Antarctoscyphus encarnae Peña Cantero, García Carrascosa and Vervoort, 1997

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 : 1456-1458

Antarctoscyphus encarnae Peña Cantero, García Carrascosa and Vervoort, 1997

( Figure 8 )

Symplectoscyphus sp. 2 Peña Cantero, 1991, p. 156 –60, pls 27, 55, 67, fig. d; Peña Cantero

and García Carrascosa, 1994, p. 125, fig. 7a–d; 1995, p. 87–90, figs 38A–E, 39A–E, 64D. Antarctoscyphus encarnae Peña Cantero et al., 1997, p. 29 –30, figs 2a–d, 3a.

Material examined

Spanish Antarctic Expedition Antártida 8611: ANT 477, 25–01–1987, 62°00.90 ʹ – 62° 02.50’ S, 58°53.80 ʹ – 58°53.70 ʹ W (off King George Island, South Shetland Islands), 100–136 m, one colony, c . 250 mm high (Holotype, Department of Zoology , University of Valencia, Coel. no. 11/ANT 477) .

Diagnosis

Stems basally polysiphonic, up to 250 mm in height. Cauline internodes heteromerous and arranged approximately in a zigzag pattern. Cauline apophyses alternately arranged in one plane, but with slight tendency to spiral disposition. Even internodes of paired branches giving rise to second-order branches (up to eight observed). Branch internodes short and wide, distinctly shortening distally. Hydrothecae arranged unilaterally, although alternately directed outwards, forming two longitudinal rows on same side of branch. Hydrothecae distinctly overlapping. At basal part of branch, internodes longer, with hydrothecae not touching, lying on internode, and adnate in about one-third of adcauline length. More distally, internodes shorter, with hydrothecae touching, more erected, and with a longer free portion of adcauline length. Branch extremity with shorter internodes, hydrothecae completely in contact, totally erected, and with fully free adcauline wall. Hydrotheca almost cylindrical, curved outwards at distal end. Hydrothecal aperture cusps unequally developed; adcauline cusp distinctly larger. Some hydrothecae with two internal cusps. Putative male gonotheca fusiform, with circular, distal aperture.

Ecology

Collected on muddy bottoms, and with gonothecae in January (Peña Cantero et al. 1997)

Bathymetric and geographic distribution

Antarctoscyphus encarnae is only known north off the coast of King George Island, in the South Shetland Islands, where it was found at depths between 100 and 220 m (Peña Cantero et al. 1997) .

Figures

Figure 8. Antarctoscyphus encarnae Peña Cantero, García Carrascosa and Vervoort, 1997: (a) fragment of lateral branch showing hydrothecal arrangement; (b) shape and arrangement of hydrothecae; (c) hydrotheca; (d) gonotheca; (e) detail of gonothecal aperture. Scale bars: 500 µm (a), 250 µm (b–d), 50 µm (e).