Bougainvillia muscoides (M. Sars, 1846 )

Galea, Horia R., 2007, Hydroids and hydromedusae (Cnidaria: Hydrozoa) from the fjords region of southern Chile, Zootaxa 1597 (1), pp. 1-116 : 19

Bougainvillia muscoides (M. Sars, 1846)

(fig. 5C, pl. 1A)

Perigonimus muscoides M. Sars, 1846: 8 , pl.1 figs 19–21; Stechow, 1923: 75.

Bougainvillia nordgaardi Browne, 1903: 14 , pl. 2 fig. 1, pl. 3 figs 5–6; Kramp, 1961: 79.

Bougainvillia muscoides: Rees, 1938: 2 , fig. 1; Edwards, 1964: 736, figs 5–6; 1966: 146; Kramp, 1968: 33, fig. 85; Rees & Rowe, 1969: 8; Russell, 1970: 243, fig. 7S; Bouillon, 1995: 226; Buecher et al., 2005: 37 .

Material examined. Stn. COM 02 —22.i.2006, 20– 25 m, S96: a stolonal, fertile colony, epizoic on Lafoea dumosa . Stn. CFA — 14.iii.2006, 10– 30 m, S88: one polysiphonic fragment, ca 5 cm high, with medusa buds ( MHNG INVE 53321). Plankton —off the Huinay Scientific Field Station, 07, 08, 09, 12, 18, 19.ii.2006, 50– 0 m, several medusae ( MHNG INVE 38775).

Type locality. Mangerfjord , Norway .

Remarks. For descriptions of both the polyp and medusa stages, see Rees (1938) and Edwards (1964). The present hydroid material is scarce; it is composed of a small, stolonal colony, epizoic on Lafoea dumosa (Stn. COM02, S96), and a fragment of polysiphonic colony (Stn. CFA, S88). Both have characteristic medusa buds, with four marginal tentacles and large microbasic euryteles scattered on exumbrella. Several mature medusae were caught from the plankton; umbrella up to 3.1 mm in height and 3.3 mm in width, with up to 8 marginal tentacles per bulb; oral tentacles dichotomously branched 4–5 times. Cnidome (newly-liberated medusa):

a) large microbasic euryteles scattered on exumbrella, (12.0–13.3) x (6.8–8.0) µm (undischarged);

b) small microbasic euryteles on tentacles, (6.8–7.2) x (2.9–3.2) µm (undischarged);

c) desmonemes ca 6 x 3.6 µm (undischarged), on tentacles.

World distribution. Boreal waters of the Atlantic and Pacific Oceans, Arabian Gulf and off Mozambique ( Buecher et al. 2005).

Records from Chile. Both the polyp and medusa stages were collected from fjord Comau. In addition, the polyp was equally found in Canal Fallos. This is the first record of this species for Chile (see also Schuchert 2007).