E
37°20.02′N 137°34.20′E
37°18.66′N, 137°32.85′E
37°26.70′N, 137°44.59′E
37°54.51′N, 136°58.43′E
37°57.04′N, 136°58.23′E
38°03.82′N, 136°55.13′E
38°09.00′N, 136°51.20′E
35°43.40′N, 134°27.55′E
35°43.11′N, 134°28.98′E
35°46.57′N, 134°32.09′E
35°55.17′N, 134°20.08′E
35°59.61′N, 134°18.82′E
36°20.18′N, 134°22.84′E

152–170
198–206
407–413
608–6271035–1080
1421–1461
222–250
388–538
563–605
802–854
160–173
207–258
383–460
561–583
794–8081410–1564
157–160
201–203402–411
603–622
164–166
143–144
203–205
370–411
603–613
1277–1290

Taxonomy
Family Lampropidae Sars, 1878
Genus Paralamprops Sars, 1878
Paralamprops sp. 1
Material examined. KT-11-9-M2 (4 ♀, 8 ♂, 72 manca), NSMT-Cr 22742; KT-11-9-E1(many ♀ and ♂), NSMT-Cr 22743; KT-11-9-E2 (2 ♀); KT-11-9-E3 (1 ♂).
Remarks. The specimens are similar to Hemilamprops pectinatus Lomakina, 1955 from the
Sea of Japan, 31–440 m, morphological characters of which suggest that the species should beplaced in the genus Paralamplops.
Paralamprops sp. 2
Material examined. KT-11-9-M3 (23 ♀, 17 ♂, 2 juv. 85 manca), NSMT-Cr 22744; KT11-9-M4 (1 ♀, 2 ♂, 2 juv. 55 manca), NSMT-Cr 22745; KT-11-9-E4 (1 ♀, 2 juv.); KT-11-9-T2 (1juv.); KT-11-9-T3 (1 ♂, 5 manca); KT-11-9-N3 (1 ♀, 3 ♂, 1 juv., 4 manca), NSMT-Cr 22746: KT11-9-N4 (2 juv., 2 manca); KT-11-9-K3 (1 ♀, 1 manca); KT-11-9-K4 (2 ♀, 4 ♂, 2 juv., 8 manca),
NSMT-Cr 22747.
Remarks. The specimens are very similar to Hemilamprops ?pectinatus Lomakina, 1955
mentioned above, but are characterized by the ridges on the dorsal surface of carapace are weak,
consisting of small brunt processes.

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159

Genus Lamprops Sars, 1863
Lamprops sp. 1
Material examined. KT-11-9-M2 (3 ♀, 4 ♂, 10 manca), NSMT-Cr 22748.
Remarks. The specimens are similar to Lamprops serratus Hart, 1930, from boreal regionof the Paciﬁc Ocean, 20–95 m and L. carinata Hart, 1930 from Alaska, 25–120 m in having acutepseudorostrum on the carapace, but can be distinguished from the latter two species by serrated
inferior margin of carapace.
Lamprops sp. 2
Material examined. KT-11-9-T2 (5 ♀, 1 ♂), NSMT-Cr 22749; KT-11-9-K2 (3 ♀), NSMT-Cr
22750.
Remarks. The specimens are similar to Lamprops japonicus Zimmer, 1937 which is characterized by obsolete anterolateral angle, but has normal length of pseudorostrum (very short in L.
japonicus).
Family Bodotriidae T. Scott, 1901
Genus Vaunthompsonia Bate, 1858
Vaunthompsonia sp.
Material examined. KT-11-9-M2 (1 ♂), NSMT-Cr 22751; KT-11-9-E1 (2 juv.), NSMT-Cr
22752.
Remarks. The carapace of the specimens, characterized by serrated dorsal crest, is similar
to that of Vaunthomsonia serratifrons, Gamô, 1964 from Sagami Bay, Japan (Gamô, 1964), however, the former species is distinguishable from the latter by the uropod endopod shorter thanpeduncle (longer in V. serratifrons).
Family Leuconidae Sars, 1878
Genus Eudorella Norman, 1867
Eudorella bathyalis Vassilenko and Tzareva, 2004
Eudorella bathyalis – Vassilenko and Tzareva, 2004: 9–13, ﬁgs. 5–6; Akiyama and Gamô, 2012, 11–15, Figs. 7–9.
Eudorella ?hispida Akiyama 2009: 486.

Materials examined. KT-11-9-M4 (1 ♀, 2 juv.), NSMT-Cr 22753; KT-11-9-M5 (1 juv.);
KT-11-9-M6 (1 ♀, 3 juv., (damaged)), NSMT-Cr 22754; KT-11-9-E3 (1 ♀, 2 juv.); KT-11-9-T4(1 ♀, 1 juv.), NSMT-Cr 22755; KT-11-9-T6 (4 juv., 1 manca); KT-11-9-K3 (1 ♀, 1 ♂, 1 juv.),
NSMT-Cr 22756; KT-11-9-K5 (1 juv.).
Distribution. The Sea of Japan, Paciﬁc coast of Japan, Okinawa Trough, East China Sea,
370–3290 m.
Eudorella emarginata (Kröyer, 1846)
Leucon emarginattus Kröyer, 1846: 181, 209–211, pl. 2, ﬁg. 3a–h.
Eudorella emarginata – Sars, 1900: 36, pls. 27–28; Stebbing 1913, 75–77, Figs. 40–42; Jones 1976, 28, Fig. 9E–H; Akiyama 2009: 486; Akiyanma and Gamô 2012, 27–30, Figs. 18–19.

Material examined.

KT-11-9-M4 (1 ♀, 1juv.), NSMT-Cr 22757; KT-11-9-M5 (1 ♀), NSMT-

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Cr 22758; KT-11-9-E3 (1 juv., 8 manca); KT-11-9-E4 (4 juv., 2 manca); KT-11-9-T3 (3juv., 4
manca); KT-11-9-T4 (4 juv.); KT-11-9-T5 (1 ♂, 8 juv.), NSMT-Cr 22759; KT-11-9-T6 (3 manca);
KT-11-9-N3 (4 juv., 3 manca); KT-11-9-N4 (8 juv., 11 manca); KT-11-9-K3 (1 juv); KT-11-9-K4(1 ♀, 3 juv., 4 manca), NSMT-Cr 22760; KT-11-9-K5 (1 juv.).
Distribution. Atlantic boreal region, Arctic region, eastern Russia, northern Japan, the Sea
of Japan, Alaska, Canada, 0–2000 m.
Eudorella orientaris Akiyama and Gamô, 2012
Eudorella orientaris – Akiyama and Gamô, 2012, 42–46, Figs. 30–31.

