Pseudostichopus mollis Théel, 1886

O'Loughlin, P. Mark & Ahearn, Cynthia, 2005, A review of pygal-furrowed Synallactidae (Echinodermata: Holothuroidea), with new species from the Antarctic, Atlantic and Pacific oceans, Memoirs of Museum Victoria 62 (2), pp. 147-179 : 171-173

publication ID

https://doi.org/ 10.24199/j.mmv.2005.62.5

persistent identifier

https://treatment.plazi.org/id/116087F5-FFB0-FFFA-FC91-7E01FA631B3E

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Felipe

scientific name

Pseudostichopus mollis Théel, 1886
status

 

Pseudostichopus mollis Théel, 1886 View in CoL

Figures 1b, c View Figure 1 , 9a, e View Figure 9 , 10b, c View Figure 10 , 11e, f View Figure 11

Pseudostichopus mollis Théel, 1886: 169–170 View in CoL , pl. 10 figs 5, 6.— Ludwig, 1898: 7.— Perrier, 1902: 337–338.— Fisher, 1907: 691.— Ekman, 1925: 5, 28–36, figs 4, 5.— Ekman, 1926: 451–470, fig. Id.— Heding, 1940: 353–360.— Imaoka, 1978: table 1–1.— Imaoka, 1990: 148.— Gutt, 1991a: 147, 152, figs 3, 6, table 2.— Gutt, 1991b: 321, 324.— Thandar, 1992: 167.— Rowe, 1995: 285.— O'Loughlin, 2002: 304.

Pseudostichopus trachus Sluiter, 1901a: 15–16 View in CoL .— Sluiter, 1901b: 52–53, pl. 5 fig. 1, pl. 8 fig. 8.— Perrier, 1902: 337–338.— Fisher, 1907: 693.— Ekman, 1925: 32–36.— Savel'eva, 1941: 74.— Djakonov, 1952: 127, 129.— Baranova, 1957: 239.— Djakonov et al., 1958: 366.— Imaoka, 1978: 384.— Cherbonnier and Féral, 1981: 383, 385, fig. 16.

Pseudostichopus nudus Ohshima, 1915: 230 View in CoL .— Ekman, 1925: 32–36.— Heding, 1940: 353–359.— Djakonov et al., 1958: 367.— Rowe, 1995: 285 (as junior synonym of Pseudostichopus pustulosus ; non Pseudostichopus pustulosus Sluiter, 1901 ; new synonym).

Pseudostichopus (Trachostichopus) trachus View in CoL .— Heding, 1940: 353–362, fig. 17.— Imaoka, 1978: table 1–2.— Thandar, 1992: 166.

Pseudostichopus (Pseudostichopus) dilatorbis Imaoka, 1978: 378–380 , 384, fig. 1 A–E, table 1–1 (part; paratypes non P. dilatorbis ; new synonym).

Pseudostichopus (Pseudostichopus) alatus Imaoka, 1990: 146–148 View in CoL , fig. 1A–E (new synonym).

Meseres trachus View in CoL .— Rowe, 1995: 285.— O'Loughlin, 1998: 497.— O'Loughlin, 2002: 300, 312, table 3 (new synonym).

Pseudostichopus pustulosus .— Rowe, 1995: 285 (non Pseudostichopus pustulosus Sluiter, 1901 ).

Material examined. Pseudostichopus mollis Théel, 1886 . Lectotype (designated here). Southern Pacific Ocean   GoogleMaps , off Chile, 52°45'S, 73°46'W, 448 m, Challenger stn 311, BMNH 2002.293 . Paralectotypes, type locality and date, 86.10.2.143 (3), 1956.10.3.6 (2); off Chile, 50°56'S, 74°14'W, 256 m, Challenger stn 309A, 86.10.2.142 (3); Southern Indian Ocean, off Marion I., 46°48'S, 37°49'E, 91–137 m, Challenger stn 144A, 86.10.2.144 (2).

Pseudostichopus trachus Sluiter, 1901 . Lectotype (designated here). Indonesia, Ceram Sea, 1°11'S, 130°09'E, 798 m, Siboga stn 161, ZMA V.Ech.H2496.2 (1). Paralectotype, Timor Sea, 8°50'S, 127°02'E, 883 m, Siboga stn 286, V.Ech.H2496.1 (1).

