Opisthosyllis brunnea Langerhans, 1879

Opisthosyllis brunnea Langerhans, 1879: 541, fig. 7.— Augener 1918: 274, text-fig. 25.— Day 1967: 253, figs. 12.5 c–e.—Can- tone 1976: 229, figs. 2, 3.— Fauvel 1953: 155, fig. 78.— Hartmann–Schröder 1979: 86; 1981: 24; 1982: 58; 1991: 25, fig. 19.— San Martín 1984: 311, figs. 75, 76; 1991: 230; 2003: 330, fig. 183.— Núñez et al. 1992:115, figs. 2H, 3F. Capa et al. 2001: 106.— Paresque et al. 2016: 37, figs. 20, 21. Non Opisthosyllis brunnea Imajima 1966a: 230, text–fig. 42.— Lee & Rho 1994: 135, fig. 2. Opisthosyllis nuchalis Verrill, 1900: 620 .— Monro 1933: 254, figs. 7a–c. Opisthosyllis australis Augener, 1913 (in part): 218, pl. 28, fig. 35.— San Martín et al. 2008: figs. 16A–I, 17A, B.

Material examined. Socotra N coast, 12º38.938N 53º58.840E, lower eulittoral, among algae, 26.02.1999, 1 specimen (SMF 24979); Socotra, Shanitan, 600 m off cold store, 12º40.156N 54º02.850E, 8 m, from almost completely dead Acropora, 22.03.1999; 1 specimen (NHCY 003) .

Habitat. Among dead corals, algae, sponges and other biological concretions; from intertidal to shallow depths (San Martín et al. 2008). In Socotra found in the same habitats.

Distribution. Circumtropical and temperate seas, including the Mediterranean Sea, Brazil and Japan; Australia (Western Australia, New South Wales, Queensland) (San Martín et al. 2008).