Antarctoscyphus elongatus ( Jäderholm, 1904 )

Peña Cantero, Álvaro L., Roig Ferrer, Estela & Miranda, Thais P., 2017, Species of Antarctoscyphus Peña Cantero, García Carrascosa and Vervoort, 1997 (Cnidaria: Hydrozoa: Symplectoscyphidae) collected by US Antarctic expeditions: biogeographic implications, Journal of Natural History (J. Nat. Hist.) 51 (25 - 26), pp. 1437-1477 : 1453-1456

Antarctoscyphus elongatus ( Jäderholm, 1904)

( Figure 7 )

Sertularella elongata Jäderholm, 1904, p. 10 ; Totton, 1930, p. 199; Broch, 1948, p. 10, fig. 2b–c; Naumov and Stepanjants, 1962, p. 80, fig. 5; 1972, p. 42, fig. 5b; Stepanjants, 1979, p. 69, pl. 12, fig. 3.

Symplectoscyphus elongatus – Vervoort, 1972, p. 136, figs 43–44a; Millard, 1977, p. 28, fig. 7d–e.; Peña Cantero, 1991, p. 133 –7, pls 22, 53, figs f-g; Peña Cantero and García Carrascosa, 1994, p. 123, fig. 6d; 1995, p. 73, figs 32a–c, 33f–g.

Sertularia articulata Allman, 1888, p. 61 , pl. 29, fig. 3–3a.

Sertularella articulata – Hartlaub, 1901, p. 24, fig. 14; Jäderholm, 1905, p. 29, pl. 11, fig. 4, pl. 12, figs 1–3; 1917, p. 9, pl. 1, fig. 7; Billard, 1910, p. 10; 1914, p. 20.

not Sertularella articulata – Vanhöffen, 1910, p. 328, fig. 42a–d [= Antarctoscyphus grandis ( Blanco, 1977) ].

Symplectoscyphus articulatus – Briggs, 1938, p. 30; Rees and Thursfield, 1965, p. 127.

Antarctoscyphus elongatus – Peña Cantero et al., 1997, p. 25; 1999, p. 1745–8, fig. 2A–F; Peña Cantero, 2006, p. 938, fig. 3J; 2008, p. 458; 2012, p. 858; 2014b, p. 1721, fig. 4h; Peña Cantero and Gili, 2006, p. 767; Galea and Schories, 2012, p. 9, fig. 2L, M.

Material examined

Eltanin: 6/410, four fragments, up to 35 mm long; 6/415, several fragments and stems, up to 90 mm high; 27/1877, one stem fragment, c. 14 mm long; 32/2021, two stem fragments, up to 45 mm long; 32/2068, one stem fragment, c. 55 mm long. Glacier: GLD/13, three stem fragments, up to 55 mm long; M-12SEP, one branch, c. 13 mm long. Hero : 721/777, one stem, c. 45 mm high, on pebbles; 731/1868, nine fragments, up to 17 mm long; 731/1938, one fragment, c. 15 mm long; 254-H-74, one fragment, c. 6 mm long; 824/004–1, several fragments, up to 50 mm long; 824/041–1, three stem fragments, up to 33 mm long. Islas Orcadas: 575/032, two stems, up to 90 mm high; 575/033, three stem fragments, c. 110, 110 and 85 mm long; 575/037, several stems, up to 75 mm high, on gravel; 575/052, one stem, c. 55 mm high; 575/066, a few stems, up to 70 mm high; 575/069, two stems, up to 180 mm high; 575/088, one stem fragment, c. 90 mm long; 575/090, three stem fragments, up to 75 mm long; 575/095, one stem fragment, c. 30 mm long. Pr Siedlecki: 601/023, one stem, c. 80 mm high, with incipient gonothecae; 601/044, one stem fragment, c. 50 mm long; 601/057, one branch fragment, c. 20 mm long; 601/074, one stem, c. 105 mm high, with gonothecae; 601/122, one stem, c. 95 mm high. Wilkes Station: 000AG, several stem fragments, up to 90 mm long; 000 AM, several fragments, up to 35 mm long; 00DAB, four stem fragments, up to 75 mm long.

