Effect of Planting Unit Size and Sediment Stabilization on Seagrass Transplants in Western Australia

Abstract The effect of increasing planting unit size and stabilizing sediment was examined for two seagrass planting methods at Carnac Island, Western Australia in 1993. The staple method (sprigs) was used to transplant Amphibolis griffithii (J. M. Black) den Hartog and the plug method was used to transplant A. griffithii and Posidonia sinuosa Cambridge and Kuo. Transplant size was varied by increasing the number of rhizomes incorporated into a staple and increasing the diameter of plugs. Planting units were transplanted into bare sand, back into the original donor seagrass bed, or into a meadow of Heterozostera tasmanica, which is an important colonizing species. Sprigs of A. griffithii were extracted from a monospecific meadow; tied into bundles of 1, 2, 5, and 10 rhizomes; and planted into unvegetated areas. Half the units were surrounded by plastic mesh and the remainder were unmeshed. All treatments were lost within 99 days after transplanting, and although larger bundles survived better than smaller ones, no significant differences could be attributed to the effects of mesh or sprig size. Plugs of P. sinuosa and A. griffithii were extracted from monospecific meadows using polyvinyl chloride pipe of three diameters, 5, 10, and 15 cm, and planted into unvegetated areas nearby. Half the units were surrounded by plastic mesh and the remainder were unmeshed. Posidonia sinuosa plugs were also placed within a meadow of H. tasmanica (Martens ex Aschers.) den Hartog. Only 60% of A. griffithii plug sizes survived 350 days after transplanting back into the donor bed; however, survival of transplants at unvegetated areas varied considerably, and analysis of variance indicated a significant two‐way interaction between treatment and plug size. Transplants survived better when meshed (90% survived) and survival improved with increasing plug size. Posidonia sinuosa transplants survived poorly (no plugs survived beyond 220 days in bare or meshed treatments) regardless of size. Survival of 10‐ and 15‐cm plugs was markedly better than the 5‐cm plugs in vegetated areas, including the H. tasmanica meadow. The use of large seagrass plugs may be appropriate for transplantation in high‐energy wave environments.     

GROWTH OF COLPOMENIA PEREGRINA (PHAEOPHYCEAE) IN CULTURE: EFFECTS OF SALINITY,TEMPERATURE AND DAYLENGTH1

Increases in size of Colpomenia peregrina (Sauv.) Hamel microthalli were determined at six different combinations of salinity and temperature under laboratory conditions. Microthalli grown at low salinity (15%) did not have a growth rate significantly different from microthalli grown at high salinity (30%). However, more macrothalli were produced in higher salinity media. Fewer macrothalli were produced at lower temperatures. Growth of C. peregrina microthalli was also determined at six different combinations of daylength and temperature. Microthalli under 15:9 h (LD cycle) did not have a growth rate significantly different from microthalli under 9:15 h LD. However, more macrothalli were produced under long day conditions. Of the three different temperatures utilized (5, 13 and 20° C) only 5° C produced significantly different growth rates. Low temperature reduced growth to such an extent that macrothalli of a size that could be recognized in the field took approximately two months to produce in culture. These results may explain the seasonal presence/absence of the delophycean phase of C. peregrina in the field. Zoospore survivorship and macrothallus production of C. peregrina in culture indicated that both PES and an artificial medium were suitable for the laboratory cultivation of this plant.     

