Two species of Dasya (Ceramiales, Rhodophyta) from Bonin Islands, southern Japan, with the description of Dasya boninensis sp. nov.

Two species of Dasya in the Dasyaceae (Ceramiales, Rhodophyta) are reported from Bonin Islands, southern Japan. Dasya murrayana Abbott et Millar, new to Japan, is characterized by the following set of features: the tufted habit (up to 30 erect axes developing from a basal disc), small‐sized (6–10 mm high and 350–500 μm in diameter in the middle region), thinly but completely corticated axes, rigid and incurved pseudolaterals forming corymbose heads at the apices of axes and branches, the absence of adventitious monosiphonous filaments, a large number of tetrasporangial stichidia and spermatangial branches per fertile pseudolateral and slender spermatangial branches (35–45 μm in diameter). Dasya boninensis Masuda, Kurihara et Kogame, sp. nov. is characterized by short but thick (10–30 mm high and 600–1000 μm in diameter at the middle portion), heavily corticated axes, indistinct pericentral cells except for the upper portion in transverse sections, soft, straight pseudolaterals and adventitious monosiphonous filaments densely covering the axis and branches, a small number of tetrasporangial stichidia and spermatangial branches per fertile pseudolateral, thick spermatangial branches (65–90 μm in diameter), and short‐necked cystocarps. A dichotomous key to the taxa found in Japanese waters is given.     

The marine algae of Orkney

Six species are described and compared with related algae. All were isolated in culture from terrestrial habitats on Signy Island, South Orkney Islands, Antarctica. They are: Botrydiopsis constricta sp. nov. (Mischococcales, Xanthophyceae), Heterothrix antarctica sp. nov. (Tribonematales, Xanthophyceae), Sphaerocystis oleifera sp. nov. (Chlorococcales, Chlorophyceae), Sphaerocystis signiensis sp. nov., Sphaerocystis bilobata sp. nov. and Fottea pyrenoidosa sp. nov. (Ulothricales, Chlorophyceae).     

New records of Malaysian marine algae

Checklists of the marine algae of Malaysia have been published. The last checklist included the marine algae of Singapore. The checklist recorded 212 taxa for the region. This paper lists an additional 7 taxa of Chlorophyta, 18 taxa of Rhodophyta and 5 taxa of Phaeophyta, which had been left out of the last checklist. These include marine algae from Pulau Pinang, Pulau Redang and Pulau Sibu. In addition, new records of Cyanophyta (2 species), Chlorophyta (4 species), Rhodophyta (10 species) and Phaeophyta (3 species) are reported.     

New records of marine benthic algae from New South Wales, eastern Australia

Twenty‐four species of marine macroalgae are recorded from the mainland coast of New South Wales for the first time. One species, Laurencia platyclada Boergesen, represents a new record for Australia and the Pacific Ocean. Included in these new records is the introduced, invasive and cold‐tolerant strain of the green alga Caulerpa taxifolia, which was formerly known only as native, non‐invasive populations from Lord Howe Island. Based on published accounts, the composition of the marine benthic algae for the state of New South Wales now stands at 131 green, 140 brown and 449 red macroalgae. This baseline information adds significantly to our knowledge of the overall marine biodiversity of the state, as well as to the phycogeography of the southwestern Pacific region.     

Additional analysis of chemical diversity of the red algal genus Laurencia (Rhodomelaceae) from Japan

