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Background: The marine red alga Plocamium naturally produces halogenated monoterpenes with varied biological activities. In our continuing efforts to discover new lead compounds for the treatment of HIV/AIDS as well as novel antibacterial compounds, various Namibian Plocamium species have been investigated. Methods: A rare but known compound namely 1E,3R,4S,5E,7Z-1-bromo-3,4,8-trichloro-7- (dichloromethyl)-3-methylocta-1,5,7-triene (1) was isolated from a Namibian Plocamium red alga. The anti-HIV activity of compound 1 was investigated against three HIV enzymes namely, HIV protease, reverse transcriptase and integrase. In addition, compound 1 was also screened for antibacterial activity against selected microbes using the disc diffusion method. Results: Compound 1 demonstrated selective in vitro inhibition against HIV-1 integrase with a 50% inhibition concentration of Conclusion: The results of this study highlight the potential of halogenated monoterpenes from red seaweed as possible leads in the development of new anti-HIV and antimicrobial pharmaceuticals.

Molecular analyses have indicated that several Australian taxa previously identified as the red alga Plocamium cartilagineum do not group with that species as known from its northern hemisphere type locality. One of these species-level genetic groups corresponds precisely with Plocamium pusillum, a species described by Sonder in 1845 based on Preiss specimens from south-western Australia, but regarded as a heterotypic synonym of P. cartilagineum in recent morphology-based treatments. A specimen of P. pusillum in the Melbourne Herbarium (MEL) has been examined and designated as lectotype; its morphology agrees with recently collected specimens included in molecular analyses and is clearly shown to differ from authentic P. cartilagineum. Plocamium pusillum is therefore resurrected and is characterized genetically and morphologically.

The common Antarctic red alga Plocamium sp. is rich in halogenated monoterpenes with known anticancer and antimicrobial properties and extracts of Plocamium sp. have strong ecological activity in deterring feeding by sympatric herbivores. Plocamium sp. collected near Anvers Island, Antarctica showed a high degree of secondary metabolite diversity between separate individuals. GC/MS results revealed 15 different combinations of metabolites (chemogroups) across individuals, which were apparent at 50% or greater Bray–Curtis similarity and also clearly distinguishable by eye when comparing chromatographic profiles of the secondary metabolomes. Sequencing of the mitochondrial cox1 gene revealed six distinct haplotypes, of which the most common two had been previously reported (now referred to as Haplotypes 1 and 2). With the exception of one individual, three of the chemogroups were only produced by individuals in Haplotype 1. All the other 12 chemogroups were produced by individuals in Haplotype 2, with five of these chemogroups also present in one of the four new, less common haplotypes that only differed from Haplotype 2 by one base pair. The functional relevance of this metabolomic and genetic diversity is unknown, but they could have important ecological and evolutionary ramifications, thus potentially providing a foundation for differential selection.

Laboratory studies that test the responses of coastal organisms to ocean acidification (OA) typically use constant pH regimes which do not reflect coastal systems, such as seaweed beds, where pH fluctuates on diel cycles. Seaweeds that use CO2 as their sole inorganic carbon source (non-carbon dioxide concentrating mechanism species) are predicted to benefit from OA as concentrations of dissolved CO2 increase, yet this prediction has rarely been tested, and no studies have tested the effect of pH fluctuations on non-CCM seaweeds. We conducted a laboratory experiment in which two ecologically dominant non-CCM red seaweeds (Callophyllis lambertii and Plocamium dilatatum) were exposed to four pH treatments: two static, pHT 8.0 and 7.7 and two fluctuating, pHT 8.0 ± 0.3 and 7.7 ± 0.3. Fluctuating pH reduced growth and net photosynthesis in C. lambertii, while P. dilatatum was unaffected. OA did not benefit P. dilatatum, while C. lambertii displayed elevated net photosynthetic rates. We provide evidence that carbon uptake strategy alone cannot be used as a predictor of seaweed responses to OA and highlight the importance of species-specific sensitivity to [H+]. We also emphasize the importance of including realistic pH fluctuations in experimental studies on coastal organisms.

The endemic South African red seaweed Plocamium maxillosum (Poiret) Lamouroux produces two unusual isomeric dichlorinated cyclohexenone monoterpenes, plaxenone A and B (1 and 2). The structures of the isolated compounds were determined from spectroscopic data and their absolute configuration was determined by comparison of the experimental and calculated ECD spectra. Compounds 1 and 2 inhibit the growth of MDA-MB-231 breast cancer cells.

International audience; Plocamium Lamouroux is a widespread genus for which 45 species are currently recognized. However, classical taxonomy based only on morphological characters, is problematic within this genus. The use of molecular tools has uncovered cryptic genetic species, mistakenly grouped under the name of mor-phological species that are common and widespread (including the generitype Plocamium cartilagineum (Linnaeus) P.S.Dixon). The aim of this work was to evaluate the species diversity of Plocamium in Southern Chile. For this purpose, three independent molecular markers were sequenced in samples collected from seven populations located between 41°S and 54°S. The species diversity was evaluated using phylogenetic reconstructions and two independent methods for species delimitation (ABGD and GMYC). The outcomes of each method were congruent, suggesting the presence of three species in Southern Chile. One species, named Plocamium sp. 1, is restricted to Punta Guabún, the only locality sampled north of the biogeographic barrier of the 42°S. The other two species, Plocamium sp. 2 and 3 are distributed in sympatry in Patagonia and Tierra del Fuego. The three Chilean species form a clade phylogenetically close to sequences obtained from New Zealand and Australia and a divergence along the coasts of Chile after past transoceanic dispersal is proposed. We propose that divergence in glacial microrefugia could have subsequently happen in the southern part of the coast, this hypothesis being supported by the strong impact of glacial maxima on population dynamics, especially in Plocamium sp. 3; es données moléculaires révèlent la présence de trois espèces de Plocamium Lamouroux présentant un patron de distribution complexe dans le sud du Chili. Quarante-cinq espèces sont actuellement reconnues dans le genre Plocamium Lamouroux, un genre présentant une très ample distribution. Cependant, la taxonomie classique, basée uniquement sur les caractères morphologiques, est problématique au sein de ce genre. L’utilisation d’outils moléculaires a permis de révéler l’existence d’espèces génétiques cryptiques, groupées par erreur sous un même nom, celui d’espèces morphologiques courantes et répandues (y compris l’espèce type du genre Plocamium : Plocamium cartilagineum (Linnaeus) P.S.Dixon)). L’objectif de notre travail était d’évaluer la diversité d’espèces de Plocamium dans le sud du Chili. À cet effet, trois marqueurs moléculaires indépendants ont été séquencés pour des échantillons prélevés dans sept populations situées entre 41°S et 54°S. La diversité en terme d’espèces a été évaluée à l’aide de reconstructions phylogénétiques et de deux méthodes indépendantes de délimitation d’espèces génétiques (ABGD et GMYC). Les résultats des différentes méthodes sont congruents, suggérant la présence de trois espèces dans le sud du Chili. Une espèce, nommée Plocamium sp. 1, est limitée à Punta Guabún, la seule localité échantillonnée au nord de la barrière biogéographique du 42°S. Les deux autres espèces, Plocamium sp. 2 et 3 sont distribuées en sympatrie en Patagonie et en Terre de Feu. Les trois espèces chiliennes forment un clade phylogénétiquement proche de séquences obtenues en Nouvelle-Zélande et en Australie et une divergence le long des côtes du Chili après un évènement historique de dispersion transocéanique passée pourrait expliquer ce résultat. Nous proposons des phénomènes postérieurs de divergence en micro-refuges glaciaires comme moteur de la spéciation en Patagonie et en Terre de Feu. Cette hypothèse est étayée par le fort impact des maxima glaciaires sur la dynamique des populations, en particulier dans le cas de Plocamium sp. 3.