Material examined. KT-11-9-T2 (5 ♀, 1 ♂, 11 juv.), NSMT-Cr 22761; KT-11-9-T3 (3 ♀, 1juv.), NSMT-Cr 22762; KT-11-9-T4 (8 ♀, 3 ♂); KT-11-9-T5 (7 ♀, 7 ♂), NSMT-Cr 22763; KT11-9-K2 (1 ♀, 13 juv.), NSMT-Cr 22764.
Distribution. Japan, 52–1219 m.
Genus Leucon Kröyer, 1846
Subgenus Crymoleucon Watling, 1991
Leucon (Crymoleucon) sp.
Material examined. KT-11-9-M3 (14 ♀, 4 ♂), NSMT-Cr 22765; KT-11-9-M4 (24 ♀, 6 ♂),NSMT-Cr 22766; KT-11-9-M5 (3 ♀, 1 ♂); KT-11-9-E3 (4 ♀, 1 ♂, 1 juv.); KT-11-9-E4 (5 ♀, 1 ♂, 1juv.); KT-11-9-T3 (19 ♀, 6 ♂, 6 manca); KT-11-9-T4 (51 ♀,16 ♂, 5 manca); KT-11-9-T5 (22 ♀,7 ♂,1 manca); KT-11-9-T6 (3 ♀, 2 ♂, 2 juv., 1 manca); KT-11-9-N3 (24 ♀, 3 ♂, 2 juv., 1 manca);
KT-11-9-N4 (35 ♀, 7 ♂, 14 juv., 6 manca), NSMT-Cr 22767; KT-11-9-K3 (4 ♀, 1 manca); KT1-9-K4 (21 ♀, 5 ♂, 3 juv.), NSMT-Cr 22768; KT-11-9-K5 (1 ♀; 2 ♂).
Remarks. The specimens are characterized by (1) acute pseudorostrum, small eye lobe, (2)pereopod 2 dactylus similar to that of the genus Eudorella, and (3) uropod peduncle shorter thanrami.
Subgenus Leucon Kröyer, 1846
Leucon (Leucon) ?nasicoides paciﬁcus Zimmer, 1937
Leucon nasicoides Liljeborg, 1855, 122.
Leucon (Leucon) nasicoides paciﬁcus – Zimmer, 1937, 38, ﬁgs. 1–2.

Material examined. KT-11-9-T6 (1 manca), NSMT-Cr 22769; KT-11-9-N4 (1 manca), NSMTCr 22770.
Remarks. The specimens from the Sea of Japan are similar to Leucon ?nasicoides (paciﬁcus) Zimmer, 1937 the Sea of Japan and Okhotsk Sea. However, further examination using additional specimens should be necessary to determine the taxonomic status of these two manca
specimens. In addition, it is problematic that Lomakina (1955) identiﬁed the Zimmerʼs species assubspecies of L. nasicoides, because morphology of the uropod differs between them.
Leucon (Leucon) sp. 1
Material examined. KT-11-9-M4 (1 ♀, 2 manca); KT-11-9-M5 (3 ♀, 2 manca); KT-11-9-E3(1 ♀); KT-11-9-E4 (6 ♀, 1 juv.); KT-11-9-T3 (3 ♀, 4 juv., 3 manca); KT-11-9-T4 (6 ♀, 1 ♂, 13juv.), NSMT-Cr 22771; KT-11-9-T5 (1 ♀, 5 juv.); KT-11-9-N3 (7 ♀, 2 ♂, 21 juv., 6 manca),Deep-sea Cumacea from the Sea of Japan

161

NSMT-Cr 22772; KT-11-9-N4 (8 ♀, 15 juv., 1 manca); KT-11-9-K4 (8 ♀, 3 ♂, 6 juv.).
Remarks. The specimens are similar to Leucon kobjakovae, Lomakina, 1955 in having
curved ridge on each side of the carapace. However, the former species is different from the latter by coarsely serrated median ridge and elongate pseudorostrum of carapace and uropod endopod which is shorter than exopod
Leucon (Leucon) sp. 2
Material examined. KT-11-9-M2 (10 ♀, 10 ♂), NSMT-Cr 22773.
Remarks. The specimens are similar to Leucon kobjakovae, but can be discriminated fromthe latter by two minute spines on the frontal lobe and uropod exopod which is slightly shorter
than endopod.
Leucon (Leucon) sp. 3
Material examined. KT-11-9-M2 (10 ♀, 10 ♂), NSMT-Cr 22774.
Remarks. The specimens are similar to Leucon sp. 1, but can be discriminated from the latter by the curved ridge on the carapace is weak, with minute spines, and uropod endopod article
1 is less than twice as article 2 (more than twice in Leucon sp. 1).
?Leucon sp.
Material examined. KT-11-9-M2 (19 ♀, 2 ♂, 2 juv., 1 manca), NSMT-Cr 22775; KT11-9-M3 (28 ♀, 3 ♂, 13 juv., 7 manca), NSMT-Cr 22776; KT-11-9-E2 (62 ♀, 10 ♂, 45 juv., 6
manca), NSMT-Cr 22777; KT-11-9-E3 (6 ♀, 1 ♂, 5 juv., 2 manca); KT-11-9-T2 (9 ♀, 1 ♂, 4
manca); KT-11-9-K2 (20 ♀, 9 juv., 1 manca); KT-11-9-K3 (12 ♀, 5 ♂, 4 juv., 2 manca), NSMT-Cr
22778.
Remarks. The specimens are similar to Leucon homorhynchus Bishop, 1981 from the deep
Atlantic. However, the specimens have no accessory ﬂagellum on antenna 1, which is unusual in
the genus Leucon (Watling, 1991).
Family Nannastacidae Bate, 1866
Genus Campylaspis Sars, 1865
Campylaspis pisum Vassilenko and Tzareva, 2004
Campylaspis pisum – Vassilenko and Tzareva, 2004: 702, 13–16, ﬁgs. 7–8.

