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| | The macro-algae are superficially plant-like protoctists that lack the vascular tissue used by higher plants to transport water and nutrients. They are almost exclusively aquatic; three of the four principal groups consisting of large-sized species are mainly marine in occurrence. These three, the green, brown and red algae ('seaweeds '), are all cosmopolitan in distribution and occur in a range of environments, although some constituent families have somewhat restricted ranges. There are more marine species of red algae (Rhodophyta) ' around 4,000 ' than the greens (Chlorophyta, ca 1 000) and browns (Phaeophyta, ca 1500) combined. | | | | The cold and cool temperate regions of the world appear to be surprisingly rich in species. Kelp forests, found in subtidal waters as deep as 30-60m, are a unique ecosystem largely restricted to the west coast of the Americas. Giant kelp, Macrocystis pyrifera, and bull kelp, Nereocystis luetkeana, are the largest non-vascular plants known. The multi-layered canopy of kelp fronds provides a complex aquatic habitat for thousands of fish and invertebrates. Elsewhere, the region around Japan (northwest Pacific), the North Atlantic, and the tropical and subtropical western Atlantic hold the most species of marine algae. Southern Australia is not so species rich but appears to have the highest proportion of endemics. | | | | There are few species of larger algae in regions of cold- water upwelling; small isolated islands and polar regions also have few species. In contrast, coral reefs support a unique and generally diverse algal flora that includes many crustose coralline algae (more species of which are likely to be discovered). Mangrove areas also support a well- defined algal vegetation. Sandy coastlines hold few species of large algae and often form barriers to seaweed dispersal. | | | | |
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| Algae That Live Inside the Cells of Salamanders Are the First Known Vertebrate Endosymbionts
by Indiana University, ScienceDaily 04 April 2011 | |
| | A species of algae long known to associate with spotted salamanders has been discovered to live inside the cells of developing embryos -- the first known example of a eukaryotic algae living stably inside the cells of any vertebrate. | |
Read more at http://www.sciencedaily. ... 51349.htm.
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