James N. Norris

Deep-water plant communities from an uncharted seamount off San Salvador Island, Bahamas: distribution, abundance, and primary productivity

Studies from a submersible on a seamount off San Salvador (Bahamas) revealed a diverse multilayered macrophyte community, with net productivity levels comparable to shallow water seaweeds although receiving only 1–2% of the light energy available at the surface. Four zonal assemblages occur over the depth range from 81 to 268 m and consist of a Labophora-dominated group (81–90 m), a Halimeda assemblage (90–130 m), a Peyssonnelia group (130–189 m), and a crustose coralline zone (189–268 m). This deep flora is composed of unique deep-water taxa combined with shallow water forms characteristics of shaded, low-light conditions.

An early Holocene reef in the western Atlantic: submersible investigations of a deep relict reef off the west coast of Barbados, W.I.

Submersible observations and collections reveal that a probable relict reef off the west coast of Barbados has a rich cover of sponges, along with algae and scattered corals, on a substrate of algal nodules in a muddy-sand matrix. The collections provide new data on the distributions of these fauna. This relict reef is about 20 km long, has a relief of up to 10 m, and is established at a depth of 80 m. Relict shallow-water features in other areas at similar depths along with data from core holes drilled off the south coast of Barbados suggest that this reef was probably established about 12,000 years ago and existed for no more than 2,000 years, during the Holocene sea-level transgression.

Chemical variation in the tropical seaweed Stypopodium zonale (dictyotaceae)

Abstract Five separate collections of the tropical seaweed Stypopodium zonale were analysed for ten secondary metabolites using a combination of high performance liquid chromatography and proton nuclear magnetic resonance spectrometry. Shallow water populations from the Caribbean were found to possess similar metabolite profiles from year to year and from widely diverse locations. Stypopodium zonale from the South Pacific (Palau) contained similar structure types; however, the profile was qualitatively and quantitatively dissimilar to the Caribbean algae. A deep water Caribbean form of S. zonale was found to contain two metabolites, epitaondiol and 6a-desmethyl-6-acetylatomaric acid, not observed in the other extracts. This latter population is morphologically and anatomically distinct from the other S. zonale Caribbean populations.

Structure and biosynthesis of novel conjugated polyene fatty acids from the marine green algaAnadyomene stellata

Novel polyunsaturated fatty acids with four conjugated double bonds were found in extracts of the green macroalga,Anadyomene stellata. The isolation of five of these with different chain lengths and varying degrees of unsaturation −16∶5, 18∶4, 20∶5, 20∶6, and 22∶7—was accomplished by organic extraction followed by a combination of vaccum and high-performarce liquid chromatography. One of these that was a novel substance (22∶7) was characterized as 4ZZ,7Z,9E,13Z,16Z,19Z-docosaheptaenoic acid and assigned the trivial name stellaheptaenoic acid. The structure of this new compound, isolated as its methyl ester derivative, was deduced from detailed nuclear magnetic resonance, gas chromatography/mass spectrometry (GC/MS), and other spectroscopic methods. Incubation of a chloroplast preparation, isolated from a crude algal homogenate by differential centrifugation, with six unsaturated fatty acids (palmitoleic, 6Z,9Z,12Z,15Z-octadecatetraenoic acid, arachidonic acid, eicosapentaenoic acid, 7Z,10Z,13Z,16Z-docosatetraenoic acid, and 4Z,7Z,10Z,13Z,16Z,19Z-docosahexaenoic acid) resulted in substantially increased synthesis of unique tetraene compouds as detected by ultraviolet spectrophotometry and tentatively identified by GC/MS.

Phospholipase A2 inhibitors from marine algae

Twelve out of twenty-nine compounds isolated from benthic marine algae from the phyla Chlorophyta, Phaeophyta and Rhodophyta have been found to be potent inhibitors of bee venom derived phospholipase A2 (PLA2) (> 50%) in the μM range. The compounds investigated were from: Bryopsis pennata, Rhipocephalus phoenix, Caulerpa prolifera, C. racemosa, C. bikinensis, Cymopolia barbata, Laurencia cf. palisada, Laurencia sp., Ochtodes crockeri, Liagora farinosa, Sphaerococcus coronipifolius, Phacelocarpus labillardieri, Dictyota sp., Bifurcaria galapagensis, Stypopodium zonale, Dictyopteris undulata, Stoechospermum marginatum, Dictyopteris divaricata, Dilophus fasciola and Dilophus sp. This is the first report of bee venom PLA2 inhibition in vitro by pure compounds isolated from marine algae.

Phylogeography of Gracilaria Tikvahiae (Gracilariaceae, Rhodophyta): A Study of Genetic Discontinuity in a Continuously Distributed Species Based on Molecular Evidence

Gracilaria tikvahiae, a highly morphologically variable red alga, is one of the most common species of Gracilariaceae inhabiting Atlantic estuarine environments and the Intracoastal Waterway of eastern North America. Populations of G. tikvahiae at the extremes of their geographic range (Canada and southern Mexico) are subjected to very different environmental regimes. In this study, we used two types of genetic markers, the chloroplast‐encoded rbcL and the nuclear internal transcribed spacer (ITS) region, to examine the genetic variability within G. tikvahiae, for inferring the taxonomic and phylogenetic relationships between geographically isolated populations, and to discuss its distributional information in a phylogeographic framework. Based on rbcL and ITS phylogenies, specimens from populations collected at the extreme distributional ranges reported for G. tikvahiae are indeed part of the same species; however, rbcL‐ but not ITS‐based phylogenies detected phylogenetic structure among the ten G. tikvahiae different haplotypes found in this study. The four distinct rbcL lineages were identified as 1) a Canadian–northeast U.S. lineage, 2) a southeast Florida lineage, 3) an eastern Gulf of Mexico lineage, and 4) a western Gulf of Mexico lineage. We found no evidence for the occurrence of G. tikvahiae in the Caribbean Sea. Observed phylogeographic patterns match patterns of genetic structures reported for marine animal taxa with continuous and quasicontinuous geographic distribution along the same geographic ranges.