Materials examined. KT-11-9-T2 (4 ♀, 2 ♂, 9 juv.), NSMT-Cr 22779; KT-11-9-N2 (1 ♂);KT-11-9-K2 (14 ♀, 5 ♂, 11 juv.), NSMT-Cr 22780.
Distribuion. The Sea of Japan, 201–950 m.
Campylaspis brevirostris n. sp.
(Figs. 1–3)
Material examined. Holotype: NSMT-Cr 22781, ovigerous female, length 2.36 mm, off
Esashi, 41°47.46′N, 139°34.49′E–41°48.96′N, 139°34.88′E, 563–605 m, 29 May 2011 (KT11-9-E3). Paratypes: NSMT-Cr 22782, 17 females, 4 subadult males, 23 juveniles (3 ovigerous
females dissected), same date and locality as holotype female (KT-11-9-E3); NSMT-Cr 22783, 3
females, 3 males, 5 juveniles (1 female and 14 adult male dissected), off Noto Peninsula,

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Tadashi Akiyama

Fig. 1. Campylaspis brevirostris n. sp., A–C, holotype ovigerous female, D–K, paratype ovigerous female. A,
lateral view; B, anterior portion of body, from above; C, anterior portion of carapace, lateral view; D, sculpture of carapace; E, antenna 1; F, antenna 2; G, left and right mandibles; H, labium; I, maxilla 1; J, maxilla 2;K, maxilliped 1; L, maxilliped 2.

Deep-sea Cumacea from the Sea of Japan

163

38°08.04′N, 136°49.64′E–38°09.00′N, 136°51.20′E, 603–622 m, 1 June 2011 (KT-11-9-N4). Other
material: KT-11-9-T1 (2 ♀, 1 juv., 3 manca); KT-11-9-T3 (9 ♀, 4 ♂, 10 juv., 4 manca), NSMT-Cr
22784; KT-11-9-T4 (7 ♀, 2 ♂, 7 juv., 1 manca); KT-11-9-T5 (16 ♀, 1 ♂, 2 juv., 1 manca), NSMTCr 22785; KT-11-9-N2 (1 ♂, 3 juv., 1 manca); KT-11-9-N3 (7 ♀, 3 juv.).
Diagnosis. Females; carapace antero-posteriorly compressed; pseudorostrum very short;each side with 3 weak oblique ridges; broad transverse ridge running above eye lobe; maxilliped
3 broad, serrated on inner margin; uropod peduncle 1.50–1.63 pleonite 6, 1.9–2.1 times endopod,
exopod longer than endopod. Males; width of pereon shorter than carapace width; maxilliped
propodus with ﬁnger-like process; uropod peduncle 2.3 times pleonite 6 and 1.9 times endopod.
Description. Holotype ovigerous female. Carapace antero-posteriorly compressed (Fig.
1A), 0.38 times total body length, smooth, greatly elevate posteriorly; integument with scale-like
sculpture; each side with 3 weak oblique ridges; pseudorostrum truncate; antennal notch very
shallow (Fig. 1C); anterolateral angle and inferior margin with a small teeth; width of eye lobe,
0.13 times carapace width; broad transverse ridge running above eye lobe. Pereon (Fig. 1A) 0.65
times carapace length; dorsal region of pereonite 1 and 2 produced anteriorly. Well-developed
exopods present on maxilliped 3 and pereopods 1–2. Pleon (Fig. 1A) 0.39 times total bodylength; posterior end of pleonite 6 round. Uropod exopod longer than endopod.
Paratype four ovigerous females. 2.33–2.59 mm. Carapace 0.37 times total body length;
width of eye lobe, 0.13–0.14 times carapace width. Pereon (Fig. 1A) 0.62–0.66 times carapace
length; Pleon (Fig. 1A) 0.32–0.39 times total body length; pleonite 6 (Fig. 2G) 0.93–0.99 times
as long as wide.
Antenna 1 (Fig. 1E), peduncle basal article curved, 0.5–0.6 times combined length of articles
2 and 3; article 3 1.0–1.2 times article 2; main ﬂagellum tri-articulate, 0.9–1.0 times peduncle 3rd
article; basal article 0.8–1.0 times combined length of articles 2 and 3; accessory ﬂagellum 0.2–
0.3 times basal article of main ﬂagellum. Antenna 2 (Fig. 1F) small, uniarticulate, with no setae.
Left and light mandibles (Fig. 4F) truncate at base, with 3 and 4 stuff setae on inner margin,respectively; lacinia mobilis ﬂat, with 4 denticle; right and left incisor processes strongly constructed, with 5–6 dentate. Maxilla 1 (Fig. 1I) with 1 ﬁlament on palp; outer endite with 10 spiniform setae on tip; inner endite with 5 stiff setae. Maxilla 2 (Fig. 1J) with a 3 simple setae on tip.
Maxilliped 1 (Fig. 1K) with 4–7 small branchial lobules; basis subequalin length to merocarpus;
merocarpus with 7 simple setae on inner margin and naked seta on ventral surface, dactylus minute. Maxilliped 2 (Fig. 1 L) basis short, 1.1–1.3 times as long as wide, with plumose seta on innerdistal corner; propodus with 1 stout, long spine on distal end; dactylus with 3 long and 1 shortspines. Maxilliped 3 (Fig. 2A) with well-developed exopod; basis 0.9–1.0 times distal articles
together, with 2 spines on inner distal corner; outer distal corner not produced, with 2 long plumose setae; ischium very short; merus with several simple setae on inner margin, 1.0–1.2 times
combined length of carpus and propodus; carpus with 3 spines and 1 plumose seta on outer margin; propodus 1.8–2.0 times dactylus.
Pereopod 1 (Fig. 2B) similar to maxilliped 3; basis 1.0–1.1 times distal articles together, with
2 plumose setae on inner distal corner; ischium with plumose seta on inner margin; merus 1.3–
1.6 times carpus, with 2 plumose and 2 simple setae on inner margin, with 2 plumose setae onouter margin; carpus 0.9 times propodus, with 2 plumose setae on outer margin, with 3–4 simple
setae on inner margin; propodus 1.4–1.5 times dactylus, with 3 plumose setae on outer margin.
Pereopod 2 (Fig. 2C) basis 0.5 times distal articles, with plumose seta on inner and outer distal
corner, respectively; dactylus 3.1–3.6 times propodus and 1.1–1.2 times combined length ofmerus and carpus. Pereopod 3 (Fig. 2D) basis 1.3–1.5 times remaining distal articles; carpus 1.2–

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Tadashi Akiyama

Fig. 2. Campylaspis brevirostris n. sp., paratype ovigerous female. A, maxilliped 3; B–F, pereopods 1–5; G, uropod with pleonite 6.

