Sponge Guide

UNCW National Science Foundation Valdosta State University Universidad Nacional de Colombia

Observed Characteristics:

Color:

  • black

Morphology:

  • encrusting
  • massive

Consistency:

  • soft

Sample Locations:

  • Bahamas

Plakortis sp.1-“under Xestospongia deweerdtae associated”

Notes: Dark brown to black, thick and large soft cushions with slightly elevated, large oscules, covered partly to completely by the thin pink, crumbly tissue of Xestospongia deweerdtae Lehnert & van Soest, 1999 “associated” morphotype, also pictured here (see further photos there). Consistency is soft but grainy. A dark ink is exuded when handled and fixed, which strongly stains the fixative. We had previously included this species within Plakortis halichondrioides (Wilson, 1902), but molecular analyses by Vicente et al. (2014) showed it to be a different species. It has a 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. Oscules of these Plakortis are free of Xestospongia deweerdtae tissue; there are also numerous holes on the surface of the upper sponge 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).