90,470 research outputs found
Oswaldella rigida Pena Cantero, Svoboda & Vervoort 1997
No full textOswaldella rigida Peña Cantero, Svoboda & Vervoort, 1997 Oswaldella rigida Peña Cantero, Svoboda & Vervoort, 1997: 373 –376, figs 10, 15 C; Peña Cantero & Vervoort, 1998: 36; 2004: 845; Peña Cantero & García Carrascosa, 1999: 214; Peña Cantero & Marques, 1999: 85; Peña Cantero, 2014: 1721, fig. 4 e, f. Schizotricha antarctica — Vanhöffen, 1910: 336, fig. 48. Ecology. Shelf and slope species, found at depths between 80 (Peña Cantero et al. 1997) and 1157 m (Peña Cantero 2014), on muddy and rocky bottoms (Peña Cantero et al. 1997). Gonothecae: January (Peña Cantero 2014). Distribution. Circum-Antarctic (Peña Cantero et al. 1997). East Antarctica: the Davis Sea (Vanhoffen 1910) and off Queen Mary Coast (Peña Cantero 2014). West Antarctica: the Weddell Sea (Peña Cantero et al. 1997).Published as part of Molinero, A. González & Peña Cantero, A. L., 2015, SEM study of species of Oswaldella Stechow, 1919 (Cnidaria, Hydrozoa, Kirchenpaueriidae), with an annotated checklist of the species of the genus, pp. 401-441 in Zootaxa 4052 (4) on pages 437-438, DOI: 10.11646/zootaxa.4052.4.1, http://zenodo.org/record/24588
Oswaldella elongata Pena Cantero, Garcia Carrascosa and Vervoort 1995
No full textOswaldella elongata Peña Cantero, García Carrascosa and Vervoort, 1995 Oswaldella elongata Peña Cantero et al., 1995: 347–350, figure 2; 1997: 344; Peña Cantero and Vervoort, 1998: 36; Peña Cantero and García Carrascosa, 1999: 212 et seq.; Peña Cantero and Marques, 1999: 85. Oswaldella sp.1 Peña Cantero, 1991: 179–182, pl. 33 figures a–e, pl. 57 figures a–f, pl. 68 figure b; Peña Cantero and García Carrascosa, 1994: 126, figure 8g, h; 1995: 104–107, figures 46A–F, 47A–F, 64F. Remarks. Oswaldella elongata is an uncommon species, well characterized by the long hydrothecae, the absence of mesial inferior nematothecae in the hydrocladial internodes, the presence of two axillary nematophores and two 'mamelons' in the cauline apophyses and the presence of only secondary hydrocladia (cf. table 1). Ecology and distribution. Oswaldella elongata is known only from off Clerke Rocks and South Georgia, where it was found between 86 and 250 m depth, growing on hydrocorals (Peña Cantero et al., 1995).Published as part of Peña Cantero, A. L. & Vervoort, W., 2004, Species of Oswaldella Stechow, 1919 (Cnidaria: Hydrozoa: Kirchenpaueriidae) from US Antarctic expeditions, with the description of three new species, pp. 805-861 in Journal of Natural History 38 on page 82
Oswaldella incognita Pena Cantero, Svoboda & Vervoort 1997
No full text<i>Oswaldella incognita</i> Peña Cantero, Svoboda & Vervoort, 1997 <p> <i>Oswaldella incognita</i> Peña Cantero, Svoboda & Vervoort, 1997: 367 –369, fig. 8; Peña Cantero & Vervoort, 1998: 36; 2004: 837–839, fig. 11; 2009: 86; Peña Cantero & García Carrascosa, 1999: 212 <i>et seq</i>.; Peña Cantero & Marques, 1999: 85; Peña Cantero, 2006: 938, fig. 3E; 2008: 457; 2009: 1748, fig. 3a; 2013: 130; Peña Cantero <i>et al.</i>, 2010: 41–57. <i>Oswaldella antarctica</i> — Peña Cantero, 1991: 168, pls 31, 56, pl. 68 fig. a; Peña Cantero & García Carrascosa, 1994: 125, fig. 8a–c; 1995: 96–101, figs 43A–E, 44A–F, 64E.</p> <p> <b>Ecology.</b> Eurybathic species, found at depths between 20 (Peña Cantero & Vervoort 2009) and 952 m (Peña Cantero & Vervoort 2004). Epilithic on gravel (Peña Cantero 2008). Basibiont of <i>Lafoea dumosa</i> (Peña Cantero 2006). <i>Gonothecae</i>: January (Peña Cantero & García Carrascosa 1995; Peña Cantero & Vervoort 2004; Peña Cantero 2013) and February (Peña Cantero & Vervoort 2004, 2009; Peña Cantero 2013).</p> <p> <b>Distribution.</b> Circum-Antarctic (Peña Cantero 2009), though mainly known from West Antarctica. <i>East Antarctica</i>: the Balleny Islands (Peña Cantero 2009). <i>West Antarctica</i>: the South Shetland Islands (Peña Cantero & García Carrascosa 1995; Peña Cantero <i>et al</i>. 1997; Peña Cantero & Vervoort 2004; 2009; Peña Cantero 2006, 2008), the South Orkney Islands and Palmer Archipelago (Peña Cantero & Vervoort 2004), off Deception Island (Peña Cantero & Vervoort 2004; Peña Cantero 2008), Low Island (Peña Cantero & Vervoort 2004; Peña Cantero 2013) and off Bransfield Island, in the Antarctic Peninsula (Peña Cantero & Vervoort 2008).</p>Published as part of <i>Molinero, A. González & Peña Cantero, A. L., 2015, SEM study of species of Oswaldella Stechow, 1919 (Cnidaria, Hydrozoa, Kirchenpaueriidae), with an annotated checklist of the species of the genus, pp. 401-441 in Zootaxa 4052 (4)</i> on page 436, DOI: 10.11646/zootaxa.4052.4.1, <a href="http://zenodo.org/record/245887">http://zenodo.org/record/245887</a>
Oswaldella terranovae Pena Cantero & Vervoort 1996
No full textOswaldella terranovae Peña Cantero & Vervoort, 1996 (Figs 4–5) Oswaldella terranovae Peña CanTerO & VerVOOrT, 1996: 136–138, fig. 1; 1998: 37; 2004: 850; Peña CanTerO et al., 1997: 344; Peña CanTerO & García CarrascOsa, 1999: 214; Peña CanTerO & Marques, 1999: 85; Peña CanTerO & GOnzález MOlinerO, 2015: 439; Peña CanTerO, 2017: 60. Oswaldella antarctica —TOTTOn, 1930: 209–210, fig. 51. Oswaldella stepanjanti El Beshbeeshy, 1991: 263, 265 (incOrrecT Original spelling); Miranda et al., 2016: 596 – 597. Oswaldella stepanjantsae Peña CanTerO et al., 1997: 344, 376–380, figs 11, 15D; Peña CanTerO & VerVOOrT, 1998: 36; 2004: 847–850, fig. 15; Peña CanTerO & García CarrascOsa, 1999: 214; Peña CanTerO & Marques, 1999: 85; Peña CanTerO et al., 2010: 41–57; Peña CanTerO, 2013: 130; 2014c: 1721, fig. 4g; 2017: 60, fig. 19B; GOnzález MOlinerO & Peña CanTerO, 2015: 419–422, 438, figs 13, 16M, 18E, 20D; Miranda et al., 2016: 596 – 597. Oswaldella antarctica – BrOch, 1948: 13 –16, fig. 4a; STepanjanTs, 1979: 112, pl. 21 fig. 5. Oswaldella antarctica p.p. NaumOV & STepanjanTs, 1972: 52, fig. 14a, b. Material examined. Syntypes, British Antarctic Terra Nova Expedition, 1910–1913, Stn 220, 2 January 1912, off Cape Adare, Ross Sea, 82 – 92 m, nine microscope slides, four with stem fragments and five with hydrocladia (1929.10.28.171, labelled n° 2), numerous stem fragments up to 180 mm high (NHM 1929.10.28.173), and a tuft of stems at least 150 mm high (NHM 1929.10.28.174). Other material previously identified as O. stepanjantsae: United States Antarctic Research Program (USARP): Stn 691/26, Hero, 10 February 1969, 63°26’–63°25’S, 62°15’–62°14’W (south of Low Island, Antarctic Peninsula), 119–124 m, numerous fragments up to 220 mm long (USNM 1003370); Stn 833/018–1, Hero, 1 April 1983, 62°41.50’S, 56°01.75’W (off Elephant Island, South Shetland Islands), 210–240 m, one stem ca. 500 mm high (USNM 1003372). New Zealand Antarctic Expedition TAN0802: Stn 17, Tangaroa, 9 February 2008, 73.1245°S, 174.3205°E (Ross Sea, Cape Adare), 321 m, a few stems and fragments, up to 470 mm high (NIWA 35451). Description from the syntypes. Stems at least 180 mm high, thick and dark brown, basally polysiphonic. Stem divided into short and wide internodes, usually with two apophyses, but internodes with four or six apophyses also present. Nodes sometimes obscure and often incomplete. Cauline apophyses strongly directed upwards, frequently followed by a few short athecate internodes. Hydrocladia initially also strongly directed upwards, curving outward later. Cauline apophyses with four to six axillary nematophores, each emerging through a perisarc hole (Fig. 4B), occasionally with extremely short collar-shaped nematotheca, and two extra nematophores, each emerging through a strongly marked ‘mamelon’ (Fig. 4B). Hydrocladia much branched (Fig. 4A), typically with two third-order hydrocladia, although up to six thirdorder hydrocladia observed. First hydrocladial internode bifurcated, with two similar prongs (Fig. 4A). Mesial inferior nematophore emerging from marked swelling at proximal third of internode (Fig. 4C–E); with nail-shaped nematotheca (Fig. 4C–F). Hydrotheca elongate, placed on middle of internode. Abcauline wall roughly straight, but usually slightly bent abcaudally at distal part. Adcauline wall mostly adnate, but with distinct free part (Fig. 4D). Hydrothecal aperture circular, perpendicular to longitudinal axis of internode (Fig. 4C–E); rim even (Fig. 4C, E). In frontal view, diameter of hydrotheca increasing distally up to the middle, then roughly constant but markedly widening at aperture, producing a sort of neck with flared rim (Fig. 4C, E). Gonothecae immaure, cone-shaped. Remarks. We observed a maximum of five axillary nematophores in the examined cauline apophyses of the type material, although one or two of the central nematophores are frequently distinctly larger and have a central constriction, which may indicate that they result from the fusion of two. The description of Oswaldella terranovae was based on a series of ten microscope slides (BMNH 1929.10.28.171) belonging to the material from the British Antarctic Terra Nova Expedition assigned to Oswaldella antarctica (Jäderholm, 1904) by Totton (1930). According to Peña Cantero & Vervoort (1996) the cauline apophyses were provided with two axillary nematophores emerging through perisarc holes and two nematophores emerging through ‘mamelons’ placed on the upper part and near the distal end of the apophyses. The SEM study carried out here has shown that O. terranovae has 4 to perhaps 6 axillary nematophores (we observed up to five, but it is likely that other cauline apophyses have six). The fact that the cauline apophyses lie closely on the cauline internodes makes it very difficult to observe the axillary nematophores, much more when the material available is in slides, as when Peña Cantero & Vervoort (1996) described the species. It has always been difficult to distinguish between Oswaldella stepanjantsae and O. terranovae because of their similarity in colony structure and in the shape and size of their hydrothecae. Peña Cantero & Vervoort (1996: 138) already indicated that O. stepanjantsae ‘resembles O. terranovae in almost all its characteristics’. According to these authors both have ‘robust colonies, stems of lower order, the stems divided into internodes, usually short athecate internodes following the cauline apophyses and hydrocladia of the third order’ (see also Peña Cantero et al. 1997). Peña Cantero et al. (1997) highlighted a few differences between the species, the most important of which was the apparent presence of two axillary nematophores in O. terranovae and four in O. stepanjantsae. Later, however, it was demonstrated that O. stepanjantsae can have up to six axillary nematophores (cf. Peña Cantero & Vervoort 2004; González Molinero & Peña Cantero 2015)] and, as it has been shown in this study, O. terranovae actually has up to five, probably six. As a result, this character can no longer be used to distinguish them. We conclude that no differences exist between the type materials of O. terranovae and O. stepanjantsae, and maintain that there is no justification for recognizing them as distinct species. We are here considering O. stepanjantsae a junior synonym of O. terranovae. See Miranda et al. (2016) for a discussion about the correct authorship for O. stepanjantsae. Even though the gonothecae in the type material of O. terranovae are immature [see fig. 1h in Peña Cantero & Vervoort (1996)], mature gonothecae have been described in material identified as O. stepanjantsae [see for example, fig. 11G – H in Peña Cantero et al. (1997)]. Distribution. Circum-Antarctic. Oswaldella terranovae had only been reported off Cape Adare (Totton 1930; Peña Cantero & Vervoort 1996), but O. stepanjantsae has been considered to have a circum-Antarctic distribution (Peña Cantero & Vervoort 1998).Published as part of Cantero, A. L. Peña & Molinero, A. González, 2018, On several species of Oswaldella Stechow, 1919 (Cnidaria, Hydrozoa), including the description of a new species, pp. 397-414 in Zootaxa 4457 (3) on pages 402-407, DOI: 10.11646/zootaxa.4457.3.3, http://zenodo.org/record/145789
