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Name derivation: |
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Lithothamnion= Gr. lithos: a stone + thamnion: a shrub glaciale= L. glacialis: frozen, glacial, ice hard and smooth Common name= rock branch alga Lithothamnion glaciale Kjellman (rhodoliths) |
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Classification:
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Lithothamnion Heydrich,
1897; There are 432 species of which 85 species have been taxonomically
accepted.
Order Corallinales; Family Hapalidiaceae; Subfamily Melobesioideae |
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Morphology: |
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Crustose on rocks. Calcareous crusts are hard and stony, firmly adherent, pink to red, to 20 cm in diam., with many knobby branches. It may also occur as detached spherical rhodoliths. Margins are entire, thin, and indistinct. Branches may form fused masses several cm deep with pale branch tips. Gametophytes are dioecious with uniporate domed conceptacles. Detached ball-shaped (i.e. aegagrophilous) populations of the crustose coralline Lithothamnion glaciale |
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Similar genera: |
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Cruoria, the “Petrocelis” stage of Mastocarpus,and Peysonnellia . Several other species of Lithothamnion form similar rhodoliths- i.e. Lithothamnion lemoineae W. H. Adey, L. norvegicum (J. E. Areschoug) Kjellman , L. tophiforme (Esper) Unger, and Lithothamnion ungeri Kjellman. |
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Habitat: |
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A very common perennial crust that is tolerant to a wide range of temperature, light, and salinity. Growing on rocks and pebbles, in tide pools and caves, and from the spray zone to 30 m. In the Northwest Atlantic (i.e. from the eastern Canadian Arctic to Cape Cod) detached ball-shaped populations or free-living rhodoliths occur within low tide pools to 50 m. Similar rhodoliths are also found from eastern Greenland, Iceland, Scandinavia to Spain, Alaska, Japan, and Australia. In Newfoundland they are apparently produced from residual fragments of crustose corallines that were scoured off by ice action and then became settled subtidally (Hooper 1981). |
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References: |
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Adey, W. H. 1966. Distribution of saxicolous crustose corallines in the Northwestern North Atlantic. J. Phycol. 2: 49-54.; Adey, W. H. 1970. The crustose corallines of the northwestern North Atlantic, including Lithothamnion lemoineae n. sp. J. Phycol. 6: 225-229. Guiry, M.D. and G.M. Guiry 2013. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 19 September 2013. Hooper, R. 1981. Recovery of Newfoundland benthic marine communities from sea ice. In: G.E. Fogg and W. E. Jones, eds., Proc. VIII Int. Seaweed Symp., Bangor, North Wales, Aug. 18-23, 1974, Mar. Sci. Lab., Menai Bridge, Univ. College, North Wales, Anglesey, pp. 360-366. Norton, T. A. and A. C. Mathieson 1983. The biology of unattached seaweeds. In: F. Round and D. Chapman, eds., Progress in Phycological Research, Vol. 2, Elsevier Science Publ., Amsterdam, pp. 333-386. Taylor, W. R. 1957. Marine Algae of the Northeastern Coast of North America. Revised edition. Univ. Michigan Press., Ann Arbor, ix + 509 pp.
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