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- A New Crustose Species of Phymatolithon (Hapalidiales, Corallinophycidae) From The Mediterranean Sea (Abu Qir, Egypt)?Publication . Kittle III, Ronald Paul; Richards, Joseph; Nguyen, A.; Gabriel, Daniela; Sauvage, Thomas; Schmidt, William E.; Fredericq, SuzannePhymatolithon is one of the most studied and ecologically important crustose coralline algae (CCA) because of their dominance in various marine ecosystems worldwide. The taxonomic history of the genus has been complex, and the genus has been revised multiple times on the basis of morphological and molecular analyses.
- Genetic diversity of Gibsmithia hawaiiensis complex (Dumontiaceae, Rhodophyta): Molecular phylogeny, taxonomic characterization, and the proposal of new speciesPublication . Gabriel, Daniela; Draisma, Stefano; Sauvage, Thomas; Schmidt, William; Fredericq, SuzanneABSTRACT: The genus Gibsmithia was erected on the basis of G. hawaiiensis Doty 1963 from the Hawaiian archipelago to accommodate a species of red algae in the Dumontiaceae consisting of clusters of gelatinous lobes growing from a cartilaginous stalk. Three additional species were subsequently described from Australia, i.e. G. dotyi Kraft & R.W. Ricker 1984, G. larkumii Kraft 1986 and G. womersleyi Kraft & Ricker ex Kraft 1986. Records of Gibsmithia have been reported from different localities throughout the Indian Ocean and the central and western Pacific, with G. hawaiiensis acknowledged as having the widest geographic distribution. Gibsmithia hawaiiensis can be easily distinguished from the other species in the genus by the presence of abundantcortical filaments extending the frond's surface giving the specimens a furry appearance. Based on new subtidal collections and existing herbarium specimens, a study was conducted on the genetic diversity of specimens identified as G. hawaiiensis. The three genetic markers employed (COI, rbcL and UPA) revealed the existence of a species-complex comprising two major lineages, with genetically distinct species. The Gibsmithia hawaiiensis complex exhibits high genetic diversity in the Indo-Malay region, with one lineage distributed throughout the E Indian Ocean and the W Pacific, and a widespread second lineage collected from East Africa to French Polynesia. In contrast, low genetic diversity characterizes members from isolated regions as the Hawaiian archipelago and the semi-closed Red Sea. The high divergence associated with poor resolution observed in geographically widespread lineages obscures species boundaries. The generitype and two new species forming the Gibsmithia hawaiiensis complex can be distinguished on the basis of anatomical characters that were previously regarded as morphological plasticity within G. hawaiiensis. Additional studies are underway to assess the large-scale phylogenetic and biogeographic patterns in Gibsmithia.
- What can the Gulf of Mexico and Panama tell us about education and outreach?Publication . Fredericq, Suzanne; Wysor, B.; Freshwater, D.W.; Krayesky-Self, S.; Collin, R.; Sauvage, Thomas; Richards, Joseph; Gabriel, Daniela; Arakaki, Natalia; Camacho, Olga; Cho, Tae Oh; Won, Boo Yeon; Ehrenhaus, Constanza; Venera-Ponton, Dagoberto; Kittle III, Ronald Paul; Krayesky, David; Gurgel, Carlos Frederico Deluqui; Schmidt, William E.ABSTRACT: A series of research grants funded by the National Science Foundation involved a major component about education and outreach as it pertained to marine algal diversity. These included comprehensive studies into 1) the diversity of the deep bank marine algae in the Gulf of Mexico (NSF Biodiversity Surveys and Inventories program) and the discovery of unsuspected eukaryotic life inhabiting rhodolith forming coralline algae (NSF DEB), 2) monographic research (NSF PEET), 3) advanced tropical phycology with the integration of modern and traditional techniques in the study of tropical algae of Panama (NSF PASI), among others.