Oswaldella grandis Pena Cantero, Svoboda & Vervoort 1997
No full textOswaldella grandis Peña Cantero, Svoboda & Vervoort, 1997 (Figs 1–2) Oswaldella grandis Peña CanTerO, SVObOda & VerVOOrT, 1997: 363–367, figs 7, 14C, D; Peña CanTerO & García CarrascOsa, 1998: 179; 1999: 212 eT seq.; Peña CanTerO & VerVOOrT, 1998: 36; 2004: 833–835, fig. 9; 2009: 86; Peña CanTerO & Marques, 1999: 85; Peña CanTerO & Ramil, 2006: 953, figs 2D, 3A–C; Peña CanTerO, 2008: 457; 2013: 129–130; GOnzález MOlinerO & Peña CanTerO, 2015: 412, 436, figs 7, 16G, 17G, 19G. Oswaldella bifurca —Peña CanTerO, 1991: 175, pl. 32; Peña CanTerO & García CarrascOsa, 1994: 125, fig. 8d–f; 1995: 101–104, fig. 45A–E. ? Oswaldella bifurca —NaumOV & STepanjanTs, 1962: 98; STepanjanTs, 1979: 112, pl. 21 fig. 4; BlancO, 1984: 43, pl. 39 figs 89, 90, pl. 40 figs 91–93, pl. 41 fig. 94. Material examined. German Polarstern Antarctic expedition ANT VIII-5: Stn 16-475, 13 February 1990, 76.85°S, 49.43°W (off Ronne Ice Shelf, Weddell Sea), 280 m, single colony c. 170 mm high, with female gonothecae (Holotype, RMNH Coel. no. 27466, three slides no. 3248). Spanish Antarctic expedition GEBRAP 96: Stn 5, 1 January 1997, 62°52’40’’–62°52’58’’S, 59°59’07’’– 59°58’02’’W (Bransfield Strait, off Livingston Island, South Shetland Islands), 922– 699 m, one stem c. 180 mm high, with gonothecae. Description (Holotype). Polysiphonic, unbranched stem 170 mm high. Angle between cauline apophyses and stem ca. 45°. Cauline apophyses with up to six nematophores, three to four axillary ones (Fig. 1B), each emerging through a simple hole in perisarc, although usually provided with a very short collar-shaped nematotheca (Fig. 1B), and up to two other nematophores, each emerging through a ‘mamelon’, sometimes little marked or even absent (Fig. 1B). Hydrocladia much branched (Fig. 1A), with up to third-order hydrocladia. First hydrocladial internode bifurcated (Fig. 1A), with two similar prongs. Mesial-inferior nematophore emerging from slightly marked swelling at proximal third of internode (Fig. 1D–E) and provided with a reduced nematotheca (Fig. 1C–E). Hydrotheca placed on distal half of internode (Fig. 1A, C–D). Hydrotheca low, about as high as wide. Abcauline hydrothecal wall straight. Hydrothecal aperture circular, perpendicular to longitudinal axis of internode; rim even (Fig. 1C–D). Female gonothecae club-shaped, with sub-terminal aperture (Fig. 1F). Remarks. The SEM study has allowed us to better study the nematophore number and structure of the cauline apophyses. These are relatively short and strongly directed upwards, which makes it really difficult to observe the axillary nematophores. This justifies, for example, that O. grandis was previously characterized as having two axillary nematophores when it actually is provided with three or four. In addition, we observed the presence of short collar-shaped nematothecae associated with the axillary nematophores, as evidenced in other species of Oswaldella (e.g. O. laertesi Peña Cantero, 2007) by González Molinero & Peña Cantero (2015). In the holotype, however, the presence of collar-shaped nematothecae is not constant. There are examples where it is absent, or not completely developed, in one or more of the axillary nematophores. On the other hand, the ‘mamelons’ of the cauline apophyses are sometimes little marked or even absent. In the material of O. grandis studied by González Molinero & Peña Cantero (2015), the mesial inferior nematophore was deprived of a nematotheca, probably due to the bad condition of the colony. This material also differs from the type material in the fact that the unforked hydrocladial internodes do not present a distinct infrathecal swelling. Concerning the number of nematophores of the cauline apophyses, there were three axillary nematophores emerging through simple holes in perisarc, but there was no collar-shaped nematotheca, perhaps related again to the bad condition of the material. In addition, there were up to two extra nematophores, each emerging through a ‘mamelon’, although they were sometimes absent. In order to evaluate if these discrepancies could be due to interspecific differences, we studied material ascribed to O. grandis by Peña Cantero & Ramil (2006). This material had been collected during the Spanish Antarctic expedition GEBRAP 96 in an area relatively close to that of the material studied by González Molinero & Peña Cantero (2015). Expecting to find similar characters to those described by González Molinero & Peña Cantero (2015), the GEBRAP material, however, agreed with the type material in every detail. The cauline apophyses also have up to six nematophores, three to four axillary ones, usually with a short collar-shaped nematotheca (Fig. 2B–C), and two other nematophores, each emerging through a well-marked ‘mamelon’ (Fig. 2B–C). Consequently, we consider that the few differences between the holotype and the material studied by González Molinero & Peña Cantero (2015) are likely related to the bad condition of the latter. As in other species of the genus [see González Molinero & Peña Cantero (2015), and O. terranovae below], the number of axillary nematophores in the cauline apophyses of O. grandis is variable, from