Ahnfeltia Plicata Research Articles

Mycotoxins in Macroalgae from the Kandalaksha Gulf of the White Sea after Natural and Experimental Alienation from the Substrate

Samples of macrophyte algae were collected from an ecotope of Kandalaksha Gulf, the White Sea. These algae were selected from substrates, storm wracks and after long-term storage in the soil, and they were assessed by indirect competitive enzyme immunoassay for the presence of low-molecular metabolites of micromycetes (mycotoxins). In Fucus distichus, F. serratus, F. vesiculosus, and Ascophyllum nodosum, the concentrations of all analyzed toxic substances from storm wracks were uniformly reduced compared to those in living thalli. For Laminaria digitata, Saccharina latissima and Ahnfeltia plicata, in living individuals of which mycotoxins were not found or were extremely rare, cases of contamination with citrinin, mycophenolic acid, emodin and sterigmatocystin were found in storm wracks. After 12 months of burial in soil F. distichus samples had only 9 components out of 16 analyzed. In F. serratus, F. vesiculosus, A. nodosum, and Pelvetia canaliculata, only emodin, mycophenolic acid, alternariol, and ergot alkaloids were determined.

Growth enhancement of agricultural crops using seaweed liquid fertilizer

Extensive use of chemical fertilizer is leading to infertility of soil and various hazardous effect on the ecosystem. Using biofertilizer reduces these harmful effects. Many are commercially available, being a poor match to chemical fertilizer they are not used on a large scale. Near coastal regions seaweeds are used as biofertilizers. Recent studies show seaweeds have multiple growth regulators, macro and micronutrients, polysaccharides which are necessary for plant growth. The study is carried out to check the bioactivity of Seaweed liquid fertilizer (SLF) as a growth stimulant. Sargassum cinereum, Ulva rigida and Ahnfeltia plicata found on the Indian coastline were used. SLFs were prepared from each of three species in varying concentration (0.02%, 0.04%, 0.06%, 0.08% and 0.1% v/v) with water and Urea as control. The test plant selected was Vigna radiata. Agronomic characters like germination rate, shoot length, flowering and fruiting period of test plants were studied. Phyto-hormones from SLF were detected by thin-layer chromatography. Elemental analysis of micronutrients in SLF was carried by ICP-AES. Along with Chlorophyll and Protein estimation of grown plants were checked. SLF shelf life was studied using chemical and biological preservatives. The effect of 0.06% concentration of all SLFs showed enhancement in growth and phytochemicals in plants. Plants treated with SLF showed flowering earlier than control plants. Thus, using SLF bio-fertilizer can become an alternative method to reduce the use of harmful chemical fertilizers.

Red alga Polysiphonia fucoides growing in community with Ahnfeltia plicata, its influence on the yield and quality of agar

This article presents the results of studies on the chemical composition of Ahnfeltia plicata and Polysiphonia fucoides. The influence of the quantitative ratio of these algae in the mixture on the yield and quality indicators of agar is shown. It was found that A. plicata contains 13% more sulfated polysaccharides than P. fucoides. It was shown that an increase in the mass fraction of P. fucoides in the mixture does not affect the total and fractional yield of agar, but leads to a deterioration in its quality characteristics. Therefore, it is recommended to remove P. fucoides from the red algae mixture when collecting A.plicata red algae.

Preparation and characterization of agar, agarose, and agaropectin from the red alga Ahnfeltia plicata

Agar, agarose, and agaropectin were extracted from the red alga Ahnfeltia plicata, and their properties and structures were characterized. Agar was extracted by a comparatively low alkaline consumption of 1.2%. It exhibited a gel strength of 1 152.50±74.25 g/cm2 and a sulfate content of 0.55%±0.08%. The yield of agar from A. plicata was 24.53%, which is higher than those of other agarophytes commonly used in China. Three kinds of the method were compared for the purification of agarose, and the physicochemical properties of agarose that was prepared under the optimal condition were identical to those of commercially available agarose. Furthermore, agaropectin was purified from A. plicata and characterized by GC, HPLC, UV-spectrum, and FI-IR to understand its composition and structure. It was the first time to comprehensively study the agar and its fractions from the red alga of A. plicata. This research provided an eco-friendly agar extraction method from A. plicata and revealed its potential application for the production of agar, agarose, and agaropectin.