MHC-1 is a halogenated natural product (HNP) produced by the red seaweed Plocamium cartilagineum. MHC-1 concentrations of 550–2700 μg/g dry weight were found in Plocamium collected by divers at Heligoland (Germany). Compared to that MHC-1 concentrations were much lower in samples collected on beaches in Ireland and Portugal. Exposure of leaves of Plocamium to sunlight showed that MHC-1 was readily transformed by hydrodebromination. At Heligoland in March, MHC-1 (δ13C value −45.2‰) was lighter in carbon by ~15‰ compared to the bulk δ13C value (‰) of Plocamium (−30.7‰). Collected at the same time and location at Heligoland, samples of Halichondria and Mastocarpus sp. were richer in carbon (by ~10‰) as Plocamium. However, the δ13C value of MHC-1 in Halichondria (−44.6‰) and Mastocarpus sp. (−42.1‰) was as negative as in Plocamium. This was indirect proof that MHC-1 was produced by Plocamium and then released into the water phase from where it then was bioconcentrated by Halichondria and Mastocarpus sp. In agreement with that, concentrations of MHC-1 in Halichondria and Mastocarpus sp. were much lower than in Plocamium. In addition, a potential isomer of MHC-1 (compound X) was detected in all samples from Heligoland at ~2% of the MHC-1 level.

The aim of this study was to determine suitable extraction solvents for antimicrobial compounds and the antimicrobial activity of two algal species, Plocamium cornutum and Plocamium rigidum collected from the coastline of Namibia. Samples were collected at low tide from the intertidal area of the coastline at Luderitz and Henties Bay. The samples were collected about 5 to 10 cm under water by hand and placed in a sealable polythene bag and refrigerated at -20°C. Dried algae extracts were reconstituted in distilled water, hexane, dichloromethane, ethanol, methanol and chloroform, respectively and tested in vitro for antimicrobial activity using the Kirby Bauer disc diffusion method against 12 pathogens (Escherichia coli, Staphylococcus aureus, Staphylococcus saprophyticus, Pseudomonas aeruginosa, Streptococcus pyogenes, Proteus mirabilis, Listeria monocytogenes, Shigella sonnei, Salmonella species, Enterococcus faecalis, Candida albicans and Staphylococcus epidermidis). Screening confirmed that water extracts showed no activity against all the pathogens as the extracts were insoluble in water. The Plocamium extracts in the remaining solvents showed varying degrees of antimicrobial activity. Both dichloromethane and methanol extracts reconstituted in chloroform showed the greatest activity amongst the five different solvents that were used. Ampicillin (10 µg/ml) showed no antimicrobial activity against S. epidermidis whilst a zone of inhibition of 6.26±0.07 mm was recorded for 10 µg/ml of P. cornutum extract reconstituted in chloroform. An ethanolic extract of P. rigidum showed a zone of inhibition of 6.35±0.25 mm against L. monocytogenes while the standard ampicillin had no activity. Extracts of P. rigidum in ethanol and P. cornutum in chloroform are evidently potential lead candidate antibiotics in vitro against L. monocytogenes and S. epidermidis, respectively. Key words: Antimicrobial activity, Plocamium cornutum, Plocamium rigidum, Listeria monocytogenes.

The antioxidant potential of various marine natural products is well documented. The aim of this study was to evaluate the antioxidant potential of a rare halogenated monoterpene, namely; 1E,3R,4S,5E,7Z-1-bromo-3,4,8-trichloro-7-(dichloromethyl)-3-methylocta-1,5,7-triene (1) for the first time. This compound was isolated from a Namibian red algal Plocamium species. The antioxidant activity of the compound was evaluated using a series of antioxidant assays, namely; 2,2-diphenyl-1-picryl-hydrazyl radical (DPPH), reducing power, nitric oxide (NO) and hydrogen peroxide (H2O2). The compound demonstrated remarkable DPPH, NO and H2O2 scavenging activities with IC50 values of 0.05 ± 0.01, 4.18 ± 0.22 and 5.58 ± 1.11 mM, respectively. The reducing power of the compound increased with an increase in concentration. These results were compared to the absorbance of ascorbic acid, which was used as a standard control in all the antioxidant assays. The results strongly suggest that compound 1 is a promising antioxidant agent with potential commercial applications.

Red algae of the genus Plocamium have been a rich source of halogenated monoterpenes. Herein, a new cyclic monoterpene, costatone C (7), was isolated from the extract of P. angustum collected in New Zealand, along with the previously reported (1E,5Z)-1,6-dichloro-2-methylhepta-1,5-dien-3-ol (8). Elucidation of the planar structure of 7 was achieved through conventional NMR and (&minus, )-HR-APCI-MS techniques, and the absolute configuration by comparison of experimental and DFT-calculated ECD spectra. The absolute configuration of 8 was determined using Mosher&rsquo, s method. Compound 7 showed mild antibacterial activity against Staphylococcus aureus and S. epidermidis. The state of Plocamium taxonomy and its implications upon natural product distributions, especially across samples from specimens collected in different countries, is also discussed.

