Sertularella liouvillei, (Billard, 1914)

Peña Cantero, A. L., 2002, Species of Symplectoscyphus Marktanner-Turneretscher, 1890 (Cnidaria: Hydrozoa, Sertulariidae) from recent Antarctic expeditions with R. V. Polarstern, with the description of four new species, Journal of Natural History 36, pp. 1509-1568 : 1540-1550

Symplectoscyphu s liouvillei (Billard, 1914)

(gures 8–10; table 9)

Sertularella liouvillei Billard, 1914: 24–26 , gures 14, 15.

Symplectoscyphus liouvillei: Stechow, 1922: 148 ; 1923: 172; Gravier-Bonnet, 1979: 52; Blanco, 1982: 41; Vervoort, 1993: 240.

Sertularella (Symplectoscyphus) liouvillei: Broch, 1948: 5 , 9–13, gure 3b–d [in part, part belonging to S. cumberlandicus (Jäderholm, 1905) ].

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? Sertularella liouvillei : Stepan’yants, 1972: 71, gure 46; 1979: 80, pl. 14, gure 2. Sertularella aggregata : Stepan’yants, 1979: 82, pl. 15, gures 2A, B.

Lafoea weddelli Blanco, 1991: 12–13 , gure 3.

Material examined. ANT II- 4 Stn 460, one complete colony, 210 mm high, with gonothecae, one stem deprived of branches and hydrothecae and numerous stem and branch fragments (RMNH-Coel. 29 182, two slides 4828); ANT VIII- 5 Stn

2014 February 13 38: 23 at] Bath of University [by Downloaded 16-407, one fragmented colony at least 190 mm long, with gonothecae (RMNH- Coel. 29 183, four slides 4829).

Description (of material from Stn 16-407). A large colony, strongly polysiphonic and fragmented. Colony polysiphonic throughout, with the exception of the most distal, youngest branches. Polysiphony due to numerous and thin secondary tubes. Basalmost stem fragment (ca 5 mm thick and 190 mm long, including hydrorhiza) completely polysiphonic, provided with a large rhizoidal hydrorhiza (ca 50 mm long) spreading on a calcareous bryozoan; originally hydrorhiza could have been discoidal, later, while the colony was growing the hydrorhiza may have developed strong hydrorhizal stolons for the attachment to less rm substratum. Hydrorhizal stolons polysiphonic, consisting of a large number of thin tubes like those giving rise to polysiphony of stem. Stem forking at 90 mm height, though previously with a few small, simple branches. Following stem fragment, ca 105 mm long, branched, giving rise to several polysiphonic lower-order stems. Branching irregular and in several planes (gures 8A, 9A), sometimes with more or less spiral arrangement. Branches originating laterally at the hydrothecal base (gures 8D, 9B), decreasing in diameter

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2014 February 13 38: 23 at] Bath of University [by Downloaded distally; plane formed by hydrothecae of lower-order branch perpendicular to that formed by hydrothecae of previous branch.

Branches divided into short hydrothecate internodes; one hydrotheca per internode. Hydrothecae alternately arranged in one plane (gures 8B, C, 9C–E), though with a spiral variation of that plane along the branches. Hydrotheca slightly abcaudally directed (gures 8B, C, 9C–F). Adcauline wall adnate to internode for approximately two-thirds of its length; free part of adcauline wall straight or slightly convex. Abcauline wall straight or slightly concave. Hydrothecal aperture provided with three cusps separated by deep embayments (gures 8B–D, 9B–F). Rim of hydrotheca l aperture with numerous renovations, even in the distalmost hydrothecae.

Gonothecae inserted on branches at hydrothecal base (gures 8E, 9A). In the material from ANT VIII-5 Stn 16-407 the gonothecae, adherent to the branches, are immature (gure 8E); they are fusiform, truncated distally and with indistinctly striated walls. In the material from ANT II-4 Stn 460, there are gonothecae of another type (gure 9A); they are fusiform, extremely long and thin, and provided with a small distal neck .