Enzymatic saccharification of seaweeds into fermentable sugars by xylanase from marine Bacillus sp. strain BT21.

Enzymatic hydrolysis of seaweed biomass was studied using xylanase produced from marine bacteria Bacillus sp. strain BT21 through solid-state fermentation of wheat bran. Three types of seaweeds, Ahnfeltia plicata, Padina tetrastromatica and Ulva lactuca, were selected as representatives of red, brown, and green seaweeds, respectively. Seaweed biomass was pretreated with hot water. The efficiency of pretreated biomass to release reducing sugar by the action of xylanase as well as the type of monosaccharide released during enzyme saccharification of seaweed biomass was studied. It was seen that pretreated biomass of seaweed A. plicata, U. lactuca, and P. tetrastroma, at 121°C for 45min, followed by incubation with 50IU xylanase released reducing sugars of 233±5.3, 100±6.1 and 73.3±4.1µg/mg of seaweed biomass, respectively. Gas chromatography analysis illustrated the release of xylose, glucose, and mannose during the treatment process. Hot water pre-treatment process enhanced enzymatic conversion of biomass into sugars. This study revealed the important role of xylanase in saccharification of seaweed, a promising feedstock for third-generation bioethanol production.

MORPHOLOGICAL ANATOMICAL AND PHITOCHEMICAL CHARACTERISTICS OF SOME ALGAE

Morphological and anatomical features of thalluses of brown (Laminaria saccharina, Fucus vesiculosus) and red (Ahnfeltia plicata) algae, procured at a coastal strip of the Northern basin in gulfs of Ura-Guba and Palkina-Guba at different depths. Compliance of Fucus and Ahnfeltia with pharmacopoeial norms and merchandising indices for Laminaria was established, except for high concentration of sand in Ahnfeltia thalluses. The identity of algae between each other was shown based on the results of qualitative analysis on polysaccharides, alginic acids, reducing sugars, iodine, mannitol, amino acids presence. Quantitative content of polysaccharides, alginic acids, reducing sugars, pentosans, iodine, cellulose, mannitol, proteins, lipids, agar was determined. In comparison with Fucus and Ahnfeltia higher concentration of the following content was noted in Laminaria: alginic acids (1.4 and 5.75 times higher), polysaccharides (1.3 and 1.4 times), iodine (4.5 and 1.8 times), mannatol (1.5 and 2.5 times) (data received is statistically reliable). Impropriety of storm algae for processing was shown as law quality raw material. The highest concentration of active substances was revealed in Laminaria thalluses which were procured at the depth of 10 m in a period from September to October. Active accumulation of sodium, potassium, calcium, iron, magnesium, manganese corresponding to similar sea water composition was established in algae. Mathematical equations of regression between protein and manganese, protein and iron content in algae were deduced. Under proper conditions of drying and storage high quality of the materials can be preserved during 3 years. Based on the findings of photochemical researches, taking into account squares of plantations and possible exploitation stocks, the possibility and prospectivity of industrial processing of Fucus vesiculosus and Ahnfeltia plicata together with Laminaria saccharina as plant sources of polysaccharides (mainly alginates) was proved.

Sulfation of agarose from subantarctic Ahnfeltia plicata (Ahnfeltiales, Rhodophyta): studies of its antioxidant and anticoagulant properties in vitro and its copolymerization with acrylamide

Aqueous extraction of Ahnfeltia plicata collected in the Magellan ecoregion afforded agarose devoid of sulfate groups. This neutral agarose was subjected to sulfation with SO3-pyridine complex, giving an aqueous soluble derivative with 35.5 % sulfate groups. Analysis by Fourier transform infrared spectroscopy (FT-IR) and by 1H and 13C NMR spectroscopy indicated that this derivative was sulfated at positions C-6 of the β-galactopyranosyl residue and C-2 of the α-3,6-anhydrogalactopyranosyl residue and partially sulfated at position C-2 of the β residue. The antioxidant capacity of sulfated agarose was evaluated by the oxygen radical absorbance capacity (ORAC) method, ABTS radical cation, hydroxyl radicals, and chelating assays. This capacity of sulfated agarose toward peroxyl radicals was higher than that of commercial λ-carrageenan, while native agarose presented good activity, with an ORAC value similar to that of commercial κ-carrageenan. Sulfated agarose presented good antioxidant capacity toward other radicals. Copolymerization of sulfated agarose with acrylamide was achieved using ceric ammonium nitrate as initiator. NMR spectroscopy indicated grafting of polyacrylamide at position C-4 of β-galactopyranosyl residues.

