Modeeria rotunda ( Quoy & Gaimard, 1827 )

Calder, Dale R., 2019, On a collection of hydroids (Cnidaria, Hydrozoa) from the southwest coast of Florida, USA, Zootaxa 4689 (1), pp. 1-141 : 34

Modeeria rotunda ( Quoy & Gaimard, 1827)

Fig. 8b

Dianaea rotunda Quoy & Gaimard, 1827: 181 , pl. 6A, figs. 1, 2 [medusa stage].

Stegopoma fastigiatum .— Leloup, 1935a: 12.

Stegopoma fastigiata .— Fraser, 1944: 178.

Type locality. Mediterranean Sea , at the Strait of Gibraltar ( Quoy & Gaimard 1827: 182) .

Material examined. Southwest Florida Shelf, middle shelf west of North Naples, 26°16.72’N, 83°46.82’W, 83 m, 24 July 1981, otter trawl, on Acryptolaria longitheca , three colony fragments, up to 3 mm high, without gonophores, coll. Continental Shelf Associates, ROMIZ B4350.

Remarks. The hydroid Stegopoma fastigiatum ( Alder, 1860) , reported earlier from southwest Florida by Leloup (1935a) and Fraser (1944), has been linked to the medusa Modeeria rotunda ( Quoy & Gaimard, 1827) in life cycle studies ( Edwards 1973). The latter name has nomenclatural priority. Hydrothecae of the species resemble those of Stegopoma plicatile in having a gable-shaped operculum ( Cornelius 1995b), but colonies of M. rotunda are stolonal rather than erect with polysiphonic hydrocauli.

Both polyp and medusa stages of this species have been widely reported, mainly in deep waters, with a bathymetric range extending from the neritic zone to a depth of at least 677 ftm (1238 m) ( Fraser 1944, as Stegopoma fastigiata ; Kramp 1959, as Tiaranna rotunda ; Cornelius 1995b).

Reported distribution. Gulf coast of Florida. S of the Dry Tortugas, 92–94 ftm (168–172 m), on a large spider crab ( Leloup 1935a: 13, as Stegopoma fastigiatum ; Fraser 1944: 179, as Stegopoma fastigiata ).

Elsewhere in western North Atlantic. Canada: off NE tip of Georges Bank, 41°25’N, 65°42.3’W, 430 ftm (786 m) ( Verrill 1873: 9, as Calycella fastigiata ).— Greenland: Davis Strait ( Levinsen 1893: 180, as Stegopoma fastigiatum ).— USA: off Martha’s Vineyard, 40°03’N, 70°31’W, 100 ftm (183 m), on Halecium ( Fraser 1940: 578, 1944: 179, as Stegopoma fastigiata ).— Canada: off Brown’s Bank, 41°47’N, 65°37’30”W, 677 ftm (1238 m) ( Fraser 1944: 179, as Stegopoma fastigiata ).— USA: off Marthas Vineyard, 40°01’N, 68°54’W, 640 ftm (1170 m) + 39°58’N, 70°37’W, 115 ftm (210 m) + 39°54’N, 69°51’30”W, 134 ftm (245 m) + 39°34’N, 71°56’W, 374 ftm (584 m) ( Fraser 1944: 179, as Stegopoma fastigiata ).— USA: off North Carolina ( Fraser 1944: 179, as Stegopoma fastigiata ).— USA: South Carolina, middle shelf (32–36 m) ( Wenner et al. 1984: 21).— USA: Georgia, outer continental shelf (59–67 m) ( Wenner et al. 1984: 21, 40).— Greenland: west coast, 66.15°N, 56.12°W, 160-200 m ( Schuchert 2001: 51).— USA: Louisiana, continental slope, 540–560 m, from vestimentiferan aggregrations on water cold seeps, on Halecium sp. ( Bergquist et al. 2003: 205).— USA: Virginia, outer continental shelf, on shipwreck ( Meyer et al. 2017: 20).

Figures

FIGURE 8. a, Hebella venusta: hydrotheca, pedicel, and stolon, Southwest Florida Shelf, ROMIZ B1929. Scale equals 0.1 mm. b, Modeeria rotunda: hydrotheca, pedicel, and stolon, Southwest Florida Shelf, ROMIZ B4350. Scale equals 0.2 mm. c, Eutima sp.: hydranth and stolon, Sanibel Island, ROMIZ B4349. Scale equals 0.1 mm. d, Genus and species indeterminate: hydrotheca, pedicel, and stolon, Southwest Florida Shelf, ROMIZ B4355. Scale equals 0.1 mm.