Diagnosis

Stems monosiphonic, up to 240 mm high. Cauline internodes in distinct zigzag arrangement. Cauline apophyses slightly spirally arranged. Paired branches recurrently branching alternately at each third internode, either in one plane or in two planes forming an obtuse angle. Hydrothecae alternately arranged in one plane or in two planes forming an obtuse angle. Hydrothecae roughly straight; both abcauline wall and free part of adcauline wall straight or slightly concave. Adcauline hydrothecal wall usually adnate in about half its length; sometimes adnate for a longer or shorter portion. Cusps of hydrothecal aperture roughly of similar development. Gonothecae fusiform, with circular, distal aperture.

Ecology

Collected on muddy ( Allman 1888; Totton 1930; Broch 1948; Peña Cantero et al. 1999), sandy ( Broch 1948) and stony (Peña Cantero et al. 1999) bottoms and on bottoms of stones with gravel ( Broch 1948; Stepanjants 1979). Found epilithic on gravel (Peña Cantero et al. 1999; Peña Cantero 2014b) and stones ( Peña Cantero and Gili 2006) and epibiotic on algae and bryozoans ( Naumov and Stepanjants 1972; Stepanjants 1979), hydroids ( Naumov and Stepanjants 1972; Stepanjants 1979; Peña Cantero et al. 1999; Peña Cantero 2014b), tubes of polychaetes ( Peña Cantero 2008) and sponges ( Galea and Schories 2012); in our material, epilithic on gravel and pebbles and basibiont of the hydroid Sertularella sp. Gonothecae observed in January (Peña Cantero et al. 1999; Peña Cantero 2008), February ( Galea and Schories 2012), April ( Millard 1977) and December ( Stepanjants 1979); here gonothecae were observed in December.

Bathymetric and geographic distribution

Eurybathic species, found at depths between 10 m ( Naumov and Stepanjants 1972) and 1958 m ( Peña Cantero 2012); present material from 18 to 1684 m.

Antarctic–Kerguélen distribution ( Peña Cantero 2012), reported for both sub-Antarctic and Antarctic waters. In the former, known off Kerguelen ( Allman 1888; Naumov and Stepanjants 1962; Stepanjants 1979), Heard and Crozet Islands ( Millard 1977) and from Lena Bank ( Stepanjants 1979). In Antarctic waters, recorded from McMurdo Sound, the Ross Sea ( Totton 1930), off Adélie Coast ( Naumov and Stepanjants 1972) and Queen Mary Coast ( Peña Cantero 2014b), in East Antarctica. In West Antarctica, reported off South Georgia ( Jäderholm 1904; Stepanjants 1979), Graham Land ( Jäderholm 1904; Broch 1948; Vervoort 1972), Deception Island ( Billard 1914; Broch 1948; Peña Cantero 2008), Robertson Island ( Jäderholm 1917), Bouvet ( Broch 1948; Peña Cantero and Gili 2006) and Elephant Island ( Peña Cantero and García Carrascosa 1995), and from the South Shetland Islands ( Stepanjants 1979; Peña Cantero and García Carrascosa 1995; Peña Cantero 2006, 2008; Galea and Schories 2012), the south and east coasts of the Weddell Sea (Peña Cantero et al. 1999) and the Bellingshausen Sea ( Peña Cantero 2012). Present material collected off Budd Coast (Wilkes Land), off Scott Coast, Pennell Bank and Moubray Bay (Victoria Land), Ruppert Coast (Mary Byrd Land), and Roosevelt Island (Ross Sea), in East Antarctica, and off South Georgia, off Visokoi and Saunder Islands ( South Sandwich Islands), off Elephant Island, off King George Island (South Shetland Islands), off Deception Island, and off d’ Urville and Anvers Islands (Antarctic Peninsula), in West Antarctica.

Figures

Figure 7. Antarctoscyphus elongatus (Jäderholm, 1904): (a) fragment of a lateral branch showing branching and hydrothecal arrangement; (b) hydrocladial branching (note hydrotheca outside axil of branches); (c) hydrothecae (lateral view); (d) hydrotheca (frontal view); (e) fragment of lateral branch showing branching, hydrothecae and a gonotheca; (f) gonotheca. Scale bars: 1 mm (a), 250 µm (b, c, e, f), 200 µm (d).