Growth responses to temperature, salinity and nutrient variations, and biomass variation and phenology of Ahnfeltia plicata (Rhodophyta, Ahnfeltiales): a commercially interesting agarophyte from the Magellanic Region, Chile

Ahnfeltia plicata (Hudson) E.M. Fries (Rhodophyta, Ahnfeltiales) is one of the most commercially important agarophytes in the world for its production of agar that is high quality and low in sulfate content. In the Magellanic Region, A. plicata forms extensive beds with high biomass production, which could be commercially exploited for agar production. The purposes of this study were to determine the optimal conditions of temperature, salinity, and culture medium; to evaluate the effects of different types and concentrations of auxins and cytokinins on growth of red and yellow gameto- phytes; and to provide background information on ecological parameters of natural population of A. plicata .T emperatures of 5, 8, 15, and 23 °C were tested, and the interaction of salinity of 25 and 35 psu with Provasoli enriched medium in half (PES/2) and quarter strength (PES/4), and with von Stosch enriched medium in half (VSES/2) and quarter strength (VSES/4) was also conducted. Concentrations of 5.0 and 50.0 μ Mo f two auxins (indole-3-acetic acid (IAA), 2,4-dichlorophenoxyacetic acid (2,4-D)), and two cytokinins (isopentenyladenine (iP) and benzylaminopurine) were added to VSES medium and gelled with 0.5 % agar. Each treatment was tested with three replicates. Red gametophytes of A. plicata tolerate a range of temperature variation, from 5 to 23 °C, and the optimum temperature for growth was 15 °C. The highest growth rate was observed in salinity of 35 psu with half strength of von Stosch culture medium. Red and yellow gametophytes showed different re- sponses to plant growth regulators, and red gametophytes were more sensitive than yellow ones to the addition of IAA and high concentration of iP. However, growth of red gametophytes of A. plicata was stimulated by 2,4-D. The differential sensitivity of red and yellow gametophytes to plant growth regulators sug- gests the need to test other types and concentrations of auxins and cytokinins.

Current knowledge on biotechnological interesting seaweeds from the Magellan Region, Chile

This paper is a compilation of data from investigations made with marine benthic algae from the Magellan Region that have biotechnological utilization in human consumption or medicine or as a source of phycolloids or food supplements or animal feed. The most important Rhodophyta species are: Ahnfeltia plicata (Hudson) E.M. Fries for agarose production, Gigartina skottsbergii Setchell & N.L.Gardner for carrageenan production, and Callophyllis variegata (Bory de Saint-Vincent) Kützing for human consumption. The most important Heterokontophyta species are: Macrocystis pyrifera (L.) C. Agardh, and Durvillaea antarctica (Chamisso) Hariot for human consumption, alginate production, and as biofertilizer for agricultural crops. M. pyrifera is also used as a food supplement for salmon, chickens, quails, sheep and bovines and for biofuel production.

DNA barcoding of Canadian Ahnfeltiales (Rhodophyta) reveals a new species – Ahnfeltia borealis sp. nov.

Milstein D. and Saunders G.W. 2012. DNA barcoding of Canadian Ahnfeltiales (Rhodophyta) reveals a new species – Ahnfeltia borealis sp. nov. Phycologia 51: 247–259. DOI: 10.2216/11-40.1The red algal genus Ahnfeltia has only two described species in Canada, Ahnfeltia fastigiata and Ahnfeltia plicata, occurring along the North Pacific and North Atlantic coasts, respectively. However, during an ongoing molecular-based floristic survey of Canadian marine algae using the mitochondrial 5′ end of the cytochrome c oxidase I gene as a screening tool, cryptic diversity was uncovered, indicating the presence of four genetic lineages. These genetic clusters were further characterized using the nuclear ribosomal internal transcribed spacers and the variable domain V of the plastid large subunit (23S) ribosomal gene (universal plastid amplicon), as well as morphological and anatomical observations. Our data indicate the presence of a third species of Ahnfeltia, A. borealis sp. nov., which is typically subarctic in its distribution and intermediate in many key anatomical features between A. fastigiata and A. plicata.

