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Deep-sea sipunculans from the Kuril-Kamchatka Trench and adjacent abyssal plain
Deep-Sea Research II ∎ (∎∎∎∎) ∎∎∎–∎∎∎
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Deep-sea sipunculans from the Kuril-Kamchatka trench and adjacent abyssal plain Anastassya S. Maiorova a,b,n, Andrey V. Adrianov a,b,c a
A.V. Zhirmunsky Institute of Marine Biology, Far Eastern Branch of Russian Academy of Sciences, Vladivostok 690041, Russia Far Eastern Federal University, Vladivostok 690950, Russia c Far Eastern Aquarium, Far Eastern Branch of Russian Academy of Sciences, Vladivostok, Russia b
art ic l e i nf o
Keywords: Sipuncula Deep-sea Golfingia Nephasoma Phascolion
a b s t r a c t Deep-sea sipunculans collected during the expedition to the Kuril-Kamchatka Trench and adjacent abyssal plain are described and illustrated using differential interference contrast microscopy (DIC) and scanning electron microscopy (SEM). Specimens were sorted from brown silt collected by giant boxcorer (GKG), epibenthic sledge (EBS) and Agassiz trawl (AGT) from the depths 4830–5780 m. Within about 150 valid species of sipunculans only 15 have been known to be abyssal and six of them were found and identified in this KURAMBIO expedition. Eight species of sipunculans have been previously recorded from the Kuril-Kamchatka region but all of them were described based on preserved museum's material collected by bottom dredge and these descriptions are far from to be complete and comparable with other samplings. All KURAMBIO species are described according to a unified protocol to illustrate the most important taxonomic characters. This is the first description and illustrating of abyssal sipunculans in live condition with natural coloration of non-preserved specimens. Abyssal species were for a first time described with SEM facilities and according to a standardized protocol. For a first time for abyssal sipunculans, species accounts also include quantitative characteristics, distribution and specific biotope data. Nephasoma abyssorum is reported for the Kuril-Kamchatka Trench and adjacent abyssal plain for a first time. & 2014 Elsevier Ltd. All rights reserved.
1. Introduction The current knowledge on North West Pacific deep-sea sipunculans is only based on the results of several Russian cruises of R/V “Vitjaz” to the Kuril-Kamchatka and Japanese Trenches. These samples of deep sea sipunculans were examined and described by Murina (1971). She has also described several new deep-sea species from other deep sea localities in the Pacific and firstly illustrated phenomenon of bipolarity for Phascolion lutense (see Murina, 1961, 1971, 1973). Eight species representing three genera of sipunculans have been recorded for the Kuril-Kamchatka Trench and adjacent abyssal plain so far. Most of these species were described based on the preserved material collected by bottom dredge and the descriptions are far from to be complete. About 30 species of sipunculans were found at abyssal depths (below 3000 m). Some eurybathic species are found between 10 and 4000 m over a wide range of temperatures but some species
n Corresponding author at: A.V. Zhirmunsky Institute of Marine Biology, Far Eastern Branch of Russian Academy of Sciences, Vladivostok 690041, Russia. E-mail address: [email protected] (A.S. Maiorova).
are restricted to cold water deeper than 3000 m and never found above this isobath. At least 15 species are known from the depth below 5000 m: Golfingia anderssoni (Theel, 1911); G. margaritacea (Sars, 1851); G. muricaudata (Southern, 1913); G. vulgaris (de Blainville, 1827); Nephasoma abyssorum (Koren and Danielssen, 1875); N. capilleforme (Murina, 1973); N. corrugatum N. Cutler et Cutler, 1986; N. diaphanes diaphanes (Gerould, 1913); N. flagriferum (Selenka, 1885); N. minutum (Keferstein, 1862); N. schuettei (Augener, 1903); Phascolion lutense Selenka, 1885; P. pacificum Murina, 1957; Onchnesoma magnibatha Cutler, 1969; Apionsoma murinae (Cutler, 1969) (see Cutler, 1994). Some species are common even at the hadal depth (more than 6000 m) (Nephasoma minutum, Golfingia muricaudata, G. anderssoni, Phascolion lutense, P. pacificum), but it should be emphasized that the hadal zone has no endemic species. Contrary to shallow water species, nothing is still known about the development of abyssal sipunculans, their larval stages, life history and population biology. Because the absence of endemic abyssal species the deep-sea fauna of sipunculans appears to be relatively young and is formed as a result of migration of some eurybathic species to a great depth. Probably, the dispersal of long-lived pelagosphera larvae by ocean currents also allows sipunculans recolonize ocean depths as
http://dx.doi.org/10.1016/j.dsr2.2014.08.011 0967-0645/& 2014 Elsevier Ltd. All rights reserved.
Please cite this article as: Maiorova, A.S., Adrianov, A.V., Deep-sea sipunculans from the Kuril-Kamchatka trench and adjacent abyssal plain. Deep-Sea Res. II (2014), http://dx.doi.org/10.1016/j.dsr2.2014.08.011i
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well as reach new geographical regions and maintain gene flow between widely separated populations. The aim of the present paper is to re-examine and illustrate six deep-sea species of Sipuncula based on non-preserved material collected at the Kuril-Kamchatka Trench and adjacent abyssal plain. All taxonomic descriptions follow to the standard protocol for description of non-preserved specimens developed by the authors (see Adrianov and Maiorova, 2012; Maiorova and Adrianov, 2013).
2. Material and methods During the joint German/Russian deep sea expedition KuramBio (Kuril Kamchatka Biodiversity Study) on board of the R/V
“Sonne” (SO 223) to the Kuril-Kamchatka Trench and adjacent abyssal plain sipunculans were collected by giant box-corer (GKG), epibenthic sledge (EBS) and AGT (Agassiz trawl). Once the gear was back on deck and the box removed, the surface water was taken out through a 300 μm mesh size sieve and a picture of the in situ surface was taken. The subsampling process started with the upper 2 cm. This layer was carefully sieved through small sieves of 1000-, 500- and 300-μm mesh sizes in order to divide the sample into different fractions. The separated animals from both layers and the 1000 μm fraction from the upper layer were usually sorted in seawater under binocular microscopes immediately after sieving, while the other fractions were fixed and sorted later. On deck samples from the epibenthic sledge were immediately transferred into pre-cooled 96% ethanol and kept at least for 48 h in
Table 1 Station data GKG stations Station
Date
Depth (m)
Coordinates
02–04 02–05 04–04 04–05 05–05 07–04 07–05 08–04 08–05 11–05
8/2/2012 8/2/2012 8/7/2012 8/7/2012 8/10/2012 8/17/2012 8/17/2012 8/20/2012 8/20/2012 8/29/2012
4870 4869 5768 5766 5378 5222 5225 5130 5129 5350
46114.01300 N 155133.07730 E 46114.02100 N 155133.06400 E 46158.01410 N 154132.46870 E 46158.01410 N 154132.46870 E 43134.97200 N 153158.01170 E 43102.32300 N 152159.09970 E 43102.04900 N 152159.11280 E 42114.60700 N 151143.4930E 42114.61910 N 151143.62310 E 40112.00000 N 148106.00000 E
Date 7/30/2012 7/30/2012 8/3/2012 8/3/2012 8/5/2012 8/7/2012 8/11/2012 8/11/2012 8/15/2012 8/15/2012 8/17/2012 8/17/2012 8/20/2012 8/21/2012 8/23/2012 8/24/2012 8/26/2012 8/27/2012 8/29/2012 8/31/2012 8/31/2012
Depth (m) 5423–5429 5418–5419 4830–4863 4859–4865 4987–4991 5681–5780 5376–5380 5375–5378 5305–5305 5304–5307 5222–5223 5223–5221 5125–5126 5127–5124 5399–5421 5399–5392 5264–5266 5245–5262 5263–5362 5350–5348 5224–5215