The genus Plocamium encompasses seaweeds that are widely distributed throughout the world’s oceans, with Plocamium brasiliense found along the tropical and subtropical coasts of the Western Atlantic. This wide distribution can lead to structured populations due to environmental differences (e.g., light levels or temperature), restricted gene flow, and the presence of cryptic species. Abiotic variation can also affect gene expression, which consequently leads to differences in the seaweeds protein profile. This study aimed to analyze the genetic and proteomic profiles of P. brasiliense sampled in two geographically distinct sites on the coastline of Rio de Janeiro state, Brazil: Arraial do Cabo (P1) and Búzios (P2). The genetic profiles of macroalgal specimens from these two sites were indistinguishable as assessed by the markers UPA/23S, rbcL, and COI-5P; however, the protein profiles varied significantly between populations from the two sites. At both sites the ribulose-1,5-biphosphate carboxylase/oxygenase was the most abundant protein found in P. brasiliense specimens. The number of phycobiliproteins differed between both sites with the highest numbers being found at P1, possibly due to water depth. The differences in proteomic profiles of the two nearly identical populations of P. brasiliense suggest that environmental parameters such as light availability and desiccation might induce distinct protein expression, probably as a result of the phenotypic plasticity within this population of seaweed.

As a result of our efforts to identify bioactive agents from marine algae, we have isolated and identified one new halogenated monoterpene 1 [(-)-(5E,7Z)-348-trichloro-7-dichloromethyl-3-methyl-157-octatriene] in addition to three known compounds (2, 3 and 4) from the red alga Plocamium cartilagineum collected by hand from the eastern coast of South Africa. Compound 1 was found to be active as a cytotoxic agent in human lung cancer (NCI-H460) and mouse neuro-2a cell lines (IC50 4 μg/mL). Two of these compounds (3 and 4) were found to have cytotoxic activity in other cell line assays, especially against human leukaemia and human colon cancers (IC50 1.3 μg/mL). None of these metabolites were active as sodium channel blockers or activators. All structures were determined by spectroscopic methods (UV, IR, LRMS, HRMS, 1D NMR and 2D NMR). 1D and 2D NOE experiments were carried out on these compounds to confirm the geometry of the double bonds.

Dye sensitized solar cells assembled using red dyes extracted from Antarctic algae were evaluated. Among all collected algae, the best performances were showed with samples coming from Plocamium hookeri , Delesseria lancifolia and Iridaea obovata . Cells were evaluated using conventional electrochemical techniques and electrochemical impedance spectroscopy. The measured conversion efficiency was lower than 0.04%, using solar simulator with a power of 1 sun, 1.5 AM.

Through the current trend for bioprospecting, marine organisms - particularly algae - are becoming increasingly known for their osteogenic potential. Such organisms may provide novel treatment options for osteoporosis and other musculoskeletal conditions, helping to address their large healthcare burden and the limitations of current therapies. In this study, extracts from two red algae – Plocamium lyngbyanum and Ceramium secundatum – were tested in vitro and in vivo for their osteogenic potential. In vitro, the growth of human bone marrow stromal cells (hBMSCs) was significantly greater in the presence of the extracts, particularly with P. lyngbyanum treatment. Osteogenic differentiation was promoted more by C. secundatum (70 µg/ml), though P. lyngbyanum had greater in vitro mineralisation potential. Both species caused a marked and dose-dependent increase in the opercular bone area of zebrafish larvae. Our findings therefore indicate the presence of bioactive components in P. lyngbyanum and C. secundatum extracts, which can promote both in vitro and in vivo osteogenic activity.

The current trend for scientific research is moving towards the production of materials and natural food products to keep overall health of individuals so this research shows methods of extracting natural dyes from green algae (Ulva lactuca L) and red algae ( Plocamium cartilegineum ) & Gelidium sp, and used as colorants and preservatives in processed foods as an alternative to the industrial colors, and as a result they contain antioxidant materials at high is used as a preservative for foods. This study showed that pigments which extracted from green algae her best solvent (acetone aqueous 80%) at wavelength (450 nm ) with an average (.6090 ), followed by ( DMF 100% + Nitrogen liquid ) degree ( -196 ) under zero , when the wavelength (450 nm ), average (.631 ) and be algae in the form of dried, the other side red algae best solvent for the extraction of pigment (Distilled water) to get the red pigment, but to get the green from red algae score the best solvent (DMF 100% + Nitrogen) at the wavelength (450 nm ) average (1.335 ) , followed by ( M.A ) at the same wavelength with an average ( .988 ). The algae are processed before preparing for the extraction of the dye (soak and rinse grinding and sonication of the cells and tissues). The drying process for green was the best and freezing process red is the best Extracting the dye from algae . Been employed in the production of dyes pomegranate jelly from fruit kiwi. Because it is a treasure trove of natural dyes and carotenoids, vitamins and unsaturated fatty acids, protein and dietary fiber. That will affect positively on the overall health of individuals helps clearly to treat (obesity _ diabetes _ osteoporosis _ increase immunity and prevention of cancer ..... etc. all from algae ). Keywords: Microalgae , Seaweeds , Ulva lactuca , Plocamium , Photopigments , solvents, extraction method , Chlorophyll , Carotene .

The family of polyhalogenated monoterpenes from Plocamium counts over a hundred known members. Using glyceraldehyde acetonide as a chiral pool precursor, an enantioselective and divergent strategy was developed that provides a blueprint for the synthesis of many of the small yet complex acyclic members of this family. The broad applicability of this approach is demonstrated with the short (eight-step) synthesis of four natural products and three analogues. These syntheses are the first of any members of the acyclic polyhalogenated Plocamium monoterpenes, and permitted the evaluation of their selectivity against a range of tumor cell lines.

This work presents a taxonomic, floristic and chorological account of the most representative turf-forming species from sand-covered rocks along the Atlantic Iberian Peninsula, including in this Part 2 species belonging to six orders of the Rhodophyta and one of the Phaeophyceae. For each species are provided morphological descriptions, distribution maps, and/or COI-5P sequences, as well as taxonomic notes. The species studied are: Rhodothamniella floridula, Ceramium ciliatum, Erythroglossum lusitanicum, Hypoglossum hypoglossoides, Ptilothamnion sphaericum, Spermothamnion repens, Tiffaniella capitata, Gelidium crinale, G. spathulatum, Pterocladiella melanoidea, Calliblepharis hypneoides, Gymnogongrus griffithsiae, Plocamium maggsiae, Gastroclonium reflexum and Bachelotia antillarum.

