Chondracanthus exasperatus, commonly called Turkish towel, is a species of seaweed in the family Gigartinaceae. The specific epithetexasperatus (lit. 'roughened') refers to the bumpy texture of the blades (leaf-like structures). This texture also leads to the common name which evokes the luxurious feel of a towel from a Turkish bath. The rough, papillae-strewn blade surface even makes it difficult to measure the temperature using infrared thermometers.[6]
Description
It is a perennial species.[7] Like many species in Gigartinaceae, the appearance of C. exasperatus can vary depending upon grown conditions.[1][2] It can be confused with Chondracanthus spinosus and Gigartina binghamiae, and it might take RFLP analysis to be sure of the species.[1][2] In addition, the names of the species in the genera Gigartina and Chondracanthus have been adjusted several times since 1961.[2] It is also similar to Mastocarpus species, known as Turkish washcloths, but is smaller, with branched blades.[8] The leaf margins of the blades are smooth in cooler water and then become toothed and jagged as the temperature increases.[2] In more exposed areas, the blades are thicker.[8] Increased water velocity will cause the blades to change shape.[9] The color of the thallus is greenish when exposed to ultraviolet light, but when it grows in deeper water it is darker red to purple.[2] Though it prefers lower water temperatures it can grow at 25 °C, but ends up dark red to black in color and having flat or cylindrical branch clusters.[10]
As originally described, C. exasperatus has a leafy stipe, with large 2–3 feet (0.61–0.91 m) long leathery-membranaceous blades that are lanceolate and simple.[11] The blade, and the majority of the thallus, is purplish-red.[7] Blade margins are thick, with rounded teeth, and appendiculate.[11] The thallus has simple, ramenta-like spiny projections (papillae) thickly strewn on both sides.[11]Coccoidpedicels are in marginal spines emerging from the thallus.[11]
C. exasperatus grows the fastest in the summer and slowest near the winter solstice.[12] Thalli have a moisture content of about 81.4% and protein content of 1.59-1.97%.[13]
C. exasperatus decomposes quickly, faster than most other species, indicating its importance to detritivores and to nutrient cycling.[15] The high rate of decomposition also means that it is harder to find washed ashore as wrack and that its importance in the ecosystem may be underrepresented in research.[15]
Commercial aquaculture in both tanks and on nets of C. exasperatus was attempted as early as the 1970s in Washington state.[18] It can also be grown in the air if sprayed with sea water, which conserves water but risks losing the crop if the pumps fail.[19] The gel within the blades has also been harvested to make cosmetics.[20] Intact blades are used in baths or for thalassotherapy, along with species such as feather boa (Egregia menziesii), finger kelp (Laminaria digitata), and Fucus.[21]
^ abcdHughey, Jeffery Ryan; Dudash, Ron; Kjeldsen, Chris K. (June 1996). "A Field and Molecular Systematic Study on species of Chondracanthus (Gigartinales, Rhodophyceae) from Pacific North America". Journal of Phycology. 32 (S3): 22–23. doi:10.1111/j.0022-3646.1996.00001.x. ISSN1529-8817. OCLC5153757978. S2CID221925155.
^ abcdefghijHughey, Jeffery Ryan (15 December 1995). A Systematic Study of Chondracanthus Kutzing (Rhodophyceae) with a Contribution to the Marine Flora of Tomales Bay, California. Rohnert Park, CA: Sonoma State University. hdl:10211.1/1688. OCLC971001627.
^"Chondracanthus exasperatus". IRMNG - Interim Register of Marine and Nonmarine Genera v.3.1. Australia: Commonwealth Scientific and Industrial Research Organisation. Retrieved 11 January 2018.
^ abcdLindeberg, Mandy; Lindstrom, Dr. Sandra. "Turkish Towel Chondracanthus exasperatus". Seaweeds of Alaska. Juneau, Alaska. Archived from the original on 10 January 2018. Retrieved 23 January 2018. Authority: (Harvey et Bailey) Hughey North Pacific Distribution: Sitka Sound, Alaska, to Baja California, Mexico. Phylum: Rhodophyta Class: Florideophyceae Order: Gigartinales Family: Gigartinaceae Former Scientific Names: Gigartina exasperata Description: Thallus is a thick (somewhat rubbery), elongate, undivided purplish to pale red blade, reaching 30 cm (12 in) tall, with short, spiny papillae covering the blade surface. Blades arise as elongate papillae-like projections from a discoidal holdfast up to 1 cm (0.4 in) in diam. Habitat: This perennial grows on rock in the low intertidal and upper subtidal of semi-protected to semi-exposed habitats.
^Gadberry, Bradley A.; Colt, John; Boratyn, Diane C.; Maynard, Desmond J.; Johnson, Ronald B. "INTENSIVE LAND-BASED FARMING OF RED AND GREEN MACROALGAE IN THE PACIFIC NORTHWEST: AN EVALUATION OF SEASONAL GROWTH AND PROXIMATE COMPOSITION". Aquaculture America 2015 - Meeting Abstract. World Aquaculture Society. Retrieved 29 January 2018. The specific growth of all three species exhibited a similar pattern with the highest specific growth rate observed during summer months (C. exasperatus 7.8%, U. rigida 6.2% and P. palmata 8.2%). Growth of all three species was lowest around the winter solstice
^Kerwin, James L.; Johnson, Lisa M.; Whisler, Howard C.; Tuininga, Amy R. (1 May 1992). "Infection and morphogenesis of Pythium marinum in species of Porphyra and other red algae". Canadian Journal of Botany. 70 (5): 1017–1024. doi:10.1139/b92-126. ISSN0008-4026. OCLC5140406448. Zoospores encysted on thalli of species of red algae other than Porphyra. Using the disc assay, encystment by Py. marinum was observed on Gigartina exasperata Harvey et Bailey (tetrasporophyte)...
^Waaland, J. Robert (2004). "Integrating Intensive Aquaculture of the Red Seaweed Chondracanthus exasperatus". 水研センター研報 (Bulletin of Fisheries Research Agency) (Supplement No. 1): 91–100. CiteSeerX10.1.1.607.7168. ISSN1346-9894. OCLC5173360127.
^US patent 6136329, Diane C. Boratyn, "Compositions and methods relating to intra-lamellar gels from algae", published 24 October 2000, assigned to Diane C. Boratyn
^Lewallen, Eleanor; Lewallen, John (21 March 1996). "Bathing with Seaweed". Sea Vegetable Gourmet Cookbook and Wildcrafter's Guide (1st ed.). Mendocino, CA: Mendocino sea Vegetable Company. pp. 62–63. ISBN978-0964764378.