Haul start 43158.350 N 157118.230 E 43158.440 N 157118.290 E 46114.780 N 155132.630 E 46114.770 N 155132.790 E 47114.660 N 154142,880 E 46158.340 N 154133.030 E 43134.460 N 153158.130 E 43134.440 N 153158.060 E 42128.610 N 153159.680 E 42128.490 N 153159.540 E 43101.780 N 152158.610 E 43101.820 N 152158.550 E 42114.320 N 151142.680 E 42114.380 N 151143.120 E 40134.510 N 150159.920 E 40134.490 N 150159.850 E 41111.370 N 150105.630 E 41112.800 N 15016.1620 E 40112.490 N 148105.400 E 40112.320 N 148105.730 E 39142.781N 147109.550 E
Haul end 43158.330 N 157117.970 E 43158.610 N 157118.130 E 46114.920 N 155132.570 E 46114.990 N 155132,620 E 47114.760 N 154143.030 E 46158.460 N 154133.390 E 43134.300 N 153158.160 E 43134.190 N 153158.140 E 42128.470 N 153159.660 E 42128.220 N 153159.710 E 43101.490 N 152158.360 E 43101.660 N 152158.450 E 42114.270 N 151142.490 E 42114.320 N 151142.940 E 40134.250 N 150159.910 E 40134.280 N 150159.180 E 41111.170 N 150105.600 E 41113.010 N 150105.650 E 40112.370 N 148105.430 E 40112.100 N 148105.530 E 39142.490 N 147109.370 E
Date 30.07.2012 7/31/2012 8/3/2012 8/5/2012 8/12/2012 8/12/2012 8/14/2012 8/14/2012 8/18/2012 8/18/2012 8/20/2012 8/21/2012 8/24/2012 8/24/2012 8/27/2012 8/27/2012 8/30/2012 8/30/2012 9/1/2012
Depth (m) 5422–5379 5427–5425 4869–4861 4977–4986 5378–5379 5379–5379 5293–5307 5295–5299 5218–5222 5222–5222 5124–5125 5121–5126 5406–5404 5401–5404 5258–5249 5257–5236 5348–5347 5349–5352 5229–5217
Haul start 43158.190 N 157119.110 E 43158.360 N 157115.700 E 46113.690 N 155133.290 E 47114.270 N 154142.170 E 43135.670 N 153157.930 E 43135.910 N 153157.940 E 42129.250 N 154100.050 E 42129.000 N 154100.090 E 43102.660 N 152159.460 E 43102.560 N 152159.480 E 42114.760 N 151143.850 E 42114.740 N 151143.530 E 40136.130 N 151100.070 E 40135.120 N 151100.150 E 41112.820 N 150105.760 E 41112.040 N 150105.870 E 40113.330 N 148106.480 E 40113.550 N 148106.770 E 39143.470 N 147110.110 E
Haul end 43157.810 N 157121.580 E 43158.260 N 157114.600 E 46114.870 N 155132.490 E 47114.940 N 154143.180 E 43134.750 N 153158.120 E 43134.720 N 153158.280 E 42128.320 N 153159.730 E 42127.880 N 154100.320 E 43101.570 N 152158.590 E 43101.460 N 152158.620 E 42114.460 N 151142.760 E 42114.400 N 151142.320 E 40135.310 N 151100.120 E 40134.440 N 151100.150 E 41111.750 N 150105.810 E 41110.780 N 150106.340 E 40112.530 N 148105.760 E 40112.900 N 148106.200 E 39142.540 N 147109.510 E
EBS stations Station 01–10 01–11 02–09 02–10 03–09 04–03 05–09 05–10 06–11 06–12 07–09 07–10 08–09 08–12 09–09 09–12 10–09 10–12 11–09 11–12 12–04 AGT stations Station 01–12 01–13 02–11 03–10 05–11 05–12 06–09 06–10 07–11 07–12 08–10 08–11 09–10 09–11 10–10 10–11 11–10 11–11 12–05
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20 1C for DNA studies or into formaldehyde (4%) at each second deployment per station. The AGT, once the samples arrive on deck, larger animals were handpicked and immediately transferred to the laboratories, measured and photographed and fixed in pre-cooled 96% ethanol or into formaldehyde (4%) at each second deployment per station. Sediment (and inhabiting smaller animals) was prior to lab handling carefully flushed with running sea water through meshes of 1000, 500 and 300 mm. Only sieve remains above 1000 mm were additionally sorted in the lab, while those of the 500 and 300 mm meshes were immediately fixed. Stations data present in Table 1. Photographs of non-preserved worms were taken on deck with a Canon 550D for illustration of the tentacular apparatus (if possible) and live coloration of the body and introvert. Representatives of all species were examined for internal morphology and species identification. Preparations of papillae and introvert hooks were mounted for all species possessing these structures. Sipunculans were examined using a light (Imager Z2 (Zeiss) with differential interference contrast (DIC)) and scanning electron microscope (SEM) (EVO 40 (Zeiss)). Species accounts include quantitative characteristics and specific biotope data. Systematics of the Sipuncula refers to Cutler (1994).
3. Results Phylum Sipuncula Linnaeus, 1766 Class Sipunculidea E. Cutler and Gibbs, 1985 Order Golfingiiformes E. Cutler and Gibbs, 1985 Family Golfingiidae Stephen and Edmonds, 1972 Genus Golfingia Lankester, 1885 Subgenus Golfingia (Golfingia) Lankester, 1885 Golfingia muricaudata (Southern, 1913) Fig. 1A–C. Material. 1–12 AGT, 2 specimens; 1–13 AGT, 3 specimens; 2–5 GKG, 1 specimen; 2–10 AGT, 1 specimen; 4–3 EBS, 5 specimens; 5–9 EBS-S, 5 specimens; 6–9 AGT, 2 specimens; 7–9 EBS, 1 specimen; 7–10 EBS, 8 specimens; 8–9 EBS, 8 specimens; 9–9 EBS, 4 specimens; 9–10 AGT 1 specimen; 9–11 AGT, 2 specimens; 10–10 AGT, 1 specimen; 10–12 EBS, 5 specimens; 11–9 EBS, 3 specimens; 11–10 AGT, 1 specimen; 11–11 AGT, 1 specimen. Description. Trunk elongated, cylindrical, with nipple like tail, 10–70 mm in length and 2–9 mm in width; introvert as long as trunk, with few 8–10 short transparent non-pigmented tentacles, arranged in a single ring around the mouth. Two reddish eyespots are visible. Anterior introvert with highly packed large papillae, small hooks (20 mm) observed only in specimens with trunk length less 5 mm. Trunk is whitish or yellowish, semitransparent,
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lustrous; minute skin bodies randomly distributed. Posteriormost trunk with wrinkled area, tail (20% of trunk length) and minute tall papillae. Ventral retractor muscles originate at about 20–21% of trunk length to posterior end; dorsal retractor muscles originate at about 8–9% of trunk length to posterior end. Contractile vessel simple. Rectal caecum present. Gut with 12–20 loops, spindle muscle not attached posteriorly. Nephridia are dark brown, smooth, unattached to the body wall, about 9–13% of trunk length, open at 3–6% of trunk length posterior to the anus. Discussion. Golfingia muricaudata differs well from all other congeners by presence of tail appendage. Only other representative of Golfingia with tail appendage, G. anderssoni is well distinguished from G. muricaudata by having of distinctive large papillae covering an area about 65–90% of the distance toward the posterior end of the trunk. Distribution. Common deep water species found in Atlantic, Indian and Pacific oceans. In the North Pacific, it has been reported from British Columbia, around the Bering Sea, to Japan, at depths from 85 to 6860 m. Genus Nephasoma Pergament, 1940 Nephasoma cf. abyssorum (Koren and Danielssen, 1875) Fig. 2A–C. Material. 2–4 GKG, 5 specimens; 2–5 GKG, 3 specimens; 2–9 EBS, 19 specimens; 2–10 EBS, 4 specimens. Description. Trunk cylindrical, 10–30 mm in length and 3–10 mm in diameter; introvert shorter than trunk (1/3–1/2 of the trunk length); anterior pseudoshield present. The whitish or opaque skin on the introvert and trunk smooth, without prominent papillae. One row of short non-pigmented tentacles presents around the mouth. Tall and sharp dark hooks (100 mm) scattered over the introvert. The thick ventral retractors originate in the middle of trunk (50–55% of the distance to the posterior end). Intestine is a tightly coiled in a double spiral with 16–18 coils; spindle muscle is very weakly developed. No gut-fixing muscles have been seen; rectal caecum present. Nephridia are brown, not attached to the body wall, length about 15–20% of the trunk length to the posterior end. Nephrodiopores open at the anus level. The species is dioecious. Discussion.These specimens classified as N. cf. abyssorum differs from other deep water congeners of Nephasoma bfrom the North West Pacific (N. diaphanes, N. corrugatum, N. lilljeborgi) by presence of well developed tentacles while other species of the genus are characterized by tentacular apparatus with ciliary lobes only. According to Cutler (1994), N. abyssorum possess unique spirally arrangement of hooks that is not evident in our specimens. Distribution. Common deep water species found in Atlantic, Arctic Ocean and North West Pacific at the depth from 500 to 5300 m.