- Genetic diversity of Gibsmithia hawaiiensis complex (Dumontiaceae, Rhodophyta)Publication . Gabriel, Daniela; Draisma, Stefano; Schmidt, William E.; Schils, Tom; Sauvage, Thomas; Maridakis, Clio; Gurgel, Carlos Frederico Deluqui; Lim, Phaik Eem; Harris, D. J.; Fredericq, SuzanneABSTRACT: The genus Gibsmithia was erected to accommodate a species with the peculiar combination of gelatinous lobes rising from cartilaginous stalks. Based on G. hawaiiensis from Hawaii, it remained monotypic for over 20 years, when three additional species were described from Australia. G. hawaiensis is unique for its furry appearance due to cortical filaments beyond the surface. Gibsmithia have been reported from the Indian Ocean and central and western Pacific, with G. hawaiensis having the widest distribution. Genetic studies based on COI, rbcL and UPA, reveal that G. hawaiiensis is monophyletic with nine distinct species sharing a similar habit. G. hawaiiensis complex exhibits high genetic diversity in Indomalaysia region, with different species presenting genetically variable populations. Species restricted to isolated region as Hawaii or the Red Sea comprises genetically conserved populations. Four of those cryptic species can be distinguished based on characters previously regarded as morphological plasticity: the generitype and the new species G. eilatensis, G. indomalayensis and G. lata distributa. Because specimens of the other species are only available dried onto herbarium paper or in silica-gel, their reproductive characters can not be characterized. New reports of the complex are given to Madagascar, Europa Island, the Red Sea and Guam, and also to new regions of Malaysia, Indonesia, the Philippines and the French Polynesia.
- New Deepwater Species Of Red Algae Growing In Rhodolith Beds In The NW Gulf Of MexicoPublication . Fredericq, Suzanne; Arakaki, Natalia; Ehrenhaus, Constanza; Norris, James N.; Richards, Joseph; Gabriel, Daniela; Sauvage, Thomas; Gurgel, Carlos Frederico Deluqui; Kittle III, Ronald Paul; Krayesky, Sherry; Schmidt, William E.This talk will focus on recently collected new species of marine red algae growing on the surface of rhodoliths at 56-85m depth in the northwestern Gulf of Mexico.
- Characterization of rhodolith beds in the northwestern Gulf of Mexico before and after the BP Deepwater Horizon oil spillPublication . Fredericq, Suzanne; Schmidt, William E.; Gabriel, Daniela; Sauvage, Thomas; Krayesky, DavidABSTRACT: In the northwestern Gulf of Mexico beds of rhodoliths and unconsolidated rubble are associated with unique offshore deep bank habitats, the salt domes or diapirs that are peculiar to that part of the northern Gulf. In contrast to being mainly composed of crustose corallines (or foraminifera), rhodoliths in the NW Gulf of Mexico at depths of 40-85 m are instead dominated by red algal crust-forming members of Peyssonneliaceae and Rhizophyllidaceae.
- Rhodoliths and their importance for macroalgal ecology and biodiversity in the NW Gulf of MexicoPublication . Fredericq, Suzanne; Krayesky-Self, Sherry; Sauvage, Thomas; Richards, Joseph; Kittle III, Ronald Paul; Gurgel, Carlos Frederico Deluqui; Gabriel, Daniela; Schmidt, WilliamUnderstanding the ecology and biodiversity of deep-water communities is a major challenge. In the NW Gulf of Mexico, unique deep bank habitats associated with salt domes occur at ~50-90m on the continental shelf offshore Louisiana and Texas. In these mesophotic rubble habitats rhodoliths are the main hard substrata for the attachment of macroalgae. Metabarcoding of environmental DNA using molecular markers for rhodolith’s endolithic portions has revealed hidden cryptic algal diversity including spores, propagules, and unsuspected life history stages. We explored cryo-SEM in the study of endolithic cell inclusions which brought to light a suite of microalgal stages. We were able to differentiate floridean starch from cellular inclusions. Analyses of combined 16S V4 metabarcodes and 16S Sanger sequences of several macroalgal orders increased the established record of diversity in the region. Progress is underway to link the eukaryotic component of the rhodolith holobiont (“total organism”) with its co-occurring prokaryotic component. Rhodoliths are marine biodiversity hotspots that may function as seedbanks, temporary reservoirs for life history stages of ecologically important eukaryotic microalgae, or as refugia for ecosystem resilience following environmental stress.