Notes: Dark brown to black (sometimes dark green), thick and large soft cushions with a few, slightly elevated, large oscules. Consistency is soft but grainy. Underwater strobe brings lighter brown color to some photos. A dark ink is exuded when handled and fixed, which strongly stains the fixative. Compared to other Caribbean species of the genus it is less soft, and has larger spicules, of a rather uniform size (usually >150 µm). In some areas there are light brown (cinnamon-tan) specimens with the same spicule shape and size that apparently do not produce the dark exudate, but more work is needed to find if they belong to a different species. Herein we have placed the dark and light specimens as separate morphotypes of P. halichondroides. We have placed any dark Plakortis with larger spicules exceeding 150 µm in lenght within P. halichondroides, in contradiction to Diaz & van Soest (1984) and Moraes & Muricy (2003) who report some P. angulospiculatus with greater spicule sizes. We had previously also included within this species those specimens that were basibionts to thin Xestospongia deweerdtae Lehnert & van Soest, 1999, but molecular analyses by Vicente et al. (2014) showed it to be a different species, Plakortis sp. 1, which we are calling here "Plakortis" sp.1-"under Xestospongia deweerdtae". This latter species appears to have smaller spicule length than P. halichondrioides (mean 113 µm vs. 166 µm respectively, Vicente et al., 2014). Detailed simultaneous comparisons of all our Plakortis species is pending.

Author Reference: (Wilson, 1902)

Link: World Porifera Database