Dysidea etheria, commonly known as the ethereal sponge or heavenly sponge, is a species of lobate sponge within the class Demospongiae.[1] This marine sponge is known for its light blue color and can be found in the Caribbean as well as off the coasts of Florida and Georgia.[2] Like all other poriferans, D. etheria is capable of both sexual and asexual reproduction.[3] The use of spicule collection as well as chemical defenses allows D. etheria to protect itself against predators such as the zebra doris and the orange knobby star.[4][5] D. etheria is also known as a host species of the invasive brittle star Ophiothela mirabilis.[6] Lastly, various molecular biology studies have utilized D. etheria to both study foreign particle transport in sponges and to isolate novel molecules.[7][8][9]

Dysidea etheria
A preserved specimen from the Caribbean
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Porifera
Class: Demospongiae
Order: Dictyoceratida
Family: Dysideidae
Genus: Dysidea
Species:
D. etheria
Binomial name
Dysidea etheria
Laubenfels, 1936

Etymology

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The specific epithet "etheria" was given to this species of sponge by Laubenfels upon its discovery in the Dry Tortugas in 1936 due to its sky-blue color.[10]

Description

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Dysidea etheria is a species of lobate sponge that are massive and semi-incrusting.[1] They are identifiable by their internal and external light blue coloration.[1] The exopinacoderm has also been observed to be colored a brownish grey.[1]

The shaping of the sponge's lobes have been described as elongated, digitated, or lamellar.[1] The size of D. etheria can range from ten to fifteen centimeters in width and four to seven centimeters in height.[1] The diameter of the sponge's lobes have been observed to range from two to four centimeters.[1]

The sponge's oscula, ranging from five to ten millimeters in width, are typically found on the tops of its lobes.[1] The oscula also have a transparent iris-membrane, and the oscular membrane openings have occasionally been observed to be compound.[1] One millimeter high sharp conules make up the surface of the sponge and are spaced three millimeters apart.[1]

D. etheria has a thin exopinacoderm and a flesh-like choanosome.[1] The sponge also has an irregular skeleton which is loosely fibroreticular. Calcareous debris is contained within the white fibers with which the skeleton is made up of.[1]

Habitat and distribution

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Found within marine environments of depths reaching up to 40 meters, D. etheria inhabits bays and lagoons.[11] This species has been spotted on a variety of natural and manmade substrates. A majority of such substrates are known to be hard and vertical, such as on docks or pilings.[11] Another manmade substrate is the hull of a concrete ship where D. etheria was seen on a scleractinian.[1] As for natural substrates, D. etheria has been seen on rocks, turtle grass blades, mangrove roots, mollusk and crab shells, coral skeletons, algae, and even other sponges.[1][11]

D. etheria is known to be distributed across the Caribbean as well as off the coasts of Florida and Georgia.[2]

Ecology

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Reproduction

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Both sexual and asexual reproduction are utilized by poriferans.[3] Sponges are hermaphroditic when sexual reproduction occurs, utilizing different timing of sperm and egg production.[12] D. etheria asexually reproduce through fragmentation.[3][12] The totipotent abilities of sponge cells allows for fragments of the sponge to regrow into a new sponge.[3][4]

Predators

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The nudibranch Felimare zebra, and the sea star Echinaster echinophorus have both been spotted preying on D. etheria.[5]

Defenses

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Through the collection and storage of spicule fragments within the mesohyl, D. etheria is capable of deterring predators.[4][13] The production of toxins is also believed to act as a defense against predators.[5] Chemical extracts from D. etheria have been shown to be deterrents to generalist reef fishes, hermit crabs, and sea stars.[14]

Host species

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Ophiothela mirabilis on host species Dysidea etheria

D. etheria is registered as one of many host species of the invasive brittle star Ophiothela mirabilis.[6] Utilizing a host species is believed to protect O. mirabilis from predation and allow for new environments to be colonized more easily.[6]

Biochemistry

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D. etheria was the first recorded sponge to have plant growth regulatory indoles isolated from it.[7] The plant growth regulator, indole-3-acetamide, promotes the growth of roots in lettuce seedlings.[7]

A new protein phosphatase inhibitor, named dysidiolide, was also isolated from D. etheria.[8]

