Notes: Massive, brown-black upper exposed side, with a field of oscules located in a depression; white unexposed sides with pore sieves. We have not yet found G. papyracea Hechtel, 1965 in the Bahamas, another species inhabiting mangrove stilt roots, which is crumblier. We base our identification in the presence of a small category of oxea spicules traversing abundantly the cortex of sterraster spicules (also present in Sidonops neptuni, which has a different form and habitat). Many oxeas appear flexuous in dried and mounted sections, as in G. flexisclera Pulitzer-Finali, 1986, described from the Bahamas but synonymized with G. gibberosa in the World Porifera Database (and by Cárdenas et al., 2009), but the flexion is, in our case, an artifact of section preparation.
Author Reference: Lamarck, 1815
Link: World Porifera Database