Lamouroux, 1816: 180 Sertularia turbinata Leloup, 1935a: 50 Van Gemerden-Hoogeveen, 1965: 38 On a collection of hydroids (Cnidaria, Hydrozoa) from the southwest coast of Florida, USA Calder, Dale R. Zootaxa 2019 2019-10-25 4689 1 1 141 8N2NP (Lamouroux, 1816) Lamouroux 1816 [151,645,1125,1152] Hydrozoa Sertulariidae Tridentata CoL Animalia Leptothecata 85 86 Cnidaria species turbinata   Fig. 21g     Dynamena turbinata  Lamouroux, 1816: 180.    Sertularia turbinata.—  Leloup, 1935a: 50.—  Van Gemerden-Hoogeveen, 1965: 38.    Typelocality.Australasia: on “  Fucus” ( Lamouroux 1816: 180, as  Dynamena turbinata).  Material examined.Sanibel Island, beach at Lighthouse Point, 26°26’58”N, 82°01’04.5”W, on stranded  Sargassum pteropleuron, 21 March 2018, 22° C, 34.5‰, two colonies, up to 9 mmhigh, without gonophores, coll. D. Calder, ROMIZB4393.   Remarks.  Tridentata turbinatais a species of tropical and subtropical waters that has been recorded but few times along the Atlantic and Gulf coasts of the United States. In inshore waters, it has not been reported north of Floridaalong the east coast except as colonies transported northwards on pelagic  Sargassumby the Gulf Stream (e.g., Stachowicz & Lindquist 1997). It has been reported twice from Louisianain the northern Gulf of Mexico, although one of those occurrences was based on specimens from gulfweed (pelagic  Sargassum) ( Cary & Spaulding 1909). Most distribution records listed below of  T. turbinatain the North Atlantic are from the Caribbean region, although the species is also well-known from Bermudaand the Bahamas. To the south, records of the species are frequent in warm waters of coastal Brazil( Oliveira et al. 2016). As records below also indicate, it is most common in shallow waters. This species has long been misassigned to a non-monophyletic genus  Sertularia Linnaeus, 1758instead of  Tridentata Stechow, 1920. As documented earlier (Calder 1990 [1991a]: 104, 2013: 33; Calder et al. 2019), significant morphological differences exist between those two genera in both trophosome and gonosome. Molecular phylograms such as those in Moura et al. (2011)and Maronna et al. (2016)reveal that  T. turbinatais very close genetically to  T. perpusilla( Stechow, 1919), typespecies of  Tridentata, and that both species are remote from  S. argenteaLinnaeus, typespecies of  Sertularia. It bears repeating, once again, that the valid name of the species should be  Tridentata turbinata. The hydroid of  T. turbinatais relatively common in shallow waters of the Atlantic, Pacific, and Indian oceans, yet specimens with gonothecae have been reported infrequently. Humara-Gil & Cruz-Gómez (2018: 466, figs. 8B, E) recently discovered fertile colonies from Oaxaca, Mexico, as did Galea & Ferry (2015: 235, fig. 6G, as  Sertularia turbinata) from Guadeloupe. Earlier accounts of colonies with gonothecae include those of Stechow (1919: 93, fig. H 1, as  Sertularia brevicyathus) from the TongaIslands, Vervoort (1959: 277, figs.36b, c, as  Sertularia turbinata) from off Freetown, Sierra Leone, Millard (1975, 310, fig. 100E, as  Sertularia turbinataforma acuta) from South Africa, and Hirohito (1995:217, figs. 73e, f, as  Sertularia turbinata) from Sagami Bay, Japan. Colonies examined here were sterile. Detailed taxonomic and nomenclatural accounts of this species include those of Calder (1990 [1991a]) and Medel & Vervoort (1998, as  Sertularia turbinata).  Reported distribution. Gulf coast of Florida.Dry Tortugas: Loggerhead Key, on algae ( Leloup 1935a: 51, as  Sertularia turbinata; Van Gemerden-Hoogeveen 1965: 38, as  Sertularia turbinata).—Dry Tortugas: S of Loggerhead Key ( Van Gemerden-Hoogeveen 1965: 38, as  Sertularia turbinata).  Elsewhere in western North Atlantic. Bahamas: between Eleutheraand Little Cat islands + near Spanish Wells( Nutting 1904: 60, as  Sertularia brevicyathus).— Bermuda: various locations, abundant, on sponges, seaweeds, large hydroids ( Congdon 1907: 481, as  Sertularia brevicyathus).— USA: Louisiana, occasional, on gulfweed ( Cary & Spaulding 1909: 6, as  Sertularia brevicyanthus(sic)).— Bermuda: Challenger Bank, 31–70 ftm ( 57–128 m), on a gorgonian and algae + Agar’s Island, on  Sargassum( Bennitt 1922: 250, as  Sertularia brevicyathus).— Bonaire: Lac, mouth, back of reef, on detached  Sargassum+ Boca Washikemba, on stranded algae + Lagoen, north coast, on stranded  Sargassum(Leloup 1935: 51, as  Sertularia turbinata).