Ventricaria J.L.Olsen & J.A.West, 1988

Holotype species: Ventricaria ventricosa (J.Agardh) J.L.Olsen & J.A.West

Currently accepted name for the type species: Valonia ventricosa J.Agardh

Original publication and holotype designation: Olsen, J.L. & West, J.A. (1988). Ventricaria (Siphonocladales-Cladophorales complex, Chlorophyta), a new genus for Valonia ventricosa. Phycologia 27: 103-108, 14 figs, 3 tables.

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Description: Thallus composed of a single, unbranched, aseptate vesicular cell, 1-4 (-10) cm diameter. Plants spherical, pyriform, lobed or irregularly deformed depending upon substratum. Cell wall iridescent. Annular constrictions, tenacular cells, and well-developed rhizoid not present. Attachment to substratum achieved by reduced rhizoidal cells at base of cell. Cell division by modified segregative division only. Cells multinucleate; chloroplasts numerous per cell and discoid with single pyrenoid. The sexual life history of Ventricaria has not been conclusively documented although a typical cladophoralean, biphasic, isomorphic alternation of generations similar to Valonia is presumed. Occasionally an adventitious rhizoid cell will expand into a minute new vesicle which detaches to become a new individual. Vegetative propagation of this type in combination with the aplanospore products of segregative division in the entire thallus are common in both cultured and field specimens. Ventricaria is widely distributed throughout the tropics in shallow intertidal habitats, often in coral rubble areas or lodged in coral crevices. It is often found in association with Dictyosphaeria. Ultrastructural studies of the flagellar apparatus support the position of Ventricaria in the Siphonocladales-Cladophorales complex. Ventricaria is one of the largest cells in nature and this makes it an ideal system for studies of cell physiology including electrophysiology and cell growth. The decision to move the former Valonia ventricosa to its own genus, was based on three considerations. First. Ventricaria was found to be immunologically more distant from other Valonia species than from Dictyosphaeria and Siphonocladus which are its closest relatives. Second, cell division in Ventricaria occurs by modified segregative division, while Valonia divides exclusively by the lenticular cell type (exogenous segregative division of Egerod). Third, Ventricaria has a unique and highly reduced habit unlike that found in any Valonia species.

Information kindly contributed by J.L. Olsen but may now be outdated.

Taxonomic status: This name is currently regarded as a synonym of Valonia.

Gender: This genus name is currently treated as feminine.

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Contributors
Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in CD format. These AlgaeBase descriptions are now being continually updated, and each current contributor is identified above. The PSA and AlgaeBase warmly acknowledge the generosity of all past and present contributors and particularly the work of Dr Parker.

Descriptions of chrysophyte genera were subsequently published in J. Kristiansen & H.R. Preisig (eds.). 2001. Encyclopedia of Chrysophyte Genera. Bibliotheca Phycologica 110: 1-260.

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Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 04 January 2011. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 16 July 2024

 
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