Fig. 1. (A) Golfingia muricaudata: a lateral view of a specimen with introvert retracted. (B) G. muricaudata: a lateral view of a specimen with introvert retracted. (C) G. muricaudata introvert papillae (DIC). Abbreviations: ta, tail. Scale bars: (A) 8 mm; (B) 8 mm; and (C) 50 mm.
Please cite this article as: Maiorova, A.S., Adrianov, A.V., Deep-sea sipunculans from the Kuril-Kamchatka trench and adjacent abyssal plain. Deep-Sea Res. II (2014), http://dx.doi.org/10.1016/j.dsr2.2014.08.011i
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Nephasoma cf. diaphanes (Gerould, 1913) Fig. 2D–G. Material. 1–10 EBS, 1 specimen; 3–10 AGT, 2 specimens; 3–9 EBS, 10 specimens; 4–4 GKG, 2 specimens; 4–5 GKG, 2 specimens; 5–5 GKG, 3 specimens; 5–9 EBS, 9 specimens; 6–10 AGT, 10 specimens; 6–11 EBS, 3 specimens; 7–9 EBS, 5 specimens; 7–10 EBS, 8 specimens; 8–5 GKG, 1 specimen; 8–10 AGT, 7 specimen; 8– 12 EBS, 8 specimens; 9–9 EBS, 2 specimens; 9–10 AGT, 1 specimen; 9–12 EBS, 1 specimen; 10–5 GKG, 1 specimen; 10–9 EBS, 2 specimens; 10–12 EBS, 1 specimen; 11–5 GKG, 1 specimen; 11–9 EBS, 5 specimens; 11–11 AGT, 1 specimen; 11–12 EBS, 2 specimens.
Description. Trunk cylindrical in shape, 2–30 mm in length and 0.5–4 mm in diameter. Introvert as long as trunk. The whitish, opaque body or brown body is smooth, with only small skin bodies, but worms that were occupied foraminifera tubes had randomly distributed brown papillae. One row of short nonpigmented tentacular lobes around mouth present. Small scattered hooks (25–30 mm) on introvert. Body wall musculature continuous. The ventral retractors originate 50–70% of the distance to the posterior end. The gut is a helix with 15–30 coils, spindle muscle not found. Caecum present. The nephridia not attached to the
Fig. 2. (A) Nephasoma cf. abyssorum: a lateral view of a specimen in sheath with retracted introvert. (B) N. cf. abyssorum: a lateral view of a specimen with retracted introvert. (C) N. cf. abyssorum hooks (DIC). (D) Nephasoma cf. corrugatum: a lateral view of a specimen with retracted introvert. (E) N. cf. corrugatum: a lateral view of a specimen with retracted introvert. (F) N. cf. corrugatum: a lateral view of a specimen with everted introvert. (G) N. cf. corrugatum hook (DIC). (H) Nephasoma cf. diaphanes: a lateral view of a specimen with retracted introvert and mature eggs in the posterior part of trunk (DIC). (I) N. cf. diaphanes trunk papillae (DIC). (J) N. cf. diaphanes hook (DIC). Scale bars: (A) 10 mm; (B) 10 mm; (C) 50 mm; (D) 3 mm; (E) 5 mm; (F) 3 mm; (G) 20 mm; (H) 3 mm; and (I–J), 20 mm.
Please cite this article as: Maiorova, A.S., Adrianov, A.V., Deep-sea sipunculans from the Kuril-Kamchatka trench and adjacent abyssal plain. Deep-Sea Res. II (2014), http://dx.doi.org/10.1016/j.dsr2.2014.08.011i
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Fig. 3. (A) Phascolion lutense: a lateral view of a specimen in a tub with introvert retracted. (B) P. lutense: a lateral view of a specimen in with introvert retracted. (C) P. lutense hooks (DIC). (D) P. lutense papillae at anterior part of trunk (DIC). (E) P. lutense regular trunk papilla (DIC). (F) P. lutense trunk papillae with cuticular edge (DIC). (G) P. lutense large trunk papillae with cuticular edge (DIC). (H) P. lutense papilla at posterior part of trunk (DIC). (I) Phascolion pacificum: a lateral view of a specimen with retracted introvert. (J) P. pacificum hooks (DIC). (K) P. pacificum papillae at anterior part of trunk (DIC). (L) P. pacificum at posterior part of trunk (DIC). (M) P. pacificum regular trunk papilla(DIC). (N) P. pacificum holdfast papilla (DIC). (O) P. pacificum papillae at anterior part of trunk (SEM). (P) P. pacificum papillae at posterior part of trunk (SEM). (Q) P. pacificum regular trunk papilla (SEM). (R) P. pacificum holdfast papilla (SEM). Scale bars: (A) 20 mm; (B) 20 mm; (C) 100 mm; (D) 100 mm; (E) 100 mm; (F) 50 mm; (G) 100 mm; (H) 50 mm; (I) 30 mm; (J) 20 mm; (K) 50 mm; (L) 100 mm; (M) 50 mm; (N)50 mm; (O) 30 mm; (P) mm; (Q) 50 mm; and (R) 50 mm.
