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Detailed morphological studies and molecular analyses based on nuclear-encoded large subunit ribosomal RNA (LSU rRNA) gene sequences were undertaken on Gloiocladia leptophylla, a poorly known species from Japan. Both newly collected samples and the holotype were examined. Herein we describe for the first time the structure of tetrasporangial nemathecia, decussately dividing tetrasporangia and male gametophytes. We show that this species has a thin cortex, decussately divided tetrasporangia formed in nemathecia and a tela arachnoidea (network of inner pericarp filaments surrounding mature carposporophytes), as in the genus Leptofauchea. LSU rRNA analyses resolved G. leptophylla in the Faucheaceae (in which it was robustly separated from Gloiocladia), forming a well-supported clade with five other species of Leptofauchea and two species of Webervanbossea. We therefore propose the new combination Leptofauchea leptophylla comb. nov. Iridescence in water, a distinct short stipe and a medulla composed of three to four cell layers are conspicuous diagnostic characters of L. leptophylla within the genus. [ABSTRACT FROM AUTHOR]

C onklin K.Y. and S herwood A.R. 2012. Molecular and morphological variation of the red alga Spyridia filamentosa (Ceramiales, Rhodophyta) in the Hawaiian Archipelago. Phycologia 51: 347-357. DOI: 10.2216/10-26.1 Genetic information is proving to be important in conservation and management efforts that involve cryptic species and their role in native ecosystem restoration. Previous molecular studies have demonstrated that the red alga Spyridia filamentosa consists of several cryptic species. Spyridia filamentosa is considered to be a native species in Hawai'i and was recently used in preliminary seagrass meadow restoration efforts in Maunalua Bay, O'ahu. It became necessary to understand the genetic diversity of this species in the Islands and determine if there are relationships between any molecular clades of S. filamentosa and anatomical characters that might be useful (e.g. sediment capture) in habitat remediation. Both molecular and morphological (determinate branch cell dimensions) analyses revealed the presence of multiple S. filamentosa clades in Hawai'i. Nuclear [partial LSU (large subunit)] sequence and determinate branch cell data recovered two broad lineages (I and II), which are known worldwide. The mitochondrial sequence ( cox2-3 spacer) data further separated samples into five distinct clades and indicated that S. filamentosa arrived in Hawai'i on at least six occasions. These results aided decisions made concerning preliminary experiments involved in seagrass habitat remediation and emphasized the importance of genetically evaluating cryptic species that are being considered for use in native ecosystem restoration or conservation. [ABSTRACT FROM AUTHOR]

Twenty-seven clones were established from elongate Alexandrium sp. cysts collected in six regions along the Russian Pacific coast. All isolates were identified as Alexandrium tamarense via detailed epifluoresence microscopy of thecal plates. Morphological differences of both cultured and wild cells from the study regions mainly occurred in the shape of the cell (length/width ratio), degree of development of the sulcal list, and the shape of the posterior sulcal (S.p.) and second antapical (2″″) plates. Cells were divided into two cell types: ‘short’ (isodiametrical or wide) and ‘tall’. Each cell type exhibits specific features of tabulation, mainly the shape of the S.p. and 2″″ plates and was dominant in each particular region of the study. The short type, with a wide S.p. and reduced length in the dorsoventral 2″″ plates, was characteristic of A. tamarense from Primorye and southern Sakhalin Island. The tall cells, i.e., with cell length exceeding width, and having and elongate S.p. and dorsoventrally elongate 2″″ plates, prevailed in Avachinskaya Guba Inlet and in the Bering Sea. The differences reported here between the two types are within the range of morphological variability of A. tamarense sensu Balech, 1995. The D1-D2 fragment of the large subunit nuclear ribosomal DNA was analyzed for 24 clones. Alexandrium tamarense from the Russian Pacific coast compose three genetically distinct populations that correspond to the Japanese temperate Asian, eastern North American, and western North American ribotypes of the ‘tamarensis’ complex. The presence and distribution of eastern and western North American ribotypes along the Russian Pacific coast suggest that dispersion to the temperate Asian region occurred long ago via natural currents and processes, and not through human-mediated introductions, as has been proposed. No strict correlation was observed between different morphological types of cells and ribotypes. High-performance liquid chromatography toxin analyses showed that all isolates were toxic and demonstrated variability in toxin content and composition among different populations. These data document the significant and previously uncharacterized risk of shellfish contamination with paralytic shellfish poisoning toxins from blooms of A. tamarense in Russian marine waters. [ABSTRACT FROM AUTHOR]