1.5 times merus and 1.8–2.4 times propodus; terminal seta fused to dactylus. Pereopod 4 (Fig,
2E) basis 0.9–1.0 times distal articles together; carpus 1.1–1.3 times merus and 1.9–2.3 times
propodus; terminal seta fused with dactylus. Pereopod 5 (Fig. 2F) basis 0.5–0.6 times distal articles together; carpus 1.3–1.6 times merus and 1.7–2.1 times propodus; terminal seta f–sed.
Pereopods 1 and 2 with well-developed exopods.
Uropod (Fig. 2G) peduncle 1.50–1.63 times pleonite 6, 1.58–1.77 times exopod and 1.89–
2.14 times endopod, without small seta on inner margin; exopod 1.17–1.21 times endopod, withstiff terminal seta; endopod uniarticulate, with 2 spiniform setae on inner margin.
Paratype adult male, 3.30 mm (Fig. 3). Carapace (Fig. 3A–B) 0.32 times total body length;
pseudorostrum truncate, very short; antennal notch distinct; inferior margin with small teeth.
Width of eye lobe 0.16 times carapace width, without corneal lenses. Pereon (Fi. 3A) 0.88 times
carapace length, dorsal surface of pereonite 1 and 2 with weak, triangular projection. Pleon (Fig.
6A) 0.41 times total body length; pleonite 1–5 with a pair of lateral grooves; pleonite 6 (Fig. 3M)
1.01 times as long as wide: posterior end not exceeding anal opening. Pleopods absent (Fig. 3A).
Antenna 1 (Fig. 3E), peduncle basal article slightly curved, 0.5 times combined length ofFig. 3. Campylaspis brevirostris n. sp., paratype adult male. A, lateral view; B, anterior portion of body, fromabove; C, anterior portion of carapace, lateral view; D, sculpture of carapace; E, antenna 1; F, antenna 2; G,maxilliped 3; H–L, pereopods 1–5; M, uropod with pleonite 6.

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Deep-sea Cumacea from the Sea of Japan167

article 2 and 3; article 3 1.0 times article 2. Main ﬂagellum tri-articulate, 1.1 times peduncle article 3; article 1 0.9 times combined length of articles 2 and 3; accessory ﬂagellum uniarticulate,
0.2 times basal article of main ﬂagellum. Antenna 2 (Fig. 3F) ﬂagellum of 20 articles, exceeding
posterior end of pleon. Maxilliped 3 (Fig. 3G) with well-developed exopod; basis 1.1 times distal
articles together, with plumose seta and 1 spine on inner margin; outer distal corner not protrude,with 2 long plumose setae; merus 0.9 times combined length of carpus and propodus; carpus 1.0
times propodus; propodus with a ﬁnger-like process (arrow head) on inner margin.
Pereopod 1 (Fig. 3H) similar to maxilliped 3; basis 1.2 times distal articles together, with 2long plumose seta on outer distal corner; ischium short; merus 1.7 times carpus; carpus 1.0 times
propodus; propodus 2.3 times dactylus. Pereopod 2 (Fig. 3I) basis 0.6 times distal articles
together, with plumose seta on inner distal corner; carpus 1.3 times merus; dactylus 4.2 times
propodus and 1.3 times combined length of merus and carpus. Pereopod 3 (Fig. 3J) basis 1.8
times distal articles together, with 2 long plumose setae on inner margin; carpus 1.4 times merus
and 2.2 times propodus; terminal seta fused with dactylus. Pereopod 4 (Fig, 3K) basis 1.2 times
distal articles together; carpus 1.5 times merus and 2.5 times propodus; terminal seta fused withdactylus. Pereopod 5 (Fig. 3 L) basis 0.6 times distal articles together; carpus 1.4 times merus
and 2.2 times propodus. Pereopods 1–4 with well-developed exopods (Fig. 3H–K).
Uropod (Fig. 3M) peduncle 2.29 times pleonite 6, 2.16 times exopod and 1.87 times endopod, 8 plumose setae on inner margin; exopod 0.87 times endopod, with plumose seta on inner
margin and 2 simple terminal setae; endopod uniarticulate, with 9 spiniform setae on serrated
inner margin.
Etymology. The species name refers to the short pseudorostrum on the carapace.
Remarks. Arrangement of ridges on the carapace are similar to Campylaspis pisum Vassilenko and Tzareva, 2004, including a transverse ridge on the frontal lobe, but can be distinguishable from the latter species by antrero-posteriorly compressted carapace with broad, weak ridges
and with very short pseudorostrum.
Campylaspis ?schnabelae Gerken, 2012
Campylaspis schnabelae – Gerken, 2012: 3524, 72–76, ﬁgs. 41–42.

Material examined. KT-11-9-M2 (2 ♀, 3 juv., 1 manca); KT-11-9-M3(1 ♀, 2 ♂, 2 juv., 5
manca), NSMT-Cr 22786; KT-11-9-E1 (4 ♀, 1 ♂, 10 juv., 78 manca); KT-11-9-E2 (8 ♀, 3 ♂),NSMT-Cr 22787; KT-11-9-E3 (6 ♀, 4 ♂, 8 juv.), NSMT-Cr 22788; KT-11-9-T3 (1 ♂, 1 juv.); KT11-9-N3 (1 juv.).
Campylaspis sp. 1
Material examined. KT-11-9-M2 (53 ♀, 22 ♂, 11 juv.), NSMT-Cr 22789; KT-11-9-E2(17 ♀, 4 ♂, 9 juv.), NSMT-Cr 22790; KT-11-9-E3 (14 ♀, 4 ♂, 10 juv.); KT-11-9-T2 (3 ♀, 6 juv., 3
manca); KT-11-9-T4 (13 ♀, 7 ♂, 29 juv., 12 manca), NSMT-Cr 22791; KT-11-9-T5 (8 ♀, 4 ♂., 13
juv.)
Remarks. Arrangement of ridges on the carapace is similar to Campylaspis pisum except
for that transvers ridge on the frontal lobe absent. The specimens are similar to Campylaspis
Fig. 4. Cumella tanseiae n. sp., A–C, holotype ovigerous female, D–M, paratype ovigerous female. A, lateralview; B, anterior portion of body, from above; D, sculpture of carapace; D, antenna 1; E, antenna 2; F, left andright mandibles; G, labium; H, maxilla 1; I, maxilla 2; J–K, maxilliped 1; L maxilliped 2; M, maxilliped 3.