Shallow-water communities along the western Antarctic Peninsula support forests of large, mostly chemically defended macroalgae and dense assemblages of macroalgal-associated amphipods, which are thought to exist together in a community-wide mutualism. The amphipods benefit the chemically defended macrophytes by consuming epiphytic algae and in turn benefit from an associational refuge from fish predation. In the present study, we document an exception to this pattern. The amphipod Paradexamine fissicauda is able to consume Plocamium carti- lagineum and Picconiella plumosa, 2 species of sympatric, chemically defended red macroalgae. In previous studies, Plocamium cartilagineum was one of the most strongly deterrent algae in the community to multiple consumers, and was found here to be unpalatable to 5 other amphipod spe- cies which utilize it as a host in nature. Paradexamine fissicauda maintained on a diet of Ploca - mium cartilagineum for 2 mo were much less likely to be eaten by fish than Paradexamine fissi- cauda maintained on a red alga which does not elaborate chemical defenses, or than a different but morphologically similar sympatric amphipod species. Halogenated secondary metabolites pro- duced by Plocamium cartilagineum were identified from tissues of the Paradexamine fissicauda that had eaten it but not those which had eaten the undefended red alga. This indicates that P. fissi- cauda is sequestering the potent chemical defenses of Plocamium cartilagineum for its own use.

Despite recent advances in polar marine biology and related fields, many aspects of the ecological interactions that are crucial for the functioning of Antarctic shallow water habitats remain poorly understood. Although epiphytic diatoms play an essential role in the Antarctic marine food web, basic information regarding their ecology, biodiversity and biogeography is largely unavailable. Here, we synthesise studies on Ross Sea epiphytic diatoms collected during 11 summer Antarctic expeditions between the years 1989/90 and 2011/12, presenting a full list of diatom taxa associated with three macroalgal species (Iridaea cordata, Phyllophora antarctica, and Plocamium cartilagineum) and their epiphytic sessile fauna. Diatom communities found during the three summer months at various depths and sampling stations differed significantly in terms of species composition, growth form structure and abundances. Densities ranged from 21 to >8000 cells mm(-2), and were significantly higher on the surface of epiphytic micro-fauna than on any of the macroalgal species examined. Generally, host organisms characterized by higher morphological heterogeneity (sessile micro-fauna, ramified Plocamium) supported richer diatom communities than those with more uniform surfaces (Iridaea). Differences between epiphytic communities associated with different macroalgae were reflected better in species composition than in growth form structure. The latter changed significantly with season, which was related strongly to the changing ice conditions. A general trend towards an increasing number of erect forms in deeper waters and tube-dwelling diatoms in the shallowest sites (2-5 m) was also observed. This study explores further important and largely previously unknown aspects of relationships and interactions between Antarctic epiphytic diatoms and their micro-and macro-environments.

Red and brown algae have been shown to produce a variety of compounds with chemotherapeutic potential. A recent report described the isolation of a range of novel polyhalogenated monoterpene compounds from the red algae Plocamium corallorhiza and Plocamium cornutum collected off the coast of South Africa, together with the previously described tetraprenylquinone, sargaquinoic acid (SQA), from the brown algae Sargassum heterophyllum. In our study, the algal compounds were screened for anti-proliferative activity against metastatic MDA-MB-231 breast cancer cells revealing that a number of compounds displayed anti-cancer activity with IC(50) values in the micromolar range. A subset of the compounds was tested for differential toxicity in the MCF-7/MCF12A system and five of these, including sargaquinoic acid, were found to be at least three times more toxic to the breast cancer than the non-malignant cell line. SQA was further analysed in terms of its mechanism of cytotoxicity in MDA-MB-231 cells. The ability to initiate apoptosis was distinguished from the induction of an inflammatory necrotic response via flow cytometry with propidium iodide and Hoescht staining, confocal microscopy with Annexin V and propidium iodide staining as well as the PARP cleavage assay. We report that SQA induced apoptosis while a polyhalogenated monoterpene RU015 induced necrosis in metastatic breast cancer cells in vitro. Furthermore, we demonstrated that apoptosis induction by SQA occurs via caspase-3, -6, -8, -9 and -13 and was associated with down-regulation of Bcl-2. In addition, cell cycle analyses revealed that the compound causes G(1) arrest in MDA-MB-231 cells.

A detailed study of the type specimen of Plocamium cartilagineum and other original material of European species of Plocamium revealed that the nomenclatural reorganization proposed by Saunders & Lehmkuhl in 2005 must be revised. The main consequences of the new interpretation are: (1) the use of Plocamium lyngbyanum to name their molecular entity EUR1 (previously considered to be equivalent to P. cartilagineum s.s.); and (2) adopting P. cartilagineum for their molecular entity EUR2, which renders P. subtile Kutzing a taxonomic synonym. Using a combination of morphological, anatomical and molecular information (barcoding), we conclude that the colour and consistency of the thallus, the number of ramuli per series, the morphology and arrangement of the tetrasporangial stichidia, the length of the tetrasporangia, and the type of habitat are the most reliable characters of classical taxonomy for discriminating between the species of Plocamium occurring in northern Europe.

Differentiating between different Plocamium species of marine algae is not a trivial task. However, a literature review reveals that each species of Plocamium has a major and minor metabolite that is unique to a particular Plocamium species being investigated. Knowledge about the chemotaxonomy of these unique major and minor metabolite standards therefore enables the potentially rapid identification of Plocamium species by means of either 1H NMR or GC-MS analysis of crude Plocamium extracts.

Halogenated monoterpenes isolated from the red alga Plocamium cartilagineum aegypticus , proved their efficacy as acaricide. Both of Violacene and Mertensene, were adulticides with LC50's, 340.56 ppm and 759.23ppm, respectively, against the cattle tick; Boophilus annulatus adult females. Moreover, they can be used as ovicides. Violacene and Mertensene caused reduction in the hatchability by 96.77% and 95% respectively. Clinico-pathological studies were carried out and showed that Plocamium extract is safe to the host and none-target animals.