Pseudostichopus nudus Ohshima, 1915 View in CoL . Neotype (designated here). North Pacific Ocean, Bering Sea, USA, Alaska, Aleutian Is   GoogleMaps , Bowers Bank   GoogleMaps , 54°33'N, 178°45'E, 1019–1068 m, RV Albatross, North-west Pacific Expedition, stn 4774, 4 Jun 1906, USNM E10787 About USNM . Same locality and date, 1008140 (4).

Pseudostichopus (Pseudostichopus) alatus Imaoka, 1990 View in CoL . Holotype. Japan, Tosa Bay , 350 m, H. Horikawa, 30 Jan 1989, OMNH Iv1188. Paratype. Tosa Bay, 390–410 m, Iv1189 (1).

Other material. North Pacific Ocean , Bering Sea , Alaska, Bowers Bank, 1068 m, USNM E10697 About USNM (1) ; off southern California , W of San Nicolas I., 825 m , 32416 (19); off Oregon , 44°36'– 46°01'N, 124°40'– 124°45'W, 320–466 m, USNM E16503 About USNM (13) GoogleMaps ; E16734– E16742 (20); E16745, E167446 (6); E16749– E16752 (9); E16886 (3); E16888 (16); E53270 (2); off San Diego, 572 m, E2042 (2); 762 m, E02035 (4); 379–636 m, E17014 (1); 914–969 m, E17016 (1); 1587 m, 32410 (3); Costa Rica, 245 m , 18269 (2).

South Pacific Ocean, south-eastern Australian continental slope, 460–1200 m , AM J16749 (1); J16836 (1); J20028 (2); J22248 (1); J22938, J22939 (3); J22943 (2); J22955 (5); J22957 (1); J22960 (7); J22964 (1); J22967– J22969 (9); J22972 (1); J22974, J22975 (6); J23218 (1); J23220 (1); J23268 (1) ; NMV F80176 About NMV , F80177 About NMV (2), F80179, F80180 (5) ; TM H3111 (1); H3114 (2); W of Cape Sorrell , 972 m , H2004 (2); Tasman Sea, Lord Howe Rise , 1920 m , NMV F97692 About NMV F97694 About NMV (4); New Zealand, Campbell I., 589–594 m , USNM E48604 About USNM (2); Chatham Is , 964–1067 m , E48641 (1); Antipodes Is , 384–397 m , E48665 (7); off Chile, 960 m , 1002911 (2); Macquarie I., NMV F89907 About NMV (1); F85036 (4); 900 m , F89908 (1); Strait of Magellan , 485 m , USNM E48639 About USNM (3); 256–320 m , E48666 (25); 769–869 m, E48656 (7).

Antarctica, Palmer Archipelago , 460–500 m, USNM 1005855 About USNM (1) ; 460–500 m, 1008441 (2); Antarctic Peninsula , 500–670 m , 1005856 (1); 630–650 m, 1022611 (2).

Description. Up to 225 mm long; body rounded in transverse section, frequently flat ventrally, high convex dorsally; sometimes thick to thin, rounded, ventrolateral brim, especially anteriorly; pygal furrow sometimes barely evident in largest specimens; body wall leathery, firm, thick to thin; anterior middorsal soft inconspicuous madreporite; ventrally frequently rugose, wrinkled with pockets and fine transverse ridges, folds and protuberances sometimes evident along ventrolateral margin, sometimes with raised multilobed tubercles pygally or midventrally or in lateroventral series, tubercles sometimes surmounted by tube feet, ventrum frequently encrusted with globigerines; papillae most evident dorsolaterally in sparse radial band, frequently 2 up to 4 wide, strongly tapered, somewhat whip-like, up to 5 mm long (170 mm long specimen), frequently withdrawn or lost leaving pits; double series of ventrolateral tube feet rarely externally evident; minute tube feet ventrally, rarely evident; ossicles in tentacles, tube feet, perianally; tentacle ossicles numerous to sparse, irregular rods, typically 120–240 µm long, frequently swollen mid-rod, some thin branches, rare blunt spines, branches rarely connecting to create perforations, lacking mesh ossicles, rare large irregular tuber-like ossicles, up to 380 µm long; tube feet ossicles predominantly irregular, smooth, rarely branched rods, frequently with swelling mid-rod, typically 100–130 µm long; pygal lobes with small globular mesh ossicles, difficult to detect.

Colour. Body, tube feet pale brown to off-white; tentacles, longitudinal muscles dark brown to brown; gonad tubules, respiratory trees pale brown.