three to four. The species was originally posited to be characterized by the presence of two axillary nematophores (cf. Peña Cantero et al. 1997), but that number was clearly underestimated due to the difficulty in observing the axillary nematophores with an optical microscope. See González Molinero & Peña Cantero (2015) for a discussion about the known variability in the number of axillary nematophores in the cauline apophyses in the species of Oswaldella studied using SEM. There is also variability concerning the “mamelons” of the cauline apophyses. Peña Cantero et al. (1997: 364) characterized the species by the presence of two “mamelons”, but pointed out that “towards distal part of the stem ‘mamelons’ of apophyses tend to become reduced or even absent”. However, they also indicated that circular perisarc holes were always present. In the present study, the variability in the number and development of the ‘mamelons’ has been confirmed. What would be characteristic for the species is the presence of two well-marked ‘mamelons’ (Fig. 2B–C), but they can be either inconspicuous (cf. Fig. 7B–C in González Molinero & Peña Cantero 2015), marked by simple circular perisarc holes, or completely absent (Fig. 1B). Although only the last state is shown in the figure from the type material (see Fig. 1B), the other conditions (i.e. the presence of two either well-marked or inconspicuous ‘mamelons’) were also observed. See González Molinero & Peña Cantero (2015) for a discussion about the variability in the number and development of the “mamelons” of the cauline apophyses in species of Oswaldella studied using SEM. Distribution. West Antarctic (Peña Cantero & Vervoort 1998).Published as part of Cantero, A. L. Peña & Molinero, A. González, 2018, On several species of Oswaldella Stechow, 1919 (Cnidaria, Hydrozoa), including the description of a new species, pp. 397-414 in Zootaxa 4457 (3) on pages 398-402, DOI: 10.11646/zootaxa.4457.3.3, http://zenodo.org/record/145789
Oswaldella incognita Pena Cantero, Svoboda and Vervoort 1997
No full textOswaldella incognita Peña Cantero, Svoboda and Vervoort, 1997 (figure 11) Oswaldella incognita Peña Cantero et al., 1997: 367–369, figure 8; Peña Cantero and Vervoort, 1998: 36; Peña Cantero and García Carrascosa, 1999: 212 et seq.; Peña Cantero and Marques, 1999: 85. Oswaldella antarctica: Peña Cantero, 1991: 168, pls 31, 56, pl. 68 figure a; Peña Cantero and García Carrascosa, 1994: 125, figure 8 a–c; 1995: 96–101, figures 43A–E, 44A–F, 64E. Material examined. 691/023, one stem ca 35 mm high, with a single hydrocladium (USNM 1003334); 691/27, two stems and one stem fragment up to 80 mm high, with male gonothecae (USNM 1003335; RMNH-Coel. 30216; MNCN 2.03 / 236); 7/484, two stems up to 60 mm high (USNM 1003336); 721/776, one basally broken stem ca 60 mm high, with male gonothecae (USNM 1003337); 721/801, one stem ca 48 mm high (USNM 1003338). Description. Colonies composed of monosiphonic and unbranched stems (forked in the material from Stn 7 / 484), provided with apophyses alternately arranged in one plane and forming two longitudinal series. Apophyses directed upwards at an angle of ca 45 °. Stem divided into internodes with one apophysis each. Cauline apophyses supporting hydrocladia; up to second-order hydrocladia present (figure 11A). Node separating cauline apophyses and hydrocladia inconspicuous (figure 11B). Cauline apophyses provided with two axillary nematophores, each emerging through an axillary perisarc hole (figure 11B); 'mamelons' absent. Top of distal hydrocladial internodes truncated. Hydrocladia homomerously segmented; internodes each with one hydrotheca and two nematophores (figure 11 C–G): one mesial inferior emerging through a perisarc hole on a slight elevation of the internode and provided with a scale-shaped nematotheca, and one mesial superior emerging through a perisarc hole situated behind the free adcauline hydrothecal wall. Hydrothecae placed either in middle of hydrocladial internode or on its distal half (figure 11A, C–G). Hydrotheca elongate, with circular aperture slightly tilted adcaudally. Rim even; sometimes with a tiny adcauline elevation. Abcauline wall of hydrotheca slightly convex, or straight; angle with long axis of internode 30 ° or less. Free adcauline hydrothecal wall distinct. Male gonothecae present, inserted at hydrothecal base on elevation of internode (figure 11A), fusiform, with a subterminal, oval aperture (figure 11A, H). Remarks. Oswaldella incognita is a well-characterized species, easily recognizable by the unbranched stems divided into internodes, the presence of secondary hydrocladia only, the existence of two axillary nematophores on the cauline apophyses and the shape of the hydrotheca (cf. table 1). Ecology and distribution. Oswaldella incognita has been found at depths from 234 (Peña Cantero and García Carrascosa, 1995) to 414 m (Peña Cantero et al., 1997); our material comes from 73 to 952 m. Peña Cantero and García Carrascosa (1995) found fertile colonies in January; colonies with gonothecae in our material were collected in January and February. The species was previously known only from off Elephant Island (Peña Cantero and García Carrascosa, 1995; Peña Cantero et al., 1997). Our material comes from north of the South Orkney Islands, off Brabant Island (Palmer Archipelago), off Deception and Livingston Islands (South Shetland Islands) and off Low Island.Published as part of Peña Cantero, A. L. & Vervoort, W., 2004, Species of Oswaldella Stechow, 1919 (Cnidaria: Hydrozoa: Kirchenpaueriidae) from US Antarctic expeditions, with the description of three new species, pp. 805-861 in Journal of Natural History 38 on pages 837-83
Halecium pseudoincertus Cantero, 2014, sp. nov.