The chemical composition of green Codium tomentosum Stackhouse and red Plocamium cartilagineum (Linnaeus) P.S. Dixon seaweeds from the Atlantic Ocean surrounding Portugal was studied. For the first time, the profile of organic acids was analysed in these matrices: seven and four organic acids were detected in green and red species, respectively. In P. cartilagineum these compounds were present in vestigial amounts, whilst C. tomentosum exhibited a higher content, with oxalic acid being the main compound. Phenolics, UV-absorbing compounds, were absent in both species. Volatiles profile was also determined for the first time and a total of 41 compounds were identified, which included alcohols, aldehydes, esters, halogenated compounds, ketones, monoterpenes (namely terrestrial ones), norisoprenoid derivatives, amongst others. Norisoprenoid derivatives and aldehydes were predominant. The main volatiles in green and red seaweeds were limonene and benzophenone, respectively. Additionally, both species revealed considerable antioxidant activity against both reactive oxygen (superoxide radical) and reactive nitrogen (nitric oxide) species, in a concentration-dependent manner. info:eu-repo/semantics/publishedVersion

We investigated species composition and variation of benthic marine algae between 2003 and 2006 at Dokdo on the East Sea. The total number of benthic algae species identified was 96, which included 15 Chlorophyta, 30 Phaeophyta, 50 Rhodophyta and 1 Spermatophyta species. The representative species in this study were Ulva pertusa, Caulerpa okamurae, Codium adhaerens, C. frgile, Undaria pinnatifida, Ecklonia cava, Eisenia bicyclis, Dictyopteris undulata, Padina arborescens, Sargassum horneri, Hildenbrandtia rubra, Lithophyllum okamurae, Amphiroa dilatata, Corallina officinalis, C. pilulifera, Prionitis cornea, Grateloupia elliptica, Plocamium telgairiae, Chondrus ocellatus, Chondracanthus intermedia, Chondria crassicaulis, Polysiphonia morrowii, Melobesioidean algae and Phyllospadix sp. Wet weight biomass according to various depths ranged between 1,094.8 to during the study period. Mean biomass at the investigated sites was greater in the 15m depth range than in the 5 and 10m depths. Vertical distribution was characterized by Ulva intestinalis, U. linza, Endarachne binghamiae, Bangia atropurpurea, Gloiopeltis furcata and Chondria crassicaulis at intertidal zone, Amphiroa dilatata, Corallina pilulifera, Gelidium amansii, Eisenia bicyclis and Ecklonia cava at 2m depth, Ecklonia cava, Eisenia bicyclis, Padina arborescens, Undaria pinnatifida and Sargasum horneri at 5m depth, Ecklonia cava, Sargassum horneri and Padina arborescens at 10m depth, Ecklonia cava, Myagropsis myagroides, Padina arborescens and Sargassum horneri at 15m depth. The R/P, C/P and (R+C)/P value were 1.67, 0.50 and 2.17, respectively.

A bacterial strain able to produce κ-carrageenase, designated WZUC10, was isolated from a live specimen of the red alga Plocamium telfainae collected in the East China Sea. The phylogenetic evidence and phenotypic features indicate that this strain belongs to the genus Pseudoalteromonas. WZUC10 requires NaCl for growth and κ-carrageenan to induce κ-carrageenase synthesis; galactose and lactose do not induce it. The optimal growth temperature is 23∼27°C. The secreted enzyme, which has a molecular mass of 45 kDa, breaks down κ-carrageenan into κ-neocarratetraose sulfate and larger oligosaccharides with a repeating β-D-Galp4S-(1→4)-α-D-AnGalp structure, but cannot degrade κ-neocarratetraose sulfate or κ-neocarrahexaose sulfate into κ-neocarrabiose sulfate. The enzyme retains 90% of its activity after 2 h at 40°C and is completely inactivated after 7.5 min at 70°C. The enzyme’s optimal temperature is 30°C and its optimal pH is 7.5. The enzyme-catalyzed reaction follows Michaelis-Menten kinetics, with the Michaelis constant (K m) and the turnover number (k) being 0.015 mM and 125 s−1, respectively. WZUC10 produces 50 U/mL κ-carrageenase after cultivation at 25°C for 35 h on a medium containing 80 g/L glucose, 5 g/L corn steep liquor, 3 g/L κ-carrageenan, and 15 g/L NaCl. κ-Neocarratetraose sulfate was prepared simply with precipitation by ethanol:water (5:1, v/v).

Introduction: Over the last decade HPLC-NMR has become a robust analytical technique that has been applied to a wide range of studies, particularly plant extracts. There have been only a few applications of the use of HPLC-NMR to profile marine natural product extracts and no studies involving marine algae. The marine alga selected for this study belongs to the genus Plocamium, which is a well known source of polyhalogenated monoterpenes. Objective: To chemically profile the marine alga P. mertensii, using a combination of on-line (HPLC-NMR) and off-line approaches. Methodology: P. mertensii was extracted with 3:1 methanol-dichloromethane and subsequently partitioned into dichloromethane and methanol-soluble fractions. The methanol partition was exclusively profiled by HPLC-NMR (on-flow, stop-flow and time-slice experiments) whilst the dichloromethane partition was investigated by conventional isolation and purification procedures. Results: HPLC-NMR analysis of the methanol partition partially identified the presence of the major compounds 7, 13, 27 and 37, the structures of which were unequivocally elucidated by off-line characterisation of the dichloromethane partition. Two additional minor metabolites (3 and 8) present in the dichloromethane partition were only tentatively identified as these co-occurred in a mixture with compounds 7 and 13. As a result of this study a number of chemical shift reassignments were made for compound 37. Conclusion: This is one of the few reports describing the application of HPLC-NMR to rapidly proftle or dereplicate a marine organism and the first application of HPLC-NMR to successfully profile the chemistry of a marine alga.

The shallow kelp forest at Santa Catalina Island, California (33.45 N, i118.49 W) is distinguished by several canopy guilds ranging from a Xoating canopy (Macrocystis pyrifera), to a stipitate, erect understory can- opy (Eisenia arborea), to a short prostrate canopy just above the substratum (Dictyopteris, Gelidium, Laminaria, Plocamium spp.), followed by algal turfs and encrusting coralline algae. The prostrate macroalgae found beneath E. arborea canopies are primarily branching red algae, while those in open habitats are foliose brown algae. Densi- ties of Corynactis californica, are signiWcantly greater under E. arborea canopies than outside (approximately 1,200 versus 300 polyps m i2 respectively). Morphological diVerences in macroalgae between these habitats may aVect the rate of C. californica particle capture and serve as a mechanism for determining polyp distribution and abun- dance. Laboratory experiments in a unidirectional Xume under low (9.5 cm s i1 ) and high (21 cm s i1 ) Xow speeds examined the eVect of two morphologically distinct macro- algae on the capture rate of Artemia sp. cysts by C. califor- nica polyps. These experiments (January-March 2006) tested the hypothesis that a foliose macroalga, D. undulata, would inhibit particle capture more than a branching alga, G. robustum. G. robustum, found predominantly under the E. arborea canopy did not aVect particle capture. However, D. undulata, found predominantly outside of the canopy, inhibited particle capture rates by 40% by redirecting parti- cles around C. californica polyps and causing contraction of the feeding tentacles. These results suggest that the mor- phology of Xexible marine organisms may aVect the distri- bution and abundance of adjacent passive suspension feeders.

