Tridentata turbinata ( Lamouroux, 1816 )

Calder, Dale R. & Faucci, Anuschka, 2021, Shallow water hydroids (Cnidaria, Hydrozoa) from the 2002 NOWRAMP cruise to the Northwestern Hawaiian Islands, Zootaxa 5085 (1), pp. 1-73 : 36

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).

Figures

FIGURE 10. Sertulariidae and Symplectoscyphidae. a, Tridentata loculosa (Bale, 1852), part of hydrocaulus with two hydrothecal pairs, Midway Atoll, ROMIZ B5434. Scale equals 0.2 mm. b, Tridentata loculosa (Bale, 1852), gonotheca, Midway Atoll, ROMIZ B5434. Scale equals 0.2 mm. c, Tridentata orthogonalis (Gibbons & Ryland, 1989), part of hydrocaulus with two hydrothecal pairs, Laysan Island, ROMIZ B5440. Scale equals 0.2 mm. d, Tridentata rugosissima (Thornely, 1904), part of hydrocaulus with one hydrothecal pair, Laysan Island, ROMIZ B5489. Scale equals 0.1 mm. e, Tridentata turbinata (Lamouroux, 1816), part of hydrocaulus with two hydrothecal pairs, Pearl & Hermes Atoll, ROMIZ B5444. Scale equals 0.1 mm. f, Tridentata turbinata (Lamouroux, 1816), gonotheca, Pearl & Hermes Atoll, ROMIZ B5444. Scale equals 0.2 mm. g, Bicaularia tongensis (Stechow, 1919b), part of hydrocaulus with two hydrothecae, Midway Atoll, ROMIZ B5445. Scale equals 0.1 mm.