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Coralline Algae (coralline + alga)
Selected AbstractsBIODIVERSITY OF CORALLINE ALGAE IN THE NORTHEASTERN ATLANTIC INCLUDING CORALLINA CAESPITOSA SP.JOURNAL OF PHYCOLOGY, Issue 1 2009NOV. (CORALLINOIDEAE, RHODOPHYTA) The Corallinoideae (Corallinaceae) is represented in the northeastern Atlantic by Corallina officinalis L.; Corallina elongata J. Ellis et Sol.; Haliptilon squamatum (L.) H. W. Johans., L. M. Irvine et A. M. Webster; and Jania rubens (L.) J. V. Lamour. The delimitation of these geniculate coralline red algae is based primarily on morphological characters. Molecular analysis based on cox1 and 18S rRNA gene phylogenies supported the division of the Corallinoideae into the tribes Janieae and Corallineae. Within the Janieae, a sequence difference of 46,48 bp (8.6%,8.9%) between specimens of H. squamatum and J. rubens in the cox1 phylogeny leads us to conclude that they are congeneric. J. rubens var. rubens and J. rubens var. corniculata (L.) Yendo clustered together in both phylogenies, suggesting that for those genes, there was no genetic basis for the morphological variation. Within the Corallineae, it appears that in some regions, the name C. elongata has been misapplied. C. officinalis samples formed two clusters that differed by 45,54 bp (8.4%,10.0%), indicating species-level divergence, and morphological differences were sufficient to define two species. One of these clusters was consistent with the morphology of the type specimen of C. officinalis (LINN 1293.9). The other species cluster is therefore described here as Corallina caespitosa sp. nov. This study has demonstrated that there is a clear need for a revision of the genus Corallina to determine the extent of "pseudocryptic" diversity in this group of red algae. [source] POTENTIAL TOOLS FOR TRACKING OCEAN CLIMATE: VARIABILITY IN STABLE ISOTOPES IN LIVING CORALLINE ALGAEJOURNAL OF PHYCOLOGY, Issue 2000R.A. Dunn Our ability to track long term climate change in coastal regions is limited in temperate and polar regions. Physical oceanographic dynamics in temperature and upwelling events can be recorded as carbon and oxygen stable isotope signals in carbonate producing organisms. Because coralline algae photosynthesize, produce calcium carbonate and are widely distributed, they may provide a new tool for detecting short-term change. However, little is known about how coralline algae incorporate stable isotopes into their calcite thallus structure. The objectives of this study were to determine if growth and isotopic signature differ in articulated coralline algae grown in different oceanographic regimes in Monterey Bay. The articulated alga Calliarthron cheiliospororioides was outplanted at three locations varying in seawater temperature and upwelling strength. New algal growth was measured by staining the algae with Alizarin Red and enumerating the amount of accumulated material at the branch tips. Growth rates varied seasonally and spatially. Low-upwelling daily growth rates averaged 0.044,0.056 mm day,1, while high-upwelling growth rates were 0.083 mm day,1. Isotope ratios were obtained by analyzing microsampled portions of the alga in a mass spectrometer. Changes in the 18O/16O and 13C/12C ratios appear to reflect change in seawater temperature and upwelling strength, respectively. [source] Symbiosis of Mycale (Mycale) vansoesti sp. nov. (Porifera, Demospongiae) with a coralline alga from North Sulawesi (Indonesia)INVERTEBRATE BIOLOGY, Issue 3 2006Barbara Calcinai Abstract. The symbiotic association between the new sponge species Mycale vansoesti and the coralline alga Amphiroa sp. from the Bunaken Marine Park (North Sulawesi, Indonesia) is described. The alga completely pervades the sponge. The color of the sponge ectosome is white, both on the external surface and on the atrial wall, but where the alga is present the sponge takes on the light pink color of the alga. The sponge spicular complement is characterized by mycalostyles, anisochelae of two types, sigmas (often "C" shaped), and extremely abundant toxas organized in bundles forming toxadragma. In the association, the sponge shows very low silicate value, and consequently the alga represents the main skeleton of the sponge. On the other hand, the sponge affects the morphology of the alga, leading to a cylindrical shape, with thalli running parallel to the sponge surface. This association seems to be obligate for the sponge, as we found no sponges of this species living in isolation. [source] DIFFERENCES IN POLYSACCHARIDE STRUCTURE BETWEEN CALCIFIED AND UNCALCIFIED SEGMENTS IN THE CORALLINE CALLIARTHRON CHEILOSPORIOIDES (CORALLINALES, RHODOPHYTA),JOURNAL OF PHYCOLOGY, Issue 3 2010Patrick T. Martone The articulated coralline Calliarthron cheilosporioides Manza produces segmented fronds composed of calcified segments (intergenicula) separated by uncalcified joints (genicula), which allow fronds to bend and reorient under breaking waves in the wave-swept intertidal zone. Genicula are formed when calcified cells decalcify and restructure to create flexible tissue. The present study has identified important differences in the main agaran disaccharidic repeating units [,3)-,- d -Galp (1, 4)-,- l -Galp(1,] synthesized by genicular and intergenicular segments. Based on chemical and