The halogenated secondary metabolite constitution of four species of the red algal genus Laurencia (Rhodomelaceae) from southern Japan is reported. Laurencia composita Yamada from Tanegashima Island (Kagoshima Prefecture) bears five sesquiterpenoids (2,10‐dibromo‐3‐chloro‐α‐chamigrene and 2,10‐dibromo‐3‐chloro‐9‐hydroxy‐α‐chamigrene, in addition to pre‐pacifenol epoxide, johnstonol and pacifenol, which are known in other populations of this species). Laurencia intricata Lamouroux from Chinzei (Saga Prefecture) and Oomura Bay (Nagasaki Prefecture) bear a C₁₅ aceto‐genin, okamurallene. Laurencia majuscula (Harvey) Lucas from Tanegashima Island produces three sesquiterpenoids, (Z)‐10,15‐dibromo‐9‐hydroxy‐chamigra‐1, 3(15),7(14)‐triene, 10‐bromo‐7‐hydroxylaurene and 10,11‐dibromo‐7‐hydroxylaurene, corresponding to those of one of its chemical races. Laurencia venusta Yamada from Tanegashima Island produces two sesquiterpenoids, cupalaurenol and cyclolaurenol, which were known only from a sea hare, Aplysia dactylomela Rang. This strongly suggests that Aplysia consumes L. venusta and concentrates these halogenated compounds.     

A new species of Laurencia, L. omaezakiana (Ceramiales, Rhodophyta), from Japan

Laurencia omaezakiana Masuda, sp. nov. (Ceramiales, Rhodophyta) is described from Japan. It is characterized by the following set of features: (i) the production of four periaxial cells from each vegetative axial cell; (ii) a shift in branching from distichous to spiral; (iii) the presence of projecting superficial cortical cells near the apices of branches; (iv) the presence of longitudinally oriented secondary pit-connections between contiguous superficial cortical cells; (v) the presence of lenticular thickenings in the walls of medullary cells; (vi) the occurrence of 1–2 corps en cerise in each superficial cortical cell and a single corps en cerise in each trichoblast cell; and (vii) a parallel arrangement of tetrasporangia. Furthermore, it produces a characteristic triterpenoid (enshuol), which has not been detected in other species of Laurencia, as a major halogenated secondary metabolite. A synoptical key to the 23 species of Laurencia growing in Japan is given. Laurencia ceytanica J, Agardh and Laurencia heteroclada Harvey are excluded from the Japanese marine algalflora. The latter is a distinct species from Laurencia filiformis (C. Agardh) Montagne.     

Pterosiphonia tanakae (Rhodomelaceae, Ceramiales), a new red algal species from Japan

The red alga Pterosiphonia tanakae Uwai et Masuda (Rhodomelaceae, Ceramiales) is established as a new species on the basis of material collected in Hiroshima Bay, the Inland Sea, Japan. It can be distinguished from the majority of previously described species of the genus by two key features, seven to 10 periaxial cells and the presence of weakly developed cortical cells. This species is further distinguished from P. pau-cicorticata Dawson by completely alternate-distichously branching and from Pjavanica (Martens) De Toni and P. spinifera (Kützing) Norris et Aken by the production of first-order laterals that bear branches of up to five orders, which results in the thallus having a widely spreading, fan-shaped appearance. The abundant production of vegetative trichoblasts is a further characteristic feature of P. tanakae.     

Some new species and new combinations of marine red algae from the central Pacific