No full textHalecium pseudoincertus sp. nov. (Figs 10 B, 12) Halecium incertus — Peña Cantero, 2008: 454 –455, fig. 1 b; 2009: 1747; 2012: 857. Material examined. Spanish Antarctic Expedition Bentart 95: Stn 22 R, two stems, up to 90 mm high, on pebbles; Stn 31 A, one stem, c. 110 mm high. Spanish Antarctic Expedition Bentart 2006: Stn 34, a stem, c. 165 mm high (Holotype, MNCN 2.03 / 445, Museo Nacional de Ciencias Naturales, Madrid, Spain), and a stem, 75 mm high (Paratype), basibiont of Stegopoma plicatile; Stn 34 - 2, a distal stem fragment, c. 43 mm long. New Zealand Antarctic Expedition TAN0402: Stn 232, one stem, c. 310 mm high; Stn 277, one stem, c. 75 mm high, on gravel. Diagnosis. Long and thin, polysiphonic, mainly unbranched stems, up to 310 mm high. Stem giving rise every third hydrotheca and alternately in two planes to monosiphonic branches at distal part. Branches originating from hydrophore of primary hydrotheca, monosiphonic, unbranched or with up to two secondary branches. Hydrothecae alternately arranged in two planes. Hydrotheca at the end of short, mostly adnate hydrophore provided with a strongly marked pseudodiaphragm. Hydrotheca distinctly widening distally; rim everted. Adcauline hydrothecal wall free; distinctly larger than abcauline one. Hydrothecal aperture directed downwards. Up to five-order hydrothecae present. Gonothecae unknown. Cnidome consisting of isorhizas, larger microbasic euryteles?, smaller microbasic euryteles and microbasic mastigophores. Description (Holotype). Stem polysiphonic, except for last 17 mm, mostly unbranched (Fig. 10 B), tortuous and relatively long (c. 165 mm high) and thin (c. 1 mm at basal part). Stem distally provided with 16 primary branches and eight secondary ones. Branching regular, alternate at every third hydrotheca in two planes, forming an obtuse angle of c. 90 ° in distal part of stem (where branches are present). Probably, angle slightly larger at basal part. Length of lateral branches decreasing upwards. Branches monosiphonic, unbranched, or with a single secondary branch (occasionally two). Secondary branches directed inwards (i.e., towards space delimited by primary branches). Lower-order branches resting on large apophysis formed at the side of primary hydrothecal hydrophore just below hydrotheca. Hydrothecae alternately arranged in two planes, making an angle of c. 90 °. Hydrothecae resting on hydrophores adnate in most of its adcauline length (Fig. 12 A–D); ratio between adcauline length of hydrophore and diameter at diaphragm 0.8–1.3. Hydrotheca low, distinctly widening from diaphragm upwards, particularly at adcauline side (Fig. 12 A, B, D). Adcauline wall distinctly higher than abcauline one (Fig. 12). Adcauline hydrothecal wall free to internode (Fig. 12 A–F). Hydrothecal aperture directed downwards (Fig. 12). Rim everted. With up to five lower-order hydrothecae on smooth hydrophores (Fig. 12 A). Lower-order hydrothecae symmetrical (Fig. 12 A–C, E). A strongly marked pseudodiaphragm present (Fig. 12). Gonothecae unknown. Measurements (in µm). Hydrothecae: diameter at aperture 220–225, diameter at diaphragm 160–180, height 25–45. Hydrophore: adcauline length 120–230. Internodes: length 750–1070, diameter at distal part 130–170. Cnidome: isorhizas [range 9.5– 11 x 3.0– 3.5, mean 10.2 ± 0.5 x 3.1 ± 0.2 (n= 10); ratio, range 2.7–3.7, mean 3.2 ± 0.3 (n= 10)], smaller microbasic euryteles [range 7 x 3, mean 7.0±0.0 x 3.0±0.0 (n= 6), ratio, range 2.3, mean 2.3 ±0.0 (n= 6)], microbasic mastigophores c. 7.5 x 2, and larger microbasic eurytele? c. 14 x 6. Remarks. Although the first 120 mm of the stem are deprived of branches, their origin is visible through a careful examination, clearly indicating that they are lost as the colony grows. Halecium pseudoincertus sp. nov. is similar to H. incertus in the hydrothecal shape and the presence of pseudodiaphragm. However, they are easily distinguishable by the colonial structure. Whereas in H. pseudoincertus sp. nov. the stem is mostly unbranched, being provided with lateral monosiphonic branches, originating alternately in two planes, at its most distal part only, in H. incertus the colonies have thick and polysiphonic stems, repeatedly branched irregularly in several planes, and primary and secondary branches also polysiphonic. In addition, the hydrothecae, and particularly the isorhizas, are distinctly smaller in H. pseudoincertus sp. nov. Internodes are also thinner and longer in H. pseudoincertus sp. nov. Furthermore, the hydrophore is completely adnate in H. incertus, whereas it has a distinct free portion in H. pseudoincertus sp. nov. Finally, whereas Millard (1977) indicated that secondary hydrophore, with or without pseudodiaphragm, are rather rare in H. incertus, up to five-order hydrothecae are present in H. pseudoincertus sp. nov. Because of all these differences, it is easy to identify both species even in the absence of gonothecae, which justifies the description of the new species to science despite the absence of information on gonothecae. Ecology and distribution. Halecium pseudoincertus sp. nov. has been collected at depths from 96 (Peña Cantero 2009) to 1019 m (Peña Cantero 2008), epilithic