Sphaerocoryne bedoti Pictet, 1893

Calder, Dale R., 2010, Some anthoathecate hydroids and limnopolyps (Cnidaria, Hydrozoa) from the Hawaiian archipelago 2590, Zootaxa 2590 (1), pp. 1-91 : 67-69

Sphaerocoryne bedoti Pictet, 1893

Figs. 44, 45

Sphaerocoryne bedoti Pictet, 1893: 10 , pl. 1, figs. 5, 6.

Type locality. Indonesia: Moluccas, Ambon ( Pictet 1893) .

Material examined. Midway Atoll: on coral rubble, 20.ix.2002, one colony, up to 6 mm high, without medusa buds, coll. A. Faucci, BPBM (without collection number) .– Midway Atoll: on coral rubble, 20.ix.2002, one colony, up to 6 mm high, without medusa buds, coll. A. Faucci, ROMIZ B3830 .

Description. Hydroid colonies stolonal, up to 6 mm high, arising from a hydrorhiza creeping over reef rubble. Hydrocaulus monosiphonic, unbranched, reaching just over 5 mm high, bearing a terminal hydranth. Perisarc transparent, with that on hydrorhiza of moderate thickness, mostly smooth but with occasional wrinkles and twists, that on hydrocauli tending to be thinner, smooth or with a few wrinkles, especially at proximal end, not regularly annulated, terminating at base of hydranth well below tentacles. Hydranths pyriform to topshaped, about 0.8 mm high, 0.5 mm wide; tentacles all capitate, about 22 in number, of varied length, scattered in a narrow band around widest part of hydranth; terminal knobs varied in size, reaching about 110 µm in diameter; hypostome elongate, proboscis-like.

Gonophores not seen.

FIGURE 44. Sphaerocoryne bedoti : part of hydrocaulus and hydranth, ROMIZ B3830. Scale equals 0.5 mm.

FIGURE 45. Sphaerocoryne bedoti : nematocysts, ROMIZ B3830. a, desmoneme. b, small stenotele. c, large stenotele. FIGURE 46. Porpita porpita : upper surface of float and mantle, BPBM D452. Scale equals 1 cm.

FIGURE 47. Velella velella : lateral view of float, mantle, and sail, BPBM D453. Scale equals 5 mm.

Remarks. Information on the taxonomy, life cycle, and cnidome of Sphaerocoryne bedoti Pictet, 1893 has been provided earlier ( Calder 1988). A more recent overview of the species is given by Schuchert (2010). Authors including Mammen (1963), Millard (1975), Hirohito (1988), Schuchert (2010) and others are followed in regarding Sphaerocoryne multitentaculata ( Warren, 1908) as conspecific with this species.

Records of the hydroid stage of Sphaerocoryne bedoti are commonly but not exclusively associated with sponge substrates (e.g. Pictet 1893; Mammen 1963; Millard 1975; Hirohito 1988; Calder 1988, 1991; Calder et al. 2003; Galea 2008; Schuchert 2010). Material examined here, the first record of the species from Hawaii, occurred on calcareous reef rubble.

The cnidome of hydroids from Hawaii examined here corresponded with that of material from Bermuda ( Calder 1988). Elongate-oval desmonemes, and small and large stenoteles, were present (Fig. 45).

Reported distribution. Hawaii. New record.

Worldwide. Circumglobal in warm waters; 0–13 m ( Pictet 1893; Millard & Bouillon 1974; Millard 1975; Wedler & Larson 1986; Hirohito 1988; Petersen 1990; Calder et al. 2003; Calder & Kirkendale 2005; Bouillon et al. 2004; Galea 2008; Schuchert 2010).