identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
ED10C428FFF32309FF5008A6FB4FF940.text	ED10C428FFF32309FF5008A6FB4FF940.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Bougainvilliidae Lutken 1850	<div><p>‘ Bougainvilliidae undetermined’(*)</p> <p>‘ Bougainvilliidae undetermined’ Peña Cantero, 2009: 1744.</p> <p>Remarks. Peña Cantero (2009) reported this species off Sturge Island, on Symplectoscyphus sp., at depths from 96 to 117 m. It could not be identified given the scarcity and infertile condition of the material.</p> </div>	http://treatment.plazi.org/id/ED10C428FFF32309FF5008A6FB4FF940	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFF32309FF500A48FE94F824.text	ED10C428FFF32309FF500A48FE94F824.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Eudendrium generale von Lendenfeld 1885	<div><p>Eudendrium generale von Lendenfeld, 1885 (*)</p> <p>Eudendrium generale — Peña Cantero, 2009: 1745.</p> <p>Remarks. Known from off Sturge Island, at depths between 640 and 702 m, basibiont for Hydractinia sp. (Peña Cantero 2009).</p> </div>	http://treatment.plazi.org/id/ED10C428FFF32309FF500A48FE94F824	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFF0230AFF500DE7FAF7FEE9.text	ED10C428FFF0230AFF500DE7FAF7FEE9.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Eudendrium scotti Puce, Cerrano & Bavestrello 2002	<div><p>Eudendrium scotti Puce, Cerrano &amp; Bavestrello, 2002 (*)</p> <p>Eudendrium scotti — Peña Cantero, 2009: 1745.</p> <p>Remarks. Peña Cantero (2009) reported this species off Sturge Island, at a depth of 111 m, on a pebble.</p></div> 	http://treatment.plazi.org/id/ED10C428FFF0230AFF500DE7FAF7FEE9	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFF0230AFF500901FC6AF9BF.text	ED10C428FFF0230AFF500901FC6AF9BF.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Filellum antarcticum (Hartlaub 1904)	<div><p>Filellum antarcticum (Hartlaub, 1904)</p> <p>(Fig. 1A–C)</p> <p>Material examined. E203, several hydrothecae and two coppiniae, on Stegella lobata (Vanhöffen, 1910) (NIWA 128467).</p> <p>Remarks. The presence of coppinia in the present material allows identification with confidence. The nestshaped coppinia consists of closely packed gonothecae (Fig. 1A) surrounded by a fence of distally open defensive tubes arching over them. The gonothecae are deprived of distal neck (Fig. 1B). Some of them, however, with distal part slightly raised (Fig. 1C), but never forming a distally everted neck as found in the other known Antarctic species of the genus, Filellum magnificum Peña Cantero, Svoboda &amp; Vervoort, 2004. The gonotheca is roughly 260 µm high, 130 µm in maximum diameter, and 65–70 µm in diameter at aperture. The shape and size of the hydrothecae in the present material also match Hartlaub’s species, with a hydrothecal diameter of 100–120 µm.</p> <p>Ecology and distribution. The material, which represents the first record for the area, was collected at a depth of 187 m off Sturge Island, epibiotic on S. lobata. Coppiniae in January.</p> </div>	http://treatment.plazi.org/id/ED10C428FFF0230AFF500901FC6AF9BF	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFF6230CFF500DE7FCCDFE2A.text	ED10C428FFF6230CFF500DE7FCCDFE2A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Lafoea dumosa (Fleming 1820)	<div><p>Lafoea dumosa (Fleming, 1820)</p> <p>(Fig. 1D)</p> <p>Material examined. TAN 0602/442, a 12-mm-high stem (NIWA 144244).</p> <p>Remarks. The present material agrees with that frequently reported in Antarctic waters. The hydrotheca, provided with a ringed pedicel, is roughly 700 µm high and 150 µm in diameter at aperture. The isorhizas are around 22 x 9 µm, coinciding with one of the two morphotypes found by Schuchert (2001) in relation to the size of the isorhizas.</p> <p>Ecology and distribution. The material, which represents the first record of the species for the Balleny Islands, was collected at a depth of 140−150 m off Buckle Island.</p></div> 	http://treatment.plazi.org/id/ED10C428FFF6230CFF500DE7FCCDFE2A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFF6230CFF500FFFFCB1FC87.text	ED10C428FFF6230CFF500FFFFCB1FC87.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Lafoeina longitheca Jaderholm 1904	<div><p>Lafoeina longitheca Jäderholm, 1904 (*)</p> <p>Lafoeina longitheca — Peña Cantero, 2009: 1746–1747, fig. 2b–d.