Six new species in five genera of Rhodophyta are described. A new combination for Polyopes hakalauensis is also proposed. These taxa were encountered while preparing a manual of marine red algae of the Hawaiian Islands. Among the Halymeniales, two blade-like species of Halymenia, H. cromwellii sp. nov. and H. stipi-tata sp. nov., are distinguished from other species by habit and anatomical differences, including the possession of a stipe by the second. Halymenia hakalauensis Tilden 1902 is transferred to Polyopes as P. hakalauensis (Tilden) Abbott, replacing P. hawaiiensis Kajimura which is considered a synonym. A new species of Prionitis, P. corymbifera sp. nov., shows a corymbose branching pattern different from the mostly pinnate to subdichotomous branching of Japanese and Californian species. In the Gigartinales, Chondracanthus okamurae Abbott is named for a specimen which Okamura included in his understanding of Gigartina (now Chondracanthus tenellus), but which has terete axes, differing from C. tenellus (Harvey) Hommersand which is com-planate throughout. Chondracanthus intermedius (Sur-ingar) Hommersand is placed in synonymy with C. tenellus. The occurrence of C. tenellus in Hawai'i is a new distribution record from Asia. Three new species are added to the Ceramiales, Ceramium tranquillum Meneses (Ceramiaceae), Dasya kristeniae sp. nov. and Dasya murrayana Abbott & Millar (Dasyaceae). Distinctive features of Ceramium tranquillum are internodes that are three to five times longer than the height of nodes, and nodes that never project beyond the diameter of the internodes, giving straight margins except when fertile. Dasya kristeniae is a diminutive epiphyte which is nearly ecorticate, with tetrasporangial stichidia that are rectangular having apices that are curved or nodding, and cystocarps that have flaring ostioles above a constricted pericarp. Dasya murrayana was earlier misidentified with Dasya iyengarii Børgesen, and re-examination of those plants show continuous cortication throughout, where cortication is almost completely lacking in D. iyengarii except near the base. Dasya murrayana has a tufted habit, with indeterminate branches about the same sizes as the main axes, the plants growing on rock, whereas plants of D. iyengarii are not tufted, with indeterminate branches attenuate, and an epiphytic habit.     

Agar from the red seaweed,Laurencia flexilis (Ceramiales,Rhodophyta) from northern Philippines

The worldwide production of the gelling agent agar mainly rely on the red algae of the order Gracilariales and Gelidiales for raw material. We investigate here the potential of a species from another red algal order, Ceramiales as an agar source. The agar from Laurencia flexilis collected in northern Philippines was extracted using native and alkali treatment procedures and the properties of the extracts were determined using chemical, spectroscopic and physical methods. The native agar, 26% dry weight basis, forms a gel with moderate gel strength (200 g cm^?2). Alkali‐treatment did not enhance the gel strength, indicating insignificant amounts of galactose‐6‐sulfate residue, the precursor of the gel‐forming 3,6‐anhydrogalactose (3,6‐AG) moieties. Furthermore, the Fourier transform infrared and chemical analysis showed low sulfate and high 3,6‐AG levels, not affected significantly by the alkali treatment. Nuclear magnetic resonance spectroscopic analysis revealed 3‐linked 6‐O‐methyl‐D‐galactose and 4‐linked 3,6‐anhydro‐L‐galactose as the major repeating unit of the native extract, with minor sulfation at 4‐position of the 3‐linked galactose residues. The native and alkali treated agars have comparably high gelling and melting temperatures, whereas the former exhibits higher gel syneresis. Laurencia flexilis could be a good source of agar that possesses physico‐chemical and rheological qualities appropriate for food applications. Due to the inability of alkali treatment to enhance the key gel qualities of the native extract, it is recommended that commercial agar extraction from this seaweed would be done without pursuing this widely‐used industrial procedure.     

Dasya enomotoi sp. nov. (Dasyaceae,Ceramiales), a new large Dasya from Japan

A new red alga, Dasya enomotoi, is described from Japan. This species is characterized by having a large thallus consisting of an elongated axis and many, radially arranged, polysiphonous branches both of which are heavily corticated and densely covered with numerous, soft monosiphonous filaments. It is distinguished from several similar species by the combination of the following: (i) indistinct pericentral cells in transverse sections except near the apices, (ii) the presence of enlarged, inner cortical cells, (iii) radially arranged adventitious monosiphonous filaments, (iv) three‐celled carpogonial branches, (v) six (sometimes five) tetrasporangia in each fertile segment of the stichidia, and (vi) three tetrasporangial cover cells that are not elongated longitudinally and usually not divided transversely. This species may have been identified as D. villosa Harvey by previous investigators in Japan.     

