Clytia noliformis ( McCrady, 1859 )

Calder, Dale R., 2013, Some shallow-water hydroids (Cnidaria: Hydrozoa) from the central east coast of Florida, USA, Zootaxa 3648 (1), pp. 1-72 : 55-57

Clytia noliformis ( McCrady, 1859)

Fig. 16a, b

Campanularia noliformis McCrady, 1859: 194 , pl. 11, fig. 4.

Type locality. Bermuda: Castle Harbour , on a dead octocoral ( International Commission on Zoological Nomenclature 2002); based on a neotype .

Voucher material. Fort Pierce , Fort Pierce Inlet State Park, 27°28’29.5”N, 80°17’25.8”W, on stranded Sargassum natans , 14.vii.2012, 28° C, 35‰, collected manually, two colonies, with gonophores, coll. D.R. Calder, ROMIZ B3984 .

Remarks. The hydroid species recorded here, widely known for a century as Clytia noliformis ( McCrady, 1859) , has been objectively defined recently by a neotype ( International Commission on Zoological Nomenclature 2002). Evidence had arisen that the binomen C. noliformis was likely applied by McCrady (1859) to a different species ( Calder 1991a; Lindner & Calder 2000), more closely resembling C. hemisphaerica ( Linnaeus, 1767) . A neotype was therefore needed to conserve prevailing usage of the name. McCrady’s hydrozoan types (including any of C. noliformis ) are believed to have been destroyed during the American Civil War ( Stephens & Calder 1992).

Clytia noliformis is an abundant epibiont on pelagic Sargassum , and especially so on S. natans (Burkenroad, in Parr 1939; Calder 1995). Colonies grow quickly outwards onto new phylloids (leaflets) and bladders of these fucoids, and are least abundant on the oldest and innermost parts of the thalli ( Ryland 1974). Niermann (1986) reported that C. noliformis was more prevalent on S. natans north of a thermal front in the Sargasso Sea than south of it. The difference was attributed to greater water stratification in the south and to a lower nutrient supply, resulting in less food (nannoplankton) for the hydroid.

A combination of morphological characters can be used to distinguish Clytia noliformis from its congeners (colonies stolonal; hydrothecae about equal in height and breadth at the margin; marginal cusps triangular; basal chambers of hydrothecae shallow; subhydrothecal spherule present; coenosarc and hydranths yellowish), and merotrichous isorhiza nematocysts are diagnostic ( Lindner & Migotto 2001, 2002). As for gonothecae, they are urn-shaped, arise from the hydrorhiza, have walls that are slightly undulated and cylindrical to laterally compressed, and the distal end bears a tubular neck ( Calder 1991a). The cnidome of C. noliformis includes microbasic b-mastigophores as well as merotrichous isorhizas.

The life cycle of C. noliformis has been followed in the laboratory from hydroid to adult medusa stages ( Lindner & Migotto 2002). A detailed taxonomic account of the species has been given earlier ( Calder 1991a).

Reported distribution. Atlantic coast of Florida. First record.

Western Atlantic. Nova Scotia, on Sargassum ( Fraser 1918) , to Brazil (Oliveira et al. submitted), and including Bermuda ( Calder 1991a), the Gulf of Mexico ( Calder & Cairns 2009), and the Caribbean Sea ( Vervoort 1968, as Campanularia (Clytia) noliformis ).

Elsewhere. Sargasso Sea ( Niermann 1986); warm waters of the eastern Atlantic ( Rees & White 1966; Wirtz 2007) including the Mediterranean Sea ( Faucci & Boero 2000), Indian Ocean ( Mammen 1965), western Pacific ( Kirkendale & Calder 2003), and eastern Pacific ( Fraser 1948).

Figures

FIGURE 16. a, Clytia noliformis: hydrotheca and distal part of pedicel, ROMIZ B3984, scale equals 0.10 mm. b, Clytia noliformis: gonotheca, ROMIZ B3984, scale equals 0.10 mm. c, Clytia paulensis: part of colony with hydrotheca and pedicel, ROMIZ B1103, scale equals 0.20 mm. d, Clytia paulensis: hydrotheca and distal part of pedicel, ROMIZ B1103, scale equals 0.10 mm. e, Obelia geniculata: part of hydrocaulus with three hydrothecae, ROMIZ B1119, scale equals 0.25 mm. f, Obelia hyalina: part of colony with three hydrothecae, ROMIZ B3985, scale equals 0.25 mm. g, Obelia oxydentata: part of colony with three hydrothecae, ROMIZ B1112, scale equals 0.25 mm.