Please refer to the accompanying glossary for definitions of the descriptive terms used in this report.
The ethereal sponge, Dysidea etheria is a massive to semi-encrusting, commonly lobate species (Wiedenmayer 1977). The lobes are often elongate, lamellar or digitate. Live specimens are light blue throughout, although the exopinacoderm may be brownish grey. The consistency in life is softly spongy, highly compressible and limp. Dried specimens are quite fragile. Sharply pointed conules 3 mm apart and at least 1 mm high adorn the sponge surface. The oscules are frequently located on the tops of the lobes, 5-10 mm wide, with thin, transparent iris-membranes. The openings in the oscular membranes are sometimes compound. The exopinacoderm is thin and semitransparent, and the choanosome is fleshy. The skeleton is an irregular, loose fibroreticulation, with white fibers loaded with calcareous debris. The secondaries are not very distinct and contain less foreign material. The primaries usually branch and connect at low angles.
Potentially Misidentified Species
S. radians may be confused with the massive starlet coral, Siderastrea siderea. However, the latter species typically forms large boulders or heads (Humann 1993). Upon closer examination, the two species are visually distinct. Corallites of S. siderea are less steeply sloped, lighter in color, and have less pronounced septa than S. radians.
HABITAT AND DISTRIBUTION
Habitat & Regional Occurence
D. etheria occurs in lagoons on unconsolidated sediment, attached to algae or blades of turtle grass, Thalassia testudinum (Wiedenmayer 1977). This species is also found encrusting rocky bottom areas, or growing over organisms such as hard corals or other sponges.
LIFE HISTORY AND POPULATION BIOLOGY
Size & Growth
D. etheria grows to widths of 10-15 cm and heights of 4-7 cm, with lobes 2-4 cm in diameter (Wiedenmayer 1977).
No information is available at this time
Although chemicals produced by D. etheria serve as a defense against many predators (e.g., Waddell & Pawlik 2000), some organisms have been observed to prey up on the sponge. These predators include the sea star Echinaster echinophorus, and most notably, the nudibranch Hypselodoris zebra (e.g., Grode & Cardellina 1984).
Several other sponge species can be found along with D. etheria. However, the ethereal sponge appears to have a competitive advantage over other sponges and is rarely overgrown by its neighbors (Engel & Pawlik 2005).
Like many other species of marine sponges, D. etheria produces chemical metabolites that are isolated, identified and studied for potential antifouling and/or pharmaceutical uses (e.g. Cardellina 1986, Boukouvalas et al. 1998).
Boukouvalas J, Cheng Y & J Robichaud. 1998. Total synthesis of (+) – Dysidiolide. J. Org. Chem. 63: 228-229.
Cardellina JH II. 1986. Marine natural products as leads to new pharmaceutical and agrochemical agents. Pure Appl. Chem. 58: 365-374.
Engel S & JR Pawlik. 2005. Interactions among Florida sponges. II. Mangrove habitats. Mar. Ecol. Prog. Ser. 303: 145-152.
Grode SH & JH Cardellina II. 1984. Sesquiterpenes from the sponge Dysidea etheria and the nudibranch Hypselodoris zebra. J. Nat. Prod. 47: 76-83.
Wiedenmayer F. 1977. Shallow-water sponges of the western Bahamas. Birkhäuser Verlag. Basel, Switzerland. 287 pp.