Please cite this article as: Maiorova, A.S., Adrianov, A.V., Deep-sea sipunculans from the Kuril-Kamchatka trench and adjacent abyssal plain. Deep-Sea Res. II (2014), http://dx.doi.org/10.1016/j.dsr2.2014.08.011i
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body wall, brown, short (only 9–10% of the distance to the posterior end). Nephrodiopores open at the anus level. Discussion. This species differs from other congeners by a combination of characters: transparent body wall, absence of tentacles, presence of small scattered hooks, attachment retractor muscles at the middle third of trunk length. Distribution. This cosmopolitan species is the most common sipunculan in deep-sea communities, found from bathyal to abyssal depth (down to 5300 m). Nephasoma cf. corrugatum N. Cutler and Cutler, 1986 Fig. 2H–J. Material. 3–10 AGT, 2 specimens; 6–9 AGT, 1 specimen; 6–10 AGT, 1 specimen; 7–4 GKG, 1 specimen; 8–4 GKG, 1 specimen; 8– 10 AGT, 1 specimen; 8–11 AGT, 5 specimen; 9–12 EBS, 1 specimen; 10–12 EBS, 1 specimen; 11–11 AGT, 1 specimen; 11–12 EBS, 1 specimens; 12–4 EBS, 2 specimens. Description. Trunk cylindrical to pyriform in shape, 2–15 mm in length and 0.5–3 mm in diameter. Introvert as long as trunk. The greyish, translucent body with irregular, zigzag, longitudinal epidermal ridges on the introvert base, the anterior and posterior parts of the trunk. One row of short non-pigmented tentacular lobes around mouth present. Small scattered hooks (30 mm in height) on introvert. Body wall musculature continuous. The ventral retractors originate 50–70% of the distance to the posterior end. The gut is a helix with 15–20 coils, spindle muscle not found. Caecum present. The nephridia not attached to the body wall, brown, short (only 9–10% of the distance to the posterior end). Nephrodiopores open at the anus level. Discussion. This species is well distinguished from other congeners by presence of zigzag cuticular ridges on the nearly pyriform body. Distribution. Common species in Atlantic and Pacific oceans, found from 80 to 5900 m depth. Family Phascolionidae E. Cutler and Gibbs, 1985 Genus Phascolion Théel, 1875 Subgenus Phascolion (Montuga) Gibbs, 1985 Phascolion lutense Selenka, 1885 Fig. 3A–H Material. 3–9 EBS, 1 specimen; 3–10 AGT, 5 specimens; 4– 3EBS, 5 specimens; 6–9 AGT, 13 specimens; 6–10 AGT, 4 specimens; 8–12 EBS, 1 specimen; 12–5 AGT, 1 specimen. Description. Trunk cylindrical and opaque, 10–50 mm in length and 3–12 mm in diameter. Often inhabit own tubes, composed of mud, clay and mucous. Introvert usually as long as trunk, but may stretch twice. Tentacles present only as short non-pigmented folds around mouth. Hooks present on distal part of the introvert, but ill-define in rough cuticle (50–70 mm in height).Tall brown papillae at anterior end (105–130 mmin height and 50–60 mm in diameter). Tall brown papillae at posterior end (100–110 mm in height and 45–50 mm in diameter).Flat rounded or elliptical papillae without hardened edge randomly distributed over trunk (400 mm outer border, inner part 140 mm).Body wall musculature continuous. Ventral nerve cord ends before the posterior end (3/4 of trunk length). Single large left brown-purple nephridium opens at anus level and not attached to body wall. Length of nephridium 50% of trunk length. Small pore present on right side. Contractile vessel very short, only on attached part of esophagus. Esophagus attached to retractor muscles before caecum. Esophagus runs to posteriormost trunk and attached to the body end by several fixing muscles; gut coil runs upward. Rectal caecum attached with wide fix muscle to posterior end of the trunk. Spindle muscle situated only in gut coil. Retractor muscles originate at 95% to the posterior end of the trunk, fused in column with three or four separate unequal origins. Discussion. This species is differs from only other representative of the subgenus Montuga, P. pacificum, by the absence or holdfast papillae. Specimens of P. lutense bears unique flattened papillae with rounded sclerotized margin, absent in other. Both
these species are well distinguished from all other species of Phascolion by fused retractor column divided only at posterior end. Distribution. Deep water species common in Atlantic, Indian and Pacific oceans in both hemispheres; found from 1800 to 6860 m depth. Phascolion pacificum Murina, 1957 Fig. 3I–R. Material. 1–12 AGT, 1 specimen; 3–9 EBS, 1 specimen; 3–10 AGT, 14 specimens; 4–3EBS, 3 specimens; 6–9 AGT, 1 specimen; 7– 5 GKG, 1 specimen; 7–7 AGT, 1 specimen; 8–11 AGT, 1 specimen; 12–4 EBS, 1 specimen. Description. Tall conical brown papillae present at anterior and posterior ends of trunk. Introvert with dark conical papillae in proximal part. Trunk cylindrical, translucent to opaque, 5–25 mm in length and 1–7 mm in diameter. Often inhabit foraminifera tubes. Introvert usually as long as trunk, but may stretch more. Rounded or elliptical papillae with hardened edge randomly distributed over trunk (50–60 mm in diameter and 45–50 mm in height). Tentacles present only as short non-pigmented folds around mouth. Hooks present (30–35 mm). Continuous body wall musculature. Ventral nerve cord ends at the 3/4 of trunk length. Single (left) medium sized brown-purple nephridium opens at the anus level and not attached to the body wall. Length of nephridium about 30% of the trunk length. Contractile vessel very short, situated only on esophagus at the part attached to retractor muscles. Esophagus attached to retractor muscles on most of it length. Esophagus attached to retractor muscles before caecum. Esophagus runs to posteriormost trunk and attached to the body end by several fixing muscles; gut coil runs upward. Rectal caecum attached with wide fix muscle to posterior end of the trunk. Spindle muscle situated only in gut coil. Retractor muscles originate at 95% to the posterior end of the trunk, fused in column with one, two or three separate unequal origins. Discussion. This species is well distinguished from P. lutense by the presence of holdfast papillae. Distribution. This species is described from Japanese and Kurile-Kamchatka Trench; it is a widespread species found from bathyal to abyssal depth (300–6860 m) in Atlantic, Indian and Pacific oceans. Nephasoma cf. diaphanes was the most abundant representative of sipunculans in the Kuril-Kamchatka Trench and adjacent abyssal plain and it was found at most stations of the KURAMBIO expedition. Stations #6 and #8 demonstrated the highest diversity of sipunculans and five of six KURAMBIO species were recorded from those stations. Acknowledgments We acknowledge the financial support of the PTJ (German Ministry for Science and Education), Grant 03G0223A to Angelika Brandt. The authors gratefully acknowledge the support of the Russian Scientific Foundation (Grant 14–14–00232). We also thank Angelika Brandt as chief scientist of the KURAMBIO cruise and Marina Maluytina for the coordination with the Russian government. In addition, we express our gratitude to two anonymous reviewers for valuable comments that improved an earlier version of this manuscript. This is KuramBio publication #23″. References Adrianov, A.V., Maiorova, A.S., 2012. Peanut worms of the phylum Sipuncula from the NhaTrang Bay (South China Sea) with a key to the species. Zootaxa 3166, 41–58. Cutler, E.B., 1994. The Sipuncula: Their Systematics, Biology and Evolution. Cornell University, New York (453 p.). Maiorova, A.S., Adrianov, A.V., 2013. Peanut worms of the phylum Sipuncula from the Sea of Japan with a key to species. Deep-Sea Res. Part II: Top. Stud. Oceanogr., 140–147.
Please cite this article as: Maiorova, A.S., Adrianov, A.V., Deep-sea sipunculans from the Kuril-Kamchatka trench and adjacent abyssal plain. Deep-Sea Res. II (2014), http://dx.doi.org/10.1016/j.dsr2.2014.08.011i
A.S. Maiorova, A.V. Adrianov / Deep-Sea Research II ∎ (∎∎∎∎) ∎∎∎–∎∎∎ Murina, V.V., 1957. Abyssal sipunculids (genus Phascolion Theel) of the northwestern part of the Pacific collected by Vitjaz expeditions in 1950–1955. Zool. Zhurnal 36 (2), 777–779. Murina, V.V., 1961. On the geographic distribution of the abyssal sipunculid Phascolion lutense. Okeanologii (Acad. Nauk SSSR) 1, 140–142. Murina, V.V., 1971. On the occurrence of deep-sea sipunculids and priapulids in the Kuril-Kamchatka Trench. Trudy Inst. Okeanol. Akad. Nauk SSSR 92, 41–45. Murina, V.V., 1973. The fauna of sipunculids from the Peruvian-Chilean Trench. Zool. Zhurnal 5, 66–71.
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Selenka, E., 1885. Report on the Gephyrea collected by H.M.S. Challenger during 1873–76. Report of Scientific Results of the Voyage of Challenger Zoology, vol. 13, pp. 1–25. Theel, H., 1911. Priapulids and Sipunculids dredged by the Swedish Antarctic Expedition 1901-1903 and the phenomenon of bipolarity. Kungliga Svenska Vetenskaps-Akad. Handlingar 47, 3–36.