Distribution. Western Antarctica, Weddell Sea, 65°19'S, 56°48'W, 400 m ( Ekman, 1925); Weddell Sea, 340–470 m (Gutt, 1991); North and South Pacific Ocean, southern Indian Ocean, eastern Australian continental slope, Antarctic Ocean in Palmer Archipelago and off Antarctic Peninsula, 91–1587 m (this work).

Remarks. Théel (1886) listed “numerous” syntypes from Challenger stn 311. Six of these specimens (in three lots) were examined in the BMNH (Apr 2002), and one disintegrated specimen examined (Apr 2002) in ZMU (ZMA V.Ech.H2999). One of these specimens is designated as lectotype above. Théel (1886) also listed six specimens from stn 309A of which three were examined in the BMNH. Théel (1886) further listed two specimens from stn 144A, and both were present in the BMNH.

During an examination (Apr 2002) of holothurian types in the University of Amsterdam, a type specimen of Pseudostichopus trachus Sluiter was found to be registered as Pseudostichopus pustulosus (discussed above under M. pustulosus ). This specimen is designated the lectotype for P. trachus . O'Loughlin (2002) judged material referred to P. trachus by Mitsukuri (1912) and Ohshima (1915) to be M. hyalegerus , and raised doubts about determination of material as P. trachus by Heding (1940), Savel'eva (1941), Baranova (1957), Djakonov et al. (1958), and Cherbonnier and Féral (1981).

Significant features of the types of P. trachus are: large size, up to 180 mm long ( Sluiter, 1901b); slightly dorsoventrally depressed, flat ventrally, convex dorsally, pygal furrow, leathery wrinkled body wall, subacute pustulose margin with distinct small irregular protuberances; densely covered with globigerine attachments; tube feet all withdrawn, paired radial series ventrolaterally, small ones ventrally ( Sluiter 1901b), dorsal tube feet sparsely evident dorsally ( Sluiter, 1901b); cylindrical longitudinal muscles ("not round in cross section" according to Sluiter, 1901b), but seen here to be round but sometimes slightly flattened); long thin unbranched gonad tubules; "teeth" on posterior margin of radial plates of ring; tentacle ossicles irregular thick rods, sometimes branched, branches sometimes fused to create perforations, smooth or with large thorny spines, sometimes with central swellings, up to 200 Μm long; tube foot ossicles short smooth tapered rods, frequently with central swelling; body wall, gonads, respiratory trees lacking ossicles. The types were taken in Indonesia at 798– 883 m. In all respects, except the dorsal cover of globigerines and uncertain distribution of dorsolateral tube feet, P. trachus is indistinguishable from P. mollis . Many specimens of P. mollis have a dense ventral encrustation of globigerines, and quite wrinkled and pitted and ridged and pustulose ventrum and lateroventral edge. The presence of encrusting globigerines dorsally is considered to be not grounds for separating the species diagnostically. The various forms and sizes of the tentacle ossicles are noticeably similar for the P. mollis and P. trachus types, as are the teeth on the radial plates of the ring. The longitudinal muscles are cylindrical, and sometimes slightly flattened, in both species. The gonad tubules are uniquely long and thin and unbranched in both species. P. mollis is found on the Australian continentlal slope at depths similar to those of the P. trachus types. This study has shown that the degree to which the ventrolateral margin develops protuberances and serrations varies from strongly developed to non-existent within the same species such as in Pseudostichopus peripatus below. Similarly the ventrum may be relatively smooth or strongly pustulose with raised protuberances as observed here for P. mollis . P. trachus is thus judged here to be a junior synonym of P. mollis .

The “Type” for P. nudus nominated by Ohshima (1915), and given USNM Cat. No. 34150, cannot be traced (see Introduction). A neotype, selected from Ohshima’s original material, is designated above. P. nudus has all but one of the distinguishing characters of P. mollis : firm, leathery body wall; potentially large sac-like form; small tapered tube feet on the paired radii; cylindrical longitudinal muscles; very long unbranched gonad tubules, in series along gonoduct; tentacles with irregular rod ossicles; tube feet with small rod ossicles with central swellings; absence of gonad, respiratory tree, posterior lobe ossicles. Ohshima (1915) distinguished P. nudus by a midventral band of tube feet which were each surrounded by pustular protuberances. A prominent midventral band of tube feet arising from protuberances was seen in a number of specimens in this study, but other specimens showed a range of ventral conditions intergrading with P. mollis . Small tube feet are present ventrally in P. mollis , and in some specimens become evident and in some arise from irregular swollen protuberances. P. nudus is also considered here to be a junior synonym of P. mollis .