</p> <p>Remarks. Peña Cantero (2009) reported this species off Sturge Island, at depths from 96 to 222 m, epibiotic on H. incertus, O. bidentata and Staurotheca compressa Briggs, 1938.</p> </div>	http://treatment.plazi.org/id/ED10C428FFF6230CFF500FFFFCB1FC87	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFF6230CFF500829FBE8F993.text	ED10C428FFF6230CFF500829FBE8F993.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Phialella belgicae (Hartlaub 1904)	<div><p>Phialella belgicae (Hartlaub, 1904)</p> <p>(Fig. 1E)</p> <p>Material examined. TAN0602/420, a few hydrothecae, on Staurotheca glomulosa Peña Cantero, Svoboda &amp; Vervoort, 1997 (NIWA 144240).</p> <p>Ecology and distribution. Present material, representing the first record of P. belgicae for the Balleny Islands, was collected at a depth of 103−108 m off Sturge Island, epibiotic on S. glomulosa.</p> </div>	http://treatment.plazi.org/id/ED10C428FFF6230CFF500829FBE8F993	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFF6230CFF500ED9FD0CFB1F.text	ED10C428FFF6230CFF500ED9FD0CFB1F.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Stegella lobata (Vanhoffen 1910)	<div><p>Stegella lobata (Vanhöffen, 1910)</p> <p>Material examined. E203, two stem fragments 50 and 55 mm long, with male gonothecae, basibiont of F. antarcticum (NIWA 128467).</p> <p>Remarks. Although only a few hydrothecae in bad condition are left, the typical colony structure allows a confident identification. The male gonotheca is roughly 1800 µm in height and 700 µm in maximum diameter.</p> <p>Ecology and distribution. The material, which represents the first record of the species for the Balleny Islands, was collected at a depth of 187 m off Sturge Island.</p></div> 	http://treatment.plazi.org/id/ED10C428FFF6230CFF500ED9FD0CFB1F	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFF7230DFF500E81FA5EFB49.text	ED10C428FFF7230DFF500E81FA5EFB49.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Billardia subrufa (Jaderholm 1904)	<div><p>Billardia subrufa (Jäderholm, 1904) (*)</p> <p>Billardia subrufa — Peña Cantero, 2009: 1749.</p> <p>Remarks. Billardia subrufa is known from depths between 96 and 702 m off Sturge Island (Peña Cantero 2009).</p> </div>	http://treatment.plazi.org/id/ED10C428FFF7230DFF500E81FA5EFB49	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFF7230DFF500F36FAA5FC87.text	ED10C428FFF7230DFF500F36FAA5FC87.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Obelia bidentata Clark 1875	<div><p>Obelia bidentata Clark, 1875</p> <p>Obelia bidentata — Peña Cantero, 2009: 1749, fig. 3g.</p> <p>Material examined. TAN 0602/420, two stems up to 10 mm high, on S. compressa (NIWA 144251).</p> <p>Ecology and distribution. Obelia bidentata had been collected at depths between 85 and 117 m (Peña Cantero 2009) off Sturge and Buckle islands, epibiotic on H. incertus and in turn as basibiont for colonies of Filellum sp. and L. longitheca. Present material found at a depth of 103−108 m off Sturge Island, growing on S. compressa.</p> </div>	http://treatment.plazi.org/id/ED10C428FFF7230DFF500F36FAA5FC87	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFF7230DFF50085FFDBBF85A.text	ED10C428FFF7230DFF50085FFDBBF85A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Staurotheca compressa Briggs 1938	<div><p>Staurotheca compressa Briggs, 1938</p> <p>Staurotheca compressa — Peña Cantero &amp; Vervoort, 2003: 2673–2676, fig. 4; Peña Cantero 2009: 1749.</p> <p>Material examined. E203, a mass of stems 50 mm in diameter, with male gonothecae (NIWA 128467); TAN 0102/ K0809, one colony fragment 35 mm long, with female gonothecae, and one colony fragment 10 mm long, with male gonothecae (NIWA 144358); TAN 0602/420, a mass of stems 70 x 90 mm, with male gonothecae, basibiont of Campanularia sp. and O. bidentata (NIWA 144251).</p> <p>Measurements (in µm). Hydrotheca: abcauline wall 430–450, free part of adcauline wall 150–250, adnate part of adcauline wall 350–520, adcauline wall 600–670, diameter at aperture 140–150.