on pebbles (Peña Cantero 2008) and gravel (Peña Cantero 2009). It is used as substratum by colonies of other hydroids (Peña Cantero 2009, 2012). Halecium pseudoincertus sp. nov. seems to have a circum-Antarctic distribution. It has been reported from the Bellingshausen Sea (Peña Cantero 2012) and off Deception Island and the north of Livingston Island (Peña Cantero 2008), in West Antarctica, and off Sturge and Young islands, the Balleny Islands (Peña Cantero 2009), in East Antarctica. Etymology. The specific name pseudoincertus refers to the fact that the shape of the hydrotheca in this species is reminiscent of that of H. incertus.Published as part of Peña Cantero, Álvaro L., 2014, Revision of the Antarctic species of Halecium Oken, 1815 (Cnidaria, Hydrozoa, Haleciidae), pp. 243-280 in Zootaxa 3790 (2) on pages 271-273, DOI: 10.11646/zootaxa.3790.2.2, http://zenodo.org/record/22689
Oswaldella vervoorti Pena Cantero & Garcia Carrascosa 1998
No full textOswaldella vervoorti Peña Cantero & García Carrascosa, 1998 (Figs 14, 16 O, 18 G, 20 G) Material examined. United States Antarctic Research Program (USARP): Stn 721 / 1063, Hero, 19 December 1971, 62°19.0’S, 59 °11.4’W (Nelson Island, South Shetland Islands), 44 m (USNM 1003380). Description. Monosiphonic, unbranched stems, up to 95 mm high, divided into internodes. Angle between cauline apophyses and stem ca. 45 °. Cauline apophyses with two axillary nematophores, each emerging through hole in apophysis perisarc, provided with slight abcauline projection of perisarc, and another one emerging through strongly developed ‘mamelon’, provided with relatively large aperture (Fig. 14 B). Hydrocladia branched (Fig. 14 A), with up to fourth-order hydrocladia. First hydrocladial internode bifurcated, with two similar prongs (Fig. 14 A). Mesial inferior nematophore emerging from marked swelling at proximal third of internode (Fig. 14 C–D); with relatively large, claw-shaped nematotheca (Fig. 14 C–E). Hydrotheca elongate, placed on distal half of internode. Abcauline wall roughly straight; adcauline wall mostly adnate (Fig. 14 D). Hydrothecal aperture perpendicular to long axis of internode, sub-circular, adcauline side more or less straight; rim even (Fig. 14 C–D). Immature gonothecae, inverted cone-shaped (Fig. 14 A, F). Remarks. Although only up to second-order hydrocladia were observed in the material examined (Fig. 14 A), up to fourth-order hydrocladia have been described (cf. Peña Cantero & García Carrascosa 1998).Published as part of Molinero, A. González & Peña Cantero, A. L., 2015, SEM study of species of Oswaldella Stechow, 1919 (Cnidaria, Hydrozoa, Kirchenpaueriidae), with an annotated checklist of the species of the genus, pp. 401-441 in Zootaxa 4052 (4) on page 422, DOI: 10.11646/zootaxa.4052.4.1, http://zenodo.org/record/24588
Oswaldella grandis Pena Cantero, Svoboda & Vervoort 1997
No full textOswaldella grandis Peña Cantero, Svoboda & Vervoort, 1997 (Figs 7, 16 G, 17 G, 19 G) Material examined. Spanish Antarctic Expedition Antártida 8611: Stn NA 172, 61°01'S – 60 ° 58 'S, 55 ° 34 '– 55 ° 56 'W (Elephant Island, South Shetland Islands) (Department of Zoology, University of Valencia, ANT NA 172). Description. Polysiphonic, unbranched stems, up to 500 mm high, usually divided into internodes. Angle between cauline apophyses and stem ca. 45 °. Cauline apophyses with four to five nematophores, two to three axillary ones, each emerging through simple hole in perisarc, and other two nematophores, each emerging through ‘mamelon’ (Fig. 7 B–C). Hydrocladia much branched (Fig. 7 A), with up to third-order hydrocladia. First hydrocladial internode bifurcated (Fig. 7 A), with two similar prongs. Mesial-inferior nematophore typically with much reduced nematotheca, though not existent in present material (Fig. 7 D–F). Unforked hydrocladial internodes without infrathecal swelling. Hydrotheca placed on distal half of internode (Fig. 7 D–E). Hydrotheca low, about as high as wide. Abcauline hydrothecal wall straight. Hydrothecal aperture circular, perpendicular to longitudinal axis of internode; rim even (Fig. 7 D–E). Male gonothecae almost cylindrical, with subterminal opening. Female larger, club-shaped, with subterminal aperture. Remarks. Peña Cantero & García Carrascosa (1995) did not find any mesial inferior nematothecae when they examined this material, a pattern corroborated herein by SEM analysis. As Peña Cantero & García Carrascosa (1995) indicated, this could be related with the poor condition of the material with just a few hydrocladia left. Until now only two axillary nematophores in the cauline apophyses had been described for this species. However, we observed three with the central one being larger and sometimes with the appearance of being the result of coalescence of two central ones (Fig. 7 C).Published as part of Molinero, A. González & Peña Cantero, A. L., 2015, SEM study of species of Oswaldella Stechow, 1919 (Cnidaria, Hydrozoa, Kirchenpaueriidae), with an annotated checklist of the species of the genus, pp. 401-441 in Zootaxa 4052 (4) on page 412, DOI: 10.11646/zootaxa.4052.4.1, http://zenodo.org/record/24588
Oswaldella occulta Cantero & Molinero 2018, sp. nov.