Please cite this article as: Maiorova, A.S., Adrianov, A.V., Deep-sea sipunculans from the Kuril-Kamchatka trench and adjacent abyssal plain. Deep-Sea Res. II (2014), http://dx.doi.org/10.1016/j.dsr2.2014.08.011i
Contents lists available at ScienceDirect
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Deep-sea sipunculans from the Kuril-Kamchatka trench and adjacent abyssal plain Anastassya S. Maiorova a,b,n, Andrey V. Adrianov a,b,c a
A.V. Zhirmunsky Institute of Marine Biology, Far Eastern Branch of Russian Academy of Sciences, Vladivostok 690041, Russia Far Eastern Federal University, Vladivostok 690950, Russia c Far Eastern Aquarium, Far Eastern Branch of Russian Academy of Sciences, Vladivostok, Russia b
art ic l e i nf o
Keywords: Sipuncula Deep-sea Golfingia Nephasoma Phascolion
a b s t r a c t Deep-sea sipunculans collected during the expedition to the Kuril-Kamchatka Trench and adjacent abyssal plain are described and illustrated using differential interference contrast microscopy (DIC) and scanning electron microscopy (SEM). Specimens were sorted from brown silt collected by giant boxcorer (GKG), epibenthic sledge (EBS) and Agassiz trawl (AGT) from the depths 4830–5780 m. Within about 150 valid species of sipunculans only 15 have been known to be abyssal and six of them were found and identified in this KURAMBIO expedition. Eight species of sipunculans have been previously recorded from the Kuril-Kamchatka region but all of them were described based on preserved museum's material collected by bottom dredge and these descriptions are far from to be complete and comparable with other samplings. All KURAMBIO species are described according to a unified protocol to illustrate the most important taxonomic characters. This is the first description and illustrating of abyssal sipunculans in live condition with natural coloration of non-preserved specimens. Abyssal species were for a first time described with SEM facilities and according to a standardized protocol. For a first time for abyssal sipunculans, species accounts also include quantitative characteristics, distribution and specific biotope data. Nephasoma abyssorum is reported for the Kuril-Kamchatka Trench and adjacent abyssal plain for a first time. & 2014 Elsevier Ltd. All rights reserved.
1. Introduction The current knowledge on North West Pacific deep-sea sipunculans is only based on the results of several Russian cruises of R/V “Vitjaz” to the Kuril-Kamchatka and Japanese Trenches. These samples of deep sea sipunculans were examined and described by Murina (1971). She has also described several new deep-sea species from other deep sea localities in the Pacific and firstly illustrated phenomenon of bipolarity for Phascolion lutense (see Murina, 1961, 1971, 1973). Eight species representing three genera of sipunculans have been recorded for the Kuril-Kamchatka Trench and adjacent abyssal plain so far. Most of these species were described based on the preserved material collected by bottom dredge and the descriptions are far from to be complete. About 30 species of sipunculans were found at abyssal depths (below 3000 m). Some eurybathic species are found between 10 and 4000 m over a wide range of temperatures but some species
n Corresponding author at: A.V. Zhirmunsky Institute of Marine Biology, Far Eastern Branch of Russian Academy of Sciences, Vladivostok 690041, Russia. E-mail address: [email protected] (A.S. Maiorova).
are restricted to cold water deeper than 3000 m and never found above this isobath. At least 15 species are known from the depth below 5000 m: Golfingia anderssoni (Theel, 1911); G. margaritacea (Sars, 1851); G. muricaudata (Southern, 1913); G. vulgaris (de Blainville, 1827); Nephasoma abyssorum (Koren and Danielssen, 1875); N. capilleforme (Murina, 1973); N. corrugatum N. Cutler et Cutler, 1986; N. diaphanes diaphanes (Gerould, 1913); N. flagriferum (Selenka, 1885); N. minutum (Keferstein, 1862); N. schuettei (Augener, 1903); Phascolion lutense Selenka, 1885; P. pacificum Murina, 1957; Onchnesoma magnibatha Cutler, 1969; Apionsoma murinae (Cutler, 1969) (see Cutler, 1994). Some species are common even at the hadal depth (more than 6000 m) (Nephasoma minutum, Golfingia muricaudata, G. anderssoni, Phascolion lutense, P. pacificum), but it should be emphasized that the hadal zone has no endemic species. Contrary to shallow water species, nothing is still known about the development of abyssal sipunculans, their larval stages, life history and population biology. Because the absence of endemic abyssal species the deep-sea fauna of sipunculans appears to be relatively young and is formed as a result of migration of some eurybathic species to a great depth. Probably, the dispersal of long-lived pelagosphera larvae by ocean currents also allows sipunculans recolonize ocean depths as
http://dx.doi.org/10.1016/j.dsr2.2014.08.011 0967-0645/& 2014 Elsevier Ltd. All rights reserved.
Please cite this article as: Maiorova, A.S., Adrianov, A.V., Deep-sea sipunculans from the Kuril-Kamchatka trench and adjacent abyssal plain. Deep-Sea Res. II (2014), http://dx.doi.org/10.1016/j.dsr2.2014.08.011i
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well as reach new geographical regions and maintain gene flow between widely separated populations. The aim of the present paper is to re-examine and illustrate six deep-sea species of Sipuncula based on non-preserved material collected at the Kuril-Kamchatka Trench and adjacent abyssal plain. All taxonomic descriptions follow to the standard protocol for description of non-preserved specimens developed by the authors (see Adrianov and Maiorova, 2012; Maiorova and Adrianov, 2013).
2. Material and methods During the joint German/Russian deep sea expedition KuramBio (Kuril Kamchatka Biodiversity Study) on board of the R/V
“Sonne” (SO 223) to the Kuril-Kamchatka Trench and adjacent abyssal plain sipunculans were collected by giant box-corer (GKG), epibenthic sledge (EBS) and AGT (Agassiz trawl). Once the gear was back on deck and the box removed, the surface water was taken out through a 300 μm mesh size sieve and a picture of the in situ surface was taken. The subsampling process started with the upper 2 cm. This layer was carefully sieved through small sieves of 1000-, 500- and 300-μm mesh sizes in order to divide the sample into different fractions. The separated animals from both layers and the 1000 μm fraction from the upper layer were usually sorted in seawater under binocular microscopes immediately after sieving, while the other fractions were fixed and sorted later. On deck samples from the epibenthic sledge were immediately transferred into pre-cooled 96% ethanol and kept at least for 48 h in
Table 1 Station data GKG stations Station
Date
Depth (m)
Coordinates
02–04 02–05 04–04 04–05 05–05 07–04 07–05 08–04 08–05 11–05
8/2/2012 8/2/2012 8/7/2012 8/7/2012 8/10/2012 8/17/2012 8/17/2012 8/20/2012 8/20/2012 8/29/2012
4870 4869 5768 5766 5378 5222 5225 5130 5129 5350
46114.01300 N 155133.07730 E 46114.02100 N 155133.06400 E 46158.01410 N 154132.46870 E 46158.01410 N 154132.46870 E 43134.97200 N 153158.01170 E 43102.32300 N 152159.09970 E 43102.04900 N 152159.11280 E 42114.60700 N 151143.4930E 42114.61910 N 151143.62310 E 40112.00000 N 148106.00000 E
Date 7/30/2012 7/30/2012 8/3/2012 8/3/2012 8/5/2012 8/7/2012 8/11/2012 8/11/2012 8/15/2012 8/15/2012 8/17/2012 8/17/2012 8/20/2012 8/21/2012 8/23/2012 8/24/2012 8/26/2012 8/27/2012 8/29/2012 8/31/2012 8/31/2012
Depth (m) 5423–5429 5418–5419 4830–4863 4859–4865 4987–4991 5681–5780 5376–5380 5375–5378 5305–5305 5304–5307 5222–5223 5223–5221 5125–5126 5127–5124 5399–5421 5399–5392 5264–5266 5245–5262 5263–5362 5350–5348 5224–5215