A new order of red algae based on the Peyssonneliaceae, with an evaluation of the ordinal classification of the Florideophyceae (Rhodophyta)

Abstract The Peyssonneliaceae Denizot comprises a worldwide group of non-calcified or calcified, crust-forming red algae found in diverse, intertidal to deep subtidal marine habitats. Eight genera have been recognized in the family, with Peyssonnelia Decaisne having the largest number of species. Both comparative morphology and rbcL and nuclear LSU rDNA sequence data support the monophyly of the family and show that it cannot be maintained in the order Gigartinales Schmitz. A new order, Peyssonneliales, is herein proposed to accommodate the Peysonneliaceae, with only two of the genera (i.e., Peyssonnelia and Sonderopelta), and its relationship to the other red algal orders is discussed. We also propose the transfer of one species, Peyssonnelia capensis Montagne to Sonderopelta Womersley & Sinkora.

The deep-water species of Halimeda Lamouroux (Halimedaceae, Chlorophyta) from San Salvador Island, Bahamas: species composition, distribution and depth records

Caribbean species of Halimeda from the steep slopes of San Salvador Island, Bahamas, were collected along vertical transects between 25 and 255 m, on the northeast, northwest, west, southwest and south sides of the island, using the Harbor Branch Oceanographic Institutions submersible Johnson Sea Link I. The characteristics delineating species (segment and utricle size) were assessed for selected species, and the depth and western Atlantic distributions of the species reviewed. Halimeda copiosa was found to show a variation of surface utricle diameter with depth, with the deeper plants having 15% larger diameter utricles than the shallower plants. Of the seven species, one variety and one form of Halimeda studied from our submersible dive sites, H. copiosa, H. cryptica and H. gracilis grew to the greatest depths, from 120 to 150-m depths. H. lacrimosa var. globosa was found growing to 91 m, and H. tuna f. platydisca and H. discoidea to a depth of 73 m. Those of lesser depth, to 61 m, were H. goreauii, H. tuna f. tuna and H. lacrimosa var. lacrimosa. These represent substantial increases in depth distribution of the nine taxa found.

GRACILARIA VERMICULOPHYLLA (RHODOPHYTA, GRACILARIALES) IN THE VIRGINIA COASTAL BAYS, USA: COX1 ANALYSIS REVEALS HIGH GENETIC RICHNESS OF AN INTRODUCED MACROALGA

Gracilaria vermiculophylla (Ohmi) Papenfuss is an invasive alga that is native to Southeast Asia and has invaded many estuaries in North America and Europe. It is difficult to differentiate G. vermiculophylla from native forms using morphology and therefore molecular techniques are needed. In this study, we used three molecular markers (rbcL, cox2‐cox3 spacer, cox1) to identify G. vermiculophylla at several locations in the western Atlantic. RbcL and cox2‐cox3 spacer markers confirmed the presence of G. vermiculophylla on the east coast of the USA from Massachusetts to South Carolina. We used a 507 base pair region of cox1 mtDNA to (i) verify the widespread distribution of G. vermiculophylla in the Virginia (VA) coastal bays and (ii) determine the intraspecific diversity of these algae. Cox1 haplotype richness in the VA coastal bays was much higher than that previously found in other invaded locations, as well as some native locations. This difference is likely attributed to the more intensive sampling design used in this study, which was able to detect richness created by multiple, diverse introductions. On the basis of our results, we recommend that future studies take differences in sampling design into account when comparing haplotype richness and diversity between native and non‐native studies in the literature.

Two New Flat Species of Gracilaria (Gracilariales, Rhodophyta) From Brazil: G. Abyssalis sp. nov. and G. Brasiliensis sp. nov

C.F.D. Gurgel, S. Fredericq, J.N. Norris and Y. Yoneshigue-Valentin. 2008. Two new flat species of Gracilaria (Gracilariales, Rhodophyta) from Brazil: G. abyssalis sp. nov. and G. brasiliensis sp. nov. Phycologia 47: 249–264. DOI: 10.2216/06-59.1 A recent survey of the Brazilian Gracilariaceae (Rhodophyta, Gracilariales) flora aided by molecular-based phylogenetic analyses and comparative morphological data revealed two unidentified flat species of Gracilaria described here: G. abyssalis sp. nov. and G. brasiliensis sp. nov. Gracilaria abyssalis is a deep-water species characterized by a conspicuous holdfast; a long, branched, robust stipe; irregular to sympodial branching of the thallus; occasional presence of midrib; and an extensive range of broad blade morphologies. Gracilaria brasiliensis is a shallow intertidal species characterized by an inconspicuous stipe (< 1 cm), regular dichotomously branched thalli, and narrow blades and rounded apices. DNA sequence analyses of the chloroplast-encoded rbcL gene showed that flat species of Gracilaria in the western Atlantic belong to two distinct lineages. Maximum parsimony results placed G. brasiliensis as a member of the G. mammillaris clade with no support, while Bayesian results identified this species as a disntict new independent lineage. Furthermore, it was found that G. cuneata and G. curtissiae are recently diverged sister species and that rbcL phylogenetic distances among the morphologically distinct G. intermedia and G. yoneshigueana are quite small.