— Aruba: Boca Prins, on stranded  Sargassum(Leloup 1935: 51, as  Sertularia turbinata).— Bahamas: Cay Sal Bank, 5–7 ftm ( 9–13 m), on benthic algae ( Leloup 1937: 106, as  Sertularia turbinata).—Atlantic Ocean: Gulf Stream, on pelagic  Sargassum+ Sargasso Sea, on pelagic  Sargassum(Burkenroad, in Parr 1939: 23, as  Sertularia brevicyathus).— Puerto Rico: northeast coast, 18°27’35”N, 65°33’35”W, 26 ftm ( 48 m) + 18°24’30”N, 65°38’30”W, 9 ftm ( 16 m) + 18°23’35”N, 65°37’10”W, 10 ftm ( 18 m) ( Fraser 1944: 291, as  Sertularia turbinata).— Panama: Caledonia Bay (Puerto Escoces), on floating  Sargassum( Fraser 1947b: 11, as  Sertularia turbinata).— Venezuela: off Isla Tortuga, 2–5 ftm ( 4–9 m) ( Fraser 1947b: 11, as  Sertularia turbinata).— Colombia: La Goajira, Rio Hacha (=Riohacha), on algae ( Van Gemerden-Hoogeveen 1965: 38, as  Sertularia turbinata).— Aruba: Boca Prins, on  Sargassum+ wharf of Arend Petroleum Co., on iron beam ( Van Gemerden-Hoogeveen 1965: 38, as  Sertularia turbinata).— Bonaire: Oranjepan, on stranded  Sargassum+ Boca Washikemba, on stranded brown algae + Playa Grandi, on  Sargassum( Van Gemerden-Hoogeveen 1965: 38, as  Sertularia turbinata).— Tobago: Rockley Bay (=Rockly Bay) on  Sargassum( Van Gemerden-Hoogeveen 1965: 38, as  Sertularia turbinata).—West Indies: between Trinidadand Grenada( Van Gemerden-Hoogeveen 1965: 38, as  Sertularia turbinata).— Antigua: Deep Bay, at Fort Barrington, on algae, sponge ( Van Gemerden-Hoogeveen 1965: 38, as  Sertularia turbinata).— Sint Maarten: Simson Lagoon, bridge, on algae ( Van Gemerden-Hoogeveen 1965: 38, as  Sertularia turbinata).— Virgin Islandsof the United States: St. Thomas, Sound, on other hydroids ( Vervoort 1968: 52, as  Sertularia turbinata).— Colombia: off Santa Marta ( Wedler 1975: 340, as  Sertularia turbinata).— USA: Florida, southeast coast ( Mergner 1977: 122, as  Sertularia turbinata; 1987: 187, as  Sertularia turbinata).— Belize: Carrie Bow Cay, 0–10 m, on dead corals, gorgonians ( Spracklin 1982: 246, as  Sertularia turbinata).— Colombia: vicinity of Bahía de Cartagena ( Flórez González 1983: 120, as  Sertularia turbinata).— Bermuda: inshore, shallow waters + offshore, on banks, buoy chains ( Calder 1986: 139, as  Sertularia turbinata).— USA: Louisiana, on a coastal petroleum platform, 46 m( Lewbel et al. 1987: 214, as  Sertularia turbinata).— Belize: Twin Cays ( Ellison & Farnsworth 1990: 96, as  Sertularia turbinata).— Bermuda: Whalebone Bay, 1 m, on ledge + Flatts Inlet, on rocks,  Thyroscyphus marginatus, 2 m(Calder 1990 [1991a]: 111).— Belize: Twin Cays, on  Rhizophora, benthic algae, sponges, other invertebrates ( Calder 1991b: 223; 1991c: 2068).— Belize: Lark Cay, on  Rhizophora+Northeast Cay, on  Rhizophora+ Twin Cays, on  Rhizophora( Ellison & Farnsworth 1992: 90, as  Sertularia turbinata).— Bermuda: Walsingham Pond ( Thomas et al. 1992: 139, 152, as  Sertularia turbinata).— Bermuda: Harrington Sound, just below tidal level ( Thomas 1996: 758, as  Sertularia turbinata).— USA: North Carolina, off Cape Lookout in Gulf Stream, 34°10’N, 76°13’W, on  Sargassum( Stachowicz & Lindquist 1997: 116).— Bermuda: Argus (=Plantagenet) Bank, on Argus Tower, 20 m( Calder 2000: 1135, 1136).— Panama: Bocas del Toroarea, Boca del Drago, 09°25’36.3”N, 82°19’30.1”W, 1-3 m+ Bocas del Toroarea, Cayos Zapotilla, 09°15.564’N, 82°02.750’W, 7-8 m+ Bocas del Toroarea, Swan’s Key, 09°27’12.2”N, 82°18’01.8”W, 1-4 m+ Bocas del Toroarea, Drago 2, mangrove, 1–2 m+ Bocas del Toroarea, Drago 2, 2– 4 m( Calder & Kirkendale 2005: 486).—French Lesser Antilles: Guade- loupe, Basse-Terre, N of Malendure, 16°10’25.00”N, 61°46’58.00”W, on algae ( Galea 2008: 37, as  Sertularia turbinata).—French Lesser Antilles: Les Saintes, Terre-de-Haut, Pain de Sucre, 15°51’45”N, 61°35’60”W, on  Dictyota,  Thyroscyphus ramosus( Galea 2008: 37, as  Sertularia turbinata).— USA: Florida: Fort Pierce Inlet, 27°28’24.1”N, 80°17’21.2”W, north jetty, intertidal, on benthic algae ( Calder 2013: 33).—French Lesser Antilles: Martinique( Galea 2013: 50, as  Sertularia turbinata).—French Lesser Antilles: Martinique, Le François, Pointe Jacob, 14.58552, - 60.84993, 0 m, on floating  Sargassum( Galea & Ferry 2015: 235, as  Sertularia turbinata).—Caribbean Sea ( Wedler 2017b: 134, figs. 141A, B, 142, 143, as  Sertularia turbinata).— Mexico: Alacranes Reef, on shipwreck (Mendoza- Becerril et al. 2018b: 130, as  Sertularia turbinata).