Abstract Maintaining the coexistence of algae and corals depends on the interactions between them. We investigated these interactions to assess: (1) recruitment patterns of algal turfs over time in dead areas on live corals; (2) the influence of fine-scale differences in coral-dominated environments on algal colonisation; (3) the influence of coral as a substrate for algal recruitment; (4) the invasion potential of algal turf on live coral tissue. This study compared algal colonisation directly on dead or damaged coral areas with algal colonisation on recruitment plates in coral-dominated or -free areas at 23, 154, and 230 days. We also monitored coral colonies over 1.5 years. Filamentous and articulated coralline algae were primarily evident in the early colonisation, reaching stability after 154 days. On a fine scale, the coral-dominated environment showed an increase in number of algal species and coverage. However, coral substrate was selective, with fewer species recruited to this substrate compared to the artificial plates. Furthermore, the competitive dynamics between corals and algal turfs did not result in a winner over time. Thus, algal turf colonisation was influenced not only by coral substrate but also by the reef environment on a fine scale.

É insuficiente a caracterização da estrutura de comunidade de costões rochosos na Estação Ecológica de Tamoios (ESEC Tamoios), Baía da Ilha Grande, estado do Rio de Janeiro, assim como em outras unidades de conservação marinhas do Brasil. No presente estudo, foi descrita a assembleia de macroalgas do infralitoral raso de substrato rochoso em duas ilhas da ESEC Tamoios: Imboassica (IM) e Búzios Pequena (BP), utilizando-se espécie e gênero como unidades observacionais. Em cada ilha, duas localidades foram amostradas no verão de 2011. Quadrados de 30x30 cm (n=3), dispostos aleatoriamente, foram raspados para coletar macroalgas, excetuando-se as incrustantes. As assembleias do infralitoral, onde 58 espécies de macroalgas foram identificadas, foram caracterizadas pela alta frequência e percentagem de cobertura de Sargassum vulgare C. Agardh (56,8±8,4%). As localidades foram significativamente diferentes no número total de espécies e no índice de diversidade Shannon-Weiner (PERMANOVA, p<0,05). De acordo com SIMPER, os gêneros de macroalgas que mais contribuíram para as dissimilaridades entre as localidades (contribuição >5%) foram: Sargassum, Laurencia, Wrangelia, Canistrocarpus, Asparagopsis, Hypnea, Ceratodictyon, Gayliella, Spyridia e Chondria.As dissimilaridades encontradas dentro e entre as ilhas, visualizadas por nMDS para dados de cobertura, apontam a necessidade de considerar diferentes escalas espaciais para o monitoramento das comunidades de costões rochosos da Baía da Ilha Grande.

The structure of subtidal rocky bottom communities at Tamoios Ecological Station (TES), situated in Ilha Grande Bay, Rio de Janeiro State, as well as in other Brazilian marine protected areas, is insufficiently characterized. The present study describes the macroalgal assemblages of shallow subtidal rocky bottoms on two islands of the TES-Imboassica (IM) and Búzios Pequena (BP)adopting species and genera as observational units. Two sites were surveyed on each island in summer 2011. Random 30x30 cm quadrats (n=3) were scraped to collect all macroalgae except crustose species. The subtidal assemblages, in which 58 macroalgal species occurred, were characterized by the high frequency and percent cover of Sargassum vulgare C. Agardh (56.8±8.4%). The sites differed significantly in total number of species and Shannon-Weiner diversity index (PERMANOVA, p<0.05). According to SIMPER, the macroalgal genera that most contributed to the dissimilarities of cover between the sites (contribution >5%) were Sargassum, Laurencia, Wrangelia, Canistrocarpus, Asparagopsis, Hypnea, Ceratodictyon, Gayliella, Spyridia and Chondria.Dissimilarities within and between the islands, as shown by nMDS of the cover data, suggest that different spatial scales should be considered in monitoring the rocky bottom communities of Ilha Grande Bay.

