Notes: Thin lavender-pink, crumbly crusts found living over sponges of the genus Plakortis [Plakortis sp. 1 in the Bahamas, also pictured here, and Plakortis sp. 2 in Puerto Rico; see Vicente et al. (2014); we originally thought that these Plakortis were P. halichondrioides (Wilson, 1902)]. Oscules of these Plakortis are free of Xestospongia deweerdtae tissue; there are also numerous holes on the surface that may serve as inhalant areas for the lower sponge, and there are tissue filaments of the upper sponge that enter the lower sponge, perhaps to aid in gas or nutrient circulation (Vicente et al., 2014). Spicules are strongyles 170-260 x 2.5-6.3 µm, arranged in an unispicular isotropic reticulation; these spicules are smaller than the "free-living" morphotype of X. deweerdtae, pictured here separately to avoid confusion, apparently from the advantage brought about by the association (Vicente et al., 2014). It should be compared to Haliclona strongylophora Lehnert & van Soest, 1996 (not included here).

Author Reference: Lehnert & van Soest, 1999

Link: World Porifera Database