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Molecular systematics of macroalgae |
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Molecular methods have emerged as an important tool for taxonomy and sytematic. In macroalgae, DNA sequences such as COI (Cytochrome Oxidase c 1) have been recently used to identify several macroalgal organisms, specially when morphological features can not be used to discriminate species. Additional markers have been also used as "barcode" in macroalgae, such as: LSU D2/D3, rbcL-3P, tufA, ITS, UPA. In our lab we carrying out DNA barcode methods to identify representative macroalgal species from Bio Bio Region (central Chile).
Example:
Molecular work carried out on the giant kelp Macrocystis, have demonstrated the monospecific status of the genus, e.g. Coyer et al. 2001 J. Phycology, 37:574-585; Macaya & Zucarello J. Phycology 2010, 46:736-742.
On the right side you can see the giant kelp M. pyrifera and different holdfast morphologies, previosly used as the most important feature to differentiate species.
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Ecology of macroalgae Using laboratory and field experiments we have studied alga-herbivore interaction, with a focus mainly on anti-herbivores defenses.
We are also carrying out descriptive studies to know the effect of the last mega-earthquake (February 27/ 2010) and coastal uplift on macroalgal communities at Bio Bio region.
On the right side you can see the uplifted kelp Lessonia nigrescens at Desembocadura del Bio Bio (August 2010). See also our photo gallery of algae after mega-earthquake.
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Non-indigenous algae
Mastocarpus papillatus a red alga (Gigartinales) has been described as a non indigenous marine species in Chile. (Castilla & Neill 2009). The distribution of this alga encompasses wider areas in Northern hemisphere but in Southern Hemisphere is restricted to Bio Bio region.
In AlgaLAB we are carrying out several studies related with its distribution, abundance and ecology. |
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Floating seaweeds. |
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Once detached from substrata, some algae can remain floating at the sea surface and travel hundreds of kilometers. These algae have structures that provide buoyancy to lift blades toward the surface (the pneumatocysts). Previous studies have demonstrated that floating kelp rafts posses viable reproductive blades (e.g.Macaya et al. 2005, J Phycology 41:913-922). In AlgaeLAB we are studying the genetic structure of benthic and floating algae from Chilean Fjords in order to know the origin of floating kelp rafts but also the possible dispersal routes.
We are also studying the distribution of a particular form of Nothogenia fastigiata, individuals that “blow up” like a balloon (see photo on the right side). This form might be an alternative dispersal methods, since several individuals are reproductive.
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Algal Phylogeography
Chile offers an unique scenario to study algal phylogeography, different factors (biotic and abiotic – historic and contemporary) have shaped the distribution and genetic structure of macroalgae. For instance, Last glacial maximum, El Niño among others had an important effect on the genetic structure of kelp species (Macaya & Zuccarello 2010, MEPS 420:103-112). |
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