Haul start 43158.350 N 157118.230 E 43158.440 N 157118.290 E 46114.780 N 155132.630 E 46114.770 N 155132.790 E 47114.660 N 154142,880 E 46158.340 N 154133.030 E 43134.460 N 153158.130 E 43134.440 N 153158.060 E 42128.610 N 153159.680 E 42128.490 N 153159.540 E 43101.780 N 152158.610 E 43101.820 N 152158.550 E 42114.320 N 151142.680 E 42114.380 N 151143.120 E 40134.510 N 150159.920 E 40134.490 N 150159.850 E 41111.370 N 150105.630 E 41112.800 N 15016.1620 E 40112.490 N 148105.400 E 40112.320 N 148105.730 E 39142.781N 147109.550 E
Haul end 43158.330 N 157117.970 E 43158.610 N 157118.130 E 46114.920 N 155132.570 E 46114.990 N 155132,620 E 47114.760 N 154143.030 E 46158.460 N 154133.390 E 43134.300 N 153158.160 E 43134.190 N 153158.140 E 42128.470 N 153159.660 E 42128.220 N 153159.710 E 43101.490 N 152158.360 E 43101.660 N 152158.450 E 42114.270 N 151142.490 E 42114.320 N 151142.940 E 40134.250 N 150159.910 E 40134.280 N 150159.180 E 41111.170 N 150105.600 E 41113.010 N 150105.650 E 40112.370 N 148105.430 E 40112.100 N 148105.530 E 39142.490 N 147109.370 E
Date 30.07.2012 7/31/2012 8/3/2012 8/5/2012 8/12/2012 8/12/2012 8/14/2012 8/14/2012 8/18/2012 8/18/2012 8/20/2012 8/21/2012 8/24/2012 8/24/2012 8/27/2012 8/27/2012 8/30/2012 8/30/2012 9/1/2012
Depth (m) 5422–5379 5427–5425 4869–4861 4977–4986 5378–5379 5379–5379 5293–5307 5295–5299 5218–5222 5222–5222 5124–5125 5121–5126 5406–5404 5401–5404 5258–5249 5257–5236 5348–5347 5349–5352 5229–5217
Haul start 43158.190 N 157119.110 E 43158.360 N 157115.700 E 46113.690 N 155133.290 E 47114.270 N 154142.170 E 43135.670 N 153157.930 E 43135.910 N 153157.940 E 42129.250 N 154100.050 E 42129.000 N 154100.090 E 43102.660 N 152159.460 E 43102.560 N 152159.480 E 42114.760 N 151143.850 E 42114.740 N 151143.530 E 40136.130 N 151100.070 E 40135.120 N 151100.150 E 41112.820 N 150105.760 E 41112.040 N 150105.870 E 40113.330 N 148106.480 E 40113.550 N 148106.770 E 39143.470 N 147110.110 E
Haul end 43157.810 N 157121.580 E 43158.260 N 157114.600 E 46114.870 N 155132.490 E 47114.940 N 154143.180 E 43134.750 N 153158.120 E 43134.720 N 153158.280 E 42128.320 N 153159.730 E 42127.880 N 154100.320 E 43101.570 N 152158.590 E 43101.460 N 152158.620 E 42114.460 N 151142.760 E 42114.400 N 151142.320 E 40135.310 N 151100.120 E 40134.440 N 151100.150 E 41111.750 N 150105.810 E 41110.780 N 150106.340 E 40112.530 N 148105.760 E 40112.900 N 148106.200 E 39142.540 N 147109.510 E
EBS stations Station 01–10 01–11 02–09 02–10 03–09 04–03 05–09 05–10 06–11 06–12 07–09 07–10 08–09 08–12 09–09 09–12 10–09 10–12 11–09 11–12 12–04 AGT stations Station 01–12 01–13 02–11 03–10 05–11 05–12 06–09 06–10 07–11 07–12 08–10 08–11 09–10 09–11 10–10 10–11 11–10 11–11 12–05
A.S. Maiorova, A.V. Adrianov / Deep-Sea Research II ∎ (∎∎∎∎) ∎∎∎–∎∎∎
20 1C for DNA studies or into formaldehyde (4%) at each second deployment per station. The AGT, once the samples arrive on deck, larger animals were handpicked and immediately transferred to the laboratories, measured and photographed and fixed in pre-cooled 96% ethanol or into formaldehyde (4%) at each second deployment per station. Sediment (and inhabiting smaller animals) was prior to lab handling carefully flushed with running sea water through meshes of 1000, 500 and 300 mm. Only sieve remains above 1000 mm were additionally sorted in the lab, while those of the 500 and 300 mm meshes were immediately fixed. Stations data present in Table 1. Photographs of non-preserved worms were taken on deck with a Canon 550D for illustration of the tentacular apparatus (if possible) and live coloration of the body and introvert. Representatives of all species were examined for internal morphology and species identification. Preparations of papillae and introvert hooks were mounted for all species possessing these structures. Sipunculans were examined using a light (Imager Z2 (Zeiss) with differential interference contrast (DIC)) and scanning electron microscope (SEM) (EVO 40 (Zeiss)). Species accounts include quantitative characteristics and specific biotope data. Systematics of the Sipuncula refers to Cutler (1994).
3. Results Phylum Sipuncula Linnaeus, 1766 Class Sipunculidea E. Cutler and Gibbs, 1985 Order Golfingiiformes E. Cutler and Gibbs, 1985 Family Golfingiidae Stephen and Edmonds, 1972 Genus Golfingia Lankester, 1885 Subgenus Golfingia (Golfingia) Lankester, 1885 Golfingia muricaudata (Southern, 1913) Fig. 1A–C. Material. 1–12 AGT, 2 specimens; 1–13 AGT, 3 specimens; 2–5 GKG, 1 specimen; 2–10 AGT, 1 specimen; 4–3 EBS, 5 specimens; 5–9 EBS-S, 5 specimens; 6–9 AGT, 2 specimens; 7–9 EBS, 1 specimen; 7–10 EBS, 8 specimens; 8–9 EBS, 8 specimens; 9–9 EBS, 4 specimens; 9–10 AGT 1 specimen; 9–11 AGT, 2 specimens; 10–10 AGT, 1 specimen; 10–12 EBS, 5 specimens; 11–9 EBS, 3 specimens; 11–10 AGT, 1 specimen; 11–11 AGT, 1 specimen. Description. Trunk elongated, cylindrical, with nipple like tail, 10–70 mm in length and 2–9 mm in width; introvert as long as trunk, with few 8–10 short transparent non-pigmented tentacles, arranged in a single ring around the mouth. Two reddish eyespots are visible. Anterior introvert with highly packed large papillae, small hooks (20 mm) observed only in specimens with trunk length less 5 mm. Trunk is whitish or yellowish, semitransparent,
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lustrous; minute skin bodies randomly distributed. Posteriormost trunk with wrinkled area, tail (20% of trunk length) and minute tall papillae. Ventral retractor muscles originate at about 20–21% of trunk length to posterior end; dorsal retractor muscles originate at about 8–9% of trunk length to posterior end. Contractile vessel simple. Rectal caecum present. Gut with 12–20 loops, spindle muscle not attached posteriorly. Nephridia are dark brown, smooth, unattached to the body wall, about 9–13% of trunk length, open at 3–6% of trunk length posterior to the anus. Discussion. Golfingia muricaudata differs well from all other congeners by presence of tail appendage. Only other representative of Golfingia with tail appendage, G. anderssoni is well distinguished from G. muricaudata by having of distinctive large papillae covering an area about 65–90% of the distance toward the posterior end of the trunk. Distribution. Common deep water species found in Atlantic, Indian and Pacific oceans. In the North Pacific, it has been reported from British Columbia, around the Bering Sea, to Japan, at depths from 85 to 6860 m. Genus Nephasoma Pergament, 1940 Nephasoma cf. abyssorum (Koren and Danielssen, 1875) Fig. 2A–C. Material. 2–4 GKG, 5 specimens; 2–5 GKG, 3 specimens; 2–9 EBS, 19 specimens; 2–10 EBS, 4 specimens. Description. Trunk cylindrical, 10–30 mm in length and 3–10 mm in diameter; introvert shorter than trunk (1/3–1/2 of the trunk length); anterior pseudoshield present. The whitish or opaque skin on the introvert and trunk smooth, without prominent papillae. One row of short non-pigmented tentacles presents around the mouth. Tall and sharp dark hooks (100 mm) scattered over the introvert. The thick ventral retractors originate in the middle of trunk (50–55% of the distance to the posterior end). Intestine is a tightly coiled in a double spiral with 16–18 coils; spindle muscle is very weakly developed. No gut-fixing muscles have been seen; rectal caecum present. Nephridia are brown, not attached to the body wall, length about 15–20% of the trunk length to the posterior end. Nephrodiopores open at the anus level. The species is dioecious. Discussion.These specimens classified as N. cf. abyssorum differs from other deep water congeners of Nephasoma bfrom the North West Pacific (N. diaphanes, N. corrugatum, N. lilljeborgi) by presence of well developed tentacles while other species of the genus are characterized by tentacular apparatus with ciliary lobes only. According to Cutler (1994), N. abyssorum possess unique spirally arrangement of hooks that is not evident in our specimens. Distribution. Common deep water species found in Atlantic, Arctic Ocean and North West Pacific at the depth from 500 to 5300 m.