spectroscopical analyses, we report that genicular cells from C. cheilosporioides biosynthesize a highly methoxylated galactan at C-6 position with low levels of branching with xylose side stubs on C-6 of the [,3)-,- d -Galp (1,] units, whereas intergenicular segments produce xylogalactans with high levels of xylose and low levels of 6- O -methyl ,- d -Gal units. These data suggest that, during genicular development, xylosyl branched, 3-linked ,- d -Galp units present in the xylogalactan backbones from intergenicular walls are mostly replaced by 6- O -methyl -d- galactose units. We speculate that this structural shift is a consequence of a putative and specific methoxyl transferase that blocks the xylosylation on C-6 of the 3-linked ,- d -Galp units. Changes in galactan substitutions may contribute to the distinct mechanical properties of genicula and may lend insight into the calcification process in coralline algae. [source] PHYLOGEOGRAPHY OF THE GENUS SPONGITES (CORALLINALES, RHODOPHYTA) FROM CHILE,JOURNAL OF PHYCOLOGY, Issue 1 2008Rodrigo Vidal Both the records and the descriptions of the crustose species of coralline algae on the southeastern coast of South America are from the early 1900s. Unlike other algae species on the coast of Chile, the biogeography and distribution of crustose corallines have not been studied despite their abundance. Through recent studies, it has been determined that the genus Spongites is the most conspicuous genus along the rocky intertidal of the Chilean coasts. It is also common to the entire coast of the Southern Hemisphere; however, the relationship between species and the possible reasons for their distribution is unknown. We used nuclear and mitochondrial genetic markers and SEM observations of morphological characters to examine Spongites samples from the Southern Hemisphere and to establish the phylogeographic relationships of Chilean Spongites with specimens from other southern coasts. The combination of these analyses revealed the following: (i) a monophyletic clade that represents the Chilean Spongites and (ii) a paraphyletic clade for South African, New Zealand, and Argentine samples. Consequently, we postulate two nonexclusive hypotheses regarding the relationship of Spongites species in the Southern Hemisphere: (i) a complex history of extinction, speciation, and recolonization that might have erased original Gondwanan split patterns, and (ii) an Antarctic Peninsula origin for the Chilean Spongites species. [source] AN SEM-BASED ANALYSIS OF THE MORPHOLOGY, ANATOMY, AND REPRODUCTION OF LITHOTHAMNION TOPHIFORME (ESPER) UNGER (CORALLINALES, RHODOPHYTA), WITH A COMPARATIVE STUDY OF ASSOCIATED NORTH ATLANTIC ARCTIC/SUBARCTIC MELOBESIOIDEAE,JOURNAL OF PHYCOLOGY, Issue 5 2005Walter H. Adey Lithothamnion tophiforme (Esper) Unger is a dominant, arctic, saxicolous species that extends southward, albeit with reduced cover, into the deeper colder waters of the North Atlantic subarctic, where it also occurs in significant rhodolith deposits with L. glaciale. The external appearance of L. tophiforme is distinctive, but typification, anatomy, reproduction, ecology, and biogeography have not been previously analyzed. These topics are now addressed, with extensive use of SEM, in comparison with other North Atlantic arctic and subarctic melobesioid genera and species. The species considered in this article comprise 95% of the coralline biomass of the colder North Atlantic and adjacent arctic (i.e. less than 12° C summer and less than 0° C winter). In the outer thallus region of coralline algae, crust extension proceeds, calcification develops, surface sloughing and grazing occur, and reproductive structures are initiated. Analysis of the ultrastructure of the outer thallus region (epithallium, meristem, and perithallium) of L. tophiforme shows distinctive generic similarities and specific differences from the other Lithothamnion species discussed here. Considerable generic differences from the Clathromorpum and Leptophytum species also encountered in the region considered are highlighted as well. We discuss the functional and taxonomic implications of these distinguishing features and recommend that they be more widely considered in future research on coralline algae to understand more fully the ecology and evolution of the Corallinales. [source] 16 Comparisons of macrophyte cover and community primary productivity on two southern california shoresJOURNAL OF PHYCOLOGY, Issue 2003A. M. Bullard Light-saturated net photosynthetic rates and cover of rocky intertidal macrophytes were determined between January and March 2003 at two southern California sites characterized by different macrophyte standing stocks. Overall macrophyte cover at Little Corona del Mar was low (75.4%) and was dominated by articulated corallines, and small, turf-forming crustose algae that provide little habitat structure. Macrophyte cover was higher at Dana Point (99.4%), where larger, frondose seaweeds were more abundant (34% vs < 5% cover). Our light-saturated photosynthetic rates for Little Corona del Mar and Dana Point macrophytes were similar to values for the same species obtained during the 1970s and 1980s. Highest photosynthetic rates were obtained for thinner, sheet-like, and branched, frondose seaweeds, while lowest rates were found for articulated coralline