106,001 research outputs found
Oswaldella blanconae CANTERO, 2017, sp. nov.
No full textOswaldella blanconae sp. nov. (*) Oswaldella blanconae El Beshbeeshy, 1991: 263, 265; Peña Cantero et al., 1997b: 344; Peña Cantero & García Carrascosa, 1998: 179; 1999: 214; Peña Cantero & Vervoort, 1998: 35, 36; 2004: 820–822, fig. 3; Peña Cantero & Marques, 1999: 85; González Molinero & Peña Cantero, 2015: 433; Miranda et al., 2016: 598 (nomen nudum) Oswaldella antarctica — Blanco, 1984: 41, pl. 38 figs 86–88. Remarks. According to Miranda et al. (2016), the binomen Oswaldella blanconae, proposed by El Beshbeeshy (1991), and later used for several authors, is a nomem nudum. I am here making it available by designating the 8 mm high stem described by Peña Cantero & Vervoort (2004) as holotype (National Museum of Natural History, Smithsonian Institution, Washington, DC, USA, USNM 1003307). Description (from Peña Cantero & Vervoort 2004: 820-822). “Stem monosiphonic, unbranched (figure 3A), provided with apophyses alternately arranged in two longitudinal rows. Stem divided into internodes each with one apophysis, internodes arranged in zigzag fashion; stem internodes with bifurcation at origin of cauline apophysis. Angle between long axis of cauline internode and apophyses wider than 45°; angle between cauline apophyses and succeeding cauline internode ca 90° (figure 3A). Cauline apophyses provided with two nematophores: one emerging through a hole in perisarc of axil (figure 3B) and another nematophore emerging through a ‘mamelon’ situated laterally on dorsal side of apophysis (figure 3C). Distinct node present between cauline apophyses and hydrocladia (figure 3C). Hydrocladia undivided or bifurcated (figure 3A); up to secondary hydrocladia present; arrangement always symmetrical. Hydrocladia homomerous; all internodes hydrothecate; distal internodes apically truncated. Hydrocladial internodes provided with one hydrotheca and two nematophores (figure 3B, D–G): one mesial superior emerging through a perisarc hole situated behind free portion of adcauline hydrothecal wall and one mesial inferior, deprived of nematotheca, emerging through a perisarc hole situated on a strongly marked elevation of internode (angle between long axis of hydrocladial internode and steep slope of infrathecal elevation almost 90°). Hydrothecae placed on basal half or basal third of hydrocladial internodes (figure 3), shallow; aperture circular and either perpendicular to longitudinal axis of internode or slightly tilted downwards; rim even. Adcauline wall of hydrotheca with conspicuous free portion, abcauline wall straight, running smoothly into wall of internode; angle with long axis of internode ca 45°. Gonothecae absent.” Distribution. Circum-Antarctic (Peña Cantero & Vervoort 2004). In the Ross Sea, known off Cape Hallett (Peña Cantero & Vervoort 2004)Published as part of ÁLVARO L. PEÑA CANTERO, 2017, Benthic hydroids (Cnidaria, Hydrozoa) from the Ross Sea (Antarctica) collected by the New Zealand Antarctic expedition BioRoss 2004 with RV Tangaroa, pp. 1-65 in Zootaxa 4293 (1) on pages 58-59, DOI: 10.11646/zootaxa.4293.1.1, http://zenodo.org/record/82847
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
Schizotricha falcata Pena Cantero 1998
No full textSchizotricha falcata Peña Cantero, 1998 (Fig. 2D–H) Material examined. TAN 0602/447, one stem 350 mm high, with gonothecae (NIWA 144248). Measurements (in µm). Hydrotheca: length of abcauline wall from 150 µm at 1 st internode to 240 µm at 12 th. Gonothecae: length 1200, maximum diameter 520, diameter at aperture 270. Hydrocladial internodes: from 900 at 1 st internode to 680 at distal ones. Nematocysts: larger microbasic mastigophores 19–21.5 x 6.5–7, smaller 6 x 2. Remarks. The presence of an ahydrothecate internode following hydrocladial and cauline apophyses (Fig. 2D), initially prompted me to consider this material different from that of S. falcata, in which no such ahydrothecate internodes had been reported (cf. Peña Cantero 1998; Peña Cantero & Vervoort 1999). Nevertheless, I have examined some slides from the holotype and found