Simple separation of anticoagulant sulfated galactan from marine red algae

In this study, hot water extracts of 22 red algal species were evaluated for their potential anticoagulant activities. The extracts from eight species (Grateloupia elliptica, Sinkoraena lancifolia, Halymenia dilatata, Grateloupia lanceolata, Lomentaria catenata, Martensia denticulata, Schizymenia dubyi, Chondrus crispus) showed potent activated partial thromboplastin time (APTT). Of these eight algae, the crude polysaccharide fraction (CpoF) from the hot water extracts of L. catenata and S. dubyi showed the highest APTT activity. Lomentaria catenata and S. dubyi were selected and an enzymatic digestion process which could effectively separate a crude polysaccharide fraction with higher yields from raw algae materials was applied. The 10 enzymes tested included five carbohydrases and five proteases. The Ultraflo and Celluclast digests of L. catenata and the AMG digest of S. dubyi exhibited the most potent anticoagulant activity. Furthermore, in both species, the active compounds were mainly concentrated in the >30 kDa fraction through ultrafiltration and showed strong APTT (>1000) and thrombin time (TT) >1000 activity. The active compounds were shown to be sulfated galactans with a greater than 80% galactose content and an 0.22 ∼ 0.31 sulfate to total sugar ratio.     

New records of marine benthic algae from the Lagon Sud-Ouest of New Caledonia, South Pacific

As part of an ongoing project to substantially increase knowledge of the marine algal flora of the French Pacific territory of New Caledonia, a survey of the Nouméa region was conducted that has resulted in the discovery of 41 previously unrecorded species of macroalgae, including 1 Chlorophyta, 1 Phaeophyceae (Heterokontophyta) and 39 Rhodophyta. Among the biogeographically interesting new records are the green macroalga Rhipilia penicilloides N’Yeurt et Keats (previously endemic to the islands of Fiji some 1000 km east of new Caledonia) and the brown alga Cutleria mollis Allender et Kraft (originally described from Lord Howe Island some 1000 km to the south). The red alga Gloiophloea articulata Weber‐van Bosse, known only from its initial discovery in 1928 from the Mascarene Islands in the western Indian Ocean, is now recorded in the deep‐water channels of the Nouméa region of New Caledonia. The widely distributed Indian Ocean species Corynomorpha prismatica (J. Agardh) J. Agardh has its easternmost distribution record from this area, and Dotyella hawaiiensis (Doty et Wainwright) Womersley et Shepley is recorded for the first time outside its central‐Pacific distribution. These new discoveries represent a 12% increase in the total number of species (377) that are reliably known from New Caledonia.     

New red alga Meristotheca imbricata (Solieriaceae, Gigartinales) from Japan

A new red alga Meristotheca imbricata Faye et Masuda (Solieriaceae, Gigartinales) was described on the basis of specimens collected from southern Japan. Although this species might have been for a long time included in the concept of M. coacta Okamura, until recently a very poorly known alga, it is distinguished from the latter by the following features: (i) each thallus consists of one primary blade and several secondary blades, the latter arising from the apical or subapical portion of terminal segments of the primary blade; (ii) the individual blades are repeatedly dichotomously divided into linear segments of which margins are neither undulate nor crispate, and are fleshy, imbricate, frequently anastomosing and often acervate; (iii) each tetrasporangial initial is attached by a basal pit-connection to the parental cell, and the position of the pit-connection changes from basal to lateral by inward growth of the tetrasporangium; and (iv) the carpogonial branches sometimes have a one-celled sterile lateral.     

Chemotaxonomy in marine algae: Secondary metabolite synthesis by Laurencia in unialgal culture

