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Name derivation:
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After Genevan botanist
Jean-Pierre-Etienne
Vaucher who studied its reproduction (circa
1800). Vaucher was one of the first botanists to
consider that such primitive protists (algae) used
sexual reproduction. At that time Vaucheria
was known as Cryptogames
(online).
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Classification:
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Vaucheria A.P.de Candolle
1801; 75 of 263 species
descriptions are currently accepted taxonomically (Guiry
and Guiry 2013). Order
Vaucheriales, Family Vaucheriaceae.
There are >40 species known (Pearson 1995), currently ~ 70 species
(Johnson and Merritt 2011).
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Morphology:
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Bright green filaments, with very few crosswalls. Asexual reproduction by vegetative growth and
formation of gonidia (multiflagellate
cells) or aplanospores (non-flagellate cells). Sexual reproduction occurs
with oospores and sperm. Grows in 'tufts' of interwoven trichomes. Similar to
fungal mycelia, the trichomes generally lack septa except at the location of
reproductive organs (antheridia, oogonia) that are
walled off from the vegetative trichome. |
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Similar genera:
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Habitat:
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Mainly
freshwater, some estuarine and marine habitats. Vaucheria is widespread
in fresh to saline water, every continent (including Antarctica); submergent, amphibious, semi-emergent or terrestrial;
intertidal to sublittoral, on mudflats, mangroves, saltmarsh, estuaries, streams, channels, farmland, lake
and pond fringes, and almost any wetland (online). Chloroplasts
of Vaucheria litorea
and other algae can be "sucked out" by the nudibranch
Elysia chlorotica.
Recent genetic information demonstrates with some certainty that E. Chlorotica
has incorporated into its genome by HGT (horizontal gene transfer) the genes
needed to manufacture chlorophyll in order to maintain its endobiotic chloroplasts for the length of its life (Rumpho et al. 2008, Pierce et al. 2009). Presumably the “solar powered” sea slug,
after its first meal of algal chloroplasts, can rely entirely on energy
generated by its endobiotic chloroplasts and never
eat again (Milius 2010). |
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References:
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Candolle, A.P. de 1801. Extrait d'un rapport sur les conferves. Bulletin des Sciences par la Société Philomathique de Paris 3: 17-21, pl. I.
Curtis,
N. E.,
C.J. Dawes, and S. K. Pierce. 2008. Phylogenetic
analysis of the large subunit RUBISCO gene supports the exclusion of Avrainvillea and Cladocephalus
from the Udoteaceae (Bryopsidales,
Chlorophyta). J. Phycol.
44 (3) 761-767. Curtis,
N. E.,
S. K. Pierce, J. A. Schwartz. 2010. An ultrastructural
comparison of chloroplast-containing cells in four sacoglossan
species with differing plastid sequestering and maintenance abilities. J. Molluscan Stud. (In review). Guiry, M.D., and G.M. Guiry 2013. AlgaeBase.
World-wide electronic publication, National University of Ireland,
Galway. http://www.algaebase.org;
searched on 16 January 2013. Johnson, L.R., and R.
Merritt. Order Vaucheriales. In:
The Freshwater Algal Flora of the British Isles, 2nd
edition. John, D.M., B.A. Whitton, and A.J. Brook, Eds. (878 pp). Milius, S. 2010. Sea slug steals genes for greens, makes
chlorophyll like a plant. Science News
177(4): 10-12. Pearson, L.C. 1995.
The Diversity and Evolution of Plants.
CRC Press Inc. Pierce S. K., N. E. Curtis, J. J. Hanten, S. L. Boerner, and J.
A. Schwartz. 2007. Transfer, integration and expression of functional nuclear
genes between multicellular species. Symbiosis 43:
57-64. Pierce, S.K., Curtis, N.E., and Schwartz, J.A. 2009. Chlorophyll a synthesis
by an animal using transferred algal genes. Symbiosis 49: 121-131. Rumpho, M.E., J.M. Worful,
J. Lee, K. Kannan, M.S. tyler,
D. Bhattachaya, A. Moustafa,
and J.R. Manhart
2008. Hirizontal
gene transfer of the algal nuclear gene psb) to the
photosynthetic sea slug Elysia chlorotica.
PNAS 105(46): 17867-17871. (URL) Schwartz, J. A., Curtis, N. E., and S. K. Pierce.
2010. Using algal transcriptome sequences to discover
transferred genes in a sea slug (Elysia chlorotica) Evol. Biol. 37:
29-37. |
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