that, at least, there are indications that such internodes might develop after the apophyses; a little, but distinct, perisarc indentation marking what would be the limit between an apophysis and an ahydrothecate internode is usually present (Fig. 2 G-H). A much more careful study of the present material revealed that the presence of an ahydrothecate internode not clearly demarcated from the apophyses was actually the rule; a clearly defined ahydrothecate internode was observed only on a few occasions. Thus, the only difference with previous material of S. falcata is related to the number of infrahydrothecal nematothecae on the cauline internodes: two to three in the holotype (on one occasion one), but only one in this material (two on one occasion). The hydrocladial forked internodes are also provided with a slightly higher number of infrahydrothecal nematothecae (two to three in the holotype, but one or two in the present material). This minor difference in the number of infrahydrothecal nematothecae does not seem important enough and, accordingly, I assign the present material to S. falcata. Present material also agrees with the concept of the species in the presence of unbranched stems, the size and shape of the hydrotheca (abcauline length increasing along hydrocladium, from 150 µm at 1 st internode to 240 µm at 12 th) and gonotheca (1200 µm long, 520 µm in maximum diameter and 270 µm at aperture, sickle-shaped and with two nematothecae) and the peculiar hydrocladial branching. In the present material, up to fifth-order hydrocladia are formed in a typical way, from the first internode of the subsequent lower-order hydrocladia, as usually occurs in other species of the genus. However, the primary hydrocladium also gives rise to another secondary hydrocladium in its fifth internode (this second-order hydrocladium was also observed giving rise to a third-order one at its first internode), as also do the first second-order, third-order and fourth-order hydrocladia. Ecology and distribution. The material, which represents the first record of the species from the area of study, was collected at depths between 74 and 130 m off Young Island; gonothecae in March. The species has been recently reported from the nearby Ross Sea (Peña Cantero 2017).Published as part of Peña Cantero, Álvaro L., 2021, Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica), pp. 321-336 in Zootaxa 4966 (3) on page 330, DOI: 10.11646/zootaxa.4966.3.4, http://zenodo.org/record/473669
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 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 vervoorti Pena Cantero & Garcia Carrascosa 1998
No full textOswaldella vervoorti Peña Cantero & García Carrascosa, 1998 (Figs 3–4) Oswaldella sp. Peña Cantero, 2009: 1749, fig. 3c. Material examined. TAN 0602/430, one stem 90 mm high, with gonotheca (NIWA 144249), one stem 50 mm high, with gonothecae (NIWA 144253) and one stem 50 mm high (NIWA 144255). Description. Stems up to 90 mm high, monosiphonic, divided into internodes (one or two apophyses per internode). Cauline apophyses alternately arranged in one plane, with two axillary nematophores and one mamelon (Fig. 3F). Cauline apophyses giving rise to hydrocladia with a distinct separation between them. Up to second order hydrocladia present. Hydrocladia divided into internodes. Unforked hydrocladial internodes (Fig. 3A–B, G) with one hydrotheca on distal half of internode and two nematophores: a mesial superior nematophore, placed behind free part of adcauline hydrothecal wall (Fig. 3E), and a mesial inferior nematophore, situated on a slightly raised part of the internode and provided with a reduced scale-shaped nematotheca (Fig. 3C–D, H). Forked hydrocladial internodes with hydrotheca between two prongs, each of them with a nematophore, and one mesial inferior nematophore provided with a scaleshaped nematotheca. Apophyses supporting lower-order hydrocladia usually smaller than distal part of internodes. Hydrotheca slightly higher than wide. Adnate to internode for about three-fourths of its adcauline length. Hydrothecal basal part distinctly