Geodia gibberosa Lamarck, 1815
Astrophorida, Geodiidae

Common name(s): None
Growth Form: Irregular massive, globular or massive lobate to at least 30 cm across; usually with one to a few often depressed sieve plates on upper surface.
Surface: Smooth, non-porous but with several sieve areas bearing inhalant openings (ostia) 50-100 μm across each. Entire surface except exhalant oscule sieve plates usually covered with a combination of sediment, algae and encrusting sponges.
Color: Externally whitish in dark habitats (or under cover of encrusting sponges), dark brown where exposed to light. Interior cream-colored.
Consistency: Firm, slightly compressible.
Exudate: None.
Oscules: Small (0.3-1.2 mm across), clustered in well-defined circular to oval sieve plates on upper surfaces (1-8 cm across).
Skeletal Components (Spicules, Fibers): Several different spicule forms: 1) straight or slightly curved long (780-1900 x 20-40 μm) and short (125-250 x 2-4 (μm) rods with 2 gradually tapering pointed ends (oxea); 2) straight rods with 1 pointed end and 2-4 short diverging rays at the other end (orthotriaene, plagiotriaene) (420-900 x 15-22 μm); 3) spherical or oval with star-shaped holes (actually the tips of fused rays) (sterraster) (40-100 μm across); 4) small stars with short rays relative to the diameter of the center (spheraster) (4-10 μm across), and 5) small stars with roughened rays longer relative to the diameter of the center (10-30 μm across). No spongin fibers.
Skeletal Architecture: Long needle-like spicules oriented radially near the surface, with forked ends outward under a thick outer layer of sterrasters, with a thin outermost crust of small spherasters. Small stars also dispersed throughout interior. Interior arrangement of spicules confused.
Ecology: On shallow inshore hard bottoms often associated with seagrasses. Many specimens in the Florida Keys are encrusted with green Haliclona viridis or purple Haliclona sp.
Distribution: Bermuda, South Florida to Brazil; tropical west Africa, including São Tomé.
Notes: Agrees well with description in the literature.
References: Hooper & van Soest (2002).
Similar species:

Spheciospongia vesparium

Spongia obscura

Spongia pertusa

Aaptos pernucleata