</p> <p>Ecology and distribution. In the area of study, Staurotheca compressa had been collected at depths from 55 to 234 m (Peña Cantero &amp; Vervoort 2003); present material between 103 and 292 m. Peña Cantero (2009) reported gonothecae in March; here, they are present in material collected in January and March. It has been observed as basibiont for colonies of L. longitheca (Peña Cantero 2009) and Campanularia sp. and O. bidentata (present material).</p> <p>Previously known off Buckle Island (Peña Cantero &amp; Vervoort 2003) and Sturge Island (Peña Cantero 2009). Here, found off Young and Sturge islands.</p></div> 	http://treatment.plazi.org/id/ED10C428FFF7230DFF50085FFDBBF85A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFF4230EFF500869FC24F9D9.text	ED10C428FFF4230EFF500869FC24F9D9.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Antarctoscyphus elongatus (Jaderholm 1904)	<div><p>Antarctoscyphus elongatus (Jäderholm, 1904)</p> <p>(Fig. 1H)</p> <p>Material examined. TAN 0102/K0809, one basally broken stem 90 mm long (NIWA 144358); TAN 0602/430, one stem 85 mm high (NIWA 144242).</p> <p>Ecology and distribution. Present material, which represents the first record of this species from the Balleny Islands, collected at depths from 70 to 292 m, off Young and Buckle islands.</p></div> 	http://treatment.plazi.org/id/ED10C428FFF4230EFF500869FC24F9D9	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFF4230EFF500DE7FB59FEEE.text	ED10C428FFF4230EFF500DE7FB59FEEE.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Staurotheca densa Pena Cantero & Vervoort 2003	<div><p>Staurotheca densa Peña Cantero &amp; Vervoort, 2003 (*)</p> <p>Staurotheca densa — Peña Cantero, 2009: 1749.</p> <p>Remarks. Peña Cantero (2009) reported this species at a depth of 111 m off Sturge Island.</p></div> 	http://treatment.plazi.org/id/ED10C428FFF4230EFF500DE7FB59FEEE	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFF4230EFF500C08FF39FC5F.text	ED10C428FFF4230EFF500C08FF39FC5F.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Staurotheca glomulosa Pena Cantero, Svoboda & Vervoort 1997	<div><p>Staurotheca glomulosa Peña Cantero, Svoboda &amp; Vervoort, 1997</p> <p>Staurotheca glomulosa — Peña Cantero &amp; Vervoort, 2003: 2687–2689, fig. 9.</p> <p>Material examined. E220B, a a mass of stems 20 mm in diameter (NIWA 128457); TAN 0602/420, one colony 100 mm high, basibiont of P. belgicae (NIWA 144240).</p> <p>Measurements (in µm). Hydrotheca: abcauline wall 630–700, free part of adcauline wall 100–130, adnate part of adcauline wall 730–780, adcauline wall 830–910, diameter at aperture 230–270.</p> <p>Remarks. The planar colonies are polysiphonic and the presence of anastomoses gives them a mesh-shaped appearance. The hydrothecae are arranged in decussate pairs, forming four longitudinal rows.</p> <p>Ecology and distribution. Staurotheca glomulosa had been previously reported at depths between 55 and 157 m (Peña Cantero &amp; Vervoort 2003); present material collected at depths from 103 to 371 m. Basibiont for colonies of P. belgicae (present material).</p> <p>Peña Cantero &amp; Vervoort (2003) reported it off Buckle Island; present material found off Young and Sturge islands.</p></div> 	http://treatment.plazi.org/id/ED10C428FFF4230EFF500C08FF39FC5F	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFF4230EFF500EB7FED1FB55.text	ED10C428FFF4230EFF500EB7FED1FB55.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Staurotheca pachyclada (Jaderholm 1904)	<div><p>Staurotheca pachyclada (Jäderholm, 1904) (*)</p> <p>Staurotheca pachyclada — Peña Cantero, 2009: 1479, fig. 3e.</p> <p>Remarks. Peña Cantero (2009) reported this hydroid at depths between 103 and 151 m off Young Island; gonothecae in March.</p></div> 	http://treatment.plazi.org/id/ED10C428FFF4230EFF500EB7FED1FB55	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFF42300FF500B3DFEA5FF26.text	ED10C428FFF42300FF500B3DFEA5FF26.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Symplectoscyphus cumberlandicus (Jaderholm 1905)	<div><p>Symplectoscyphus cumberlandicus (Jäderholm, 1905)</p> <p>(Fig. 2A–B)</p> <p>Material examined. TAN 0602/420, three stems up to 10 mm high (NIWA 144240); TAN 0602/448, one stem 100 mm high, with gonothecae (NIWA 144241).</p> <p>Measurements (in µm). Hydrotheca: length abcauline wall 350–450, length free part of adcauline wall 140– 200, length adnate part of adcauline wall 370, length adcauline wall 510–570, diameter at aperture 160–200.