oblique; abcauline side lower. Abcauline hydrothecal wall longer than adcauline side, aperture slightly directed adcaudally. Distal third of abcauline wall distinctly directed outwards (Fig. 3C–D, H). Gonotheca elongated, club-shaped (Fig. 3I). Measurements (in µm). Hydrotheca: length of abcauline wall from 200 µm at 1 st internode to 300 µm at 7 th, free part of adcauline length 50, diameter at aperture 230–250. Gonothecae: length 2000, maximum diameter 480–700. Nematocysts: larger microbasic mastigophores, 11–12.5 x 3–3.5. Remarks. One of the 50-mm-high stems (NIWA 144253) is provided with a secondary stem originating from a forked hydrocladial internode at the usual location of the gonothecal insertion. This second-order stem has a typical structure. Most cauline apophyses of the 90-mm-high stem are deprived of mamelons; a little prominent mamelon was observed only twice. In one of the 50-mm-long stems (NIWA 144255) only some apophyses, particularly at the basal part of the stem, also present mamelon. In the material studied most hydrocladia are either unforked or just bifurcated (the first internode of primary hydrocladia giving rise to a single secondary hydrocladium). In one of the 50-mm-long stems (NIWA 144255) only seven of its last eight hydrocladia are bifurcated with apophyses quite similar to the distal part of the internode and the hydrotheca approximately in the middle of the bifurcation. There are, however, signs of other branching below. In one case, one first-order hydrocladium has the basal part of four secondary ones, one on each of its four first internodes, resting on distinctly smaller apophyses situated laterally under the hydrotheca. On a few occasions there are secondary hydrocladia that do not originate from the first internodes of the primary hydrocladium, but from others (i.e. there are unforked hydrothecate internodes before the forked ones). This material (NIWA 144255) has hydrothecae (Fig. 3G–H) less elongated (abcauline length up to 250 µm) and wider (diameter at aperture up to 280 µm) than those from the remaining material (Fig. 3A–D). It also has some nematothecae clearly more developed, with a distinct adcauline wall (Fig. 3H). This material, however, is the closest to O. vervoorti by the branching, with unforked hydrothecate internodes between forked ones. According to Peña Cantero & García Carrascosa (1998), although lower-order hydrocladia typically arise from the first internodes of the primary hydrocladia, in many cases unforked hydrothecate internodes were present preceding forked ones. On the other hand, looking at their figures (cf. fig. 1a–c in Peña Cantero & García Carrascosa 1998) it is evident that the apophyses supporting lower-order hydrocladia are smaller than the distal part of the internode. Clearly, it is not a simple bifurcation of the internode. Instead, it is like a normal hydrothecate internode laterally giving rise to the lower-order hydrocladium. In order to confirm this point, I have examined the holotype of O. vervoorti. The first forked hydrocladial internode is the most misleading as sometimes the apophysis supporting the second-order hydrocladium is similar to the distal part of the internode (Fig. 4A); in addition, both the apophysis and the distal part of internode are provided with a nematophore placed at approximately the same level. In all the remaining forked hydrocladial internodes, the prongs are markedly dissimilar (Fig. 4B), one is clearly the distal part of the internode, the other is undoubtedly the apophysis. Both are also provided with nematophores, but that of the apophysis is placed at a lower level (Fig. 4B). The first internodes originating from the apophyses are relatively very long (up to 1300 µm) (Fig. 4C). The primary hydrocladium might give rise to several second-order hydrocladia (up to six according to Peña Cantero & García Carrascosa 1998). Most secondary hydrocladia originate sequentially from the first (up to the fourth) internodes of the primary one, but it is not unusual to observe extra secondary hydrocladia originating after some unforked internodes (this