Fig. 1. (A) Golfingia muricaudata: a lateral view of a specimen with introvert retracted. (B) G. muricaudata: a lateral view of a specimen with introvert retracted. (C) G. muricaudata introvert papillae (DIC). Abbreviations: ta, tail. Scale bars: (A) 8 mm; (B) 8 mm; and (C) 50 mm.
Please cite this article as: Maiorova, A.S., Adrianov, A.V., Deep-sea sipunculans from the Kuril-Kamchatka trench and adjacent abyssal plain. Deep-Sea Res. II (2014), http://dx.doi.org/10.1016/j.dsr2.2014.08.011i
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Nephasoma cf. diaphanes (Gerould, 1913) Fig. 2D–G. Material. 1–10 EBS, 1 specimen; 3–10 AGT, 2 specimens; 3–9 EBS, 10 specimens; 4–4 GKG, 2 specimens; 4–5 GKG, 2 specimens; 5–5 GKG, 3 specimens; 5–9 EBS, 9 specimens; 6–10 AGT, 10 specimens; 6–11 EBS, 3 specimens; 7–9 EBS, 5 specimens; 7–10 EBS, 8 specimens; 8–5 GKG, 1 specimen; 8–10 AGT, 7 specimen; 8– 12 EBS, 8 specimens; 9–9 EBS, 2 specimens; 9–10 AGT, 1 specimen; 9–12 EBS, 1 specimen; 10–5 GKG, 1 specimen; 10–9 EBS, 2 specimens; 10–12 EBS, 1 specimen; 11–5 GKG, 1 specimen; 11–9 EBS, 5 specimens; 11–11 AGT, 1 specimen; 11–12 EBS, 2 specimens.
Description. Trunk cylindrical in shape, 2–30 mm in length and 0.5–4 mm in diameter. Introvert as long as trunk. The whitish, opaque body or brown body is smooth, with only small skin bodies, but worms that were occupied foraminifera tubes had randomly distributed brown papillae. One row of short nonpigmented tentacular lobes around mouth present. Small scattered hooks (25–30 mm) on introvert. Body wall musculature continuous. The ventral retractors originate 50–70% of the distance to the posterior end. The gut is a helix with 15–30 coils, spindle muscle not found. Caecum present. The nephridia not attached to the
Fig. 2. (A) Nephasoma cf. abyssorum: a lateral view of a specimen in sheath with retracted introvert. (B) N. cf. abyssorum: a lateral view of a specimen with retracted introvert. (C) N. cf. abyssorum hooks (DIC). (D) Nephasoma cf. corrugatum: a lateral view of a specimen with retracted introvert. (E) N. cf. corrugatum: a lateral view of a specimen with retracted introvert. (F) N. cf. corrugatum: a lateral view of a specimen with everted introvert. (G) N. cf. corrugatum hook (DIC). (H) Nephasoma cf. diaphanes: a lateral view of a specimen with retracted introvert and mature eggs in the posterior part of trunk (DIC). (I) N. cf. diaphanes trunk papillae (DIC). (J) N. cf. diaphanes hook (DIC). Scale bars: (A) 10 mm; (B) 10 mm; (C) 50 mm; (D) 3 mm; (E) 5 mm; (F) 3 mm; (G) 20 mm; (H) 3 mm; and (I–J), 20 mm.
Please cite this article as: Maiorova, A.S., Adrianov, A.V., Deep-sea sipunculans from the Kuril-Kamchatka trench and adjacent abyssal plain. Deep-Sea Res. II (2014), http://dx.doi.org/10.1016/j.dsr2.2014.08.011i
A.S. Maiorova, A.V. Adrianov / Deep-Sea Research II ∎ (∎∎∎∎) ∎∎∎–∎∎∎
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Fig. 3. (A) Phascolion lutense: a lateral view of a specimen in a tub with introvert retracted. (B) P. lutense: a lateral view of a specimen in with introvert retracted. (C) P. lutense hooks (DIC). (D) P. lutense papillae at anterior part of trunk (DIC). (E) P. lutense regular trunk papilla (DIC). (F) P. lutense trunk papillae with cuticular edge (DIC). (G) P. lutense large trunk papillae with cuticular edge (DIC). (H) P. lutense papilla at posterior part of trunk (DIC). (I) Phascolion pacificum: a lateral view of a specimen with retracted introvert. (J) P. pacificum hooks (DIC). (K) P. pacificum papillae at anterior part of trunk (DIC). (L) P. pacificum at posterior part of trunk (DIC). (M) P. pacificum regular trunk papilla(DIC). (N) P. pacificum holdfast papilla (DIC). (O) P. pacificum papillae at anterior part of trunk (SEM). (P) P. pacificum papillae at posterior part of trunk (SEM). (Q) P. pacificum regular trunk papilla (SEM). (R) P. pacificum holdfast papilla (SEM). Scale bars: (A) 20 mm; (B) 20 mm; (C) 100 mm; (D) 100 mm; (E) 100 mm; (F) 50 mm; (G) 100 mm; (H) 50 mm; (I) 30 mm; (J) 20 mm; (K) 50 mm; (L) 100 mm; (M) 50 mm; (N)50 mm; (O) 30 mm; (P) mm; (Q) 50 mm; and (R) 50 mm.