The ability of crude extracts of the brown seaweed Spatoglossum schröederi to counteract some of the biological activities of Lachesis muta snake venom was evaluated. In vitro assays showed that only the extract of S. schröederi prepared in ethyl acetate was able to inhibit the clotting of fibrinogen induced by L. muta venom. On the other hand, all extracts were able to inhibit partially the hemolysis caused by venom and those prepared in dichloromethane or ethyl acetate fully neutralized the proteolysis and hemorrhage produced by the venom. Moreover, the dichloromethane or ethyl acetate extracts inhibited the hemolysis induced by an isolated phospholipase A2 from L. muta venom, called LM-PLA2-I. In contrast, the hexane extract failed to protect mice from hemorrhage or to inhibit proteolysis and clotting. These results show that the polarity of the solvent used to prepare the extracts of S. schröederi algae influenced the potency of the inhibitory effect of the biological activities induced by L. muta venom. Thus, the seaweed S. schröederi may be a promising source of natural inhibitors of the enzymes involved in biological activities of L. muta venom.

About 80% of the human adult population is infected with HSV-1. Although there are many anti-HSV-1 drugs available (acyclovir, ganciclovir, valaciclovir, foscarnet), their continuous use promotes the selection of resistant strains, mainly in ACV patients. In addition to resistance, the drugs also have toxicity, particularly when administration is prolonged. The study of new molecules isolated from green algae with potential antiviral activity represents a good opportunity for the development of antiviral drugs. Caulerpin, the major product from the marine algae Caulerpa Lamouroux (Caulerpales), is known for its biological activities such as antioxidant, antifungal, acetylcholinesterase inhibitor (AChE) and antibacterial activity. In this work, we show that caulerpin could be an alternative to acyclovir as an anti-HSV-1 drug that inhibits the alpha and beta phases of the replication cycle.

Bovine viral diarrhea virus (BVDV) is an etiologic agent that causes important economic losses in the world. It is endemic in cattle herds in most parts of the world. The purpose of this study was to evaluate the in vitro cytotoxic effect and antiviral properties of several marine natural products obtained from seaweeds: the indole alkaloid caulerpin (CAV, 1) and three diterpenes: 6-hydroxydichotoma-3,14-diene-1,17-dial (DA, 2), 10,18-diacetoxy-8-hydroxy-2,6-dolabelladiene (DB1, 3) and 8,10,18-trihydroxy-2,6-dolabelladiene (DB3, 4). The screening to evaluate the cytotoxicity of compounds did not show toxic effects to MDBK cells. The antiviral activity of the compounds was measured by the inhibition of the cytopathic effect on infected cells by plaque assay (PA) and EC50 values were calculated for CAV (EC=2,0± 5.8), DA (EC 2,8± 7.7), DB1 (EC 2,0±9.7), and DB3 (EC 2,3±7.4). Acyclovir (EC50 322± 5.9) was used in all experiments as the control standard. Although the results of the antiviral activity suggest that all compounds are promising as antiviral agents against BVDV, the Selectivity Index suggests that DB1 is the safest of the compounds tested.

As algas calcárias incrustantes exercem um papel fundamental na construção de recifes ao redor do mundo. Neste trabalho os objetivos foram: identificar e estimar a abundância da alga calcária incrustante dominante nas partes rasas do recife, verificando suas taxas de colonização, crescimento e produtividade. Crostas de diferentes habitats foram estudadas em locais a barlavento e sotavento. Discos feitos com massa epóxi foram fixados na superfície do recife para acompanhar a colonização das algas calcárias e discos contendo a alga calcária dominante foram fixados em diferentes habitats para medir o crescimento de suas margens. Os experimentos de produtividade seguiram o método de frascos claros e escuros para leitura de oxigênio dissolvido. Porolithon pachydermum foi confirmado como a espécie de alga calcária incrustante dominante no recife do Atol das Rocas. O local abrigado apresentou maior crescimento da forma plana e típica de crista de P. pachydermum em relação ao exposto. Esta forma também teve um crescimento maior na crista recifal (0,05 mm.dia-1) do que no platô (0,01 mm.dia-1). A forma protuberante e típica de fendas de P. pachydermum apresentou tendência, não significativa, para maior crescimento na crista e poça em relação ao platô. A colonização apresentou baixas coberturas quando comparada a outros estudos recifais. P. pachydermum é uma planta produtiva tanto em ambientes ensolarados como sombreados.