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crispa Lomakina, 1955 from the Sea of Japan (Lomakina, 1955, 1958), but are distinguishable
from C. crispa by that the uropod peduncle twice as long as endopod (three times in C. crispa).
Campylaspis sp. 2
Material examined. KT-11-9-E3 (53 ♀, 22 ♂, 11 juv.), NSMT-Cr 22792.
Remarks. The specimens are very similar to Campylaspis sp. 1. The former species is discriminated from the latter by weak ridges on the carapace.
Campylaspis sp. 3
Material examined. KT-11-9-M2 (1 ♂, 1 juv., 1 manca); KT-11-9-M3 (2 ♀, 2 ♂, 8 juv., 11
manca), NSMT-Cr 22793; KT-11-9-E3 (2 ♀, 1 ♂, 3 juv., 1 manca), NSMT-Cr 22794; KT-11-9-T2(1 ♂, 2 juv., 2 manca); KT-11-9-T4 (1 ♀, 1 ♂, 2 juv., 1 manca); KT-11-9-T5 (1 ♀ 2 juv., 1 manca);
KT-11-9-N2 (2 juv.); KT-11-9-N3 (1 ♀, 4 juv., 1 manca); KT-11-9-N4 (3 juv., 1 manca); KT11-9-K5 (1 ♀, 1 ♂, 2 manca).
Remarks. There are several Campylaspis species with smooth carapace lacking no redges
and sulcus. Among them, the Japanese specimens are similar to C. rufus Gerken, 2012 from New
Zealand, 346–530 m, but is distinguishable from the latter by the uropod peduncle less than twotimes as endopod (more than two times in C. rufus).
Genus Cumella Sars, 1865
Cumella tanseiae sp. nov.
(Fig. 4–6)
Material examined. Holotype: NSMT-Cr 22795, preparatory female, length 2.66 mm,
Musashi-tai, 44°40.48′N, 140°02.38′E–44°39.53′N, 140°02.83′E, 198–206 m, 28 May 2011 (KT11-9-M2). Paratypes: NSMT-Cr 22796, many preparatory females (4 specimens dissected), many
subadult males, same date and locality as holotype female (KT-11-9-M2); NSMT-Cr 22797, 83
preparatory females, 41 adult males (3 specimens dissected), 1 subadult males, 45 manca larvae,
off Esashi, 41°52.01′N, 139°33.90′E–41°52.94′N, 139°34.33′E, 222–250 m, 29 May 2011 (KT11-9- E1).
Diagnosis. Females; carapace without teeth or spines on median ridge; lateral and dorsal
surface with 3 pairs of shallow depressions, forming weak transverse ridges; lower margin with
two-cornered teeth; antenna 1 main ﬂagellum article 2 longer than article 1; antenna 2 with article-like swellings at basal region of 2 plumose setae; outer distal corner of maxilliped 3 basis notreaching distal end of ischium; pereopod 2 propodus with shallow notch on distal end; uropod
peduncle 1.4–1.5 times pleonite 6 and 1.4–1.8 times endopod. Males; lenses on eye love notwell-developed; pleonite 1–5 with lateral grooves; antenna 2 ﬂagellum exceeding posterior endof pleon.
Description. Holotype preparatory female. Carapace (Fig. 4A–B), 0.30 times total bodylength; integument with scale-like sculpture; median dorsal ridge running for entire length, without spines; anterior and posterior regions of dorsal surface and lateral surface with 3 pairs ofshallow depressions, forming weak transverse ridges; pseudorostrum 0.05 times carapace length;
antennal notch obsolete; anterolateral angle (Fig. 4A) and inferior margin with 18 two-cornered
tooth directing forward (Fig. 4A); width of eye lobe 0.16 times carapace width; corneal lenses
not well developed. Pereon (Fig. 4A) 0.64 times carapace length. Well-developed exopods pres-Deep-sea Cumacea from the Sea of Japan

169

Fig. 5. Cumella tanseiae n. sp., paratype ovigerous female. A–E, pereopods 1–5; F, uropod with pleonite 6.

ent on maxilliped 3 and pereopods 1–2. Pleon (Fig. 4A) 0.52 times total body length..
Paratype four preparatory females, 2.59–2.78 mm (Figs. 4, 5). Carapace, 0.28–0.29 times
total body length; pseudorostrum 0.05–0.07 times carapace length; inferior margin with 16–18
two-cornered tooth; width of eye lobe 0.15–0.18 times carapace width; Pereon (Fig. 4A) 0.59–
0.70 times carapace length. Pleon (Fig. 4A) 0.52–0.54 times total body length; pleonite 6 (Fig.
5F) 1.42–1.54 times as long as wide.
Antenna 1 (Fig. 4D), peduncle basal article curved, 0.7–0.9 times combined length of articles
2 and 3; article 3 0.9 times article 2. Tri-articulate main ﬂagellum 1.4–1.6 times peduncle 3rd
article; article 1 0.5–0.6 times combined length of articles 2 and 3; article 2 1.4–1.6 times article
1; accessory ﬂagellum 0.6–0.7 times basal article of main ﬂagellum: Antenna 2 (Fig 4E) with 2
article-like swellings and 3 plumose setae present on outer margin. Left and light mandibles (Fig.
4F) navicular form, with 5 and 6 ciliated setae on inner margin, respectively; lacinia mobilis bidentate; inscissor process 3 or 4 dentate. Labium (Fig. 4G) with 4 setae; Maxilla 1 (Fig. 4H) with
3 ﬁlaments on palp; outer endite with 10 spiniform setae on outer margin; inner endite with 4
minute setae on outer margin. Maxilla 2 (Fig. 4I) with a row of 13 thin simple setae on inferior
margin; narrow endites with 6 and 3 setae, respectively.
Maxilliped 1 (Fig. J–K) with 2–4 small branchial lobules; basis much shorter than remaining
articles combined, with simple seta at proximal region; carpus with 5 broad, tridentate setae andseveral simple setae on inner margin. Maxilliped 2 (Fig. 4 L) basis 0.8 times combined length ofsucceeding 4 articles, with stiff plumose seta on inner distal corner; carpus with 3 plumose setae
on inner margin; propodus with 3 setae on inner margin. Maxilliped 3 (Fig. 4M) with well-developed exopod; basis 1.1–1.2 times distal articles together, with 2 stiff plumose setae on distal
region of inner margin; outer distal corner not produced, with 2 long plumose setae and 1–2 thinsetae; merus and carpus 0.9–1.0 times propodus, with 2 and 1 setae on inner and outer margin,respectively.

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Fig. 6. Cumella tanseiae n. sp., paratype adult male. A, lateral view; B, anterior portion of body, from above; C,antenna 1; D, antenna 2; E, maxilliped 3; F–J, pereopods 1–5; K, uropod with pleonite 6.