From thallus to communities: scale effects and photosynthetic performance in macroalgae communities

Experiments on aquatic plant photosynthesis are often performed on spatial scales much smaller than natural systems. The photosynthesis-irradiance relationship (P-I curve) depends, however, on whether photosynthesis is measured on leaves, shoots, plants or entire communities, so that results cannot be reliably extrapolated from the limited spatial scale of experiments to the larger scale of natural systems. To evaluate how the photosynthetic response changes with spatial scale for aquatic plants, we measured the photosynthetic production as a function of irradiance for thallus pieces, single-species and multi-species communities of 4 different marine algae (Fucus serratus, Chordaria flagelliformis, Enteromorpha sp. and Ahnfeltia plicata). Thallus pieces followed the well- known hyperbolic shape of P-I curves; that is, the community P-I curves approached linearity. Thal- lus pieces, thus, saturated at irradiances below 160 µmol photons m -2 s -1 , while the communities started to saturate at values 4 times higher and never became fully saturated even at 1750 µmol pho- tons m -2 s -1 . This increasing linearisation of the P-I relationship for communities influenced the pho- tosynthetic parameters, as maximum gross photosynthesis and compensation irradiances increased 3 to 8 times. The increasing linearisation of the P-I curves is attributed to the 3-dimensional structure of the communities, since communities with a low extinction per unit leaf area, and thus an even dis- tribution of irradiance among thallus parts, used their potential photosynthesis capacity more effi- ciently. Although not significantly different, multi-species communities had a slightly more linear response and a higher gross photosynthesis than single-species communities, suggesting a more effi- cient distribution and photosynthetic use of light among the photosynthetic tissue. An increase in spatial scale from thallus pieces to communities decreased variation in photosynthetic rates between species, implying that differences between species are much smaller on natural scales than experi- ments on single thallus pieces suggest. The findings imply that experiments on the thallus scale should be avoided or treated with caution when predicting the ecological performance of plants in their natural habitat.

Red algal farming in Chile: a review

Production of seaweeds in Chile has fluctuated between 74,000 and 322,000 wet metric tons/year during the last 14 years, involving different species of Phaeophyta and Rhodophyta. Among Rhodophyta, the most important harvested species include the carrageenophytes Sarcothalia crispata, Mazzaella laminarioides, Gigartina skottsbergii, Chondracanthus chamissoi, and the agarophytes Gracilaria chilensis and Gelidium lingulatum. Other less important taxa are Gel. rex, M. membranacea, Ahnfeltia plicata, Ahnfeltiopsis furcellata, Porphyra columbina, Callophyllis variegata, Mastocarpus papillatus and Chondrus canaliculatus. Chilean production comes mainly from wild stocks, as at present, cultivation on a commercial scale is restricted to Gra. chilensis. Total landings of Gracilaria currently stand at 120,000 wet tons. Large-scale cultivated biomass of this species, on the other hand, has been the result of a sharp increase in the number of farms, from less than 10 in 1982 to almost 322 in 1996. A basic understanding of key biological and ecophysiological aspects, as well as the availability of propagation methods, permitted the development of large-scale Gracilaria farming operations. However, during the cultivation process, new problems arose for the farmers, such as abrupt production decline, pests and pathogens. Similar key knowledge is lacking for other Chilean Rhodophyta, which creates a bottleneck that prevents the development of seaweed farming activities other than Gracilaria. This situation prevails in spite of the growing pressure on wild stocks triggered by an increase in the demand for raw material by the industry, with the obvious danger of over-exploitation and the resulting collapse of fisheries. Taking the above into consideration, an effort has been made in recent years to provide the basic knowledge necessary for the management and cultivation of some of the most valuable seaweed resources in Chile. Thus, the main objective of this contribution is to summarize the present situation of red seaweed cultivation in the country. We will address this issue by reviewing the landing statistics of these resources, followed by a summary of recent information that favours cultivation. These include propagation methods, culture conditions and techniques, product quality, pest management, strain selection and the diversification of seaweeds currently exploited in Chile.