</p> <p>Remarks. The polysiphonic stem, branched in one plane, and the shape and size of hydrothecae (Fig. 2A) and gonothecae (Fig. 2B), the latter with about 13 spirally arranged rings, make certain the identification of the material from TAN 0602/448. The material from TAN 0602/420, although consisting of small stems up to 10 mm high, also agrees in the shape and size of the hydrothecae. One of the stems has, in addition, a basal 3-mm-long stolon, pointing to the polysiphonic condition found in larger stems.</p> <p>Ecology and distribution. Present material, the first record of Symplectoscyphus cumberlandicus from the Balleny Islands, was collected at depths between 63 and 108 m off Young and Sturge islands. Gonothecae in material collected in March.</p> </div>	http://treatment.plazi.org/id/ED10C428FFF42300FF500B3DFEA5FF26	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFFA2300FF500FBBFB76FCAE.text	ED10C428FFFA2300FF500FBBFB76FCAE.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Abietinella operculata (Jaderholm 1903)	<div><p>Abietinella operculata (Jäderholm, 1903) (*)</p> <p>Abietinella operculata — Peña Cantero, 2009: 1747.</p> <p>Remarks. Known off Sturge Island, at depths between 640 and 702 m (Peña Cantero 2009).</p></div> 	http://treatment.plazi.org/id/ED10C428FFFA2300FF500FBBFB76FCAE	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFFA2300FF50097AFBD1FA52.text	ED10C428FFFA2300FF50097AFBD1FA52.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Halecium exaggeratum Pena Cantero, Boero & Piraino 2013	<div><p>Halecium exaggeratum Peña Cantero, Boero &amp; Piraino, 2013</p> <p>(Fig. 2C)</p> <p>Material examined. TAN 0102/K0809, a few stems up to 10 mm high, with putative male gonothecae, on tube of benthic organism (NIWA 144358).</p> <p>Measurements (in µm). Hydrotheca: diameter at aperture 190–200, diameter at diaphragm 125, height 50. Hydrophore: adcauline length 300.</p> <p>Remarks. The relatively long hydrophore and the shape and size of the hydrotheca allow a certain identification. It is worth mentioning the occasional presence of a pseudodiaphragm, faintly visible in stained material (Fig. 2C).</p> <p>Ecology and distribution. The material, which represents the first record from the Balleny Islands, was collected at a depth of 292 m, off Young Island. Gonothecae present in March.</p></div> 	http://treatment.plazi.org/id/ED10C428FFFA2300FF50097AFBD1FA52	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFFA2300FF5008AEFF34F914.text	ED10C428FFFA2300FF5008AEFF34F914.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Halecium incertus Naumov & Stepanjants 1962	<div><p>Halecium incertus Naumov &amp; Stepanjants, 1962 (*)</p> <p>Halecium incertus — Peña Cantero, 2009: 1747.</p> <p>Remarks. Known from off Sturge and Young islands, at depths between 96 and 127 m, where it was found growing on gravel; it was observed as basibiont for colonies of Filellum sp., L. longitheca and O. bidentata (Peña Cantero 2009).</p> </div>	http://treatment.plazi.org/id/ED10C428FFFA2300FF5008AEFF34F914	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFFA2300FF500A62FE94F804.text	ED10C428FFFA2300FF500A62FE94F804.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Halecium interpolatum Ritchie 1907	<div><p>Halecium interpolatum Ritchie, 1907 (*)</p> <p>Halecium ovatum — Peña Cantero, 2009: 1747, fig. 2f.</p> <p>Remarks. Halecium interpolatum is known off Buckle Island, where it was collected at a depth of 80 m (Peña Cantero 2009).</p> </div>	http://treatment.plazi.org/id/ED10C428FFFA2300FF500A62FE94F804	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFFB2301FF500DAFFE94FE77.text	ED10C428FFFB2301FF500DAFFE94FE77.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Hydrodendron arboreum (Allman 1888)	<div><p>Hydrodendron arboreum (Allman, 1888) (*)</p> <p>Hydrodendron arboreum — Peña Cantero, 2009: 1747.</p> <p>Remarks. Reported off Sturge and Young islands, from depths between 96 and 127 m, growing on pebbles (Peña Cantero 2009).</p></div> 	http://treatment.plazi.org/id/ED10C428FFFB2301FF500DAFFE94FE77	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFFB2301FF500F31FCC5F967.text	ED10C428FFFB2301FF500F31FCC5F967.