Halecium tenellum Hincks, 1861a

Synonyms in the area: Halecium tenue Fraser, 1938b; [polyp]; Halecium washingtoni —Fraser 1938a, 1938b, 1939, 1948; Calder et al. 2003 [polyp].

Distribution in South America: polyp—Pacific Ocean, Ecuador, from 1.3°N to 1.4°S in Galápagos Archipelago, Peru, at 6.95°S 80.70°W in Isla Lobos de Afuera, at 15.33°S 75.16°W in Bahia San Juan, Chile, at 29.25°S 71.52°W, and from 41.77°S to 55.21°S (Jäderholm 1903 p. 267, 1905 p.13–14, 1910 p. 2; Hartlaub 1905 p. 609; Fraser 1938a, 1938b, 1939, 1948; Leloup 1974 p. 11–12; Calder et al. 2003; Galea et al. 2007b p. 311, 316, 2007c p. 59–61; Galea & Schories 2012a p. 22, 24); Atlantic Ocean, at Curaçao Island, at Bonaire Island, Brazil to Argentina, at 8.71°S 35°W, from 23.5°S to 27.30°S, from 40° to 54ºS (Jäderholm 1905; Leloup 1935; El Beshbeeshy 1991, 2011; Blanco 1994a; Migotto 1996; Genzano & Zamponi 1997; Calder & Maÿal 1998; Migotto et al. 2002; Oliveira 2003; Miranda & Marques 2006, abstract; Oliveira et al. 2006; Oliveira & Marques 2007, 2011; Shimabukuro 2007; Cunha & Jacobucci 2010; Silveira & Morandini 2011; Miranda et al. 2011, 2015; Marques et al. 2013; Fernandez et al. 2014, 2015).

Habitat: polyp—from intertidal zone to 835m depth, on algae, fouling, bryozoans, hydroids, Lophogorgia punicea, mud, mussels, Rhizophora mangle roots, Schizoporella unicornis, mud, shells, shellgravel, worm tubes (Jäderholm 1903 p. 267, 1905 p. 13–14, 1910 p. 2; Hartlaub 1905 p. 609; Fraser 1938a, 1938b; Leloup 1974 p. 11–12; El Beshbeeshy 1991, 2011; Blanco 1994a; Migotto 1996; Calder & Maÿal 1998; Calder et al. 2003; Oliveira 2003; Oliveira et al. 2006; Galea et al. 2007c p. 59–61; Oliveira & Marques 2007, 2 0 11; Shimabukuro 2007; Cunha & Jacobucci 2010; Miranda et al. 2011; Fernandez et al. 2014, 2015).