Remarks. In addition to the shape of the gonothecae, the material from ANT II- 4 Stn 460 has other diVerences from the remaining material. The hydrorhiza, little developed, is composed of a few short and thin stolons; the stem is tortuous (gure 10). Though there are no anastomoses between the polysiphonic branches, they may become attached by the development of polysiphony. The colonial structure is extremely irregular at the branched part, due to the irregular and dense branching in several planes (gure 10). The hydrothecal internodes are usually provided with a basal constriction (Billard’s ‘bourrelet’) at the side of the hydrotheca. The rim of the hydrothecal aperture has few renovations.

Broch (1948) identi ed colonies from Bouvet and Peter I Islands as S. liouvillei . He did not give a description of that material, but pointed out that it agreed with that of Billard (1914). The two hydrothecae drawn by Broch, from Bouvet Island, are similar to those found in the Polarstern material. Broch also gured young gonothecae present in a large colony from Peter I Island. These gonothecae, with deeply furrowed, ringed wall, are completely diVerent from the gonothecae found in the Polarstern material. We think that Broch’s material from Peter I Island does not belong to S. liouvillei but could be conspeci c with Sertularella cumberlandica Jäderholm, 1905 , a species with which it shares the shape of the gonothecae. The gonothecae of S. liouvillei were still unknown at the time of Broch’s description, consequently we should consider Broch’s reference with some reserve. Moreover, Broch pointed out that S. liouvillei and S. cumberlandicus could possibly be conspeci c. The material from Peter I Island that Broch studied actually belonged to Jäderholm’s (1905) species.

As stated above when discussing S. aggregatus , we have considered the material assigned to that species by Stepan’yants (1979) conspeci c with S. liouvillei .

Blanco (1991) described as Lafoea weddelli a new species of lafoeid, characterized by the extremely long hydrotheca (2900–3490 m m length and 300–460 m m diameter at aperture) and its wavy walls. The gonothecae of this species were unknown. Moreover, the species was described growing abundantl y on well developed colonies of Symplectoscyphu s cumberlandicus ; the only gure of L. weddelli given shows one hydrotheca of this species inserting at the hydrothecal base of S. cumberlandicus , which species is not further described or gured. After studying the Polarstern material from ANT II- 4 Stn 460 we believe that L. weddelli actually represents the gonotheca of Symplectoscyphus liouvillei . Blanco’s (1991) gure, as just mentioned, shows the ‘hydrotheca’ of L. weddelli emerging just at the position occupied by the gonothecae in the species of Symplectoscyphus . Moreover, size and shape of the ‘hydrothecae’ of L. weddelli are in complete agreement with immature gonothecae of S. liouvillei also found in the Polarstern material from ANT II- 4 Stn 460.

We think the material referred by Stepan’yants (1972) to S. liouvillei belongs to another species, the more so since Stepan’yants (1979) herself doubted the identi cation. The drawings in Stepan’yants’ (1972) paper suggest that her material had a diVerent structure and the gonothecae had a pattern of rings absent in S. liouvillei but present in other species of the genus Symplectoscyphus .

Ecology and distribution. Symplectoscyphus liouvillei has been collected from depths of 200 (Broch, 1948) to 420 m (Billard, 1914), on bottoms of mud and gravel (Billard, 1914) and on muddy bottoms (Broch, 1948). Our material comes from depths of 240 to 330 m.

2014 This species has also been reported growing on gravel and rocks (Stepan’yants, 1979 as S. aggregatus ). Symplectoscyphus liouvillei is used as substratum by other

February the gatus hydroids fertile) recorded ( Symplectoscyphus colonies fertile were colonies collected sp. and collected in January Filellum in February and sp.). February Stepan’yants and. March (1979; in, our as S material. aggre-

13 Symplectoscyphus liouvillei seems to have a West Antarctic–Patagonian distribu-

38

: tion. It is known from oV King George Island , South Shetland Islands (Billard,

23 1914), Bouvet Island (Broch, 1948), South Orkney Islands [Stepan’yants (1979) as at

]

S. aggregatus ] and at 76ss43¾S, 50ss29¾W (Blanco, 1991), in West Antarctica. The

Bath Ronne Polarstern Ice material Shelf and comes McDonald from oIce V the Rumples south) and. Outside east coasts Antarctic of the waters Weddell it has Sea been (oV of recorded from oV the Falkland Islands [Stepan’yants (1979) as S. aggregatus ].

