Staurocladia vallentini ( Browne, 1902 )

Galea, Horia R. & Schories, Dirk, 2012, Some hydrozoans (Cnidaria) from Central Chile and the Strait of Magellan, Zootaxa 3296, pp. 19-67 : 29-30

Staurocladia vallentini ( Browne, 1902)

(pl. 2A–E)

Eleutheria vallentini Browne, 1902: 279 . — Mayer, 1910: 96.

Staurocladia vallentini — Browne & Kramp, 1939: 274, pl. 14 figs 3, 4, pl. 15 fig. 4, pl. 19 fig. 2. — Kramp, 1959: 98, fig. 58. — Kramp, 1961: 62. —? Millard, 1975: 57, fig. 23D–G. —? Hirohito, 1988: 42, fig. 12C–E. —? Schuchert, 1996: 133, fig. 81.

? Cnidonema vallentini — Ralph, 1947 (pro parte): 415: pl. 35, figs 1–3, 4A.

? Cnidonema capensis Gilchrist, 1919: 509 , pl. 30.

? Cnidonema haswelli Briggs, 1920: 97 , pl. 17 figs 1–4, pl. 18 figs 1–5.

Material examined. Stn. CHN — 05.xi.2010, S01 (5 m): a single medusa, alcohol-fixed (MHNG-INVE-79609); 28.xi.2010, S02 (5 m): nine medusae (six of which as MHNG-INVE-79610); 06.xii.2010, S21 (5 m): a single medusa.

Description. Formalin-fixed medusae ca. 3 mm in diameter from tip to tip of opposite tentacles, possibly slightly larger in life. Umbrella flattened dorso-ventrally. Radial canals from 8 to 10; circular canal broad; a thick cushion of nematocysts in the form of an uninterrupted ring under the circular canal; velum broad though lying appressed to manubrium and difficult to see; manubrium conical to funnel shaped when fully extended, mouth without lips. In one specimen photographed upside down (plate 2D), eight gastric pouches are visible as orange bodies. Gonads surround the upper part of the gastric cavity, then divide into 8 or 9 pear-shaped lobes occupying the whole of the upper part of the digestive cavity and spread downwards alongside of the manubrium. Tentacles up to 42, divided into two branches, the lower with a terminal adhesive disk, the upper with clusters of nematocysts. Upper branch of tentacles invariably with a distal nematocysts cluster, and up to 7 additional ones, median in position, alternately placed on the aboral (up to 4 clusters) and oral (up to 3 clusters) sides of the branch. An ocellus at each tentacle base. Color in life: circular canal, gastric cavity and endoderm of distal part of the oral branch of the tentacles, orange; radial canals bright white; adhesive pad and clusters of nematocysts white; ocelli reddish.

Remarks. For a good, comprehensive discussion on the taxonomy and distribution of S. vallentini , see Hirano et al. (2006).

Distribution in Chile. This is the first record of this species from the country. It is expected to occur southwards of Chaihuin, the locality of the present collection, to the Strait of Magellan.

World records. Falkland Islands ( Browne 1902, Browne & Kramp 1939). Doubtful records are from South Africa [ Gilchrist 1919 (as S. capensis ), Millard 1975], Japan (Hirohito 1988, Hirano et al. 2006), Bermuda ( Weill 1937), Australia ( Briggs 1920, as S. haswelli ), and New Zealand ( Ralph 1947, Schuchert 1996, Bouillon & Barnett 1999).