Lafoea gracillima ( Alder, 1856 )

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 : 29-30

Lafoea gracillima ( Alder, 1856)

Fig. 28

Campanularia gracillima Alder, 1856: 361 , pl. 14, figs. 5, 6.

Lafoea fruticosa .— Segerstedt, 1889: 15, 26 [not Campanularia fruticosa M. Sars, 1850 ].

Lafoea gracillima .— Jäderholm, 1909: 74, pl. 7, figs. 6, 7.— Rees & Rowe, 1969: 15.— Jägerskiöld, 1971: 63.

Type locality. UK: England, Northumberland coast ( Alder 1856: 361; Cornelius & Garfath 1980: 281).

Museum material. Kosterhavet, 58°53.093’N, 11°05.668’E, 30– 20 m, 09.ix.2010, biological dredge, R / V Nereus , one colony, up to 3.8 cm high, on stems of Tubularia indivisa , without gonophores, ROMIZ B3912.

Remarks. There has been longstanding debate whether Lafoea gracillima ( Alder, 1856) is conspecific with L. fruticosa (M. Sars, 1850) . Cornelius (1975b) reviewed the evidence, concluded that they were identical, and referred both to the synonymy of L. dumosa ( Fleming, 1820) . His concept of the species has been widely adopted in recent major taxonomic accounts of this hydrozoan (e.g. Rees & Vervoort 1987; Cornelius 1995a; Hirohito 1995; Schuchert 2001 a, 2003; Watson 2003; Bouillon et al. 2006; Vervoort 2006).While acknowledging the high degree of variation apparent in these hydroids, and the overlap in morphotypes that may occur, evidence from molecular work is needed to resolve their relationships. Moura et al. (2008) suggested from preliminary molecular analyses that L. dumosa could be a species complex, and Schuchert (2001a) discovered some nematocyst differences in materials assigned to the species. For now, as with Cairns et al. (2002: 56), I prefer to maintain L. gracillima as valid.

Lafoea gracillima , or the typical form corresponding to it, is common in southwestern Scandinavia ( Kramp 1935b; Rees & Rowe 1969; Jägerskiöld 1971; Christiansen 1972). Reported distribution. West coast of Sweden.—Säcken Reef to Gullmarfjord ( Rees & Rowe 1969). Elsewhere.—North Atlantic from Spitzbergen to Madeira ( Christiansen 1972) in the east, and from Greenland and the Canadian Arctic to Nantucket Sound ( Calder 1970, 2004) in the west.