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Schizotricha falcata Pena Cantero 1998	<div><p>Schizotricha falcata Peña Cantero, 1998</p> <p>(Fig. 2D–H)</p> <p>Material examined. TAN 0602/447, one stem 350 mm high, with gonothecae (NIWA 144248).</p> <p>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.</p> <p>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 &amp; 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.</p> <p>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.</p> <p>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.</p> <p>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).</p></div> 	http://treatment.plazi.org/id/ED10C428FFFB2301FF500F31FCC5F967	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFFB2301FF500A79FB7BF870.text	ED10C428FFFB2301FF500A79FB7BF870.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Schizotricha nana Pena Cantero, Svoboda & Vervoort 1996	<div><p>Schizotricha nana Peña Cantero, Svoboda &amp; Vervoort, 1996 (*)</p> <p>Schizotricha nana — Peña Cantero, 2009: 1747.</p> <p>Remarks. Reported off Sturge Island, at depths between 640 and 702 m (Peña Cantero 2009)</p></div> 	http://treatment.plazi.org/id/ED10C428FFFB2301FF500A79FB7BF870	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFF82302FF500EBDFE11FB48.text	ED10C428FFF82302FF500EBDFE11FB48.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Oswaldella bifurca (Hartlaub 1904)	<div><p>Oswaldella bifurca (Hartlaub, 1904) (*)</p> <p>Oswaldella bifurca — Peña Cantero &amp; Vervoort, 2004: 816–818, fig. 1.</p> <p>Remarks. Oswaldella bifurca is known off Buckle Island, where it was collected at a depth of 1442–1444 m (Peña Cantero &amp; Vervoort 2004).</p> </div>	http://treatment.plazi.org/id/ED10C428FFF82302FF500EBDFE11FB48	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFF82302FF500998FD6BF9BA.text	ED10C428FFF82302FF500998FD6BF9BA.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Oswaldella incognita Pena Cantero, Svoboda & Vervoort 1997	<div><p>Oswaldella incognita Peña Cantero, Svoboda &amp; Vervoort, 1997</p> <p>Oswaldella incognita — Peña Cantero, 2009: 1748–1749, fig. 3a.</p> <p>Material examined. TAN 0102/K0809, one stem 120 mm high, with gonothecae (NIWA 144358); TAN 0602/430, one stem 90 mm high, with only a few hydrocladia left, in bad condition (NIWA 144253), one stem 200 mm high, with gonothecae (NIWA 144250) and one stem 110 mm high, with just a few hydrocladia left (NIWA 144249); TAN 0602/436, one stem 80 mm high, with one gonotheca (NIWA 144257).</p> <p>Ecology and distribution. Previously known off Buckle Island, from depths between 70 and 584 m (Peña Cantero 2009). The material studied here was collected at depths from 70 to 292 m off Young and Buckle islands; gonothecae found in material collected in March.</p></div> 	http://treatment.plazi.org/id/ED10C428FFF82302FF500998FD6BF9BA	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFF82302FF500BC7FAE6F87B.text	ED10C428FFF82302FF500BC7FAE6F87B.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Oswaldella terranovae Pena Cantero & Vervoort 1996	<div><p>Oswaldella terranovae Peña Cantero &amp; Vervoort, 1996</p> <p>Oswaldella stepanjantsae — Peña Cantero &amp; Vervoort, 2004: 847–850, fig. 15.</p> <p>Material examined. TAN 0602/447, one colony with two stems up to 130 mm high (NIWA 144247).</p> <p>Ecology and distribution. Previously known in the area from depths between 55 and 146 m off Buckle Island (Peña Cantero &amp; Vervoort 2004); present material collected at depths from 74 to 130 m off Young Island.</p></div> 	http://treatment.plazi.org/id/ED10C428FFF82302FF500BC7FAE6F87B	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFF82302FF500DE7FB6EFCEB.text	ED10C428FFF82302FF500DE7FB6EFCEB.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Schizotricha trinematotheca Pena Cantero & Vervoort 2005	<div><p>Schizotricha trinematotheca Peña Cantero &amp; Vervoort, 2005</p> <p>Schizotricha trinematotheca Peña Cantero &amp; Vervoort, 2005: 809–812, fig. 2; Peña Cantero, 2009: 1747, fig. 2g –h.</p> <p>Material examined. TAN 0602/420, one stem 85 mm high and another at least 130 mm high, with immature gonothecae (NIWA 144243); TAN 0602/422, one stem 90 mm high (NIWA 144252); TAN 0602/430, one stem 230 mm high, with gonothecae (NIWA 144249).