University Symplectoscyphus (gure 11A naumovi –D; table Blanco 10), 1969

[ Sertularella sp.1 Naumov and Stepan’yants, 1962: 85–86, gure 8.

by Symplectoscyphus naumovi Blanco, 1969: 14 , gures 1–9; 1984: 28–29, gures 54–57 on pls

Downloaded Sertularella Symplectoscyphus 24 1979 1993, 25::; 70 240 Blanco, naumovi . pl. 13 plectilis and,: gure Naumov Bellusci: 1 Blanco. de and, Miralles 1984 Stepan’yants: 29, 1970 –31,:, 1 gures – 1972 9,: gures 58 34 –, 61 48 1,, on 2; gures pls Tang 26, 10, 1991 27, 11.:; 3 Stepan’yants, 5; Vervoort,, Symplectoscyphus densestriatus Tang, 1991: 1–5 , gure 1A–D.

Not Symplectoscyphus naumovi: Blanco and Bellusci de Miralles, 1972: 19 , gure 53 5 S . plectilis (Hickson and Gravely, 1907).

Material examined. ANT I-2 Stn 135, one stem ca 10 mm high; ANT II- 4 Stn

460, one stem ca 8 mm high (RMNH-Coel. 29 185, slide 4830); ANT VIII- 5 Stn

16-399, one stem ca 7 mm high, on polychaete tube (RMNH-Coel. 29 186, slide

4831); ANT VIII- 5 Stn 16-407, three stems up to 4 mm, epibiotic on Billardia subrufa

(Jäderholm, 1904) (RMNH-Coel. 29 187, slide 4832); ANT VIII- 5 Stn 16-423, one colony with three stems up to 10 mm high, on Billardia sp. (RMNH-Coel. 29 188,

slide 4833); ANT VIII- 5 Stn 16-434, a few stems up to 8 mm high, on tube of benthic organisms, with gonothecae (RMNH-Coel. 29 189, slide 4834); ANT VIII- 5

Stn 16-459, numerous stems up to 20 mm high, on sponges and polychaete tubes,

with gonothecae (RMNH-Coel. 29 190, slide 4835); ANT VIII- 5 Stn 16-481, two colonies with a few stems up to 20 mm high on gorgonian skeleton and a few small

2014 February 13 38: 23 at] Bath of University [by Downloaded stems on Billardia sp. , with gonothecae (RMNH-Coel. 29 191, slide 4836); ANT VIII-5 Stn 16-484, numerous colonies with stems up to 25 mm high, on polychaete tubes, with gonothecae (RMNH-Coel. 29 192, two slides 4837); ANT VIII-5 Stn 16-492, a few stems up to 10 mm high, on sponges and pedicel of benthic organisms (RMNH-Coel. 29 193, slide 4838); ANT IX-3 Stn 135, one colony with three stems up to 4 mm high (RMNH-Coel. 29 194, slide 4839).

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†Taken from the gures.

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Description. Colonies composed of stolonal hydrorhiza giving rise to monosiphonic stems up to 25 mm high. Stems unbranched or scarcely branched; branches without anastomoses.

Hydrothecate internodes long and thin, usually longer than hydrothecal length (gure 11A–C). Hydrotheca placed on distal third or quarter of internode.

Hydrothecae alternately arranged in one plane, large and tubular (gure 11A–C). Adcauline hydrothecal wall adnate for approximately one-third of its length. Free part of adcauline hydrothecal wall straight or slightly convex. Abcauline hydrothecal wall straight or slightly concave. Cusps of hydrothecal aperture sharp and separated by deep embayments (gure 11A–C). Occasionally with hydrothecal renovations.

Gonothecae ovoid, with short distal neck (gure 11D); walls smooth or slightly wavy, with indistinct striae.