Four new halogenated monoterpene aldehydes (1-4) have been isolated from the South African marine red alga Plocamium corallorhiza, along with the known compounds 4,6-dibromo-1,1-dichloro-3,7-dimethyl-2E,7-octadiene (5) and 1,4,8-tribromo-3,7-dichloro-3,7-dimethyl-1E,5E-octadiene (10). The structures of the new compounds were determined by interpretation of their spectroscopic data and synthesis and mass spectrometric analysis of their pentafluorobenzyloxime (PFBO) derivatives.

Among five species of the genus Plocamium Lamouroux distributed around Japan, P. cartilagineum (Linnaeus) Dixon, P. recurvatum Okamura and P. telfairiae (Hooker and Harvey) Harvey are often difficult to distinguish morphologically from each other. Our previous study demonstrated that P. recurvatum and P. telfairiae were divided into two groups, A and C, based on RUBISCO spacer sequence and that the specimens belonging to group C had acidic cell saps. In this study, we inferred evolutionary relationships of these Plocamium species from internal transcribed spacer sequence of the ribosomal RNA genes and obtained a similar topology to the RUBISCO spacer tree. Color of the dried specimens in the acidic group C was darker red than that in the non-acidic group A, although there was no difference in color in living thalli. The Br - concentration in the cell sap of the acidic group C was 20 times higher than that of the non-acidic group. We could not find any morphological differences to distinguish clearly between groups A and C despite exhaustive investigation of field-collected and cultured thalli in both P. recurvatum and P. telfairiae. These results suggest that the color of dried specimens and the composition of intracellular inorganic ions are significant criteria for interpreting phylogenetic relationships in Japanese Plocamium spp.

The Plocamiaceae currently includes two genera: the free-living Plocamium and the adelphoparasite, Plocamiocolax. Plocamium includes ca. 40 species that are widely distributed throughout the world's oceans. Most species are clearly defined anatomically and biogeographically; however, the type species Plocamium cartilagineum (type locality: considered northern Europe) is an exception. Although reportedly cosmopolitan in distribution, our investigations unequivocally indicate that there is substantial genetic diversity among isolates from different geographic locations and that there are at least eight divergent cryptic species currently included in P. cartilagineum. In this investigation we focused on populations of P. cartilagineum from northern Europe. We used a combination of molecular and morphological characters in order to establish boundaries between four cryptic species in this geographical area. Our molecular results not only resolve these four entities as distinct, but also indicate that they are...

Among five species of the genus Plocamium present in Japan, P. cartilagineum, P. recurvatum and P. telfairiae show similar blade morphology, and intermediates exist between them. We investigated th...

A new species of red algae, Plocamium fimbriatum, is described from the Sultanate of Oman. It is distinguished by the following suite of characteristics: robust main axes (to 25 cm in length by 4-6 mm in width) with marginal branches produced in series of alternating pairs; production of abundant marginal proliferations resulting in a densely fringed appearance, and tetrasporangial stichidia arising along axillary margins and in the proliferations. The species joins the growing number of new taxa that have been described recently from the benthic marine algal flora of the northern Arabian Sea, a region impacted by the summertime monsoon of nutrient-rich, relatively cold-water conditions. A census of the 35 other species now recognized as belonging to the genus Plocamium is provided. The combination Plocamium cartilagineum (Linnaeus) P. Dixon var. uncinatum (C. Agardh) M.J. Wynne comb. nov. is effected.

The status of Fucus cirrhosus, described from Dusky Sound, New Zealand, is clarified. Type material in BM has been examined and shown to be identical to the red alga currently known as Plocamium costatum and not a taxonomic synonym of the South African‐based P. corallorhiza. Plocamium cirrhosum comb. nov. is proposed as the correct name for this alga occurring in New Zealand and Australia

Plocamium species collected from the Namibian coast display morphological features similar to those of both P. rigidum and P. suhrii which makes identification of these species a difficult task. It has been reported that the major secondary metabolites found in various Plocamium species are unique to each species [1]. In this study GC-MS combined with a retention index (RI) prediction strategy was used for the rapid identification of halogenated monoterpenes characteristic of a particular Namibian Plocamium species. The RIs of the metabolites were matched with the predicted RIs of halogenated monoterpenes for which similar MS data have been reported for the same species of Plocamium. Based on the identification of the major secondary metabolite, 1 E,3 R,4 S,5 E,7 Z-1-bromo-3,4,8- trichloro-7-(dichloromethyl)-3-methylocta-1,5,7-triene [2], it was proposed that these Namibian samples are closely related to that of P. suhrii. From this, it was determined that the proposed P. suhrii specimens collected in Namibia contain four additional metabolites (with molecular formulae C10H16Br2Cl2, C10H11BrCl4, C10H9BrCl6 and an unknown compound) previously not reported in P. suhrii species. In addition, a compound previously identified in South African P. suhrii was not present in the Namibian Plocamium specimens.

Two species of red algae belonging to the genus Plocamium, P. hamatum from Moreton Bay, Queensland, and P. costatum, from Pandalowie Bay, South Australia, were investigated to assess their chemical variation and as potential sources of new halogenated monoterpenes. The hyphenated technique HPLC-UV-MS-SPE-NMR was used to assess the algal extracts and to determine its potential for accelerated identification of halogenated monoterpenes generally. A combination of the hyphenated and traditional chromatographic techniques resulted in the isolation and characterization of a total of 10 halogenated monoterpene metabolites, eight of which are reported for the first time. Their structures, including configurations, were determined through interpretation of their 1D and 2D NMR, mass spectrometric, infrared, and X-ray data. The two species of Plocamium produced different secondary metabolites and contained a significant number of new polyhalogenated monoterpenes. The investigation also showed the hyphenated technique HPLC-UV-MS-SPE-NMR to be useful for preliminary investigation of the chemical content of algal extracts.

