Tag Archives: red algae

Friday Fellow: Irish Moss

by Piter Kehoma Boll

Growing abundantly along the North Atlantic coasts, our newest Friday Fellow is a cartilaginous red alga commonly known as Irish moss or scientifically as Chondrus crispus, which means something like “curly cartilage”.

chondrus_crispus

The Irish moss usually appears as a mass of curly cartilaginous and soft seaweed with a red or purple tinge. Photo by Wikimedia user Kontos.*

Reaching about 20 cm in length, the Irish moss is attached to the substrate by a discoid base and its thallus branches dichotomously four or five times. The width of the branches may vary from about 2 to 15 mm and the color is even more variable, ranging from green or yellowish to dark red, purple, brown or even white. As with all plants, the Irish moss has a gametophyte (haploid) and a sporophyte (diploid) form. The gametophytes have a blue iridescence (as seen in the photo above), while the sporophytes show a dotted pattern (seen above as well).

The Irish moss is edible and relatively well known among the communities living where it grows. In Ireland and Scotland, it is boiled in milk and sweetened to produce a jelly-like product. The cartilaginous or jelly-like appearance of this alga and its derivatives are due to the presence of high amounts of carrageenan, a polysaccharide that is widely used in food industry as a thickening and stabilizing agent and as a vegan alternative to gelatin.

Due to its economic importance, the Irish moss is cultivated in tanks for the extraction of carrageenan and other products. Both gametophytes and sporophytes produce carrageenans of different types that can be used for different purposes.

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References:

Chen, L. C.-M.; McLachlan, J. (1972) The life history of Chondrus crispus in culture. Canadian Journal of Botany 50(5): 1055–1060. http://doi.org/10.1139/b72-129

McCandless, E. L.; Craigie, J. S.; Walter, J. A. (1973) Carrageenans in the gametophytic and sporophytic stages of Chondrus crispus. Planta 112(3): 201–212.

Wikipedia. Chondrus crispus. Available at < https://en.wikipedia.org/wiki/Chondrus_crispus >. Access on August 1, 2017.

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*Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

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Friday Fellow: Elegant Claudea

by Piter Kehoma Boll

Today I’m going to introduce you to the possibly most beautiful alga. Its name is Claudea elegans, which I adapted as “elegant claudea” to serve as a popular name.

I first became aware of the existence of such an organism in my childhood when I saw a drawing of it in an encyclopedia. It had a very beautiful shape, a nice pink color and a cute name. But it was simply depicted among several other algae on that page and besides the drawing and the name, nothing else was said.

Drawing of Claudea elegans from Phycologia Australica.

Drawing of Claudea elegans from Phycologia Australica.

Unfortunately, there is not much information available online on the elegant claudea. It is a marine species found in Australia, Brazil, India, Pakistan and probably many other tropical waters around the world, being usually attached to rocks near sand and in places with a good current flow.

The net of the elegant claudea as seen under the microscope. The small sacs disrupting the net are the tetrasporangia, reproductive structures. Photo by Dr. Robert Ricker, NOAA/NOS/ORR.

The net of the elegant claudea as seen under the microscope. The small sacs disrupting the net are the tetrasporangia, reproductive structures. Photo by Dr. Robert Ricker, NOAA/NOS/ORR.

It reaches up to 40 cm in height/length and is composed of branched stalks with a very peculiar pattern. The stalk has a sort of net on one of its sides that makes it look like a one-sided feather. The net is formed by many smaller stalks connected to each other by even smaller ones, one those again to each other by the smallest of all. The branches from the main stalk always come out from the opposite side of the net and have themselves a net on one of its sides and smaller stalks growing opposite to it. The elegant claudea is, therefore, somewhat a double fractal.

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References:

Baldock, R. N. Algae revealed: Claudea elegans. State Herbarium S Australia. Availabe at: <http://www.flora.sa.gov.au/efsa/algae_revealed/pdf/Claudea_elegans.pdf&gt;. Access on February 25, 2016.

Pacheco, M. R. 2011. Macroalgas marinhas associadas a bancos de rodolitos do infralitoral do Espírito Santo, Brasil. Doctoral thesis. USP.

Electronic Flora of South Australia: Claudea elegans. Available online at: <http://www.flora.sa.gov.au/efsa/Marine_Benthic_Flora_SA/Part_IIID/Claudea_elegans.shtml&gt;. Access on February 15, 2016.

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Filed under Algae, Botany, Friday Fellow