''Dysidea etheria'', commonly known as the ethereal sponge or heavenly sponge, is a species of lobate

sponge Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate throug ...

within the class Demospongiae. 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 Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, a ...

and

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.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 Like all other poriferans, ''D. etheria'' is capable of both sexual and asexual reproduction. 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. ''D. etheria'' is also known as a host species of the invasive brittle star ''Ophiothela mirabilis.'' Lastly, various molecular biology studies have utilized D. etheria to both study foreign particle transport in sponges and to isolate novel molecules.

Etymology

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.

Description

''Dysidea etheria'' is a species of lobate sponge that are massive and semi-incrusting. They are identifiable by their internal and external light blue coloration. The exopinacoderm has also been observed to be colored a brownish grey. The shaping of the sponge's lobes have been described as elongated, digitated, or lamellar. The size of ''D. etheria'' can range from ten to fifteen centimeters in width and four to seven centimeters in height. The diameter of the sponge's lobes have been observed to range from two to four centimeters. The sponge's

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

Habitat and distribution

Found within marine environments of depths reaching up to 40 meters, ''D. etheria'' inhabits bays and lagoons. 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. Another manmade substrate is the hull of a concrete ship where ''D. etheria'' was seen on a scleractinian. As for natural substrates, ''D. etheria'' has been seen on rocks,

turtle grass ''Thalassia testudinum'', commonly known as turtlegrass, is a species of Marine (ocean), marine seagrass. It forms meadows in shallow sandy or muddy locations in the Caribbean Sea and the Gulf of Mexico. Turtle grass and other seagrasses form sea ...

blades, mangrove roots, mollusk and crab shells, coral skeletons, algae, and even other sponges. ''D. etheria'' is known to be distributed across the Caribbean as well as off the coasts of Florida and Georgia.

Ecology

Reproduction

Both sexual and asexual reproduction are utilized by poriferans. Sponges are hermaphroditic when sexual reproduction occurs, utilizing different timing of sperm and egg production. ''D. etheria'' asexually reproduce through

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. The totipotent abilities of sponge cells allows for fragments of the sponge to regrow into a new sponge.

Predators

The nudibranch ''

Felimare zebra ''Felimare zebra'', common name the zebra doris, is a colourful species of sea slug or dorid nudibranch, a marine gastropod mollusc in the family Chromodorididae.Bouchet, P. (2012). ''Felimare zebra''. Accessed through: World Register of Mar ...

'', and the sea star ''

Echinaster echinophorus The orange knobby star, ''Echinaster echinophorus'', is a species of sea star found in the Caribbean Sea and along the Atlantic coast of South America. Description It is a small species with a diameter of up to . It has a small central disc and ...

'' have both been spotted preying on ''D. etheria''.

Defenses

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

Host species

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

Biochemistry

''D. etheria'' was the first recorded sponge to have plant growth regulatory indoles isolated from it. The plant growth regulator, indole-3-acetamide, promotes the growth of roots in lettuce seedlings. A new protein phosphatase inhibitor, named dysidiolide, was also isolated from ''D. etheria''. ''D. etheria'' has also been utilized in research to understand how sponges transport foreign particles to specific locations within their bodies. Mesohyl cells have been observed to migrate in a coordinated fashion that allows for organized transport of particles.

References

{{wikispecies Dictyoceratida Sponges described in the 20th century