Two species of red algae belonging to the genus Plocamium, P. hamatum from Moreton Bay, Queensland, and P. costatum, from Pandalowie Bay, South Australia, were investigated to assess their chemical variation and as potential sources of new halogenated monoterpenes. The hyphenated technique HPLC-UV-MS-SPE-NMR was used to assess the algal extracts and to determine its potential for accelerated identification of halogenated monoterpenes generally. A combination of the hyphenated and traditional chromatographic techniques resulted in the isolation and characterization of a total of 10 halogenated monoterpene metabolites, eight of which are reported for the first time. Their structures, including configurations, were determined through interpretation of their 1D and 2D NMR, mass spectrometric, infrared, and X-ray data. The two species of Plocamium produced different secondary metabolites and contained a significant number of new polyhalogenated monoterpenes. The investigation also showed the hyphenated technique HPLC-UV-MS-SPE-NMR to be useful for preliminary investigation of the chemical content of algal extracts.

Three distinct samples of the sea hare Aplysia dactylomela from two different locations around Tenerife (Spain) were investigated for their secondary metabolite content. The investigation resulted in the isolation of five new natural products (1, 2, 5-7), a number of compounds known from red algae of the genera Laurencia (4, 8-14) and Plocamium (17-19), and three known sea-hare metabolites (3, 15, 16). This is the first report of monoterpenes (17-19) from A. dactylomela. All structures were determined mainly by spectroscopic methods (1D and 2D NMR, MS, IR). Compounds 11, 14, 15, and 17 demonstrated significant cytotoxicity toward three cancer cell lines (HM02, HEP G2, and MCF 7; IC(50) for 11, 7.0 to1.0 microg/mL; 14,1.0 microg/mL; 15, 17 to1.0 microg/mL; 17, 1.0 to 1.5 microg/mL). Compounds 3, 8, 9, 11, 15, 18, and 19 exhibited activity in a brine shrimp bioassay in the range of 100% lethality within 24 h to 40% after 48 h. Metabolites 11, 14, 15, and 19 showed moderate antimicrobial activities (2-25 mm total/growth inhibition of several organisms), with 19 also being strongly algicidal (MIC 7-11 microg/filter disk).

Plocamium cartilagineum is a common red alga on the benthos of Antarctica and can be a dominant understory species along the western Antarctic Peninsula. Algae from this region have been studied chemically, and like “P. cartilagineum” from other worldwide locations where it is common, it is rich in halogenated monoterpenes, some of which have been implicated as feeding deterrents toward sympatric algal predators. Secondary metabolites are highly variable in this alga, both qualitatively and quantitatively, leading us to probe individual plants to track the possible link of variability to genetic or other factors. Using cox1 and rbcL gene sequencing, we find that the Antarctic alga divides into two closely related phylogroups, but not species, each of which is further divided into one of five chemogroups. The chemogroups themselves, defined on the basis of Bray-Curtis similarity profiling of GC/QqQ chromatographic analyses, are largely site specific within a 10 km2 area. Thus, on the limited geographical range of this analysis, P. cartilagineum displays only modest genetic radiation, but its secondary metabolome was found to have experienced more extensive radiation. Such metabogenomic divergence demonstrated on the larger geographical scale of the Antarctic Peninsula, or perhaps even continent-wide, may contribute to the discovery of cryptic speciation.

Thirteen species from the red algal flora of Helgoland (southern North Sea) were exposed to UVA + UVB radiation for various periods in the laboratory, and dark-adapted variable fluorescence (F v:F m) was measured immediately after the UV treatment and again after various recovery times in white light. With the exception of Porphyra umbilicalis, all species showed a decrease in F v:F m on exposure to UV radiation, followed by recovery towards the initial values during the next 24–48 h in white light. The rate of the initial decrease was greater, and the extent of recovery was less, in deep subtidal species (e.g. Delesseria sanguinea, Plocamium cartilagineum) than in intertidal or shallow subtidal species, although there was no direct correlation between these indicators of sensitivity to UV radiation and the depth range of a species, and only slight differences were detected between populations of a single species collected from different depths. There was also little evidence of a seasonal change in sensi...

Five protein-rich ingredients, casein, fishmeal, soya oil cake, Spirulina spp. and torula yeast, were fed to Haliotis midae in semi-purified diets to evaluate their suitability as practical feed ingredients in abalone diets. All diets contained 30% protein and 5% fat, except for the Spirulina spp.-based diet which contained 19% protein. Two algal diets, fresh Plocamium corallorhiza and dried Ecklonia maxima were fed as controls. Abalone fed on fishmeal and Spirulina spp.-based diets displayed significantly higher growth rates than those fed on diets containing soya oil cake, torula yeast, casein and E. maxima. Growth rates of abalone fed P. corallorhiza were significantly lower than those on any other diets. The feed conversion ratios of the formulated diets ranged from 0.7 for the casein-based diet to 1.0 for the torula yeast-based diet. These values were lower than those obtained for the abalone fed the seaweed control diets. Protein efficiency ratios of abalone fed the formulated diets ranged from 3.3 for the torula yeast-based diet to 6.5 for the Spirulina spp.-based diet. These values were higher than those obtained from abalone fed the seaweed control diets. It was concluded that fishmeal and Spirulina spp. algae are the most suitable proteins for inclusion in practical diets for H. midae.

A combination of on-line HPLC-NMR and off-line chemical investigations has resulted in the identification of the previously reported polyhalogenated monoterpene plocamenone, together with the new structural analogue isoplocamenone from the crude extract of the marine alga Plocamium angustum. On-flow and stop-flow HPLC-NMR analyses (including the acquisition of WET 2D NMR spectra) rapidly assisted in the identification of the major component plocamenone and in the partial identification of its unstable double bond isomer isoplocamenone. Conventional off-line isolation and structural characterization techniques were employed to unequivocally confirm both structures, leading to a structural revision for plocamenone, as well as to obtain sufficient quantities for biological testing.

Species of Plocamium are known as prolific sources of halogenated secondary metabolites exhibiting few explored ecological roles. In this study the crude extracts from specimens of P. brasiliensecollected in two distinct places, Enseada do Forno and Praia Rasa, Búzios, Estado do Rio de Janeiro, were evaluated as defense against the sea urchin Lytechinus variegatus and the crab Acanthonyx scutiformis. These specimens produce a similar amount of crude extract and also halogenated monoterpene compound-types, but individuals of P. brasiliense from Praia Rasa exhibit a major compound representing about 59% of the total chemicals. Natural concentrations of the crude extracts obtained from both specimens of P. brasiliense significantly inhibited the herbivory by the sea urchin L. variegatus, but had no significant effect on the feeding by A. scutiformis, a crab commonly associated to chemically defended host. Crude extract from P. brasiliense collected at Praia Rasa was more efficient as defense against L. variegatusthan that crude extract from populations of this alga from Enseada do Forno, probably due to presence of a major secondary metabolite. These two studied population live under different environmental conditions, but they are only about 30 Km apart. However, it is impossible to affirm that environmental characteristics (abiotic or biotic) would be responsible for the difference of defensive potential found in the two populations of P. brasiliense studied here. Further genetic studies will be necessary to clarify this question and to explain why populations of a single species living in different but close locations can exhibit distinct chemicals.