</p> <p>Remarks. In the present material cauline internodes are provided with three infrahydrothecal nematothecae and, sometimes, one suprahydrothecal nematotheca. Intermediate ahydrothecate internodes, following cauline and hydrocladial apophyses, are provided with two to three nematothecae. Unforked hydrocladial internodes with two to four infrahydrothecal nematothecae and one to two suprahydrothecal nematothecae. Double internodes with three nematothecae below first hydrotheca, three nematothecae between both hydrothecae and one nematotheca above second hydrotheca. As typical, hydrocladia very long, with up to 47 hydrothecae.</p> <p>Ecology and distribution. Schizotricha trinematotheca has been collected at depths from 70 to 579 m, on stones and gravel (Peña Cantero 2009); present material between 70 and 315 m. Gonothecae in February (Peña Cantero &amp; Vervoort 2005) and March (Peña Cantero 2009; present material).</p> <p>Peña Cantero &amp; Vervoort (2005) reported it from off Buckle Island and Peña Cantero (2009) off Sturge, Buckle and Young islands; present material off Sturge and Buckle islands. Until the study by Peña Cantero (2019), who reported it from a seamount off Scott Island, it was considered endemic to the Balleny Islands.</p></div> 	http://treatment.plazi.org/id/ED10C428FFF82302FF500DE7FB6EFCEB	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFF92306FF500DE7FB21FD12.text	ED10C428FFF92306FF500DE7FB21FD12.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Oswaldella vervoorti Pena Cantero & Garcia Carrascosa 1998	<div><p>Oswaldella vervoorti Peña Cantero &amp; García Carrascosa, 1998</p> <p>(Figs 3–4)</p> <p>Oswaldella sp. Peña Cantero, 2009: 1749, fig. 3c.</p> <p>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).</p> <p>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.</p> <p>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.</p> <p>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).</p> <p>Gonotheca elongated, club-shaped (Fig. 3I).</p> <p>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.</p> <p>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.</p> <p>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.</p> <p>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 &amp; 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 &amp; 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.</p> <p>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).</p> <p>The primary hydrocladium might give rise to several second-order hydrocladia (up to six according to Peña Cantero &amp; 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 &amp; García Carrascosa 1998).</p> <p>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 &amp; García Carrascosa 1998), sometimes also beyond unforked internodes (see also figure 1a in Peña Cantero &amp; García Carrascosa 1998). According to these authors, the first third-order hydrocladium sometimes even forms a fourth-order one.</p> <p>Mamelons are more prominent in the holotype than in the present material (compare Fig. 3F with Fig. 4E).</p> <p>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.</p> <p>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.</p> <p>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.</p> </div>	http://treatment.plazi.org/id/ED10C428FFF92306FF500DE7FB21FD12	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
ED10C428FFFC2306FF500E6EFF22FBD3.text	ED10C428FFFC2306FF500E6EFF22FBD3.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Oswaldella undefined-1	<div><p>Oswaldella sp. 1 (*)</p> <p>Oswaldella sp. 1 — Peña Cantero, 2009: 1749, fig. 3b.</p> <p>Remarks. Peña Cantero (2009) considered material of Oswaldella he studied conspecific with the material described as Oswaldella sp. 1 by Peña Cantero &amp; Vervoort (2004). The material was collected off Buckle Island, at a depth of 85 m.</p> </div>	http://treatment.plazi.org/id/ED10C428FFFC2306FF500E6EFF22FBD3	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Peña Cantero, Álvaro L.	Peña Cantero, Álvaro L. (2021): Additions to knowledge of the biodiversity of benthic hydroids (Cnidaria: Hydrozoa) in the Balleny Islands (Antarctica). Zootaxa 4966 (3): 321-336, DOI: https://doi.org/10.11646/zootaxa.4966.3.4
