Bioacoustics of Tridentata turbinata

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).