Shallow water hydroids (Cnidaria, Hydrozoa) from the 2002 NOWRAMP cruise to the Northwestern Hawaiian Islands Author Calder, Dale R. Author Faucci, Anuschka 0000-0001-9002-8987 anuschka@hawaii.edu text Zootaxa 2021 2021-12-24 5085 1 1 73 journal article 10.11646/zootaxa.5085.1.1 1175-5326 5802920 12FC3342-F2A0-4EE1-9853-9C5855076A10 Tridentata turbinata ( Lamouroux, 1816 ) Fig. 10e, f Dynamena turbinata Lamouroux, 1816: 180 . Tridentata turbinata .— Coles et al ., 2002b: 177 .— Carlton & Eldredge, 2009: 39 .— Calder, 2020: 224 , fig. 6h, i. Type locality. Australasia: on “ Fucus ” ( Lamouroux 1816 , as Dynamena turbinata ). Voucher material. Laysan Island , on Halimeda sp. , 18.ix.2002 , two colonies or colony fragments, to 6 mm high, without gonothecae, coll. A. Faucci , ROMIZ B5441 .— Laysan Island , on Halimeda sp. , 17.ix.2002 , one colony, 5 mm high, with gonothecae, coll. A. Faucci , ROMIZ B5442 .— Laysan Island , on Halimeda sp. , 17.ix.2002 , three colonies or colony fragments, to 3.5 mm high, with gonothecae, coll. A. Faucci , ROMIZ B5443 .— Pearl & Hermes Atoll , on Macrorhynchia philippina , 19.ix.2002 , one colony, 6 mm high, with gonothecae, coll. A. Faucci , ROMIZ B5444 . Remarks. The hydroid Tridentata turbinata ( Lamouroux, 1816 ) is widespread and relatively well-known in shallow, tropical to subtropical waters. Worldwide, it has been reported from the Pacific, Atlantic, and Indian oceans ( Redier 1971 , as Sertularia turbinata ; Millard 1975 , as S. turbinata ; Rees & Vervoort 1987 , as S. turbinata ; Gibbons & Ryland 1989 , as S. turbinata ; Calder 1991 a , 2020; Hirohito 1995 , as S. turbinata ; Migotto 1996 , as S. turbinata ; Medel & Vervoort 1998 , as S. turbinata ; Schuchert 2003 , as S. turbinata ; Humara-Gil & Cruz-Gómez 2018 ). In terms of relationships, the molecular phylogenies of Maronna et al . (2016) , Song (2019), and Galea & Maggioni (2021) combine T. turbinata in a clade with T. marginata ( Kirchenpauer, 1864 ) , T. tumida ( Allman, 1877 ) , and T. perpusilla ( Stechow, 1919b ) , with the last of these being the type species of the genus Tridentata Stechow, 1920 . Added to that clade by Galea & Maggioni was Sertularia trigonostoma Busk, 1852 . In another clade relatively close to them are species here assigned to Disertasia Neppi, 2017 , including Dynamena crisioides Lamouroux, 1824 , Sertularia disticha Bosc, 1802 and S. moluccana Pictet, 1893 . In a series of clades more distant from them in the phylograms are Sertularia pumila Linnaeus, 1758 , type species of Dynamena Lamouroux, 1812 , S. operculata Linnaeus, 1758 , type species of Amphisbetia L. Agassiz, 1862 , and Sertularia argentea Linnaeus, 1758 , type species of Sertularia Linnaeus, 1758 . Discussion of the hydroid T. turbinata in Hawaiian waters has been given elsewhere ( Calder 2020 ). In being a predominantly shallow-water species, it was not reported by Nutting (1905) in collections from mostly deep waters of the state by the United States Bureau of Fisheries steamer Albatross . Reported Distribution. Hawaiian archipelago. Oahu: Waikiki, Outside Pop’s, 6 m ( Coles et al . 2002b ); Waikiki, Atlantis Submarine site, 20 m ( Coles et al . 2002b ); Waikiki, Ala Wai buoy ( Coles et al . 2002b ); Waikiki, Kapua Channel, 5 m ( Coles et al . 2002b ).—Maui: Molokini outer rim ( Calder 2020 ). Elsewhere. Circumglobal in shallow, tropical and subtropical waters (Calder 2019, 2020).