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Pereopod 1 (Fig. 5A) with well-developed exopod; basis 0.6–0.7 times distal articles
together, with robust spiniform seta on inner margin distally; carpus 1.0–1.1 times propodus; propodus 2.0–2.3 times dactylus; dactylus with 4 terminal setae. Pereopod 2 (Fig. 5B) basis 0.7
times distal articles together, propodus with shallow notch on distal end; dactylus 2.5–2.9 times
propodus, 1.0–1.1 times combined length of merus and carpus. Pereopod 3 (Fig. 5C) basis 1.5–
1.6 times remaining distal articles; carpus 1.5–1.7 times merus and 1.7–1.8 times propodus.
Pereopod 4 (Fig, 5D) basis 1.1–1.2 times distal articles together; carpus 1.6–1.8 times merus and1.7–2.0 times propodus. Pereopod 5 (Fig. 5E) basis 0.6–0.7 times distal articles together; carpus
1.9–2.1 times merus and 1.9–2.7 times propodus. Pereopods 1 and 2 with well-developed exopods.
Uropod (Fig. 5F) peduncle 1.41–1.49 times pleonite 6, 1.54–1.86 times exopod, 1.44–1.76
times endopod, with 4–5 thin short setae on inner margin; exopod 0.86–1.01 times endopod;
endopod uniarticulate, with 4 spiniform setae on inner margin; terminal seta robust.
Paratype three adult males, 2.88–3.04 mm (Fig. 6). Carapace (Fig. 6A–B) 0.29–0.30 times
total body length; median dorsal ridge running for anterior half of carapace, with no spines; pseudorostrum very short, 0.03–0.05 times carapace length, not contact each other; siphon shorter
than females; antennal notch very shallow; anterolateral angle and anterior portion of inferior
margin with 3–6 triangular teeth; width of eye lobe 0.20–0.21 times carapace width, without corneal lenses. Pereon (Fig. 6A) 0.64–0.67 times carapace length. Pleon (Fig. 6A) 0.50–0.52 times
total body length; pleonite 1–5 with a pair of lateral grooves. Pleonite 6 1.29–1.41 times as longas wide; slightly exceeding anal opening; posterior end round. Pleopods absent.
Antenna 1 (Fig. 6C) peduncle article 1 0.8–0.9 times combined length of article 2 and 3; article 3 0.8–0.9 times article 2. Main ﬂagellum tri-articulate, 1.4–1.5 times peduncle article 3; article 1 0.5–0.6 times combined length of articles 2 and 3; article 2 1.3–1.5 times article 1, article 3
minute; accessory ﬂagellum bi-articulate, 0.4–0.6 times main ﬂagellum article 1. Antenna 2 (Fig.
6D) articles 4 and 5 with numerous short setae; ﬂagellum of 20–21 articles, exceeding posterior
end of pleon.
Maxilliped 3 (Fig. 6E) with well-developed exopod; basis 1.4–1.6 times distal articles
together; with 1–2 plumose setae and 1 spine on inner distal corner; outer distal corner not protrude, with 2 long plumose setae; carpus 0.8 times propodus; propodus 1.6–1.87 times dactylus,
with 3 plumose setae on inner margin; merus and carpus with long plumose seta on outer distal
corner.
Pereopod 1 (Fig. 6F), basis 0.8–0.9 times distal articles together, with 3 setae on inner margin, with simple seta on outer distal corner; carpus 0.8–0.9 times propodus; propodus 2.3 times
dactylus; dactylus with 5 terminal setae. Pereopod 2 (Fig. 6G) basis 1.2 times distal articles
together; propodus with shallow notch on distal end; dactylus 2.3–2.5 times propodus, 0.9times
combined length of merus and carpus. Pereopod 3 (Fig. 6H) basis 1.7–2.0 times distal articles
together; carpus 1.5–1.9 times merus and 1.8–2.3 times propodus seta fused with dactylus.
Pereopod 4 (Fig, 6I) basis 1.2–1.3 times distal articles together; carpus 1.7–2.3 times merus and
2.0–2.6 times propodus; terminal seta fused with dactylus. Pereopod 5 (Fig. 6J) basis 0.6–0.7
times distal articles together; carpus 2.1 times merus and 2.2 times propodus. Pereopods 1–4
with well-developed exopods (Fig. 6F–I).
Uropod (Fig. 6K) peduncle 1.89–2.04 times pleonite 6, 1.58–1.70 times exopod and 1.31–
1.43 times endopod, with 5 setae on inner margin; exopod 0.83–0.84 times endopod; terminal
setae long; endopod uni-articulate, with 8–9 spiniform setae on inner margin; terminal setarobust.

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Etymology. The species name is dedicated to the research vessel Tansei-maru.
Remarks. Carapace of the new species is similar to Cumella sadoensis Gamô, 1968 and C.
alveata Gamô, 1964, both of which are from shores of Japanese and Korean waters (Gamô,1964, 1968; Lee and Lee, 1999). The female specimens of the former species is discriminatedfrom the latter two by (1) lower margin of carapace with two-cornered teeth, (2) antenna 2 main
ﬂagellum article 2 longer than article 1 (3) pereopod 1 carpus subequal in length to propodus,and (4) uropod peduncle 1.4–1.5 times pleonite 6.
Distribution. The Sea of Japan, 198–250 m.
Family Diastylidae Bate, 1856
Genus Diastylis Say, 1818
Diastylis samurai Zimmer, 1943
Diastylis samurai – Zimmer, 1943: 133, ﬁgs. 1–3; Gamô, 1968: 149–150, ﬁg. 22.

Material examined. KT-11-9-E2 (1 ♀, 5 juv.), NSMT-Cr 22798; KT-11-9-K3 (1 ♀, 1 juv.),
NSMT-Cr 22799.
Distribution. Paciﬁc coast of northern Japan, the Sea of Japan, 320–1511 m.
Disatylis ?moskalevi Vassilenko and Tzareva, 2004
Material examined. KT-11-9, E1 (9 ♀, 4 ♂, 2 juv.), NSMT-Cr 22800; KT-11-9-E2 (4 ♀, 11
juv., 51 manca), NSMT-Cr 22801; KT-11-9-T3 (2 ♀, 1 ♂, 3 manca), NSMT-Cr 22802; KT11-9-K4 (2 ♀, 4 manca), NSMT-Cr 22803.
Genus Leptostylis Sars, 1869
Leptostylis ?villosa Sars, 1869
Materials examined. KT-11-9-E1 (7 ♀, 13 ♂, 19 juv.), NSMT-Cr 22804; KT-11-9-E2 (27 ♀,15 ♂), NSMT-Cr 22805; KT-11-9-E3 (30 ♀, 9 ♂); KT-11-9-E4 (1 ♀); KT-11-9-T2 (2 ♀); KT11-9-T3 (2 ♀); KT-11-9-N2 (1 ♀, 2 ♂, 3 juv.), NSMT-Cr 22806; KT-11-9-K3 (4 ♀, 3 ♂), NSMTCr 22807.
Remarks. The carapace of the specimens from off Esashi has sparse short hairs, whereas
Leptostylis villosa and the specimens from Toyama Bay, Noto Peninsula and off Kasumi arecharacterized by dense hairs on the carapace.
Genus Paraleptostylis Vassilenko, 1990
Paraleptostylis vityazi Vassilenko and Tzareva, 2004
Paraleptostylis vityazi – Vassilenko and Tzareva, 2004: 702, 6–9, ﬁgs. 3–4.

