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- 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.
- 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.
- What lies beneath - Southeast Asia’s hidden seaweed diversityPublication . Draisma, Stefano; Gabriel, Daniela; Liu, Shao Lun; Lim, Phaik EemABSTRACT: Southcast Asia is a marine biodiversity hotspot. Assessmentes of marine flora diversity in the region are traditionaly based on the morphological species concept. However, several molecular studies have revealed that there is more species diversity in scaweeds than the naked eye can see.