and crustose algae. We estimated the net community productivity of the two sites using photosynthetic rates (calculated as mg C m,2 · h,1) and percent cover data for the most abundant populations. We also compared our community productivity estimates for Little Corona del Mar and Dana Point with values for the same sites calculated using macrophyte cover values obtained during the mid-1970s. Re-sampling studies of these and other regional sites reveal that lower-producing, crustose and coralline algae have become increasingly abundant while the cover of higher-producing, frondose algae has declined on many southern California shores. Our studies at Little Corona del Mar and Dana Point, indicate that changing macrophyte abundances can have significant effects on the primary productivity of rocky intertidal communities. [source] POTENTIAL TOOLS FOR TRACKING OCEAN CLIMATE: VARIABILITY IN STABLE ISOTOPES IN LIVING CORALLINE ALGAEJOURNAL OF PHYCOLOGY, Issue 2000R.A. Dunn Our ability to track long term climate change in coastal regions is limited in temperate and polar regions. Physical oceanographic dynamics in temperature and upwelling events can be recorded as carbon and oxygen stable isotope signals in carbonate producing organisms. Because coralline algae photosynthesize, produce calcium carbonate and are widely distributed, they may provide a new tool for detecting short-term change. However, little is known about how coralline algae incorporate stable isotopes into their calcite thallus structure. The objectives of this study were to determine if growth and isotopic signature differ in articulated coralline algae grown in different oceanographic regimes in Monterey Bay. The articulated alga Calliarthron cheiliospororioides was outplanted at three locations varying in seawater temperature and upwelling strength. New algal growth was measured by staining the algae with Alizarin Red and enumerating the amount of accumulated material at the branch tips. Growth rates varied seasonally and spatially. Low-upwelling daily growth rates averaged 0.044,0.056 mm day,1, while high-upwelling growth rates were 0.083 mm day,1. Isotope ratios were obtained by analyzing microsampled portions of the alga in a mass spectrometer. Changes in the 18O/16O and 13C/12C ratios appear to reflect change in seawater temperature and upwelling strength, respectively. [source] Maerl growth, carbonate production rates and accumulation rates in the ne atlanticAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue S1 2003Dan Bosence Abstract 1.Accumulations of maerl occur widely in ocean facing coastal waters (<20,30 m depth) of the northeast Atlantic, that are sheltered from the direct SW approach of storm waves and have little terrigenous sediment supply. 2.The different methods that have been used to assess the rate of formation of cool temperate, coralline algal gravels (maerl) are outlined. 3.Formation rates of maerl may be expressed as short-term, branch growth rates (mm yr,1), as calcium carbonate production rates (g CaCO3 m,2 yr,1), or as longer-term accumulation rates (m kyr,1=m 1000 yr,1). 4.Branch growth rates of the free living, branching coralline algae that form maerl in northwest Spain and western Ireland vary from 0.1 to 1.0 mm yr,1. Rates from Norway are either 0.05,0.15 or up to 1.0 mm yr,1. 5.Production rates vary from 30,250 g CaCO3 m,2 yr,1 in western Ireland, 876 g CaCO3 m,2 yr,1 in northwest France and 90,143 or 895,1423 g CaCO3 m,2 yr,1 in Norway. 6.Accumulation rates vary from 0.08 m ky,1 in Orkney to 0.5 m ky,1 in Cornwall, to 0.8,1.4 m kyr,1 in Norway. 7.These production and accumulation rates are similar to the lower end of such rates from tropical coral reef environments. This is achieved by high standing crops that compensate for the lower growth rates of the temperate algae. Although rapid on a geological time-scale these accumulation rates are far too low for the maerl to be regarded as a sustainable resource for extraction for agricultural and industrial use. Copyright © 2003 John Wiley & Sons, Ltd. [source] Bivalve fishing and maerl-bed conservation in France and the UK,retrospect and prospectAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue S1 2003J.M. Hall-Spencer Abstract 1.Maerl beds are carbonate sediments, built by a surface layer of slow-growing coralline algae, forming structurally fragile habitats. 2.They are of international conservation significance, often supporting a high biodiversity and abundant bivalve molluscs. 3.Experimental fishing for scallops (Pecten maximus) on French and UK grounds has shown that although large epifauna are often killed, many organisms escape harm as they burrow deeply or are small enough to pass through the dredges. 4.Bivalve dredging is currently one of the main threats to European maerl grounds as it reduces their biodiversity and structural complexity and can lead to long-term degradation of the habitat. 5.Protecting maerl grounds is of importance for fisheries since they provide structurally complex feeding areas for juvenile fish (e.g. Atlantic cod - Gadus morhua) and reserves of commercial brood stock (e.g. Ensis spp., P. maximus and Venus verrucosa). 6.We outline improved mechanisms to conserve these ancient and unique biogenic habitats. Copyright © 2003 John Wiley & Sons, Ltd. [source] | ||||||||||