No full textOswaldella occulta sp. nov. (Figs 7–8) Oswaldella sp. GOnzález MOlinerO & Peña CanTerO, 2015: 422, figs 15, 16P, 18H, 20H; Peña CanTerO, 2017: 60, fig. 19C. Material examined. From the type series of Oswaldella terranovae: British Antarctic Terra Nova Expedition 1910–1913, Stn 220, 3 January 1912, off Cape Adare, Ross Sea, 82 – 92 m, several stems up to 120 mm high (NHM 1929.10.28.171), one slide with hydrocladia (1929.10.28.171, labelled n° 4), and four stems up to 130 mm high (NHM 1929.10.28.172). A 57-mm-long, basally broken stem from the material with the collection number NHM 1929.10.28.172 is designated as holotype (all the remaining material is paratype). Other material examined: New Zealand Antarctic Expedition TAN0402, Stn 178, Tangaroa, 27 February 2004, 71°31’89’’–71°32’16’’S, 171°18’31’’–171°18’70’’E (Cape Adare, Ross Sea), 343–348 m (identified as Oswaldella sp. by González Molinero & Peña Cantero 2015). Description. Stems at least 130 mm high, unbranched and slightly polysiphonic basally. Stem thin, yellowbrown, divided into internodes separated by strongly marked nodes. From one to three apophyses per internode. Angle between cauline apophyses and stem c. 45°. Cauline apophyses with two axillary nematophores, each emerging through a simple hole in perisarc (Fig. 7B); no ‘mamelons’ present. Apophyses short, distinctly separated from hydrocladia. Hydrocladia much branched (Fig. 7A), with up to six third-order hydrocladia, three on each secondary hydrocladium (in one case with four tertiary hydrocladia on a secondary hydrocladium); occasionally, a short fourth-order hydrocladium was present. Tertiary hydrocladia placed lower than secondary ones. Hydrocladia divided into internodes, barely decreasing distally in size; e.g. 1000–930 µm in length and 280–270 µm in diameter under hydrotheca, in 1 st and 8th unforked internodes of secondary hydrocladium, respectively. First hydrocladial internode bifurcated (Fig. 7A), with two similar prongs, distinctly separated from first internode of secondary hydrocladia. Mesial-inferior nematophore emerging from marked swelling at proximal third of internode (Figs 7C– E, 8A) and provided with a prominent nematotheca placed on frontal side of swelling (Figs 7C–F, 8); usually nematotheca abcauline wall distinctly directed outwards. Hydrotheca placed on distal half of internode (Figs 7A, C–E, 8). Hydrotheca low, about as high as wide. Abcauline hydrothecal wall straight, directed abcaudally; length slightly increasing along hydrocladium (e.g. 210 µm in 1 st internode of secondary hydrocladium and 240 µm in 7th internode). Perisarc of hydrotheca distinctly thickened (Fig. 7C). Hydrothecal aperture circular (Fig. 7C), 210–200 µm in diameter, roughly perpendicular to longitudinal axis of internode (Figs 7D–E, 8); rim even (Figs 7C–E, 8). In frontal view, hydrotheca usually jar-shaped, with a swollen basal half and a narrower distal one, but markedly widening again at aperture, producing a sort of narrow neck with flared rim (Fig. 7C, E). Gonothecae unknown. Cnidome composed of microbasic mastigophores in two size groups: larger, range 11–15 x 3.5–4, mean 12.8 ± 1.2 x 3.8 ± 0.3 (n = 14); smaller, range 6– 7 x 2. Remarks. The material of Oswaldella occulta sp. nov. was in the material assigned to O. antarctica (Jäderholm, 1904) by Totton (1930) and later described as O. terranovae by Peña Cantero & Vervoort (1996). On two occasions a secondary hydrocladium forms a third-order hydrocladium in its first and third internodes, but not in the second one (i.e. the second internode is unforked). The species seems to have stems slightly polysiphonic only basally. Most of the stems available are deprived of the basal part and it was not possible to ascertain if they were polysiphonic. There are, however, hints indicating that the species can develop a sort of polysiphonic condition. Among the material examined, there is a stem, 105 mm high, provided with the basal part. Its first 13 mm have a few creeping stolons originating from cauline apophyses, some of them running downwards and acting as hydrorhizal stolons. In addition, some of the basally broken stems also have creeping stolons originating from cauline apophyses, although not in their most basal part. It is therefore highly likely that O. occulta sp. nov. can develop stems with a slightly polysiphonic basal part. Oswaldella occulta sp. nov. appears to have unbranched stems, although the issue is as yet unresolved. The available material, however, points to the unbranched condition. The species seems to develop colonies with tuft appearance, with several unbranched stems growing together. In the available material there are some stems apparently branched, but the ‘branches’ are actually new stems. The ‘branching’ is associated with those parts of the stem with creeping stolons originating from cauline apophyses mentioned above. The new stems originate from those stolons, and in all cases they begin with an intermediate internode deprived of cauline apophyses, followed by a normal series of hydrocladia-bearing internodes provided with cauline apophyses. Only in one occasion a secondary stem/branch was observed, developing from a basally and distally broken, 90-mm-high stem. Apart from a basal new stem, with intermediate internode, originating from stolons as explained above, there is a distal stem/branch originating directly from the stem through a hole in the perisarc, not from a stolon. This secondary stem differs from the new stems in being composed of a normal