Synthecium robustum Nutting 1904

• Main Author: Galea, Horia R.
• Format: Text
• Language: unknown
• Published: Zenodo 2007
• Subjects: Biodiversity; Taxonomy; Animalia; Cnidaria; Hydrozoa; Leptothecata; Syntheciidae; Synthecium; Synthecium robustum; Argentina; Blanco; Detroit; Rotunda; Yelcho; Antarc*; Antarctica; Tierra del Fuego
• Online Access: https://dx.doi.org/10.5281/zenodo.5098609; https://zenodo.org/record/5098609

Synthecium robustum Nutting, 1904 (fig. 18E–J, table 31) Synthecium robustum Nutting, 1904: 136, pl. 41 figs 4–6; Hartlaub, 1905: 673, fig. H 5; Fraser, 1944: 236, pl. 49 fig. 221; Blanco, 1976: 51, pl. 6 figs 3–5, pl. 7 figs 1–3; Vervoort, 1972a: 193, figs 65, 66, 68A; Leloup, 1974: 24, fig. 19; Stepanjants, 1979: 101, pl. 16 fig 5A–B; El Beshbeeshy, 1991: 121, fig. 28; Blanco et al ., 2000b: 293, figs 17–19. Synthecium chilense Hartlaub, 1905: 671, figs E 5 –G 5. Material examined . Stn. CHL 02 —04.iii.2005, 13– 20 m, S2: eight fertile stems, up to 5.5 cm high, some poorly preserved, 1 slide (MHNG INVE 53155). Stn. AIN – 11.iii. 2006, 25 m, S111: one sterile colony, 3.1 cm high (MHNG INVE 53362). Stn. CCO — 09.iii.2006, S144 (18 m): several fertile fragments, abundantly overgrown by other hydroids; S140 (0–20 m): a poorly preserved colony, 3.5 cm high, with remnants of gonothecae. Stn. CPI — 07.iii.2006, S118 (20 m): one sterile colony, 7 cm high (MHNG INVE 53374); S121 (24 m): several sterile stems, up to 7.5 cm high, and smaller fragments (MHNG INVE 53378). Type locality . Strait of Magellan, 52°41' S, 69°55.5' W. Description . Stems erect, monosiphonic, unbranched, up to 7.5 cm high, arising from a creeping stolon. Stems compressed on both anterior and posterior sides. Most basal part undivided and generally devoid of hydrothecae or having several damaged hydrothecae and apophyses with broken branches; remainder of stem divided by transverse nodes into internodes, each with three pairs of hydrothecae and a pair of apophyses arising below second pair of hydrothecae. Up to 16 side branches per stem, borne on their corresponding stem apophyses; opposite and pinnately arranged in same plane. Stem and branches with hydrothecae in opposite pairs, forming two longitudinal rows. There is one unpaired hydrotheca in proximal part of each side branch, followed by first pair of subopposite hydrothecae; next pairs opposite; up to 9 pairs per branch. Hydrothecae partly embedded in hydrocaulus; cylindrical, distal part curving outwards (angle of opening at about 45°); hydrothecal rim lower on lateral sides, circular, slightly everted, renovation of margin very frequent. Gonothecae arising directly from aperture of most basal stem hydrothecae and borne on short pedicel; pear-shaped, with up to 9 deep, transversal ridges in distal part, slightly marked towards basal part; gonothecal aperture circular. Gonothecae generally empty, no intact contents have been seen. Remarks . I follow Vervoort (1972a) by including Synthecium chilense Hartlaub, 1905 in the synonymy of S. robustum Nutting, 1904. Hydroid epibionts . Eudendrium cf. nambuccense Watson, 1985; Modeeria rotunda (Quoy & Gaimard, 1827); Sertularella robusta Coughtrey, 1876; Symplectoscyphus subdichotomus (Kirchenpauer, 1884); Symplectoscyphus sp. World distribution . Argentina, Strait of Magellan, Falkland Islands, Tierra del Fuego, Antarctica (Vervoort 1972a). Records from Chile . Previously reported from Calbuco (Hartlaub 1905), Golfo de Ancud and Seno Reloncavi (Leloup 1974). The present material was found roughly between 43°10' S and 50°50' S. : Published as part of Galea, Horia R., 2007, Hydroids and hydromedusae (Cnidaria: Hydrozoa) from the fjords region of southern Chile, pp. 1-116 in Zootaxa 1597 (1) on pages 77-78, DOI: 10.11646/zootaxa.1650.1.4, http://zenodo.org/record/5097970 : {"references": ["Nutting, C. C. (1904) American hydroids. Part II. The Sertularidae. Special Bulletin of the United States National Museum, 4 (2), 1 - 325.", "Hartlaub, C. (1905) Die Hydroiden der Magalhaensischen Region und chilenischen Kuste. In: Fauna chilensis. Zoologische Jahrbucher, Suppl. 6 (3), 497 - 714.", "Fraser, C. M. (1944) Hydroids of the Atlantic coast of North America. The University of Toronto Press, 1 - 451.", "Blanco, O. M. (1976) Hidrozoos de la expedicion Walther Herwig. Revista del Museo de La Plata, 12 (113), 27 - 74.", "Vervoort, W. (1972 a) Hydroids from the Theta, Vema and Yelcho cruises of the Lamont-Doherty geological observatory. Zoologische Verhandelingen, Leiden, 120, 1 - 247.", "Leloup, E. (1974) Hydropolypes calyptoblastiques du Chili. Report no. 48 of the Lund University Chile Expedition 1948 - 1949. Sarsia, 55, 1 - 61.", "Stepanjants, S. D. (1979) Gidroidy vod antarktiki i subantarktiki. In: Rezul'taty biologicheskikh issledovanii sovetskikh antarkticheskikh ekspeditsii, 6. Issledovaniya Fauny Morei, 22 (30), 1 - 99.", "El Beshbeeshy, M. (1991) Systematische, Morphologische und Zoogeographische Untersuchungen an den Thekaten Hydroiden des Patagonischen Schelfs. Dissertation, Universitat Hamburg, 390 p.", "Blanco, O. M., Zamponi, M. O. & Genzano, G. N. (2000 b) Syntheciidae de la Argentina (Coelenterata, Hydrozoa, Hydroida). Revista del Museo de La Plata, 14 (165), 285 - 295.", "Watson, J. E. (1985) The genus Eudendrium (Hydrozoa: Hydroida) from Australia. Proceedings of the Royal Society of Victoria, 97 (4), 179 - 221.", "* Quoy, J. C. R. & Gaimard, J. P. (1827) Observations zoologiques faites a bord de l'Astrolabe, en mai 1826, dans le detroit de Gibraltar. Annales des Sciences naturelles, 10, 1 - 21, 172 - 193, 225 - 239.", "* Kirchenpauer, G. H. (1884) Nordische Gattungen und Arten von Sertulariden. Abhandlungen aus dem Gebiete der Naturwissenschaften, Hamburg, 8, 93 - 144."]}