Rowe (1995) considered P. nudus to be a junior synonym of P. pustulosus . This synonymy is rejected above (see M. pustulosus ). Rowe (1995) identified material from off Newcastle on the eastern Australian slope as Pseudostichopus pustulosus . All Australian slope material has been examined and none determined as P. pustulosus . Material from off Newcastle (AM J16749) was determined as P. mollis . Ludwig (1894) referred material to P. mollis , but illustrated ( Ludwig, 1894, pl. 9 figs 5–9) ossicles from the genital tubules that are similar to those in the gonads of P. peripatus (see below). At least some of the material was not P. mollis , which consistently lacks gonad ossicles.

The two paratypes of P. dilatorbis have all the diagnostic characters of P. mollis , and are so assigned (see above).

The distinctive features of the two type specimens of P. alatus are: up to 115 mm long; pale brown to white, opaque body encrusted with sponge spicules, foraminiferans, shell, sand; 19 pale brown tentacles; tube feet on paired radii, more numerous ventrolaterally; very small tube feet ventrally; long thin unbranched gonad tubules in series along gonoduct; ossicles in tentacles only, not in gonads or tube feet; tentacle ossicles irregular rods about 150–400 µm long, frequently with fairly large spines, rare branching. The types of P. alatus exhibit all of the characteristics of P. mollis and P. trachus , and these observations are confirmed by the description of Imaoka (1990). P. alatus is considered here to be a junior synonym of P. mollis .

Amongst Pseudostichopus species, the distinguishing characters of P. mollis are: leathery brown body wall; typical absence of a dense cover of globigerines or sponge spicules; distinct papillae on the paired radii; absence of gonad ossicles.

ZMA

Universiteit van Amsterdam, Zoologisch Museum

USNM

Smithsonian Institution, National Museum of Natural History

AM

Australian Museum

NMV

Museum Victoria

TM

Teylers Museum, Paleontologische

Kingdom

Animalia

Phylum

Echinodermata

Class

Holothuroidea

Order

Persiculida

Family

Pseudostichopodidae

Genus

Pseudostichopus

Loc

Pseudostichopus mollis Théel, 1886

O'Loughlin, P. Mark & Ahearn, Cynthia 2005
2005
Loc

Meseres trachus

O'Loughlin, P. M. 2002: 300
O'Loughlin, P. M. 1998: 497
Rowe, F. W. E. & Gates, J. 1995: 285
1995
Loc

Pseudostichopus pustulosus

Rowe, F. W. E. & Gates, J. 1995: 285
1995
Loc

Pseudostichopus (Pseudostichopus) alatus

Imaoka, T. 1990: 148
1990
Loc

Pseudostichopus (Pseudostichopus) dilatorbis

Imaoka, T. 1978: 380
1978
Loc

Pseudostichopus (Trachostichopus) trachus

Thandar, A. S. 1992: 166
Heding, S. G. 1940: 353
1940
Loc

Pseudostichopus nudus

Rowe, F. W. E. & Gates, J. 1995: 285
Djakonov, A. M. & Baranova, Z. I. & Savel'eva, T. S. 1958: 367
Heding, S. G. 1940: 353
Ekman, S. 1925: 32
Ohshima, H. 1915: 230
1915
Loc

Pseudostichopus trachus

Cherbonnier, G. & Feral, J. P. 1981: 383
Imaoka, T. 1978: 384
Djakonov, A. M. & Baranova, Z. I. & Savel'eva, T. S. 1958: 366
Baranova, Z. I. 1957: 239
Djakonov, A. M. 1952: 127
Savel'eva, T. S. 1941: 74
Ekman, S. 1925: 32
Fisher, W. K. 1907: 693
Perrier, R. 1902: 337
Sluiter, C. P. 1901: 16
Sluiter, C. P. 1901: 52
1901
Loc

Pseudostichopus mollis Théel, 1886: 169–170

O'Loughlin, P. M. 2002: 304
Rowe, F. W. E. & Gates, J. 1995: 285
Thandar, A. S. 1992: 167
Gutt, J. 1991: 147
Gutt, J. 1991: 321
Imaoka, T. 1990: 148
Heding, S. G. 1940: 353
Ekman, S. 1926: 451
Ekman, S. 1925: 5
Fisher, W. K. 1907: 691
Perrier, R. 1902: 337
Ludwig, H. 1898: 7
Theel, H. 1886: 170
1886
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