Hebellopsis gigas ( Pieper, 1884 )

Calder, Dale R., 2013, Some shallow-water hydroids (Cnidaria: Hydrozoa) from the central east coast of Florida, USA, Zootaxa 3648 (1), pp. 1-72 : 19-20

Hebellopsis gigas ( Pieper, 1884)

Fig. 5d

Lafoea gigas Pieper, 1884: 165 .

Type locality. Adriatic Sea: east coast ( Pieper 1884).

Voucher material. Off Melbourne, 28°04.0’N, 80°12.8’W, 25 m, 01.iii.1974, R/ V Gosnold Station 222/281B, Smith-McIntyre grab, one colony, on a bivalve shell, 3 mm high, without gonophores, ROMIZ B1082 .

Remarks. Galea (2008) presented evidence that Laomedea michaelsarsi Leloup, 1935 , originally from the Tortugas, Florida, and Lafoea gigas Pieper, 1884 , first described from the Adriatic Sea, are conspecific. His conclusion is followed here, although a molecular comparison of material from the two regions is needed to confirm synonymy of the two names.

Few morphological characters exist in hydroid stages of taxa currently assigned to Hebellidae Fraser, 1912b , and classification within the family overall remains flawed. Efforts to resolve relationships from molecular work have only just begun, although both Hebellidae and the supposedly related Lafoeidae A. Agassiz, 1865 appear to be polyphyletic ( Peña Cantero et al., 2010; Moura et al. 2012). Relationships to other families, including Laodiceidae L. Agassiz, 1862 , Zygophylacidae Quelch, 1885 , and Tiarannidae Russell, 1940 , are still unclear. Disagreement continues over the number and scope of genera within Hebellidae .

As for the present species, its frequent referral to Scandia Fraser, 1912b is incorrect in my opinion. Scandia , as defined by its type species S. mutabilis Ritchie, 1907 , is characterized by having a rounded annular perisarcal thickening at the base of the hydrotheca, a feature lacking in both Lafoea gigas Pieper, 1884 and its putative synonym Laomedea michaelsarsi Leloup, 1935 . For the same reason this species is not referable to Staurodiscus Haeckel, 1879 , Hebella Allman, 1888 , or Anthohebella Boero, Bouillon & Kubota, 1997 (distinguished from Hebella in having swimming gonophores instead of eumedusoids or medusae). For now I continue to recognize Hebellopsis Hadži, 1913 (type species: Hebellopsis brochii Hadži, 1913 ) as valid, distinguishing it amongst genera of this group in having a distinct diaphragm rather than a rounded annular thickening at the base of the hydrotheca, as in those genera above. In possessing that character, Lafoea gigas conforms with Hebellopsis and is referred to it here. As for the type species of the genus, Hadži (1913) spelled the specific name of the type species of the genus as both brochi (in the title, and in captions to figs. 30–32) and brochii (p. 188) in the original description. Under the First Reviser Principle, the name brochii , more widely used of the two in recent key works ( Bouillon et al. 2006; Schuchert 2012a), is taken as the correct original spelling.

Detailed recent accounts of this species are given by Peña Cantero & García Carrascosa (2002) based on collections from the Mediterranean, and by Galea (2008) from Caribbean material.

Reported distribution. Atlantic coast of Florida. First record.

Western Atlantic. Bermuda area ( Calder 1998, 2000, as Hebellopsis michaelsarsi ) to the Caribbean Sea ( Galea 2008, as Scandia gigas ).

Elsewhere. Eastern Atlantic ( Altuna Prados 1994, as Scandia gigas ) and Mediterranean ( Broch 1933; Peña Cantero & García Carrascosa 2002, as S. gigas ); Galápagos ( Calder et al. 2003, as H. michaelsarsi ).

Figures

FIGURE 5. a, Hebella venusta: pedicel and hydrotheca, ROMIZ B1097, scale equals 0.20 mm. b, Hebella sp.: pedicel and hydrotheca, ROMIZ B1132, scale equals 0.25 mm. c, Hebellopsis communis: pedicel and hydrotheca, ROMIZ B1100, scale equals 0.10 mm. d, Hebellopsis gigas: pedicel and hydrotheca, ROMIZ B1082, scale equals 0.25 mm. e, Hebellopsis scandens: pedicel and hydrotheca, ROMIZ B1091, scale equals 0.10 mm. f, Cryptolaria pectinata: distal part of a hydrocladium, ROMIZ B1120, scale equals 0.25 mm.