is clearly shown in figure 1a in Peña Cantero & García Carrascosa 1998). The first secondary hydrocladium usually gives rise to a third-order hydrocladium at its first internode, but it can also form other tertiary hydrocladia (up to three according to Peña Cantero & García Carrascosa 1998), sometimes also beyond unforked internodes (see also figure 1a in Peña Cantero & García Carrascosa 1998). According to these authors, the first third-order hydrocladium sometimes even forms a fourth-order one. Mamelons are more prominent in the holotype than in the present material (compare Fig. 3F with Fig. 4E). Although suspicious on geographic grounds, there is no evidence to consider the material studied here different from O. vervoorti. This would not be the first Antarctic benthic hydroid previously considered endemic to West Antarctica and later found in East Antarctica. Peña Cantero (2009) reported, as Oswaldella sp., material likely conspecific with the one studied here, which is considered to belong to O. vervoorti. The young stems, up to 20 mm high, are divided into internodes with one or two apophyses each, the hydrocladia are unforked and the cauline apophyses are provided with two axillary nematophores and the most distal ones have mamelon. The size of the hydrotheca also agrees. Ecology and distribution. Present material was collected at depths between 70 and 120 m off Buckle Island; gonothecae in March. The material described as Oswaldella sp. by Peña Cantero (2009) came from a depth of 70–85 m off Buckle Island. Not only is O. vervoorti reported for the first time from the area of study, but also for East Antarctica, which indicate that its geographical distribution may be considered as circum-Antarctic.Published as part of Peña Cantero, Álvaro L., 2021, Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica), pp. 321-336 in Zootaxa 4966 (3) on pages 332-335, DOI: 10.11646/zootaxa.4966.3.4, http://zenodo.org/record/473669
Oswaldella erratum Pena Cantero & Vervoort 1997
No full textOswaldella erratum Peña Cantero & Vervoort, 1997 (Figs 4, 16 D, 17 D, 19 D) Material examined. German Antarctic Expedition ANT-XXI/ 2: Stn PS 65 / 166 - 1, Polarstern, 15 December 2003, 70°56.83’– 70 °56.00’, 10 °32.61’– 10 °30.53’W (off Cape Norvegia, Weddell Sea), 338 – 253 m. Spanish Antarctic Expedition Bentart 95: Stn 24 R, Hespérides, 30 January 1995, 63°58.4715’S, 60 °51.9882’W (off Trinity Island, Graham Land), 214 m (Department of Zoology, University of Valencia, BENTART 95 - 24 R). Description. Monosiphonic (occasionally polysiphonic), unbranched stems, up to 130 mm high, usually not divided into internodes. Typically, perisarc strongly developed. Angle between cauline apophyses and stem ca. 70 °. Cauline apophyses with two axillary nematophores, each provided with a much-reduced nematotheca (Fig. 4 B). Hydrocladia branched, up to third-order hydrocladia reported. First hydrocladial internode bifurcated, with two similar prongs (Fig. 4 A). Mesial-inferior nematophore on a strongly marked swelling at proximal third of internode (Fig. 4 D–E); with scale-shaped nematotheca (Fig. 4 D–F). Hydrotheca elongate, placed on middle of internode (Fig. 4 A, D–E). Abcauline wall of hydrotheca basally straight, but strongly curving adcaudally at distal part (Fig. 4 E). Hydrothecal aperture kidney-shaped (Fig. 4 C), adcaudally directed (Fig. 4 E). Gonothecae fusiform. Female gonotheca larger than male one, with subterminal, circular aperture. Male gonotheca with distal, circular aperture (Fig. 4 G). Remarks. The most remarkable finding in relation to this species is the presence of much-reduced nematothecae in the axillary nematophores, never described before.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 406-409, DOI: 10.11646/zootaxa.4052.4.1, http://zenodo.org/record/24588
G. Garcia Cantero, El vincido de matrimonio civil en el derecho espanol
No full textG. Garcia Cantero, El vincido de matrimonio civil en el derecho espanol. In: Revue internationale de droit comparé. Vol. 14 N°2, Avril-juin 1962. pp. 460-461
Zygophylax pseudoabietinella Peña Cantero 2020, sp. nov.
