Bougainvillia muscus ( Allman, 1863 )

Calder, Dale R., 2012, On a collection of hydroids (Cnidaria, Hydrozoa, Hydroidolina) from the west coast of Sweden, with a checklist of species from the region 3171, Zootaxa 3171 (1), pp. 1-77 : 12-13

Bougainvillia muscus ( Allman, 1863)

Figs. 9 , 10

Eudendrium ramosum .— Van Beneden, 1844b: 56, pl. 4, figs. 1–13 [not Eudendrium ramosum ( Linnaeus, 1758) ].

Perigonymus muscus Allman, 1863: 12 [incorrect subsequent spelling of Perigonimus M. Sars, 1846 ].

Bougainvillia muscus .— Segerstedt, 1889: 10, 24.

Bougainvillia ramosa .— Segerstedt, 1889: 10, 24.— Jäderholm, 1909: 47, pl. 3, fig. 4.— Rees & Rowe, 1969: 9.— Jägerskiöld, 1971: 61.

Bougainvillea ramosa .— Gislén, 1930: 315 [incorrect subsequent spelling of Bougainvillia Lesson, 1830 ].

Bougainvillia van benedeni .— Jäderholm, 1909: 46, pl. 3, fig. 5 [incorrect subsequent spelling of B. benedenii Bonnevie, 1898 ].

Type locality. UK: England, Devon, Torquay (Torbay) ( Allman 1863: 12) .

Museum material. Tjärnö, floating dock at Sven Lovén Centre for Marine Sciences , 58°52’33.68”N, 11°08’43.65”E, <1 m, 07.ix.2010, collected manually, along edge of dock near surface, two colonies, up to 5.3 cm high, with medusa buds, ROMIZ B3893 .— Saltö naturreservat, outer ledge, 58°52’40”N, 11°06’53”E, <1 m, 11.ix.2010, collected manually, on attached red algae, one colony, up to 2 cm high, with numerous gonophores, ROMIZ B3925 .

Remarks. Colonies of Bougainvillia muscus ( Allman, 1863) in collections from the two sites above were distinctly different in the form of their trophosomes. Those from Saltö naturreservat, an exposed location with distinct water movement, were short, compact, and polysiphonic ( Fig. 9 ). Such colonies resembled Jäderholm’s (1909) description of B. van benedeni (= B. benedenii Bonnevie, 1898 ). Those from sheltered, quiet waters on the floating dock at Tjärnö were tall, slender, and monosiphonic or mostly so (Fig. 10). They resembled Jäderholm’s (1909) account of B. ramosa ( Van Beneden, 1844b) . Nevertheless, hydroids from both locations fall within the limits of B. muscus as defined in a detailed recent account of the species by Schuchert (2007).

Illustrations of specimens from Bohuslän were provided by Jäderholm (1909, as both B. ramosa and B. vanbenedeni ). The species has also been reported, as B. ramosa , from Denmark ( Kramp 1935b) and the Oslofjord, Norway ( Christiansen 1972).

Reported distribution. West coast of Sweden.—Säcken area ( Jägerskiöld 1971) to southern Kattegat ( Segerstedt 1889).

Elsewhere.—Thought to be essentially circumglobal ( Calder 2010); in the North Atlantic from Norway to the Cape Verde Islands in the east, and from southern New England and Bermuda in the west (Mayer 1910, as Bougainvillia autumnalis Hartlaub, 1897 ; Calder 1988; Schuchert 2007).

Figures

FIGURE 9. Bougainvillia muscus: part of colony with polysiphonic hydrocaulus, four hydranths, and two medusa buds, ROMIZ B3925. Scale equals 0.5 mm.