Species diversity and distribution of aquatic macrophytes in the Northern Quark, Baltic Sea

The occurrence of aquatic macrophytes was studied in a northern transition area of the Baltic Sea; the Northern Quark, Gulf of Bothnia. In the area there is a gradual, marked change in environmental conditions, the most prominent of which is a decrease in salinity from 5.0% in the Bothnian Sea to 3.5% in the Bothnian Bay. In all, 40 species of macrophytes were observed; 10 fucophyceans, 10 bangiophyceans, 8 chlorophyceans, 3 charophyceans, 1 tribophycean, 1 nostocophycean, 6 phanerogams and 1 water moss. 26 of the observed species were of marine and 14 of lacustrine origin. There was a clear change in species composition and community structure from south to north over the area. The vegetation at the southernmost localities had a marine character, with belt‐forming Fucus vesiculosus and a comparatively diverse flora of macroalgae. Further north, an ephemeral, lacustrine vegetation dominated by benthic diatoms and Cladophora aegagropila prevailed. The ratio marine: lacustrine species decreased from 4.2 to 1 when comparing a southern and a northern sub‐area of the Northern Quark. The species observed include 57 % of the marine macrophytes noted in the Aland and Archipelago Seas (N Baltic Proper) during the past two decades. Two marine species, Aglaothamnion roseum and Ahnfeltia plicata, are reported for the first time from the Northern Quark. This comprises a northern extension of their distribution limit with approximately 300 km.

INFRAGENERIC TAXONOMY OF AHNFELTIA (AHNFELTIALES, RHODOPHYTA)1

ABSTRACTAhnfeltia plicata (Hudson) Fries, the type species of Ahnfeltia Fries, is reported to be a widespread alga which is an important source of agar. However, after characterizing type material and representative populations of A. plicata, we found that several taxa usually considered to be synonyms of A. plicata instead represent separate species with differing geographic distributions. Ahnfeltia plicata sensu stricto is characterized by the development of external carposporophytes on female sori that are present only on mature axes. Pseudocarposporophytes bearing monosporangia and cortical monosporangial sori occur on both young and old axes. Characteristic vegetative features include long medullary cells and cortical growth rings. Ahnfeltia plicata s.s. is circumpolar in both hemispheres and is harvested for agar in the White Sea. Ahnfeltia setacea (Kútzing) Schmitz from the Falkland Islands, Gymnogongrus comosus Kützing from Chile and Gymnogongrus filiformis Kützing from southern Argentina appear to be synonymous with A. plicata. Ahnfeltia fastigiata (Postels et Ruprecht) Makienko, from the North Pacific, differs from A. plicata principally in the development of female sori and carposporophytes only near apices; medullary cells are shorter and cortical growth rings, cortical monosporangia and pseudocarposporophytes are not formed. It is dioecious and its life history involves the development from carpospores of a crustose Porphyrodiscus tetrasporophyte. We suggest that A. plicata var. tobuchiensis Kanno et Matsubara, the principal form of Ahnfeltia utilized for agar production in the North Pacific, represents an unattached ecad of A. fastigiata. Ahnfeltia elongata Montagne, known only from Chile and with carposporophytes restricted to main axes, is more closely related to A. plicata than to A. fastigiata. Thalli are large and regularly dichotomous, with long medullary cells, and do not form pseudocarposporophytes or monosporangia.

TEMPERATURE TOLERANCE OF NORTHEAST PACIFIC MARINE ALGAE1

ABSTRACTTemperature tolerance (1 week exposure time) was investigated in 49 species of benthic marine macroalgae and two seagrass species from San Juan Island (Washington) or Vancouver Island, British Columbia. Positive net photosynthesis was the parameter used to detect survival. Most algal species survived ‐1.5° C (the lowest applied temperature), and none 30° C. The most heat‐tolerant, eurythermal algal species survived 28° C: these were Ahnfeltia plicata, Mastocarpus papillatus (as crustose tetrasporophyte), Endocladia muricata, and Sargassum muticum. In contrast, most representatives of the Laminariales exhibited a cold‐stenothermic character: Cymathere triplicata, Pleurophycus gardneri, Hedophyllum sessile, Postelsia palmaeformis survived up to only 15° C, and Laminaria saccharina, L. groenlandica, L. setchellii to 18° C. As to the seagrass species, Zostera marina survived a temperature range of ‐ 1.5 to 30° C and Phyllospadix scouleri a range of ‐ 1.5 to 25° C. For many of the sublittoral species there was agreement between maximum survived temperatures in our experiments and average maxima of summer temperatures at the southern geographical limits of the species. Specimens of four species exhibited upper survival limits similar to those of conspecifics in the North Atlantic; namely, Desmarestia ‘aculeata, D. viridis, Plocamium cartilagineum, and Ahnfeltia plicata. These results favor the interpretation of upper temperature survival limits as conservative taxonomic traits.