No full textZygophylax pseudoabietinella sp. nov. (Figs 1 G–H, 7D–E, 9) urn:lsid:zoobank.org:act: 93001359-55B9-4478-8297-A435BE8AA730 Material examined. MUSORSTOM 4 Stn CP 155, 18°52.8’S– 163°19.5’E (N of New Calendonia), 500–570 m, 15.09.1985: seven stems up to 25 mm high, one with coppinia (25-mm-high stem with coppinia holotype, MNHN-IK-2019-2048; remaining material paratype, MNHN-IK-2019-2049). Description. Stems up to 25 mm high (Fig. 1G), polysiphonic for most of their extension. Stem giving rise to hydrocladia alternately in one plane, but with hydrocladia grouped in sub-opposite pairs (Fig. 1G) and with two hydrothecae between successive pairs. Hydrocladia basally polysiphonic, except those from distal monosiphonic part of stems. Some basal hydrocladia much developed (Fig. 1G), becoming polysiphonic branches or lower-order stems and giving rise in turn to hydrocladia (up to fourth-order hydrocladia present).Angle between hydrocladia and branches or stems 70°. Branches and hydrocladia in a slight zigzag pattern. Stems, branches and hydrocladia giving rise to hydrothecae alternately arranged almost in one plane (Figs 1G, 7 D–E, 9A–B). Hydrotheca roughly cylindrical (Figs 7 D–E), diameter more or less constant, sigmoid. Hydrotheca bent outwards and then inwards at distal part. Adcauline wall convex for its basal two thirds and concave at its distal third. Abcauline wall slightly concave at basal half and slightly convex at distal half. Walls faintly striated transversally. Hydrothecal aperture circular, slightly oblique to hydrothecal long axis. Some hydrothecae with a closing apparatus consisting of a circular flap (Figs 7E, 9 D–E). Hydrothecal diaphragm consisting of a strongly developed ring of perisarc, slightly oblique (abcauline side somewhat higher); diaphragm sometimes duplicated or even triplicated (Fig. 9F) Hydrothecal pedicel indistinguishable from apophysis (Figs 7 D–E, 9A–G). Typically two nematothecae on hydrothecal apophyses, one on each side (Fig. 9G). Sometimes only one present and occasionally both absent, particularly in the youngest distal hydrothecae (Fig. 7E). For hydrocladial apophyses, pair of nematothecae placed beyond first hydrothecal apophysis, which is deprived of nematothecae (Figs 7D, 9A). Nematothecae also present on accessory tubes, though not very abundant. Nematotheca cylindrical, short, with a wide distal aperture (Fig. 9G). One coppinia, 3 mm in diameter, present on one stem, on one side (Fig. 1 G–H). With a few branched tubes arising between gonothecae (Fig. 1H). Abietinella -like gonotheca, distal part forming a hood-like structure, provided with a lateral aperture (Figs 1H, 9H). Measurements (in µm). Hydrothecae: length of abcauline wall 420–460, length of adcauline wall 400–420, diameter at aperture 130–140, diameter at diaphragm 80–100, maximum diameter 120, length of pedicel 140–200. Nematothecae: height 60–75, diameter at aperture 25–30, maximum diameter 30–35. Gonothecae: height of distal hooded part 300, aperture 150. Remarks. The circular flap found at the distal part of several hydrothecae seems to have no fixed insertion (it was observed on the adcauline side in some hydrothecae, but on the abcauline side in others). Among the known species of Zygophylax, the present species is morphologically similar to Z. kakaiba Campos, Marques, Puce & Pérez, 2016 in colony structure, but their trophosomes differ in the shape of the hydrothecae. In Z. kakaiba the hydrotheca is swollen with the adcauline wall convex except for the most distal part, whereas in Z. pseudoabietinella sp. nov. the diameter of the hydrotheca is more or less constant and the adcauline wall is slightly convex for its basal two thirds and slightly concave at its distal third. Furthermore, whereas the aperture is parallel to the longitudinal axis of the hydrotheca in Z. kakaiba, it is almost perpendicular to that axis in Z. pseudoabietinella sp. nov. The