Zygophylax convallaria ( Allman, 1877 )

Calder, Dale R., 2019, On a collection of hydroids (Cnidaria, Hydrozoa) from the southwest coast of Florida, USA, Zootaxa 4689 (1), pp. 1-141 : 31-32

Zygophylax convallaria ( Allman, 1877)

Figs. 6 g–j

Lafoea convallaria Allman, 1877: 12 , pl. 9, figs. 1, 2.— Clarke, 1879: 243, pl. 4, fig. 23. Type locality. USA: Florida, off Florida Reef, 152 ftm (278 m) ( Allman 1877: 12).

Material examined. Southwest Florida Shelf, outer shelf northwest of the Dry Tortugas, 25°44.84’N, 84°21.03’W, 159 m, 26 July 1981, triangle dredge, one colony fragment, 2.8 cm high, without gonophores, coll. Continental Shelf Associates, ROMIZ B1920. — Southwest Florida Shelf , outer shelf northwest of the Dry Tortugas, 25°16.50’N, 84°14.77’W, 159 m, 02 August 1981, triangle dredge, three colony fragments, up to 3.1 cm high, one fragment with gonophores, coll. Continental Shelf Associates, ROMIZ B1921 .

Remarks. Both the trophosome and gonosome of Zygophylax convallaria ( Allman, 1877) have been thoroughly described by Vervoort (1972) based on specimens from the continental slope off Georgia, USA. He correctly noted that Fraser’s (1944) account of the species, in a book on hydroids of the Atlantic coast, was based on specimens of Z. cervicornis ( Nutting, 1905) from Hawaii. The two, considered conspecific by Fraser, are now considered distinct ( Rees & Vervoort 1987; Vervoort & Watson 2003; Schuchert 2015). Most notably, differences exist in the morphology of their gonosomes, with gonothecae of Z. convallaria having long horizontal necks and being protected by few tubules, and those of Z. cervicornis usually lacking gonothecal necks but having numerous protective tubules ( Schuchert 2015).

Zygophylax convallaria is a deep-sea species, having been reported largely from bathyal bottoms. As apparent from present material, however, it also ranges upwards into the lower neritic zone. The known bathymetric range on this coast is from 139 m ( Fewkes, 1881a) to 748 m ( Henry et al. 2008). Geographically, it has been reported in the western Atlantic from North Carolina ( Henry et al. 2008) to the southern Caribbean Sea ( Fewkes 1881a). Although recorded from the Pacific Ocean as well (e.g., Hirohito 1995; Stepanjants 2013), confirmation of its occurrence there seems warranted.

Henry et al. (2008) considered Z. convallaria to be a “characteristic species” of deep-water coral habitats off the southeastern United States. The species was collected at more than half of the stations they occupied, all located in slope waters between Cape Lookout, North Carolina, and Cape Canaveral, Florida. Colonies were found on live and dead coral, as well as other invertebrates. Fertile specimens were observed in that area during October and November.

Nomenclaturally, the specific name convallaria is a noun in apposition, and its ending need not be changed to agree in gender with any generic name with which it is combined.

Classification of the family Zygophylacidae Quelch, 1885 is unsettled ( Maronna et al. 2016), with few species having been included in molecular analyses to date. The taxon has therefore been included here in the suborder Lafoeida Bouillon, 1984, following many traditional taxonomic accounts.

Reported distribution. Gulf coast of Florida. Off the Florida Reef, 152 ftm (278 m) ( Allman 1877: 12, as Lafoea convallaria ).— SW Florida shelf, outer shelf NW of Dry Tortugas, 25°33’N, 84°21’W, 101 ftm (185 m) ( Clarke 1879: 243, as Lafoea convallaria ).

Elsewhere in western North Atlantic. Cuba: off Havana, 160–177 ftm (293–324 m) ( Clarke 1879: 243, as Lafoea convallaria ); 23°09’N, 81°27’30”W, off Matanzas, 190 ftm (347 m) Fraser 1943: 91, as Lictorella convallaria ).— Barbados: 76 ftm (139 m) + 94 ftm (172 m) ( Fewkes 1881a: 128, as Lafoea convallaria ); 13°03’50”N, 59°37’05”W, 94 fathoms (172 m) ( Fraser 1943: 91, as Lictorella convallaria ).—French Lesser Antilles: Martinique, 76 ftm (139 m) ( Fewkes 1881a: 128, as Lafoea convallaria ).—French Lesser Antilles: Guadeloupe, 150 ftm (274 m) ( Fewkes 1881a: 128, as Lafoea convallaria ).— USA: continental slope east of Georgia, 31°54’N, 79°05’W, 413 m ( Vervoort 1972: 74).— USA: Texas, banks on the continental shelf ( Rezak et al. 1985: 224).— Cuba: north coast ( Ortiz Rosado 2000: 88, as Lictorella convallaria ).— USA: North Carolina, continental slope SE of Cape Lookout, 34.1876, -75.8966, 389 m + 34.3232, -75.7923, 369 m ( Henry et al. 2008: 790, as Zygophylax convallarius ).— USA: South Carolina, Stetson Banks on continental slope E of Hilton Head Island, 32.2689, -77.4746, 582 m ( Henry et al. 2008: 790, as Zygophylax convallarius ).— USA: Georgia, Savannah Banks on continental slope E of St. Catherines Sound, 31.7042, -79.1233, 551 m ( Henry et al. 2008: 790, as Zygophylax convallarius ).— USA: Florida, Jacksonville lithoherms on continental slope E of Jacksonville, 30.5168, -79.6618, 548 m + 30.5016, -79.6531, 593 m + 30.8008, -79.6420, 538 m + 30.5191, -79.6597, 585 m + 30.5186, -79.6603, 590 m ( Henry et al. 2008: 791, as Zygophylax convallarius ).— USA: Florida, off Cape Canaveral, 28.7771, -79.6161, 748 m + 28.0393, -79.6130, 686 m ( Henry et al. 2008: 791, as Zygophylax convallarius ).

Figures

FIGURE 6. a, Acryptolaria longitheca: part of colony with two hydrothecae, Southwest Florida Shelf, ROMIZ B1902. Scale equals 0.2 mm. b, Acryptolaria longitheca: two gonothecae from a coppinia, Southwest Florida Shelf, ROMIZ B1902. Scale equals 0.1 mm. c, Acryptolaria tortugasensis: part of colony with three hydrothecae, Southwest Florida Shelf, ROMIZ B1906. Scale equals 0.2 mm. d, Acryptolaria tortugasensis: part of colony with a hydrotheca, Southwest Florida Shelf, ROMIZ B1906. Scale equals 0.1 mm. e, Lafoea coalescens: part of colony with four hydrothecae, Southwest Florida Shelf, ROMIZ B1915. Scale equals 0.2 mm. f, Synthecium tubithecum: part of colony with two hydrothecal pairs, Southwest Florida Shelf, ROMIZ B1929. Scale equals 0.2 mm. g, Zygophylax convallaria: part of colony with four hydrothecae, Southwest Florida Shelf, ROMIZ B1921. Scale equals 0.2 mm. h, Zygophylax convallaria: part of colony with a hydrotheca, Southwest Florida Shelf, ROMIZ B1921. Scale equals 0.1 mm. i, Zygophylax convallaria: nematophorous ramule, Southwest Florida Shelf, ROMIZ B1921. Scale equals 0.1 mm. j, Zygophylax convallaria: gonotheca, Southwest Florida Shelf, ROMIZ B1921. Scale equals 0.1 mm.