FATTY ACIDS,AMINO ACIDS,MINERAL CONTENTS,AND PROXIMATE COMPOSITION OF SOME BROWN SEAWEEDS1

This study was conducted to create a nutritional database on brown seaweeds and to popularize their consumption and utilization in Iran. The fatty acid contents, amino acids profiles, and certain mineral elements composition of some brown seaweeds, Padina pavonica (L.) Thivy, Dictyota dichotoma (Huds.) J. V. Lamour., and Colpomenia sinuosa (Mert. ex Roth) Derbés et Solier were determined. Total lipid content ranged from 1.46 ± 0.38 to 2.94 ± 0.94 g · 100 g^?1dry weight (dwt), and the most abundant fatty acids were C16:0, C18:1, C20:4 ω6, and C20:5 ω3. The unsaturated fatty acids predominated in all species and had balanced sources of ω3 and ω6 acids. Highest total polyunsaturated fatty acid (PUFA) levels occurred in C. sinuosa. The protein content of D. dichotoma was 17.73 ± 0.29 g · 100 g^?1dwt, significantly higher than the other seaweeds examined. Among amino acids essential to human nutrition, methionine (Met; in D. dichotoma and P. pavonica) and lysine (Lys; in C. sinuosa) were present in high concentrations. The crude fiber content varied by 9.5 ± 11.6 g · 100 g^?1dwt in all species. Chemical analysis indicated that ash content was between 27.02 ± 0.6 and 39.28 ± 0.7 g · 100 g^?1dwt, and that these seaweeds contained higher amounts of both macrominerals (7,308–9,160 mg · 100 g^?1dwt; Na, K, Ca) and trace elements (263–1,594 mg · 100 g^?1dwt; Fe, Ni, Mn, Cu, Co) than have been reported for edible land plants. C. sinuosa had the highest amount of Ca, Fe, and a considerable content of Na was measured in P. pavonica.     

Sequence repeats enlarge the internal transcribed spacer 1 region of the brown alga Colpomenia sinuosa (Scytosiphonaceae, Phaeophyceae)

Colpomenia sinuosa is an annual brown algal species that occurs in temperate to tropical waters of the world. In order to examine the genetic diversity among populations of the species and to discuss its current distribution, we analyzed the nuclear ribosomal DNA internal transcribed spacer (ITS) region from 18 specimens of C. sinuosa , and, for comparison, plastid rbc L from the same specimens. The C. sinuosa ITS region (2141–2534 base pairs) is approximately 2.2 times the length of most other brown algae. We found a long repeated sequence of approximately 190 base pairs in the first half of the ITS1 region; five repeats in Northern Hemisphere collections and three in those from the Southern Hemisphere, which result in ITS length variation. The unequal occurrence of tandem repeats of C. sinuosa corresponds to the geographical distribution of the species. The rbc L sequences from all the specimens of C. sinuosa , except the Canary Island samples, were identical, indicating that they indeed belong to the same species.     

Ethanol Production from Colpomenia sinuosa by an Alginate Fermentation Strain Meyerozyma guilliermondii

With the consumption of energy and the spread of COVID-19, the demand for ethanol production is increasing in the world. The industrial ethanol fermentation microbes cannot metabolize the alginate component of macro algae, which affects the ethanol yield. In this research, the ethanol production process from macro algae by an alginate fermentation yeast Meyerozyma guilliermondii, especially the pretreatment process of Colpomenia sinuosa, was studied. At the same time, the experimental design of Box-Behnken was carried out to achieve the optimum fermentation performance. The concentration of KH₂PO₄ (A: 2–6 g.L⁻¹), pH (B: 4–7), reaction time (C: 60–120 h) and temperature (D: 24–34 °C) were variable input parameters. During the ethanol production process, the algae powder was firstly mixed with water at 90 °C for 0.5 h. Later the fermentation culture medium was prepared and then it was fermented by the yeast Meyerozyma guilliermondii to produce ethanol. And the optimal fermentation parameters were as follows: fermentation temperature of 28 °C, KH₂PO₄ dosage of 4.7 g.L⁻¹, initial pH of 6, and fermentation time of 99 h. The ethanol yield reached 0.268 g.g⁻¹ (ethanol to algae), close to the predicted value of model. The generation of alginate lyase during the fermentation of algae was also examined. The highest alginate lyase activity reached 46.42 U.mL⁻¹.     

Six new species of the genus Dicranosepsis Duda (Diptera, Sepsidae) from Vietnam, with a revised key to the species

The flies of the genus Dicranosepsis from Vietnam were investigated and classified taxonomically. Six new species (D. longa sp. nov., D. kurahashii sp. nov., D. monoseta sp. nov., D. sinuosa sp. nov., D. barbata sp. nov., and D. vietnamensis sp. nov.) are described and illustrated. Dicranosepsis is redefined and a revised key to the species is also provided.     

