Obelia geniculata ( Linnaeus, 1758 )

Galea, Horia R., 2007, Hydroids and hydromedusae (Cnidaria: Hydrozoa) from the fjords region of southern Chile, Zootaxa 1597 (1), pp. 1-116 : 93-94

Obelia geniculata ( Linnaeus, 1758)

(fig. 21K–L, table 40)

Sertularia geniculata Linnaeus 1758: 812 .

Obelia geniculata: Hincks, 1868: 149 , pl. 25 figs 1, 1A; Hartlaub, 1901: 362; Hartlaub, 1905: 581, fig. D 2; Nutting, 1915: 73, pl. 18 figs 1–5; Stechow, 1919: 50; 1923: 114; Fraser, 1944: 158, pl. 28 fig. 130; Russell, 1953: 302, fig. 185A; Ralph, 1957: 831, fig. 4I; Naumov, 1969: 282, figs 147–148; Calder, 1970: 1522, pl. 4 fig. 7; 1971: 55, pl. 4C; 1975: 303, fig. 4E–F; Cornelius, 1975: 272, figs 1, 5; Millard, 1975: 229, fig. 75A–B; Stepanjants, 1979: 36, pl. 5 fig. 7; Morri, 1981: 69, fig. 22; Cornelius, 1982: 119; Hirohito, 1983: 17; Gili et al., 1989: 108, fig. 32C; El Beshbeeshy, 1991: 114, fig. 26; Cornelius, 1995b: 301, fig. 70; Hirohito, 1995 (English text): 76, fig. 22A–B; Migotto, 1996: 90, fig. 16E; Ramil et al., 1998a: 200; Medel & Vervoort, 2000: 54; Schuchert, 2001b: 155, fig. 135; Peña Cantero & García Carrascosa, 2002: 162, fig. 31D; Vervoort & Watson, 2003: 427, fig. 104F–H; Bouillon et al., 2004: 200, figs 114H–I, 115A–E; Watson, 2005: 583.

Obelia geniculata var. subsessilis Jäderholm, 1904a: 2 , fig. 2.

Laomedea geniculata: Leloup, 1974: 19 , fig. 16.

Material examined. Stn. CHL 02 – 04.iii.2005, 13– 20 m, S44: one sterile colony, about 1 cm high, on Macrocystis pyrifera ( MHNG INVE 53210). Stn. COM 08 —03.v.2005, 5– 8 m, S39: one fertile colony, 1–2 cm high, on Macrocystis pyrifera ( MHNG INVE 53202). Stn. COM 09 —04.v.2005, 5– 8 m, S31: one fertile colony, 1–2 cm high, on Macrocystis pyrifera , 1 slide ( MHNG INVE 53188). Stn. COM 13 —25.i.2006, 25– 32 m, S99: several fertile colonies up to 1.5 cm high, on Macrocystis pyrifera ( MHNG INVE 53353). Stn. COF — 16.iii.2006, S138 (3 m): a fertile colony, on Macrocystis pyrifera ( MHNG INVE 53424); S119 (4 m): a fertile colony, on Macrocystis pyrifera ( MHNG INVE 53375).

Type locality. Dover , Kent, United Kingdom .

Remarks. For descriptions of this species, see Cornelius (1982, 1995b). An extensive synonymy is provided by Cornelius (1975) and Medel & Vervoort (2000).

The present material is characterized by being occasionally branched and having moderate thickening of the perisarc (63–130 µm on thickened side, and 13–27 µm on opposite side of internodes).

World distribution. Near-cosmopolitan, penetrating at high latitudes in the northern hemisphere and into sub-Antarctic waters in the southern hemisphere ( Medel & Vervoort, 2000).

Records from Chile. This species was previously reported from Canal Beagle ( Hartlaub 1904), Corral ( Jäderholm 1904a), Valparaíso, Talcahuano, Canal Smyth, Strait of Magellan, Islas Navarino and Lennox ( Hartlaub 1905), Tocopilla, Archipelago de los Chonos ( Leloup 1974). The present records are roughly from 43°10' S to 48°10' S.