series of hydrocladia-bearing internodes provided with cauline apophyses (i.e. there is no basal intermediate internode). Among the species of the genus, Oswaldella occulta sp. nov. is morphologically closer to O. tottoni in the presence of a low hydrotheca, its position on the distal half of internode, and in the number of axillary nematophores in the cauline apophyses. However, they are clearly distinguishable in several important features. The stem is divided into internodes by strongly marked nodes in Oswaldella occulta sp. nov., whereas there is no stem division in O. tottoni; nodes are only occasionally present (cf. Peña Cantero & Vervoort 1996: 139). The degree of hydrocladial branching is also different: hydrocladia are much branched in Oswaldella occulta sp. nov., with up to six third-order hydrocladia, but only bifurcated in O. tottoni, with only two secondary hydrocladia, which, in addition, bend inwards. Another important difference concerns the separation between the prongs of the first branched hydrocladial internode and the second-order hydrocladia. In Oswaldella occulta sp. nov. there is always a distinct node between the prongs and the first internode of the secondary hydrocladia (Fig. 7A), whereas in O. tottoni one, or both, of the prongs are frequently fused with the first internode of the second-order hydrocladia (Fig. 6A, see also Fig. 2a in Peña Cantero & Vervoort 1996). In O. tottoni, as it was characterized by Peña Cantero & Vervoort (1996), the first hydrocladial internode, the branched one, lacks mesial inferior nematophore (cf. Fig. 6B, see also Fig. 2a–b in Peña Cantero & Vervoort 1996 and Fig. 12A, C in Peña Cantero et al. 1997); we can also confirm this observation, although occasionally that nematophore was present (Fig. 6A). Another important difference is related to the position of the mesial inferior nematotheca, which is located at the most external point of the infrathecal swelling and its abcauline wall is distinctly directed outwards in Oswaldella occulta sp. nov. (Fig. 7C–F), whereas in O. tottoni, and the remaining species of the genus with infrathecal swelling, it is located on the upper side and its abcauline wall is not directed abcaudally. Oswaldella tottoni and Oswaldella occulta sp. nov. also differ in the shape of the hydrotheca. Both species have low hydrothecae, but in O. tottoni the diameter of the hydrotheca increases from the base to the top (Fig. 6C), whereas in Oswaldella occulta sp. nov. the hydrotheca has a swollen basal half and a narrower distal one, although markedly widening again at aperture, producing a sort of narrow neck with flared rim (Fig. 7C, E). Oswaldella occulta sp. nov. also has distinctly thicker perisarc (compare Fig. 6C to Fig. 7C), which gives it a slight stony appearance. By the absence of ‘mamelons’ and the presence of two axillary nematophores on the cauline apophyses, Oswaldella occulta sp. nov. is also similar to O. bifurca (Hartlaub, 1904), O. billardi Briggs, 1938, O. encarnae Peña Cantero, Svoboda & Vervoort, 1997, O. erratum Peña Cantero & Vervoort, 1997, O. incognita Peña Cantero, Svoboda & Vervoort, 1997 and O. rigida Peña Cantero, Svoboda & Vervoort, 1997. Of these species, only O. bifurca and O. encarnae have a low hydrotheca, the remaining species have an elongate hydrotheca, being easily distinguished from O. occulta sp. nov. Oswaldella bifurca differs from O. occulta sp. nov. by the shape of the hydrotheca, which has a frontally depressed aperture, and its position on the basal half of the internode. Oswaldella encarnae clearly differs by the unbranched hydrocladia, the position of the hydrotheca on the middle of the internode, and the size and shape of the hydrotheca, which has an abcaudally directed aperture. The material described as Oswaldella sp. by González Molinero & Peña Cantero (2015) likely belongs to O. occulta sp. nov. It is morphologically alike and was also collected off Cape Adare. González Molinero & Peña Cantero (2015) indicated that Oswaldella sp. has usually bifurcated hydrocladia with two secondary hydrocladia, although a third-order hydrocladium was not uncommon. A re-examination of the material has allowed us to put into evidence, despite the low number of hydrocladia left, that the presence of two third-order hydrocladia (one on each secondary hydrocladium) is quite common; on one occasion even two tertiary hydrocladia on the same secondary hydrocladium were observed, which indicates a likely higher degree of hydrocladial branching. The material of Owaldella sp. also shares with Oswaldella occulta sp. nov. the division of the stem into internodes, the presence of two axillary nematophores on the cauline apophyses, the position of the hydrotheca on the distal half of internode, the size and shape of the hydrotheca, and the relatively large mesial inferior nematotheca. Distribution. Oswaldella occulta sp. nov. is currently considered endemic to the Ross Sea. Etymology. The species name occulta comes from the Latin occultus, meaning hidden, concealed, and refers to the fact that the species was hidden among material of O. terranovae and was not noticed by Totton (1930) when he first studied this material.Published as part of Cantero, A. L. Peña & Molinero, A. González, 2018, On several species of Oswaldella Stechow, 1919 (Cnidaria, Hydrozoa), including the description of a new species, pp. 397-414 in Zootaxa 4457 (3) on pages 407-412, DOI: 10.11646/zootaxa.4457.3.3, http://zenodo.org/record/145789
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