D. etheria has also been utilized in research to understand how sponges transport foreign particles to specific locations within their bodies.[9] Mesohyl cells have been observed to migrate in a coordinated fashion that allows for organized transport of particles.[9]

References

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  1. ^ a b c d e f g h i j k l m n Wiedenmayer, F. (1977). Shallow-water sponges of the western Bahamas. Experientia Supplementum. Birkhäuser Basel. pp. 73–74. ISBN 978-3-0348-5797-0.
  2. ^ a b Diaz M.C. (2011) Mangrove and coral reef sponge faunas: untold stories about shallow water Porifera in the Caribbean. In: Maldonado M., Turon X., Becerro M., Jesús Uriz M. (eds) Ancient Animals, New Challenges. Developments in Hydrobiology, vol 219. Springer, Dordrecht. https://doi.org/10.1007/978-94-007-4688-6_15
  3. ^ a b c d Pechenik, J.A. (2000). Biology of the Invertebrates Fourth Edition. Boston: McGraw Hill Companies, Inc. p. 73.
  4. ^ a b c Cowden, R.R. (1970). "Connective Tissue in Six Marine Sponges: A Histological and Histochemical Study". Special Edition Magazine for Microscopic-Anatomical Research. 82 (4): 557–569. PMID 5501157.
  5. ^ a b c Grode, Stephen H.; Cardellina, John H. (1984). "Sesquiterpenes from the Sponge Dysidea etheria and the Nudibranch Hypselodoris zebra". Journal of Natural Products. 47 (1): 76–83. doi:10.1021/np50031a009. ISSN 0163-3864.
  6. ^ a b c Mantelatto, Marcelo Checoli; Vidon, Lara Figueiredo; Silveira, Rosana Beatriz; Menegola, Carla; Rocha, Rosana Moreira da; Creed, Joel Christopher (2016-03-30). "Host species of the non-indigenous brittle star Ophiothela mirabilis (Echinodermata: Ophiuroidea): an invasive generalist in Brazil?". Marine Biodiversity Records. 9 (1): 8. doi:10.1186/s41200-016-0013-x. ISSN 1755-2672.
  7. ^ a b c Cardellina, John H.; Nigh, David; VanWagenen, Bradford C. (1986). "Plant Growth Regulatory Indoles from the Sponges Dysidea etheria and Ulosa ruetzleri". Journal of Natural Products. 49 (6): 1065–1067. doi:10.1021/np50048a015. ISSN 0163-3864.
  8. ^ a b Gunasekera, Sarath P.; McCarthy, Peter J.; Kelly-Borges, Michelle; Lobkovsky, Emil; Clardy, Jon (1996-01-01). "Dysidiolide: A Novel Protein Phosphatase Inhibitor from the Caribbean Sponge Dysidea etheria de Laubenfels". Journal of the American Chemical Society. 118 (36): 8759–8760. doi:10.1021/ja961961+. ISSN 0002-7863.
  9. ^ a b c Teragawa, Carolyn K. (1986-04-01). "Particle transport and incorporation during skeleton formation in a keratose sponge: dysidea etheria". The Biological Bulletin. 170 (2): 321–334. doi:10.2307/1541812. ISSN 0006-3185. JSTOR 1541812.
  10. ^ De Laubenfels, Max Walker (1936). A discussion of the sponge fauna of the Dry Tortugas in particular and the West Indies in general, with material for a revision of the families and orders of the Porifera. [Washington]. hdl:2027/wu.89036561199.
  11. ^ a b c Sterrer, W. (1986). Marine Fauna and Flora of Bermuda: A Systematic Guide to Identification of Marine Organisms. New York: John Wiley and Sons.
  12. ^ a b Ruppert, E.E.; Fox, R.S; Barnes, R.D. (2004). Invertebrate Zoology. Seventh Edition. Belmont, CA: Thomson-Brooks/Cole.
  13. ^ Teragawa, C.K. (1985). "Mechanical Function and Regulation of the skeletal Network in Dysidea". 3rd International Sponge Conference.
  14. ^ Waddell, B.; Pawlik, J. R. (2000). "Defenses of Caribbean sponges against invertebrate predators. II. Assays with sea stars". Marine Ecology Progress Series. 195: 133–144. Bibcode:2000MEPS..195..133W. doi:10.3354/meps195133.