BACKGROUND: Algae species have been used as an important source of food because they are highly nutritive considering their vitamin, protein, mineral, fiber, essential fatty acid and carbohydrate contents. However, a large number of seaweeds have been poorly studied, especially Brazilian species. Two red macroalgae species from the Brazilian coast (Plocamium brasiliense and Ochtodes secundiramea) were assessed with respect to their total lipid, fatty acid, total nitrogen, protein, amino acid and total carbohydrate contents. RESULTS: The total lipid contents (dry weight) were 36.3 and 35.4 g kg−1; fatty acid contents were 9.3 and 12.1 g kg−1; total nitrogen contents were 37.4 and 24.9 g kg−1; protein contents were 157.2 and 101.0 g kg−1; amino acid contents were 127.5 and 91.4 g kg−1; and total carbohydrate contents were 520.3 and 450.7 g kg−1 for P. brasiliense and O. secundiramea, respectively. CONCLUSION: Considering these compositions, both algae species were determined to have sources of protein, essential amino acids and carbohydrates similar to the edible seaweeds Laminaria japonica and Palmaria palmata. Copyright © 2011 Society of Chemical Industry

Five known (1, 2, 4, 6 and 7) halogenated monoterpenes together with 1Z,3R∗,4S∗,5E,7Z)-1-bromo-3,4,8-trichloro-7-(dichloromethyl)-3-methylocta-1,5,7-triene (3) and (3R∗,4S∗)-3,4,6,7-tetrachloro-3,7-dimethyl-octen-1-ene (5) were isolated from the red macroalga Plocamium suhrii and their structures deduced from their spectroscopic data. The seven compounds from P. suhrii together with five related compounds from Plocamium cornutum have been evaluated for their cytotoxic effects on an esophageal cancer cell line (WHCO1). Compounds 1–6 showed greater cytotoxicity in this assay as compared to the known anticancer drug cisplatin.

Photosynthetic performance of distinct marine macroalgae, Ulva fasciata Delile (green alga), Lobophora variegata (J. V. Lamouroux) Womersley ex E. C. Oliveira (brown alga), and Plocamium brasiliensis (Greville) M. A. Howe & W. R. Taylor (red alga), were compared using a pulse amplitude-modulated fluorometer. The maximum quantum yield (Fv/Fm) ranged from 0.80 to 0.51, and the lowest value was found in P. brasiliensis. Under 400 µmol photons m-2 s-1 irradiance, the highest value of photochemical quenching (qP = 0.92 ± 0.13) was observed for U. fasciata. The red alga P. brasiliensis dissipated high amounts of excitation energy (qN = 0.56 ± 0.09), resulting in relatively low values for the effective quantum yield of PS-II (0.23 ± 0.04), as well as for the relative electron transport rate (3.3 ± 0.7). The high photosynthetic potential found for U. fasciata partially explains the species ability for rapid growth and high productivity. O desempenho fotossintético de três grupos distintos de macroalgas marinhas, Ulva fasciata Delile (alga verde), Lobophora variegata (J. V. Lamouroux) Womersley ex E. C. Oliveira (alga parda) e Plocamium brasiliensis (Greville) M. A. Howe & W. R. Taylor (alga vermelha), foi comparado com auxílio de um fluorímetro de pulso e amplitude modulada. O potencial fotoquímico máximo do PS II (Fv/Fm) variou de 0,80 a 0,51, sendo que os menores valores foram observados em P. brasiliensis. Sob a irradiância de 400 µmol fótons m-2 s-1, o maior valor de dissipação fotoquímica (qP = 0,92 ± 0,13) foi observado para U. fasciata. A alga vermelha P. brasiliensis dissipou elevada quantidade de energia de excitação (qN = 0,56 ± 0,09), resultando em valores baixos de potencial fotoquímico efetivo do PS II (0,23 ± 0,04), e também de taxa relativa de transporte de elétrons (3,3 ± 0,7). O elevado potencial fotossintético encontrado para U. fasciata explica, parcialmente, a capacidade da espécie de crescimento rápido e de alta produtividade.

In our continuing search for antimalarial leads from South African marine organisms we have examined the antiplasmodial organic extracts of the endemic marine red alga Plocamium cornutum (Turner) Harvey. Two new and three known halogenated monoterpenes were isolated and their structures determined by standard spectroscopic techniques. The 3,7-dimethyl-3,4-dichloro-octa-1,5,7-triene skeleton is common to all five compounds. Interestingly, compounds bearing the 7-dichloromethyl substituent showed significantly higher antiplasmodial activity toward a chloroquine sensitive strain of Plasmodium falciparum.

Recruitment of the sea hare, Aplysia californica Cooper, was examined at 10 rocky reefs off the coast of Santa Catalina Island, CA, for up to 3 yrs or more. A. californica recruit primarily to the red alga Plocamium cartilagineum Dixon. Recruitment intensity (number of recruits/kg Plocamium ) differed dramatically but consistently between reefs, and varied between months. Recruitment during January—February probably consists of larvae spawned locally, in the Channel Islands area, during the summer peak in reproduction. Recruitment during June to September probably consists of larvae spawned in the Baja California, Mexico, region which are carried north by summer currents. Reproduction is cued by high temperatures in the summer, and occurs over a large range of body sizes. Winter thcruits that survive to the summer reproduce at masses of 500 g or more, while summer recruits reproduce the same season at masses of around 0.75 g. Survival of winter recruits is low, but survivors have high fecundity because of their large body size. Consequently, the average winter recruit has a greater expected fecundity than the average summer recruit. Summer recruits represent regular larval immigration from souther A. californica populations, and contribute a measurable amount to the yearly egg production at Santa Catalina Island. The asynchronous seasonal reproductive patterns of Channel Island and Baja California populations may be important to the population dynamics of these populations since they are linked by a common larval pool.