LIFE HISTORY OF COLPOMENIA SINUOSA (SYCTOSIPHONACEAE,PHAEOPHYCEAE) IN THE AZORES1

Colpomenia sinuosa (Mertens ex Roth) Derbès and Solier (Scytosiphonaceae, Phaeophyceae) is a common species on the rocky intertidal shores of the Azores, where reproductive gametophytes occur throughout the year. Life‐history studies of this species were carried out in culture, and both sexual and asexual reproduction were observed. Anisogamous gametes fused to form zygotes. The zygotes gave rise to a filamentous prostrate sporophyte generation bearing unilocular sporangia, under both short‐day and long‐day conditions at 15 and 22°C, and to both unilocular and plurilocular sporangia, under the lower temperature condition. Unispores developed into gametophytes, and plurispores gave rise to filamentous sporophytes. Asexual reproduction was carried out by unfused female gametes and asexual plurispores produced from the same gametophyte. Unfused gametes developed into filamentous prostrate sporophytes producing unilocular sporangia in both culture conditions, and unispores released from the sporangia gave rise to gametophytes. Asexual plurispores from field gametophytes, under both culture conditions, developed directly into new gametophytes. The species exhibited three types of life history: a heteromorphic, diplohaplontic; a heteromorphic, monophasic (both with alternation between the erect and filamentous prostrate thalli); and a monomorphic, monophasic.     

Life histories of Colpomenia sinuosa and Hydroclathrus clathratus (Scytosiphonaceae, Phaeophyceae) in culture

Life-history studies in culture were carried out on Colpomenia sinuosa (Mertens ex Roth) Derbès et Solier and Hydroclathrus clathratus (C. Agardh) Howe (Scytosiphonales, Phaeophyceae) from Japan. These species showed a heteromorphic life-history pattern with an alternation between erect thalli bearing plurilocular zoidangia and prostrate thalli bearing ectocarpoid plurilocular and unilocular zoidangia. Plurizoids released from erect and prostrate thalli developed into prostrate thalli. Unizoids, however, developed into erect thalli. Prostrate thalli produced plurilocular zoidangia in long-day conditions and unilocular zoidangia in short-day conditions at 10-20°C. Prostrate thalli of C. sinuosa formed ascocysts. Germlings of both species did not grow at 5°C.     

French Polynesian Scytosiphonaceae (Ectocarpales,Phaeophyceae): A combined molecular and morphological approach to their diversity and systematics

This study revisited the taxonomy and diversity of brown macroalgae within the Scytosiphonaceae family in French Polynesia, which had previously been recognized as encompassing only six species. Using the chloroplast and mitochondrial genes rbcL, psbA, and cox3 as molecular markers in conjunction with morpho-anatomical observations, we unveiled the presence of 11 species spanning six genera: Chnoospora minima, Colpomenia claytoniae, Co. sinuosa [groups IIIa and IIIb], Hydroclathrus rapanuii, H. tenuis, H. tilesii, Manzaea minuta, Pseudochnoospora implexa, Rosenvingea australis, and the newly described species R. polynesiensis sp. nov. and R. tahitiensis sp. nov. This encompasses the recognition of two previously unreported genera in this region: Manzaea and Pseudochnoospora. Sequences were successfully acquired for four taxa that had been documented previously, while the absence of sequences for H. clathratus and H. tumulis in French Polynesia raises queries about their presence in this region. With these additions, the total species count now stands at 13 (including H. clathratus and H. tumulis), one being an endemic species. The molecular-assisted alpha taxonomic approach used here allowed for a critical revision of the Scytosiphonaceae species checklist for French Polynesia. The diversity revealed in this region accounts for a substantial 20% of the family's global diversity. Additionally, our study presents an updated species-level phylogeny for the Scytosiphonaceae.