Please cite this article as: Maiorova, A.S., Adrianov, A.V., Deep-sea sipunculans from the Kuril-Kamchatka trench and adjacent abyssal plain. Deep-Sea Res. II (2014), http://dx.doi.org/10.1016/j.dsr2.2014.08.011i
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A.S. Maiorova, A.V. Adrianov / Deep-Sea Research II ∎ (∎∎∎∎) ∎∎∎–∎∎∎
body wall, brown, short (only 9–10% of the distance to the posterior end). Nephrodiopores open at the anus level. Discussion. This species differs from other congeners by a combination of characters: transparent body wall, absence of tentacles, presence of small scattered hooks, attachment retractor muscles at the middle third of trunk length. Distribution. This cosmopolitan species is the most common sipunculan in deep-sea communities, found from bathyal to abyssal depth (down to 5300 m). Nephasoma cf. corrugatum N. Cutler and Cutler, 1986 Fig. 2H–J. Material. 3–10 AGT, 2 specimens; 6–9 AGT, 1 specimen; 6–10 AGT, 1 specimen; 7–4 GKG, 1 specimen; 8–4 GKG, 1 specimen; 8– 10 AGT, 1 specimen; 8–11 AGT, 5 specimen; 9–12 EBS, 1 specimen; 10–12 EBS, 1 specimen; 11–11 AGT, 1 specimen; 11–12 EBS, 1 specimens; 12–4 EBS, 2 specimens. Description. Trunk cylindrical to pyriform in shape, 2–15 mm in length and 0.5–3 mm in diameter. Introvert as long as trunk. The greyish, translucent body with irregular, zigzag, longitudinal epidermal ridges on the introvert base, the anterior and posterior parts of the trunk. One row of short non-pigmented tentacular lobes around mouth present. Small scattered hooks (30 mm in height) on introvert. Body wall musculature continuous. The ventral retractors originate 50–70% of the distance to the posterior end. The gut is a helix with 15–20 coils, spindle muscle not found. Caecum present. The nephridia not attached to the body wall, brown, short (only 9–10% of the distance to the posterior end). Nephrodiopores open at the anus level. Discussion. This species is well distinguished from other congeners by presence of zigzag cuticular ridges on the nearly pyriform body. Distribution. Common species in Atlantic and Pacific oceans, found from 80 to 5900 m depth. Family Phascolionidae E. Cutler and Gibbs, 1985 Genus Phascolion Théel, 1875 Subgenus Phascolion (Montuga) Gibbs, 1985 Phascolion lutense Selenka, 1885 Fig. 3A–H Material. 3–9 EBS, 1 specimen; 3–10 AGT, 5 specimens; 4– 3EBS, 5 specimens; 6–9 AGT, 13 specimens; 6–10 AGT, 4 specimens; 8–12 EBS, 1 specimen; 12–5 AGT, 1 specimen. Description. Trunk cylindrical and opaque, 10–50 mm in length and 3–12 mm in diameter. Often inhabit own tubes, composed of mud, clay and mucous. Introvert usually as long as trunk, but may stretch twice. Tentacles present only as short non-pigmented folds around mouth. Hooks present on distal part of the introvert, but ill-define in rough cuticle (50–70 mm in height).Tall brown papillae at anterior end (105–130 mmin height and 50–60 mm in diameter). Tall brown papillae at posterior end (100–110 mm in height and 45–50 mm in diameter).Flat rounded or elliptical papillae without hardened edge randomly distributed over trunk (400 mm outer border, inner part 140 mm).Body wall musculature continuous. Ventral nerve cord ends before the posterior end (3/4 of trunk length). Single large left brown-purple nephridium opens at anus level and not attached to body wall. Length of nephridium 50% of trunk length. Small pore present on right side. Contractile vessel very short, only on attached part of esophagus. Esophagus attached to retractor muscles before caecum. Esophagus runs to posteriormost trunk and attached to the body end by several fixing muscles; gut coil runs upward. Rectal caecum attached with wide fix muscle to posterior end of the trunk. Spindle muscle situated only in gut coil. Retractor muscles originate at 95% to the posterior end of the trunk, fused in column with three or four separate unequal origins. Discussion. This species is differs from only other representative of the subgenus Montuga, P. pacificum, by the absence or holdfast papillae. Specimens of P. lutense bears unique flattened papillae with rounded sclerotized margin, absent in other. Both
these species are well distinguished from all other species of Phascolion by fused retractor column divided only at posterior end. Distribution. Deep water species common in Atlantic, Indian and Pacific oceans in both hemispheres; found from 1800 to 6860 m depth. Phascolion pacificum Murina, 1957 Fig. 3I–R. Material. 1–12 AGT, 1 specimen; 3–9 EBS, 1 specimen; 3–10 AGT, 14 specimens; 4–3EBS, 3 specimens; 6–9 AGT, 1 specimen; 7– 5 GKG, 1 specimen; 7–7 AGT, 1 specimen; 8–11 AGT, 1 specimen; 12–4 EBS, 1 specimen. Description. Tall conical brown papillae present at anterior and posterior ends of trunk. Introvert with dark conical papillae in proximal part. Trunk cylindrical, translucent to opaque, 5–25 mm in length and 1–7 mm in diameter. Often inhabit foraminifera tubes. Introvert usually as long as trunk, but may stretch more. Rounded or elliptical papillae with hardened edge randomly distributed over trunk (50–60 mm in diameter and 45–50 mm in height). Tentacles present only as short non-pigmented folds around mouth. Hooks present (30–35 mm). Continuous body wall musculature. Ventral nerve cord ends at the 3/4 of trunk length. Single (left) medium sized brown-purple nephridium opens at the anus level and not attached to the body wall. Length of nephridium about 30% of the trunk length. Contractile vessel very short, situated only on esophagus at the part attached to retractor muscles. Esophagus attached to retractor muscles on most of it length. Esophagus attached to retractor muscles before caecum. Esophagus runs to posteriormost trunk and attached to the body end by several fixing muscles; gut coil runs upward. Rectal caecum attached with wide fix muscle to posterior end of the trunk. Spindle muscle situated only in gut coil. Retractor muscles originate at 95% to the posterior end of the trunk, fused in column with one, two or three separate unequal origins. Discussion. This species is well distinguished from P. lutense by the presence of holdfast papillae. Distribution. This species is described from Japanese and Kurile-Kamchatka Trench; it is a widespread species found from bathyal to abyssal depth (300–6860 m) in Atlantic, Indian and Pacific oceans. Nephasoma cf. diaphanes was the most abundant representative of sipunculans in the Kuril-Kamchatka Trench and adjacent abyssal plain and it was found at most stations of the KURAMBIO expedition. Stations #6 and #8 demonstrated the highest diversity of sipunculans and five of six KURAMBIO species were recorded from those stations. Acknowledgments We acknowledge the financial support of the PTJ (German Ministry for Science and Education), Grant 03G0223A to Angelika Brandt. The authors gratefully acknowledge the support of the Russian Scientific Foundation (Grant 14–14–00232). We also thank Angelika Brandt as chief scientist of the KURAMBIO cruise and Marina Maluytina for the coordination with the Russian government. In addition, we express our gratitude to two anonymous reviewers for valuable comments that improved an earlier version of this manuscript. This is KuramBio publication #23″. References Adrianov, A.V., Maiorova, A.S., 2012. Peanut worms of the phylum Sipuncula from the NhaTrang Bay (South China Sea) with a key to the species. Zootaxa 3166, 41–58. Cutler, E.B., 1994. The Sipuncula: Their Systematics, Biology and Evolution. Cornell University, New York (453 p.). Maiorova, A.S., Adrianov, A.V., 2013. Peanut worms of the phylum Sipuncula from the Sea of Japan with a key to species. Deep-Sea Res. Part II: Top. Stud. Oceanogr., 140–147.
Please cite this article as: Maiorova, A.S., Adrianov, A.V., Deep-sea sipunculans from the Kuril-Kamchatka trench and adjacent abyssal plain. Deep-Sea Res. II (2014), http://dx.doi.org/10.1016/j.dsr2.2014.08.011i
A.S. Maiorova, A.V. Adrianov / Deep-Sea Research II ∎ (∎∎∎∎) ∎∎∎–∎∎∎ Murina, V.V., 1957. Abyssal sipunculids (genus Phascolion Theel) of the northwestern part of the Pacific collected by Vitjaz expeditions in 1950–1955. Zool. Zhurnal 36 (2), 777–779. Murina, V.V., 1961. On the geographic distribution of the abyssal sipunculid Phascolion lutense. Okeanologii (Acad. Nauk SSSR) 1, 140–142. Murina, V.V., 1971. On the occurrence of deep-sea sipunculids and priapulids in the Kuril-Kamchatka Trench. Trudy Inst. Okeanol. Akad. Nauk SSSR 92, 41–45. Murina, V.V., 1973. The fauna of sipunculids from the Peruvian-Chilean Trench. Zool. Zhurnal 5, 66–71.
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Selenka, E., 1885. Report on the Gephyrea collected by H.M.S. Challenger during 1873–76. Report of Scientific Results of the Voyage of Challenger Zoology, vol. 13, pp. 1–25. Theel, H., 1911. Priapulids and Sipunculids dredged by the Swedish Antarctic Expedition 1901-1903 and the phenomenon of bipolarity. Kungliga Svenska Vetenskaps-Akad. Handlingar 47, 3–36.
Please cite this article as: Maiorova, A.S., Adrianov, A.V., Deep-sea sipunculans from the Kuril-Kamchatka trench and adjacent abyssal plain. Deep-Sea Res. II (2014), http://dx.doi.org/10.1016/j.dsr2.2014.08.011i