Marine Invertebrates of Bermuda Etherial Sponge (Dysidea etheria) By Callie Stewart and James B. Wood (Ed) Abstract Taxonomy  Habitat  Ecology  Recent Research  Commercial Importance  Bermuda Laws  Personal Interest  References  Links

Abstract


Dysidea etheria is a metazoan life form of the phylum Porifera. Although many poriferans have endosymbiotic algae, sponges are not considered autotrophs. D. etheria can be found in salt water in depths as great as 40m in both tropical and subtropical regions. D. etheria is a leuconoid sponge in the class Demospongiae. This filter-feeding sponge exhibits both sexual and asexual reproduction and defends itself from predation with spicules and toxins. D. etheria is not a commercially important sponge and there are no laws specifically pertaining to it.

Taxonomy


Phylum: Porifera
  Class: Demospongiae
    Order: Dictyoceratida
      Family: Dysideidae


Poriferans have no true tissues, organs, or systems. This sets them apart from most of the other animal phyla. As a member of the class Demospongiae, Dysidea etheria contains spongin but does not have its own spicules. D. etheria collects spicules and sand from its surroundings.

Habitat


Dysidea etheria is a marine species typically found throughout the Caribbean, norht to Florida and Georgia at depths up to 40 m (Gleason et al. 2007). Avoiding high energy environments, D. etheria is mainly found on vertical hard substrates including natural and manmade formations (pilings, docks, etc.) in inshore waters (Sterrer 1986). D. etheria has also been found on subtidal mangrove roots, shells of mollusks and crabs, and coral skeletons (Sterrer 1986).

Ecology


General Biology:
There are three different classes of Poriferans including Calcarea, Hexactinallida, and Demospongiae. The class Demospongiae contains 80% of all known sponges. Nearly all Demospongiae sp. have the leuconoid body form (Pechenik 2000). The leuconoid body form causes increased invagination of the choanocyte layer from the spongocoel, which augments the size of the flagellated surface area enclosed by the sponge; it is the most intricate body form possible (Pechenik 2000). Having such a complex body form allows the sponge to grow to a size greater than 1 m by allowing it to capture a higher quantity of food for energy (Ruppert et al. 2004). Demospongiae have a skeleton made up of spongin fibers and silica spicules (Cowden 1970). Some Demospongiae contain only one of the two (Pechenik 2000). In some cases, Demospongiae such as Dysidea sp. have only spongin but collect sand and fragments of calcium carbonate (CaCO3) spicules from it's environment (Teragawa 1985; Pechenik 2000; Ruppert et al. 2004; Gleason et al. 2007). The collected sand and spicule fragments are stored in the mesohyl (Stachowitsch 1992).

Feeding:
Sponges are relatively unselective filter feeders (Sterrer 1986; Ruppert 2004). All Poriferans have a main chamber within the body wall called the spongocoel, which is lined with flagellated cells called choanocytes (Pechenik 2000). Choanocytes, or collar cells, generate currents that maintain seawater flow through the sponge allowing it to capture small food particles (Pechenik 2000; Riisgård and Larsen 2001). Sponges are able to adjust the amount of flow through their bodies by the constriction of ostia which are small incurrent openings (Sterrer 1984; Collins and Waggoner 1994). The volume of water passing through a sponge in a 24 hour period can be up to 20,000 times the volume of the sponge (Collins and Waggoner 1994). Poriferans can trap up to 90 percent of the bacteria in the water they filter (Collins and Waggoner 1994). Digestion takes place intracellularly via phagocytosis (Sterrer 1986).

Reproduction:
Poriferans reproduce by both asexual and sexual means (Pechenik 2000). Sexual reproduction in poriferans is hermaphroditic; however, the hermaphroditic sponge will produce sperm and eggs at different times (Ruppert et al. 2004). Sperm are released into the water column via excurrent openings (Collins and Waggoner 1994). These sperm are subsequently captured by female sponges of the same species. The captured sperm are transported to eggs by cells called archaeocytes (Stachowitsch 1992; Pechenik 2000; Ruppert et al. 2004). Fertilization occurs in the mesenhyl and the zygotes grow into ciliated larvae (Stachowitsch 1992; Pechenik 2000; Ruppert et al. 20004). Sponges release the larvae into the water column where the larvae spend little time before settling and developing into juvenile sponges (Ruppert et al. 2004). Asexual reproduction in Dysidea etheria occurs by fragmentation (Pechenik 2000; Ruppert et al. 2004). Fragmentation, typically caused by hurricanes and predation, is easily overcome by the sponge (Pechenik 2000; Ruppert et al. 2004). Sponges have totipotent cells capable of becoming whatever cell the sponge needs for survival (Cowden 1970; McClay 1971; McClay 1974). Totipotent cells allow pieces of a sponge to settle and grow a completely new sponge (Cowden 1970; McClay 1971; McClay 1974; Pechenik 2000).