Material examined. KT-11-9-M3 (1 ♀, 4 ♂, 19 manca), NSMT-Cr 22808; KT-11-9-M4(1 ♂, 5 manca); KT-11-9-M5 (1 ♀); KT-11-9-E1 (3 ♀); KT-11-9-E2 (47 ♀, 24 ♂, 1 juv., 113
manca); KT-11-9-E3 (36 ♀, 25 ♂, 55 manca), NSMT-Cr 22809; KT-11-9-E4 (1 ♀); KT-11-9-T4(1 ♀, 1 ♂, 2 manca); KT-11-9-T5 (1 manca); KT-11-9-N2 (3 ♀, 1 ♂, 1 juv.); KT-11-9-K3 (3 ♀,2 ♂, 5 manca), NSMT-Cr 22810; KT-11-9-K4 (1 ♀, 2 ♂, 8 manca).
Distribution. The Sea of Japan, 201–1130 m.

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173

Fig. 7. Petalosarsia declivis (Sars, 1865), adult male. A, lateral view; B, anterior portion of body, from above; C,antenna 1; D, antenna 2; E, maxilliped 3; F–J, pereopods 1–5; K–L, pleopods 1–2; M, uropod with pleonite 6.

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Family Pseudocumatidae Sars, 1878
Genus Petalosarsia Stebbing, 1893
Petalosarsia declivis (Sars, 1865)(Fig. 7)
Petalopus declivis Sars, 1865: 197.
Petalomera declivis Sars, 1883, 13.
Petalosarsia declivis – Stebbing, 1893: 308; Sars, 1900, 77–79, pl. 54; Given, 1965, 222, Fig. 5; Bacescu and Muradian,1974, 224–227, Figs. 5–7; Akiyama and Gerken, 2012, 3–5, Figs. 1, 2.

Material examined. KT-11-9-M2 (3 ♀, 1 ♂, 6juv.); KT-11-9-M3 (1 ♀); KT-11-9-E1 (2 ♀,1 ♂, 6 juv.) KT-11-9-E3 (6 ♀, 2 ♂, 7 juv., 2 manca), NSMT-Cr 22811; KT-11-9-T2 (6 ♀); KT11-9-T4 (2 ♀, 1 ♂, 4 manca); KT-11-9-T5 (1juv,); KT-11-9-N3 (4 ♂, 1 specimen dissected, 2juv,), NSMT-Cr 22812; KT-11-9-K2 (2 ♀); KT-11-9-K4 (9 ♀, 6 ♂, 2 specimens dissected, 9 juv.),
NSMT-Cr 22813.
Description. Adult males (Fig. 7), 4.17–4.34 mm. Carapace (Fig. 7A–B) length 0.32–0.34
times total animal length, 1.47–1.55 times greatest width and 1.89–2.01 times depth; lateralcarina running for entire length, with a teeth on anterior end; hind margin of dorsal surface withtransverse ridge; frontal margin between lateral carina 0.61–0.63 times greatest width; pseudorostrum 0.10–0.11 times length of carapace; width of eye lobe 0.16–0.18 times carapace width.
Pereon (Fig, 7A) 0.55–0.63 times carapace. Pleon 0.47–0.48 times total animal length, with 2
pairs of pleopods. Pleonites 1–6 with groove on ventral surface, very shallow on pleonite 6; pleonite 6 length as long as wide.
Antenna 1 (Fig. 7C) basal article of peduncle 1.1–1.5 times combined length of 2nd and 3rd;
main ﬂagellum of 4–5 articles; 1st article with 8–9 aesthetascs; accessory ﬂagellum of 3 articles,
0.4 times main ﬂagellum. Antenna 2 (Fig. 7D) peduncle with plumose seta on basal article; ﬂagellum reaching posterior end of pleonite 6, of 22 articles. Maxilliped 3 (Fig. 7E) basis 1.2–1.3
times remaining distal articles, with 4–6 plumose setae on inner margin.
Pereopod 1(Fig. 7F) basis 1.43–1.50 times combined length of ischium and carpus; carpus
length 1.9–2.0 times width, 2.5 times dactylus length, 0.6 times basis length. Pereopod 2 (Fig.
7G) basis 1.1–1.2 times length of remaining distal articles. Pereopod 3 (Fig. 7H) basis 1.9 times
distal articles combined. Pereopod 4 (Fig. 7I) basis 1.4 times distal articles combined. Pereopod
5 (Fig. 7J) basis 0.7 times remaining distal articles. Pleopod 1 (Fig. 7K) outer and inner ramus
fused. Pleopod 2 (Fig. 7 L) rudimentary, with minute lamus, basal aricle with robust seta on outermargin distally.
Uropod (Fig. 7M) peduncle 1.5–1.6 times pleonite 6 length, 0.70–0.73 times exopod lengthand 0.59–0.63 times endopod length; exopod 0.80–0.88 times endopod; endopod with 8–10 spiniform setae on inner margin. Telson (Fig. 7M) round, 0.62–0.75 times pleonite 6.
Remarks. The male specimens agree with description by Sars (1900) and Bacescu and
Muradian, 1974. Local variation of morphology of femalesʼ carapace suggests the name P. declivis may represent a species complex (Given, 1965; Akiyama and Gerken, 2012), which is also
supported by a secondary sexual character in the males from the Sea of Japan, minute pereopod 3
dactylus (along with curved carpus) (Fig. 7H). Telsons of the adult male specimens are round,
whereas those of Petalosarsia adult males from southern Japan and the Sulu Sea is triangular.
Distribution. North Atlantic boreal and Arctic region, NW Canada, Detroit de Davis, Iceland, Scandinavia, Spitsbergen, Beloe More, Novaya Zemlya, Kamchatka, the Sea of Japan.
Okhotsk Sea, Alaska, 18–808 m. Habitat of the species from the Sea of Japan seems to be deeper