The application of chemistry to taxonomy assumes that the secondary metabolites of an organism used in chemotaxonomic investigations are quantitatively constant and independent of the continually changing physical and chemical factors experienced in nature. To determine the extent to which chemical changes occur with varying environmental conditions in marine algae, we have investigated the haloterpenoids of Laurencia snyderae Dawson, L. subopposita (J. Agardh) Setchell, and L. pacifica Kylin. Gas chromatographic and thin-layer chromatographic comparisons were made of the haloterpenoid components from both natural populations and from cultured algae grown under varying conditions of temperature and photoperiod. In addition, L. spectabilis Postels and Ruprecht, L. gardneri Hollenberg, L. undulata Yamada, L. nipponica Yamada, L. intermedia Yamada and L. okamurai Yamada were cultured and, where appropriate, their secondary metabolites compared to those reported in the literature. It was found that normal secondary metabolites synthesis occurs in culture and is largely unaffected by modification of the culture conditions. Furthermore, the chemical compounds produced are both qualitatively and quantitatively identical to those produced in the natural populations. In order to study the effect of genetic variables on secondary metabolites, we have investigated sympatric populations of L. pacifica that are morphologically similar but chemically distinct. These populations were intrafertile, but not interfertile in culture. The unique secondary metabolites of the populations and their reproductive isolation probably reflect genetic differences.     

Neorhodomela enomotoi sp. nov. (Ceramiales, Rhodophyta) from Japan

The red alga Neorhodomela enomotoi Masuda et Kogame (Rhodomelaceae, Ceramiales) is described as a new species from Japan. It is characterized by the following combination of features: (i) thalli reddish-brown and slightly rigid; (ii) first-order branches mostly indeterminately branched; (iii) adventitious branches infrequent, determinately branched and formed chiefly in the axils of lateral branches; (iv) vegetative trichoblasts abundant; (v) tetrasporangia produced on paniculate ultimate and penultimate branches; and (vi) cystocarps flask-shaped (urceolate). This species has been found growing only in the upper subtidal zone in the warm temperate waters of Japan.     

Characterization of the edible red alga Meristotheca papulosa (Solieriaceae, Gigartinales) from Japan

The vegetative and reproductive morphology of the edible red alga Meristotheca papulosa (Montagne) J. Agardh (Solieriaceae) was reexamined based on material collected from various localities in Japan. Although the habit of the blades is variable according to the length and width of the axes, the frequency of branching and the abundance of proliferations, rbcL sequence analyses indicate their conspecificity. M. papulosa displays four distinctive reproductive features (presence of an auxiliary cell complex, occurrence of cystocarps on marginal proliferations and the blade surface (although very rare) in addition to the margins of axes, frequent production of spinose outgrowths on the pericarp and tetrasporangial initials typically basally attached to their parental cells) that have not been reported for M. papulosa from other areas. Although these features might warrant recognition of the Japanese entity as a separate species, a better understanding of their possible taxonomic value requires comparisons with M. papulosa from other geographic regions, including the type locality.     

Amino acids and low-molecular-weight carbohydrates of some marine red algae

Amino acids and low-MW carbohydrates of 18 red algae have been analyzed. Several non-protein amino acids have been identified, including pyrrolidine-2,5-dicarboxylic acid (3c) and N-methylmethionine sulfoxide (5), new natural products, and 13 known compounds, citrulline, β-alanine, γ-aminobutyric acid, baikiain (1), pipecolic acid (2), domoic acid (3a), kainic acid (3b), azetidine-2-carboxylic acid (4), methionine sulfoxide taurine, N-methyltaurine, N,N-dimethyltaurine and N,N,N-trimethyltaurine. Sugars present were mainly floridoside, isofloridoside and mannoglyceric acid. Details of the structural elucidation of new compounds are also given.     

Habitat characteristics and seasonal changes of Laurencia brongniartii (CeramiaIes, Rhodophyta) in Kagoshima, Southern Japan

The seasonal change in size of Laurencia brongniartii was observed for the year 2002 at Banshobana Park, Satsuma Peninsula and Tsuchihama Beach, Amami Oshima, both in Kagoshima Prefecture, Japan. Additionally, the vertical distribution of this species was also studied at Tsuchihama Beach (second site), where the largest populations were found. Maximum lengths were observed in October ‐ November with a size of 100 ± 6 mm at Banshobana Park and 111 ± 5 mm at Tsuchihama Beach. Line‐transects conducted at Tsuchihama Beach, were analyzed to determine the vertical distribution of L. brongniartii due to depth and the slope of the substrate. Alga was found growing in areas restricted to low levels of light.