Defense:
Dysidea etheria collect sand and spicule fragments which are kept in the mesohyl (Cowden 1970; Teragawa 1985). The spicule fragments make the sponge less appetizing to predators as ingestion would be somewhat painful (Ruppert et al. 2004). Some toxins have been found in D. etheria which may cause potential predators to avoid consumption of the sponge (Grode and Cardellina 1984; Uriz et al. 1996). The main predator of D. etheria in Bermuda is the nudibranch Hypselodoris zebra; however, other Hypselodoris sp. are predators of D. etheria in other locations (Grode and Cardellina 1984; Rudman 1999).

Recent Research


In general, current research regarding Dysidea etheria involves chemical compounds found in the sponge.Occasionally new fatty acids, solvents, toxins, and protein inhibitors are found in sponges; however, discoveries of new compounds in D. etheria are few and far between (Faulkner 1999; Stapleton et al. 2001). In 1998 two syntheses of (+) -dysidiolide, a cdc25A protein phosphatase inhibitor, were reported in D. etheria (Faulkner 1999). In 2001, five chlorinated peptides were located in a Dysidea sp. and identified by two-dimensional NMR spectroscopy; however these were not found in D. etheria (Stapleton et al. 2001).

Commercial Importance


There is no commercial importance of Dysidea etheria. Known auxins which regulate plant growth have been found in D. etheria but are of no commercial value (Cardellina et al. 1986). A solvent has been identified in D. etheria; however, further research showed the solvent to be highly toxic (Grode and Cardellina 1984).

Bermuda Laws


There are no laws specifically regarding Dysidea etheria. The Coral Reef Reserve Act of 1966 and the Bermuda National Park Act of 1986 both monitor collection of marine species in specified locations.

Personal Interest


While Poriferans are among the simplest life forms, they are capable of maintaining a comfortable life in a harsh environment. Sponges are incredibly beautiful life forms that somehow recognized a niche early on in evolutionary time and stopped changing. I think Porifera is an interesting phylum because of its simplicity.

References

Cardellina II, J.H., D. Nigh, and B.C. VanWagenen. 1986. Plant growth regulatory indoles from the sponges Dysidea etheria and Ulosa ruetzleri. Journal of Natural Products 49 (6): 1065.

Collins, A.G., and B.M. Waggoner. 1994. Porifera: Life History and Ecology. University of California Museum of Paleontology. (www.ucmp.berkeley.edu/porifera/poriferalh.html)

Cowden, R.R. 1970. Connective Tissue in Six Marine Sponges: A Histological and Histochemical Study. Special Edition Magazine for Microscopic-Anatomical Research 82 (4): 557.

Faulkner, D.J. 1999. Marine Natural Products.

Gleason, D.F., A.W. Harvey, and S.P. Vives. 2007. (www.bio.georgiasouthern.edu/GR-inverts)

Grode, S.H., and J.H. Cardellina II. 1984. Sesquiterpenes from the sponge Dysidea etheria and the nudibranch Hypselodoris zebra. Journal of Natural Products 47 (1): 76.

McClay, D.R. 1974. Cell Aggregation: Properties of Cell Surface Factors from Five Species of Sponge. Journal of Experimental Zoology 188 (1): 89.

McClay, D.R. 1971. An autoradiographic analysis of the species specificity during sponge cell reaggregation. The Biological Bulletin 141 (2): 319.

Pechenik, J.A. 2000. Biology of the Invertebrates Fourth Edition. Boston: McGraw Hill Companies, Inc. pp. 73.

Riisgård, H.U., and P.S. Larsen. 2001. Minireview: Ciliary filter feeding and bio-fluid mechanics—present understanding and unsolved problems. Limnology and Oceanography 46 (4): 882.

Rudman W.B. (1999) Hypselodoris zebra. Sea Slug Forum. http://www.seaslugforum.net/factsheet.cfm?base=hypszebr

Ruppert, E.E.; Fox, R.S; Barnes, R.D. 2004. Invertebrate Zoology. Seventh Edition.

Stapleton, B.L., G.M. Cameron, and M.J. Garson. 2001. New chlorinated peptides from the tropical marine sponge Dysidea sp. Tetrahedron 57:4603.

Stachowitsch, M. 1992. The Invertebrates: An Illustrated Glossary. New York: John Wiley and Sons Publication.

Sterrer, W. ed. 1986. Marine Fauna and Flora of Bermuda: A Systematic Guide to Identification of Marine Organisms. New York: John Wiley and Sons.

Teragawa, C.K. 1985. Mechanical Function and Regulation of the skeletal Network in Dysidea. 3rd International Sponge Conference.

Uriz, M.J., X. Turon, M.A. Becerro, and J. Galera. 1996. Feeding deterence in sponges. The role of toxicity, physical defenses, energetic contents, and life-history stage. Journal of Experimental Marine Biology and Ecology 205: 987.

Links


Sea Slug Forum
A Guide to the Benthic Invertebrates and Cryptic Fishes of Gray's Reef
Porifera: Life History and Ecology: University of California Museum of Paleontology
Bermudian Laws