Remarks. Blanco (1969) considered the material described by Naumov and Stepan’yants (1962) as Sertularella sp. conspeci c with Symplectoscyphus naumovi , though she drew attention to the larger size of the hydrothecae in that material. The same applies to the material assigned to S. naumovi by Naumov and Stepan’yants (1972). However, the appearance of the colonies and the shape of hydrothecae and gonothecae are similar.

The size of the gonothecae in the specimens studied by Naumov and Stepan’yants (1962) is distinctly smaller than that in other material identi ed as S. naumovi , being about half as large. This, however, may be due to a mistake in the scale of the gures.

Blanco and Bellusci de Miralles (1972) assigned to S. naumovi an infertile form with hydrothecae distinctly smaller than those found by other authors. We believe that material to be probably conspeci c with S. plectilis since, as re-examination of the type material of S. plectilis shows, Blanco and Bellusci de Miralles’s material agrees with the type in both size and shape of the hydrothecae. Also, Blanco (1969), in the original description of S. naumovi , pointed out that the hydrothecae of S. naumovi are almost identical to those of S. plectilis as gured by Totton (1930).

Blanco (1984) assigned to S. plectilis material that we believe to belong to S. naumovi . Blanco pointed out that she was not completely certain of the speci c assignation of her material because of diVerences in colony structure, without the frequent branching and anastomoses characterizing the large colonies of S. plectilis , and by the larger dimensions of the hydrothecae. The shape and size of the hydrothecae and the colony structure are in agreement with those of S. naumovi .

Tang (1991) described a new species, Symplectoscyphus densestriatus , stating that it diVers from the remaining species of the genus by ‘the presence of dense annulations on the surface of the hydrothecal (should be gonothecal) wall, in the surface of the hydrothecal wall being smooth, and in the free part of the adcauline wall marked(ly) longer than adnate part’. Tang pointed out that in S. naumovi the gonothecal wall has no distinct annulations. Nevertheless, as it is possible to observe both in the Polarstern material and in the material described by other authors [as for instance the original description of S. naumovi by Blanco (1969)], the gonothecae have dense transversal striae. Moreover, the remaining features noted by Tang are also present in Blanco’s species and even the colonial structure and size are similar. Therefore, we consider S. densestriatus conspeci c with S. naumovi .

Ecology and distribution. Symplectoscyphus naumovi has been found from the tidal level (Blanco, 1984) to a depth of 378 m ( Tang, 1991), on bottoms of boulders, stones and sand, sand and stones, and sandy bottoms (Naumov and Stepan’yants, 1972), and clayey silt ( Tang, 1991). Our material was collected at depths from 205 to 640 m, on bottoms of large rocks, mud and fragments of bryozoans.

Table 11. Measurements of Symplectoscyphus nesioticus Blanco, 1977 (in m m).

2014 February 13 38: 23 at] Bath of University [by Downloaded becomes free. Abcauline wall straight or slightly abcaudally directed at its distal part. Cusps of hydrothecal aperture sharp and separated by deep embayments (gure 11F, G). Hydrotheca widening at the aperture.

Remarks. Symplectoscyphus nesioticus is a rare species, hitherto recorded once by Blanco (1977b). It is easily recognizable by the strongly geniculate stem and the shape of hydrothecae and gonothecae. The latter have a distal, funnel-shaped neck hidden by the rst ring-shaped keel.

Symplectoscyphus nesioticus seems to be an inconspicuous species, as is shown by the scarce records and the small size of the stems. Though Blanco (1977b) found numerous colonies, the mature stems reached a maximum height of only 15 mm.

Ecology and distribution. Symplectoscyphus nesioticus had been collected at depths of 90–100 m (Blanco, 1977b). Our material comes from depths of 240– 522 m. Blanco (1977b) found it on Bryozoa [ Carbasea ovoidea Busk, 1852 , Nemato ustra agellata (Waters, 1904) and Cellaria vitrimuralis Rogick, 1956 ] and hydroids [ Sertularella polyzonias (Linnaeus, 1758) ]. We also found it epibiotic on hydroids.

Symplectoscyphus nesioticus was only known previously from Low Island, in the South Shetland Islands region (Blanco, 1977b). Our material comes from the east coast of the Weddell Sea (oV Cape Norvegia).