Valonia ventricosa

Valonia ventricosa has a coenocytic structure with multiple nuclei and chloroplasts.{{Cite journal |last1=Shepherd |first1=VA |last2=Beilby |first2=MJ |last3=Bisson |first3=MA |date=June 2004 |title=When is a cell not a cell? A theory relating coenocytic structure to the unusual electrophysiology of Ventricaria ventricosa (Valonia ventricosa) |url=http://newt.phys.unsw.edu.au/~mjb/vals.pdf |journal=Protoplasma |language=en |volume=223 |issue=2–4 |pages=79–91 |doi=10.1007/s00709-003-0032-4 |issn=0033-183X |pmid=15221513 |s2cid=13373143}} This organism possesses a large central vacuole that is multilobular in structure (lobules radiating from a central spheroid region).{{cn|date=January 2025}}

The entire cell contains several cytoplasmic domains, with each domain having a nucleus and a few chloroplasts. Cytoplasmic domains are interconnected by cytoplasmic "bridges" that are supported by microtubules. The peripheral cytoplasm (whose membrane is overlaid by the cell wall) is only about 40 nm thick.

Valonia ventricosa typically grow individually, but in rare cases they can grow in groups.{{cn|date=January 2025}}

They appear in tidal zones of tropical and subtropical areas, like the Caribbean, north through Florida, south to Brazil, and in the Indo-Pacific. Overall, they inhabit every ocean throughout the world,{{citation |chapter=Valonia ventricosa J.Agardh |title=Algaebase |chapter-url=http://www.algaebase.org/search/species/detail/?species_id=a97ca4948a80ef374 |access-date=4 September 2015}} often living in coral rubble.{{cite book |last=Lee |first=Robert Edward |year=2008 |title=Phycology |chapter=Siphonoclades |publisher=Cambridge University Press |isbn=978-0-521-68277-0 |page=189 |chapter-url=https://books.google.com/books?id=gfoIAFHgusgC&pg=PA189 |access-date=27 August 2010}}

The greatest observed depth for viability is approximately {{convert|80|m|ft}}.{{Citation needed|date=May 2022|reason=Dubious claim}}

The single-cell organism has forms ranging from spherical to ovoid, and the color varies from grass green to dark green, although in water they may appear to be silver, teal, or even blackish. This is determined by the quantity of chloroplasts of the specimen. The surface of the cell shines like glass when clean due to being extremely smooth with no texture.{{cn|date=January 2025}}

Valonia ventricosa is among the largest known single-celled organisms. Its thallus consists of a thin-walled, tough, multinucleate cell with a diameter that ranges typically from {{convert|1|to|4|cm|in|1}}, although it may achieve a diameter of up to {{convert|5.1|cm|in}} in rarer cases. The "bubble" alga is attached by rhizoids to the substrate fibers.

Valonia ventricosa has been studied particularly because the cells are so unusually large that they provide a convenient subject for studying the transfer of water and water-soluble molecules across biological membranes. It was concluded that the properties of permeability in both osmosis and diffusion were identical, and that urea and formaldehyde molecules did not require any kind of postulated water-filled pores in the membrane to move through it.{{cite book |last=Thellier |first=M. |year=1977 |title=Échanges ioniques transmembranaires chez les végétaux |publisher=Publication Univ Rouen Havre |isbn=978-2-222-02021-9 |page=341 |url=https://books.google.com/books?id=OtQBaAUbDBMC&pg=PA341}}{{cite journal |last=Gutknecht |first=John |year=1967 |title=Membranes of Valonia ventricosa: Apparent Absence of Water-Filled Pores |journal=Science |publisher=Science Magazine |doi=10.1126/science.158.3802.787 |volume=158 |issue=3802 |pages=787–788|pmid=6048117 |bibcode=1967Sci...158..787G |s2cid=206566223 }} In studying the cellulose lattice and its orientation in biological structures, Valonia ventricosa has undergone extensive X-ray analytical procedures.{{cite journal |last1=Astbury |first1=W. T. |last2=Marwick |first2=T. C. |last3=Bernal |first3=J. D. |year=1932 |title=X-Ray Analysis of the Structure of the Wall of Valonia ventricosa.--I |journal=Proceedings of the Royal Society of London. Series B |doi=10.1098/rspb.1932.0005 |jstor=81568 |volume=109 |issue=764 |page=443|doi-access=free }} It has also been studied for its electrical properties due to its unusually high electrical potential relative to the seawater that surrounds it.

Valonia ventricosa is considered a pest by some aquarium owners, as it can reproduce quickly and potentially endanger the health of fish or other organisms.{{Cite web |title=Valonia Ventricosa |url=https://seatechaquariums.com/tag/valonia-ventricosa/ |access-date=2023-01-20 |website=Seatech Aquariums |date=13 May 2019 |language=en-US}}{{Cite web |last=Cortes-Jorge |first=Hugh |title='Bubble' Alage: Selected Descriptions, Controls and Comments by Horge Cortes-Jorge, Jr. - Reefkeeping.com |url=http://reefkeeping.com/issues/2002-02/hcj/feature/index.php |access-date=2023-01-20 |website=reefkeeping.com |language=en-US}}

• Xenophyophore

{{Reflist}}

• {{cite journal |last1=Wardrop |first1=A. B. |last2=Jutte |first2=S. M. |year=1968 |title=The enzymatic degradation of cellulose from Valonia ventricosa |journal=Wood Science and Technology |doi=10.1007/BF00394959 |volume=2 |issue=2 |page=105|s2cid=22579550 }}
• {{cite journal |last=Revol |first=J |year=1982 |title=On the cross-sectional shape of cellulose crystallites in Valonia ventricosa |journal=Carbohydrate Polymers |doi=10.1016/0144-8617(82)90058-3 |volume=2 |issue=2 |pages=123–134}}
• [https://earthlingnature.wordpress.com/2016/04/08/friday-fellow-sailors-eyeball/ Friday Fellow: Sailor's Eyeball] at Earthling Nature.

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Category:Cladophorales