Photosynthesis and respiration in the alga Ahnfeltia plicata in a flow-through system

Photosynthesis and respiration in Ahnfeltia plicata (Huds.) Fries (Gigartinales) was measured in a seawater flowthrough system at different temperatures, salinities and photon flux densities (PFD). The exchanges of dissolved oxygen and inorganic carbon were continuously recorded with an oxygen probe and a pH electrode measuring variation in CO2−HCO3-equilibrium as pH changes. Highest apparent photosynthesis at moderate photon flux density (PFD 50 μE m-2 s-1) was found at 15°C and 33‰ S. Photosynthesis was measured up to PFD 500 μE m-2 s-1 and no light saturation was documented. In the present experimental set-up, with continuous supply of fresh seawater, the number of limiting factors during photosynthesis measurements is reduced.

Growth studies of macroalgae in a microcomputer-assisted spray cultivation system

Apical growth rates of Furcellaria lumbricalis (Huds.) Lamour. and Ahnfeltia plicata (Huds.) Fries (Gigartinales: Rhodophyceae), and Ascophyllum nodosum (L.) Le Jol. (Fucales: Phaeophyceae), were studied in spray culture, applying independent microcomputer systems for control, data-logging, and apical growth measurements. The system functioned with a minimum of maintenance. Sea-water temperature and light seemed to be more important for growth than nutrient supply under the prevailing conditions. Basal shoots (young, undivided parts of the plants close to the holdfast) of Furcellaria lumbricalis had growth rates three times higher than the apices (apical meristem on the distal end of mature plants) from the older parts of the thallus. For Ascophyllum nodosum apical growth rates of basal shoots, divided and undivided apices were similar. Whereas apical growth rate of A. nodosum was normal, the biomass yield was low. A. nodosum cultivated simultaneously in tanks and in continuous spray had similar growth rates. The spray cultivation technique facilitated control of the experimental conditions, and handling of the plants during the experimental work while excluding epiphytes.

La structure hildenbrandioïde, stratégie adaptative chez les Floridées

The structure of the encrusting thallus of Hildenbrandia prototypus shows a type of organization quite similar to that found in the basal crust of a certain number of erect Rhodophyta (Grateloupia filicina, Dermocorynus montagnei, Ahnfeltia plicata). This similarity appears markedly in the cytophysiological features such as the small cell size, the thickness of the cell wall, the type of the cytoplasmic inclusions and the cell arrangement. All these similarities seem to reflect an adaptational strategy.

The sporophyte of Ahnfeltia plicata (Huds.) Fries (Rhodophyceae, Gigartinales) in culture

A discoid tetrasphorophyte is involved in the life history of Ahnfeltia plicata (Huds.) Fries in culture. Monospores, discharged from nemathecia on upright plants collected from nature, gave rise to a crustose tetrasporic phase, producing zonate tetraspores in hemispherical nemathecia. Anatomical features of this crustose stage are similar to Porphyrodiscus simulans Batters. Released tetraspores, in turn, formed a disc from which the typical Ahnfeltia upright frond developed.

The occurrence and seasonal variation of gigartinine and L-citrullinyl-L-arginine in Chondrus crispus Stackh.

Gigartinine, 5-(3-amidinoureido)-2-aminovaleric acid, and L-citrullinyl-L-arginine were islated from aqueous extracts of Chondrus crispus (Rhodophyceae). Their identifications were confirmed by chemical procedures, and 1H and 13C nuclear magnetic resonance and infrared spectroscopic methods. Citrullinylarginine, gigartinine, taurine, citrulline, and glutamic acid were the predominant free amino compounds. Citrullinylarginine showed the most pronounced change in concentration. This occurred during the winter months when it reached a maximum (in March) of 58 mumol/g fresh weight, a value 10 times greater than that of any of the free amino acids and equal to 50% of the total organic nitrogen in the plant; All of these compounds were depleted to a minimum of about 1 mumol/g fresh weight in October. Both gigartinine and citrullinylarginine were detected in Ahnfeltia plicata, Gracilaria sp. Petrocelis middendorfii, Polyides rotundus, Polysiphonia lanosa, and Rhodomela confervoides.