Crustose coralline algae play a fundamental role in reef construction all over the world. The aims fo this study were to identify and estimate the abundance of the dominant crustose coralline algae in shallow reef habitats, measuring their colonization, growth rates and productivity. Crusts sampled from different habitats were collected on leeward and windward reefs. Discs made of epoxy putty were fixed on the reef surface to follow coralline colonization and discs containing the dominant coralline algae were fixed on different habitats to measure the crusts' marginal growth. The primary production experiments followed the clear and dark bottle method for dissolved oxygen reading. Porolithon pachydermum was confirmed as the dominant crustose coralline alga on the Rocas Atoll. The non-cryptic flat form of P. pachydermum showed a faster growth rate on the leeward than on the windward reef. This form also had a faster growth rate on the reef crest (0.05 mm.day-1) than on the reef flat (0.01 mm.day-1). The cryptic protuberant form showed a trend, though not significant, towards a faster growth rate on the reef crest and in tidal pools than on the reef flat. Colonization was, in general, very slow as compared to that presented by other reef studies. P. pachydermum was a productive crust both in non-cryptic and cryptic habitats.

Laurencia caraibica P.C. Silva is being referred occurring in Atol das Rocas, a small island located about 147 miles off Brazilian northeastern coast. The specimens are characterized by the soft, reduced size thalli with four periaxial cells per each axial segment and tetrasporangia in parallel arrangement; presence of lenticular thickenings in the wall of the medullary cells; epidermal cells near the apex not projected beyond the surface of the thalli; presence of anastomose between branches and the occurrence of secondary pit connections between epidermal cells. In this paper, previously unknown detailed morphological characters are presented and compared to related species.

Se registra por primera vez Laurencia caraibica P.C. Silva en Atol das Rocas, el cual es una pequeña isla localizada a 237 km fuera de la costa del noreste de Brasil. Los especímenes se caracterizan por tener talos suaves, pequeños en talla, con cuatro células pericentrales por cada segmento axial; tetrasporangios en arreglo paralelo; presencia de engrosamientos lenticulares en la pared de las células medulares; células corticales cerca del ápice no proyectadas en la superficie del talo; presencia de anastomosis entre las ramas y con uniones intercelulares secundarias entre las células corticales. En este trabajo, se detallan algunos caracteres morfológicos y se comparan con especies relacionadas.

Foram estudadas comunidades bentônicas de pouca profundidade nos recifes em franja e chapeirões da região de Abrolhos (costa sul da Bahia). A cobertura das espécies foi estimada pelo método de transect de linha. Mussismilia braziliensis é a espécie de coral mais importante na maioria das comunidades estudadas, porém as algas em tufo são os organismos dominantes em todos os recifes estudados à exceção de apenas um. Em geral, as comunidades nos chapeirões têm maior diversidade e maior cobertura de coral do que as dos recifes em franja. Nos dois tipos de recife, a relação de cobertura coral-alga não apresenta diferença significativa no tempo, apesar da alta produtividade característica do tipo de alga dominante.

The benthic communities of fringing and mushroom-shaped shallow-water reefs of the Abrolhos region (southern coast of Bahia) were surveyed. Line transects were used to estimate coral and algal percentage cover. Mussismilia braziliensis is the most conspicuous coral species in the majority of the communities surveyed, but turf algal make up the dominant cover in all but one studied reef. In general, communities on mushroom-shaped reefs have higher diversity and higher coral cover than on fringing reefs. For both reef morphologies, the coral to alga cover ratio does. not show marked differences between annual surveys, despite the high productivity characteristic of the dominant algal species.