hydrotheca of Z. kakaiba is also smaller (e.g. 290–330 µm in length of adcauline wall). The reproductive structure is unknown for Z. kakaiba. Zygophylax pseudoabietinella sp. nov. is also morphologically similar to Abietinella operculata (Jäderholm, 1903), but Jäderholm’s species has distinctly larger and more robust hydrothecae (e.g. 715–748 µm in height and 215–241 µm in diameter at aperture in Peña Cantero et al. 2004) and nematothecae (e.g. 163–280 µm in height and 52–65 µm in diameter at aperture in Peña Cantero et al. 2004). Furthermore, the hydrotheca is swollen in A. operculata. Both species also share the presence of a circular flap as a closing apparatus in some hydrothecae, but whereas it is inserted on the adcauline side of the hydrothecal aperture in A. operculata, it has no fixed insertion in Z. pseudoabietinella sp. nov. Etymology. The specific name pseudoabietinella refers to the fact that in this species the shape of the hydrotheca resembles that of Abietinella operculata (Jäderholm, 1903).Published as part of Peña Cantero, Álvaro L., 2020, On six new species of Zygophylax Quelch, 1885 (Cnidaria, Hydrozoa Zygophylacidae) from the New Calendonian region, pp. 389-404 in Zootaxa 4822 (3) on pages 400-403, DOI: 10.11646/zootaxa.4822.3.4, http://zenodo.org/record/440171
Schizotricha auroraaustralis Peña Cantero & Marzal 2018, sp. nov.
No full textSchizotricha auroraaustralis sp. nov. (Figs 4–5) Material examined. 63EV314 , a colony 250 mm high, with gonothecae (Holotype, IK–2009–0483). Description. Stem polysiphonic, unbranched, composed of a main aXial tube and several accompanying ones, whose number decreases distally; most distal part of stem only with main tube. Main aXial tube on one side of stem, not covered by accessory tubes for most of its length. Main tube divided into homomerous hydrothecate internodes, bearing hydrothecae and nematothecae. Secondary tubes only provided with nematothecae. Cauline internodes with a short apophysis without nematothecae (Fig. 4B). Cauline apophyses alternately arranged, forming an angle slightly smaller than 90° at basal part of stem, but opening distally, being almost in one plane at distal part. Cauline internodes (Fig. 4B) with a hydrotheca at aXil between apophysis and internode and three nematothecae: two flanking hydrothecal aperture and one infrathecal nematotheca (occasionally two). Cauline apophyses giving rise to hydrocladia, forming an acute angle with stem. A basal ahydrothecate internode, provided with one nematotheca, present between cauline apophysis and first hydrothecate hydrocladial internode (Fig. 4A–B). Only occasionally basal ahydrothecate internode absent (in this case, cauline apophyses might be slightly longer and have a nematotheca). Hydrocladia homomerously divided into internodes (Fig. 4A), but with a short ahydrothecate internode following hydrocladial apophyses of forked internodes (Figs 4A, 5A), typically provided with one nematotheca (occasionally two). Hydrocladia branched, up to fifth order (Fig. 4A). Forked hydrocladial internodes following ahydrothecate internodes. Hydrocladial apophyses forming an acute angle with internode, and provided with one or no nematothecae (Fig. 4A, C). Length of hydrocladial internodes roughly constant along hydrocladia. Forked hydrocladial internodes (Figs 4C, 5A) with an aXillary hydrotheca, two nematothecae flanking hydrothecal aperture, one infrathecal nematotheca (occasionally two), and one nematotheca on apophysis in third and/or fourth internodes (occasionally on the second too) (Fig. 4A). Unforked hydrothecate hydrocladial internodes (Figs 4D–G, 5B–C) with one hydrotheca in the middle and three nematothecae: two flanking hydrothecal aperture and one infrathecal nematotheca. Hydrotheca elongate (Figs 4D–G, 5B–D), length increasing along hydrocladia. Adcauline wall completely adnate to internode. Abcauline wall straight. Hydrothecal aperture