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175

than those of the other localities.
Acknowledgements
I thank Dr. K. Hasegawa of the National Museum of Nature and Science (NSMT), director of
R/V Tansei-maru cruise KT-11-9 for facility for this work. I also thank the stuff members of
NSMT, Dr. T. Kubodera, Dr. H. Saito, Dr. K. Hasegawa, and other researchers on board for cooperation in collecting benthic animals during the cruise. Dr. Y. Imahara of Biological Instituteon Kuroshio improved the manuscript. Thanks are also due to captain and crew of R/V Tanseimaru for every kind of their help.
References
Akiyama, T., 2009. Deep-sea cumacean crustaceans (Peracarida) collected from Paciﬁc coast of northern Honshu, Japan.
In: Fujita, T. (ed). Deep-sea Fauna and Pollutants off Paciﬁc Coast of Northern Japan. National Museum of Natureand Science Monographs, 39: 483–493.
Akiyama, T. and S. Gamô, 2012. The cumacean genus Eudorella (Crustacea: Peracarida) from Japanese waters, Northwest Paciﬁc, and E. suluensis from the Sulu Sea, Indo-West Paciﬁc. Zootaxa, 3319: 1–56.
Akiyama, T. and S. Gerken, 2012. The cumacean (Crustacea: Peracarida) genus Petalosarsia from the Paciﬁc Ocean.
Zootaxa, 3320: 1–35.
Barnard, J. L. and R. R. Given, 1961. Morphology and ecology of some sublittoral Crustacea of southern California.
Paciﬁc Naturalist, 2: 153–165.
Bacescu M. and Z. Muradian, 1974. New cumacea from the North-Western Atlantic: Ceratocuma panamensis n. sp.,
Cimmerius costlowi n. sp. and some comments upon Petalosarsia declivis (G. O. Sars). Revue Româine de Biologie, 19: 217–227.
Bate, C. S., 1856. On the British Diastylidae. The Annals and Magazine of Natural History, Series 2, 17: 449–465.
Bishop, J. D. D. (1981). Two new leuconids (Peracarida, Cumacea) of widespread occurrence in the deep Atlantic. Crustaceana, 40: 144–159.
Gamô, S., 1964. On some cumacean Crustacea from Sagami Bay, with the description of two new species. The Scientiﬁc
Reports of the Yokohama National University, II, 11: 17–28.
Gamô, S., 1967. Studies on the Cumacea (Crustacea, Malacostraca) of Japan. Part I. Publications of the Seto Marine Biological Laboratory, 15: 133–163.
Gamô, S., 1968. Studies on the Cumacea (Crustacea, Malacostraca) of Japan. III. Publication of the Seto Marine Biological Laboratory, 16: 147–192.
Gerken, S., 2012. New Zealand Ceratocumatidae and Nannastacidae (Crustacea: Cumacea). Zootaxa, 3524: 1–124.
Given, R., 1965. Five collections of Cumacea from the Alaskan Arctic. Arctic, 18: 213–229.
Hart, J. F. L., 1930. Some Cumacea of the Vancouver Island region. Contributions to Canadian Biology and Fisheries (N.
S.), 6: 23–40.
Jones, N. S., 1976. British cumaceans. Synopsis of the British Fauna 7. 66 pp. Academic Press, London.
Kröyer, H., 1846. Im Cumaernes Familie. Naturhistorisk Tidsskrift, Raekke, 2(2): 123–211.
Lilljeborg, W., 1855. Om Hafs-Crustaceer vid Kulleberg I Skåne. Öfversigt af Kongl. Vetenskaps-Akademiens Förhandlingar, 12: 117–138. (in Swedish and Latin)
Lomakina, N. B., 1955. Cumacea from Far-East Seas. Trudy Zoologicheskogo Instituta Academia Nauka SSSR, 18: 112–165. (In Russian)
Lomakina, N. B., 1958. Cumacea of the seas of U.S.S.R. USSR Publication of Academy of Science, Moscow, USSR,
1–310. (In Russian)Sars, G. O., 1863. IV. Beretning om en I Sommenren 1862 foretagen zoologisk Reise I Christianiasog Trondhjems Stifter.
Nyt Magazi for Naturvidenskaberne, 12: 193–252.
Sars, G. O., 1865. Om den abberante Krebsdyrgruppe Cumacea og dens nordiske Arter. Förhandlinger I Videnskabs-Selskabet I Christiania, 1864, 128–208.
Sars, G.O., 1869. VII. Undersøgelser over Christianiafjordens Dybvandsfauna. Nyt Magazin for Naturvidenskaberne 16:

176

Tadashi Akiyama

305–362.
Sars, G. O., 1878. Nye Bidrag til Kundskaben om Middelhalvets Invertebratfauna. Archiv for Mathematik og Naturvidenskab, 3: 461–512 (In Latin and Norwegian.)Sars, G. O., 1887. Report on the Cumacea collected by H. M. S. Challenger during the year 1873–1876. Report on the
Scientiﬁc Results of the Voyage of the H. M. S. Challenger During 1873–1876 under the Command of George S.
Nares and Frank Tourle Thomson, 19: 1–73.
Sars, G. O., 1900. Cumacea. An account of the Crustacea of Norway, 3: 1–115. Bergen Museum, Bergen, Norway.
Say, T., 1818. An account of the Crustacea of the United States. Journal of the Academy of Natural Science of Philadelphia, 1: 313–319.
Scott, T., 1901. Notes on gatherings of Crustacea, collected for the most part by the ﬁshery steamer “Garland” and thesteam trawler “St. Andrew” of Aberdeen, and examined during the year 1900. Report of the Fishery Board of
Scotland, Part III, 19: 235–281.
Stebbing, T. R. R., 1893. Chapter XX. Order II. –Edriophthalma. Sub-order 1. –Cumacea. In: Stebbing T. R. R.(ed.), A
History of Crustacea/ Recent Malacostraca. International Science Series , No. 71. D. pp 291–313. Appleton andCompany, New York.
Stebbing, T. R. R., 1913. Cumacea (Sympoda). Das Tierreich im Auftrage der Königl. Preuß. Akademie der Wissenschaften zu Berlin, 39 Crustacea. R. Friedlander und Sohn, Berlin.
Vassilenko, S., 1990. Fauna of cumaceans from the Leptiv Sea, Novosibiorsky shallow water and adjacent deep waters of
the Arctic Ocean. Sea Fauna Investigation, 37: 210–234.
Vassilenko, S. and L. Tzareva, 2004. New Cumacea species (Malacostraca, Peracarida) from the deep-water area of the
Sea of Japan (Collections of the 52nd Cruise by the R/V «Vityaz», 1972). Zootaxa, 702: 1–16.
Watling, L., 1991. Revision of the cumacean family Leuconidae. Journal of Crustacean Biology, 11: 569–582.
Zimmer, C., 1937. Paziﬁsche Cumaceen. – Exprolations des Mers dʼU. R. S. S. Issledvaniia Morei S. S. S. R., 23: 38–54.
Zimmer, C., 1943. Über neue und weniger bekannte Cumaceen. Zoologischer Anzeiger, 141: 147–167.