| Species name | Common name | Distribution | Max. Length (cm) |
|---|---|---|---|
| Halecium annulatum Torrey, 1902 |
Eastern Pacific | ||
| Halecium arcticum Ronowicz & Schuchert, 2007 |
Northeast Atlantic | ||
| Halecium articulosum Clark, 1875 |
Atlantic and Pacific Oceans | ||
| Halecium beanii (Johnston, 1838) |
Thornbush hydroid | Atlantic, Arctic and Pacific Oceans | |
| Halecium bermudense Congdon, 1907 |
Western Atlantic | ||
| Halecium capillare (Pourtales, 1907) |
Western Atlantic | ||
| Halecium corrugatum Nutting, 1899 |
Atlantic, Pacific and Arctic Oceans | ||
| Halecium curvicaule von Lorenz, 1886 |
Atlantic and Arctic Oceans | ||
| Halecium delicatulum Coughtrey, 1876 |
Delicate hydroid | Cosmopolitan | |
| Halecium densum Calkins, 1899 |
Dense bushy hydroid | Eastern Pacific | |
| Halecium dichotomum Allman, 1888 |
Southwest Atlantic | ||
| Halecium diminutivum Fraser, 1940 |
Western Atlantic | ||
| Halecium dyssymetrum Billard, 1929 |
Western Atlantic | ||
| Halecium dysymmetrum Billard, 1929 |
Southwest Atlantic | ||
| Halecium filicula Allman, 1877 |
Western Central Atlantic | ||
| Halecium fjordlandicum Galea, 2007 |
Fjord sapling | Southeast Pacific | |
| Halecium fraseri Ralph, 1958 |
Southeast Pacific | ||
| Halecium fruticosum Fraser, 1943 |
Western Atlantic | ||
| Halecium groenlandicum Kramp, 1911 |
Atlantic and Arctic Oceans | ||
| Halecium halecinum (Linnaeus, 1758) |
Herringbone hydroid | Atlantic and Pacific Oceans | |
| Halecium incertus Naumov & Stepan'yants, 1962 |
Antarctic, Kerguélen and Bouvet | ||
| Halecium insolens Fraser, 1938 |
Eastern Pacific | ||
| Halecium jaederholmi Vervoort, 1972 |
Antarctic Atlantic | ||
| Halecium kofoidi Torrey, 1902 |
Eastern Pacific | ||
| Halecium labrosum Alder, 1859 |
Atlantic, Pacific and Arctic Oceans | ||
| Halecium lightbourni Calder, 1991 |
Western Atlantic | ||
| Halecium macrocephalum Allman, 1877 |
Atlantic and Pacific Oceans | ||
| Halecium minutum Broch, 1903 |
Atlantic and Arctic Oceans | ||
| Halecium muricatum (Ellis & Solander, 1786) |
Sea hedgehog hydroid | Mediterranean, Atlantic, Pacific and Arctic Oceans | |
| Halecium mutilum Allman, 1876 |
Antarctic Indian Ocean | ||
| Halecium nanum Alder, 1859 |
Mediterranean, Atlantic and Arctic Oceans | ||
| Halecium obovatum Watson, 2018 |
Eastern Indian Ocean | ||
| Halecium ornatum Nutting, 1901 |
Pacific and Arctic Oceans | ||
| Halecium ovatum Totton, 1930 |
Southwest Pacific and Antarctic Atlantic | ||
| Halecium pallens Jäderholm, 1904 |
Antarctic Atlantic | ||
| Halecium paucinodum (Fraser, 1947) |
Eastern Pacific | ||
| Halecium petrosum Stechow, 1919 |
Mediterranean | 19 | |
| Halecium pusillum Sars, 1850 |
Mediterranean | 27 | |
| Halecium pygmaeum Fraser, 1911 |
Eastern Pacific | ||
| Halecium ralpha Watson & Vervoort, 2001 |
Indo-West Pacific | ||
| Halecium reversum Nutting, 1901 |
Eastern Pacific | ||
| Halecium scutum Clark, 1877 |
Atlantic, Pacific and Arctic Oceans | ||
| Halecium sessile Norman, 1867 |
Western Atlantic | ||
| Halecium speciosum Nutting, 1901 |
Central and north Atlantic, Pacific and Arctic Oceans | ||
| Halecium telescopicum Allman, 1888 |
Eastern Pacific | ||
| Halecium tenellum Hincks, 1861 |
Arctic, Atlantic, Pacific and the Antarctic | ||
| Halecium undulatum Billard, 1921 |
Atlantic and Arctic Oceans | ||
| Halecium vagans Fraser, 1938 |
Eastern Pacific | ||
| Halecium washingtoni Nutting, 1899 |
Eastern Pacific | ||
| Halecium wilsoni Calkins, 1899 |
Eastern Pacific |