Hebellopsis scandens ( Bale, 1888 )

Calder, Dale R. & Faucci, Anuschka, 2021, Shallow water hydroids (Cnidaria, Hydrozoa) from the 2002 NOWRAMP cruise to the Northwestern Hawaiian Islands, Zootaxa 5085 (1), pp. 1-73 : 15

Hebellopsis scandens ( Bale, 1888)

Fig. 4c

Lafoea scandens Bale, 1888: 758 , pl. 13 figs 16–19.

Type locality. Australia: Port Stephens ; Port Jackson ( Bale 1888, as Lafoea scandens ) .

Voucher material. Pearl & Hermes Atoll , on Pasya heterodonta , 28.ix.2002, three colonies, to 0.5 mm high, without gonothecae, coll. A. Faucci, ROMIZ B5413 .

Remarks. Hebellopsis scandens Bale, 1888 is common as an epizoite on other hydroids, especially sertulariids and syntheciids. In typically curving from back to front of the substrate, its long, slender, and nearly cylindrical hydrothecae tend to be variously contorted.

Taxonomic and nomenclatural accounts of this species have been given in works including Calder (1991a), Boero et al. (1997, as Hebella scandens ), and Vervoort & Watson (2003). In having a distinct diaphragm rather than a variably developed annular perisarcal thickening at the base of the hydrotheca, the species is assigned here to Hebellopsis Hadži, 1913 rather than to Hebella Allman, 1888 . Meanwhile, confusion over the names H. scandens and Hebella calcarata (A. Agassiz, in L. Agassiz, 1862), as applied to this species, has been addressed in the works by Calder (1991a) and Boero et al. (1997).

Of the putative hebellids included in the molecular study of Maronna et al. (2016), H. scandens was closest genetically to Staurodiscus gotoi ( Uchida, 1927) . By contrast, it was distant from Hebella venusta ( Allman, 1877) and H. parasitica ( Ciamician, 1880) . Similar results had been reported earlier by Moura et al. (2012).

A juvenile medusa has been described in the life cycle of H. scandens (e.g., Altuna 1996; Boero et al. 1997), but the identity of the adult stage is as yet unresolved. Thus, the nomenclature of this hydrozoan remains unsettled at the rank of both species and genus.

Reported Distribution. Hawaiian archipelago. First record.

Elsewhere. Considered circumglobal, temperate to tropical waters: western Pacific ( Xu et al. 2014b, as Hebella scandens ); central Pacific ( Vervoort & Vasseur 1977, as H. scandens var. contorta ; Coles et al. 2003); eastern Pacific ( Fraser 1948, as Hebella calcarata ); western Atlantic ( Calder 2013); eastern Atlantic ( Altuna 1996, as H. scandens ); Indian Ocean ( Millard 1975, as H. scandens ).

Figures

FIGURE 4. Hebellidae. a, Hebella furax Millard, 1957, hydrotheca, Midway Atoll, ROMIZ B5407. Scale equals 0.1 mm. b. Hebella sp., hydrotheca, pedicel, and stolon, Midway Atoll, ROMIZ B5493. Scale equals 0.2 mm. c, Hebellopsis scandens (Bale, 1888), hydrotheca and pedicel, Pearl & Hermes Atoll, ROMIZ B5413. Scale equals 0.1 mm. d, Hebellopsis sibogae Billard, 1942, hydrotheca and pedicel, Pearl & Hermes Atoll, ROMIZ B5410. Scales equal 0.1 mm. e, Hebellopsis sibogae Billard, 1942, hydrotheca and pedicel, Pearl & Hermes Atoll, ROMIZ B5411. Scale equal 0.1 mm. e,