circular; rim even. Gonothecae inserted on small apophyses between hydrotheca and infrathecal nematotheca of hydrocladial internodes. Gonothecae elongate pear-shaped (Fig. 4H), provided with a distal, slightly oblique, circular aperture, and a basal chamber delimited by a circular diaphragm and provided with two nematothecae. Measurements (in µm). Hydrotheca: length, 220–350 (1 st and 16th unforked hydrocladial internodes, respectively), diameter at aperture, 190–210. Hydrocladial internodes: length, 640–800 (1 st and 16th unforked hydrocladial internodes, respectively), diameter under hydrotheca, 280–180 (1 st and 16th unforked hydrocladial internodes, respectively). Cauline internodes: length, 620–720, diameter under apophysis, 260. Gonotheca: height, 1000–1100, maXimum diameter, 400–500, diameter at aperture, 220–240. Remarks. Schizotricha auroraaustralis sp. nov. is recognizable from other Antarctic/sub-Antarctic species of the genus by the constant presence of a single infrathecal nematotheca on the unforked hydrocladial internodes, the forked hydrocladial internodes and the cauline internodes (only occasionally a second nematotheca has been noticed in the last two). In addition, it is also characterized by the presence of one nematotheca on the ahydrothecate internodes, one or none on the hydrocladial apophyses, and none on the cauline apophyses, although when the basal ahydrothecate internode is absent the cauline apophysis may be longer and provided with a nematotheca. From the known Antarctic/sub-Antarctic species of the genus, Schizotricha auroraaustralis sp. nov. is allied with Schizotricha discovery Soto Àngel & Peña Cantero, 2015, Schizotricha multifurcata Allman, 1883, Schizotricha nana Peña Cantero, Svoboda & Vervoort, 1996, Schizotricha southgeorgiae Peña Cantero & Vervoort, 2004a, Schizotricha trinematotheca Peña Cantero & Vervoort, 2005 and Schizotricha unifurcata Allman, 1883 by the presence of ahydrothecate internodes, but differs from all of them by several important features. Schizotricha nana has the closest nematotheca sets, but it is easily distinguishable by having branched stems, hydrocladia up to second order and, particularly, low hydrothecae. Schizotricha multifurcata and S. unifurcata differ, amongst other things, by having branched stems, two nematothecae on the ahydrothecate internodes and a much higher number of infrathecal nematothecae on the cauline and forked hydrocladial internodes. Schizotricha discovery, S. southgeorgiae and S. trinematothecae all have unbranched stems. However, S. trinematotheca differs in having two to four nematothecae on the ahydrothecate internodes and a much higher number of nematothecae everywhere, even having suprathecal nematothecae. Schizotricha discovery differs in having one or two nematothecae on the ahydrothecate internode, one or two infrathecal nematothecae on the hydrocladial internodes and, particularly, in having four to five infrathecal nematothecae on the cauline internodes. Finally, S. southgeorgiae differs in having two infrathecal nematothecae on the forked hydrocladial internodes, two to five infrathecal nematothecae on the cauline internodes and the complete absence of nematothecae on the hydrocladial apophyses. Etymology. The specific name auroraaustralis honors to the research vessel Aurora Australis, and its crew, with which the material studied was collected. Ecology and distribution. The material of Schizotricha auroraaustralis sp. nov. was collected at depths between 423 and 433 m, with gonothecae in January. It is tentatively considered endemic to East Antarctica.Published as part of Peña Cantero, Álvaro L. & Marzal, Marina Fresneda, 2018, Benthic hydroids (Cnidaria: Hydrozoa) from off George V Coast (East Antarctica), pp. 121-136 in Zootaxa 4441 (1) on pages 130-132, DOI: 10.11646/zootaxa.4441.1.7, http://zenodo.org/record/130192
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