Oswaldella obscura Peña Cantero, Svoboda & Vervoort, 1997: 370 –373, figs 9, 15 A, B; Peña Cantero & Vervoort, 1998: 36; 2004: 844; Peña Cantero & García Carrascosa, 1998: 178; 1999: 214; Peña Cantero & Marques, 1999: 85.
Ecology. Shelf and slope species, found at depths from 260 to 830 m, on muddy bottoms (Peña Cantero et al. 1997). Basibiont for other hydroids (Peña Cantero et al. 1997). Gonothecae: January and February (Peña Cantero et al. 1997).
Distribution. Hitherto, considered endemic to the Weddell Sea, known from the south and east coasts (Peña Cantero et al. 1997).