Halecium tenellum Hincks, 1861

(fig. 2 L–N, table 2)

Halecium tenellum Hincks, 1861: 252, pl. 6 figs 1–4; Hincks, 1868: 226, pl. 45 fig. 1; Hartlaub, 1904: 13, pl. 1 fig. 5; Hartlaub, 1905: 609, fig. G 3; Stechow, 1919: 41, figs J, K; Vervoort, 1959: 229, fig. 8; Vervoort, 1966: 102, fig. 2; Naumov, 1969: 490, fig. 344; Hirohito, 1974: 8, fig. 2; Leloup, 1974: 11; Cornelius, 1975: 409, fig. 12; Millard, 1975: 156, fig. 50 F–L; Stepanjants, 1979: 104, pl. 20 fig. 5 A–B; Gili et al., 1989: 81, fig. 10 A; Calder, 1991: 22, fig. 14; El Beshbeeshy, 1991: 40, fig. 6; Ramil & Vervoort, 1992: 90, fig. 21 F–G; Cornelius, 1995 a: 296, fig. 69; Hirohito, 1995: 29, fig. 8 A–C; Migotto, 1996: 34, fig. 6 H; Cornelius, 1998: 90, fig. 5; Medel et al., 1998: 41, fig. 6; Ramil et al., 1998: 8; Medel & Vervoort, 2000: 23; Schuchert, 2001: 84, fig. 70 A–E; Peña Cantero & García Carrascosa, 2002: 75, fig. 12 C–E; Vervoort & Watson, 2003: 98, fig. 19 A–B; Bouillon et al., 2004: 143, fig. 77 A–E.

. al Medel et 1998 () – 580 810 70 60 – – – 120 160 – 30 40 –

Migotto 1996 () 380 800 – – 112 64 – 200 360 – 96 104 – 108 – 232 80 – 158 60 25 – – 720 700 – 330 290 Cornelius 1995) (a – 850 500> 50 – – – 100 – 130 – – 30 25 1070 510 ) & (1992 – 1060 – – 65 – – 150 – – 40 – – – Ramil Vervoort 560 40 125 25

Beshbeeshy() 1991 – 974 253 116 69 – – – – 170– 284 – 46 75 – – – El Calder) 1991 ( 848 401 – – 56 – 47 123 149 – 77 93 – 26 –38 – –. et Gili al (1989) – – – 800 – 120 – 50 70 95 – 115 – 40 25 – – –.)

µm

in Stepanjants(1979) 1000 810 – 80 100 – – 180 – 530 – – 200 160 – 130 140 – 98 56 – –

(

1861, Vervoort) (1966 1300 – 875 – 65 55 – – – – 135 120 – 65 30 – – –

Hincks Vervoort) (1959 – 1100 500 – 75 50 – – – – 120 130 – – 20 25 – –

tenellum Ralph 1958) (– 250 700 – 120 100 – – – 180 120 – – – 30 40 – –

Halecium Millard) (1957 380 90 – – – 40 70 – – 170 120 – – 40 30 – – –

study

of, Chile present 783 985 – – 107 98 – 84 92 515 110 – – 110 100 – 224 185 113 133 – 58 49– 815 – 988 – 523 617

Measurements

2.

Table Stem

internodes

– length – diameter

at node

– diameter

Hydrothecae of – hydrophores length of diameter hydrophores – – rim at diameter diameter diaphragm at – height – gonothecae Female – length width – maximum Halecium (?) tenellum: Ralph, 1958: 340, fig. 11 F–G.

not Halecium tenellum: Fraser, 1944: 201, pl. 37 fig. 179 (= H. textum Kramp, 1911).

Material examined. Stn. RM 2 – 11.iii. 2007, Fjord Piti Palena, Raul Marin, 43 ° 46.477 ’ S, 72 ° 55.230 ’ W, 25 m: several stems and fragments, up to 2 cm high, with and without gonothecae (MHNG INVE 54635), epizoic on Bougainvillia sp.

Type locality. Salcombe Bay, Devon, Great Britain.

Remarks. This is a well-known species that needs little additional comment. Descriptions are available in Vervoort (1959), Ramil & Vervoort (1992), and Bouillon et al. (2004). Details on live hydranths of this species were provided by Cornelius (1998). Data on nematocyst complement from Brazilian material were given by Migotto (1996). Extensive data on bibliography, synonymy and geographical distribution are available in Medel & Vervoort (2000).

Substantial size differences exist among populations from different localities around the world, as shown in Table 2. These differences, most probably without any taxonomic significance, are certainly due to a combination of both geographical and ecological factors.

Calder (1991) regarded the Arctic and Antarctic reports of this species as doubtful, arguing that numerous samples were based on infertile material and/or erroneous identifications.

World distribution. Regarded as cosmopolitan by Cornelius (1995 a), and as a largely temperate and tropical species by Calder (1991).

Records from Chile. Navarino Island, Smith Channel (Hartlaub 1905), Fitzroy Channel (Jäderholm 1910), Chacao Channel, Gulf of Ancud, Magellan Strait (Leloup 1974), Fjord Piti Palena (present study).