Abstract: The coastal waters of Ecuador have emerged as a favorable environment for the growth and development of several species of edible macroalgae or seaweeds. In this study, fatty acid profiles, total soluble polyphenol content, and antioxidant capacity of seven species of macroalgae (four red algae, two brown algae and one green algae) collected from Salinas Bay, Santa Elena Province, Ecuador, were evaluated. Saturated fatty acids C14:0, C15:0, C16:0 and C18:0 were found in almost all organisms, from which palmitic acid showed the highest proportion (10.7-37.1%). Green and brown seaweeds exhibited a major content of unsaturated fatty acids. Monounsaturated fatty acid composition was represented by several isomers of C16:1 and C18:1, mainly palmitoleic (3.0-6.6%) and oleic (0.8-11.1%) acids. Polyunsaturated fatty acid composition ranged from 5.47 to 26.61%, with ratios of total n-6/n-3 acids lower than 3.3. Linoleic (C18:2, n-6, 1.16-7.73%) and eicosapentaenoic (C22:5, EPA, n-3, 1.44-5.92%) acids were found in the majority of the seaweeds. The total polyphenol content of the seaweeds was determined by the Folin-Ciocalteu method (765 nm), and ranged from 147.28 to 1,062.20 mg equivalents of gallic acid (GAE) per 100 g of dry seaweed. The antioxidant capacity was determined by the Trolox equivalent antioxidant capacity (517 nm). Only Acanthophora spicifera, Spatoglossum schroederi, and Ulva lactuca showed good radical-scavenging (14.18-3,379.47 mg Trolox equivalents (TE) per 100 g of dry seaweed). The results confirm the potential use of macroalgae in the study area as an important source of nutritional compounds, especially brown and green algae, which could be a recommended food supplement even in the treatment of some diseases.

Abstract Seaweed aggregates form secondary substrates on rocky shores, providing habitats for phytal organisms such as the spider crab Epialtus brasiliensis Dana, 1852. This species is one of the most abundant macroinvertebrate component from seaweed communities. Although the literature suggests that E. brasiliensis lives in many species of seaweed, their density has only been reported in communities of Sargassum spp. This study assessed the density of the spider crab E. brasiliensis associated with the seaweed Sargassum cymosum Agardh, 1820, Hypnea musciformis (Wulfen) Lamouroux and Acanthophora spicifera (Vahl) Borgesen. We expected to observe a higher density of E. brasiliensis in S. cymosum, which shows greater morphological complexity, followed by H. musciformis, with intermediate complexity, and then by A. spicifera, with low complexity. We found that the density of these crabs can be as abundant in H. musciformis as has been previously reported for S. cymosum, but in both species, the density was higher than in A. spicifera. Overall, our findings improve the knowledge of the phytal habitats used by E. brasiliensis in rocky shore environments.

ABSTRACT Salinity is an important abiotic factor since it is responsible for the local and/or regional distribution of algae. In coastal regions, salinity changes with prevailing winds, precipitation and tide, and particularly in extreme intertidal conditions. Acanthophora spicifera is a red seaweed that occurs in the supratidal region in which changes in abiotic conditions occur frequently. This study evaluated the effects of salinity on the metabolism and morphology of A. spicifera. Algae were acclimatized under culture conditions with sterilized seawater for seven days. Experiments used different salinities (15 to 50 psu) for seven days, followed by metabolic analyses. This study demonstrates that extreme salinities affect physiological parameters of A. spicifera, such as decrease in growth rate, as well as morphological parameters and concentrations of secondary metabolites. Acanthophora spicifera exhibited high tolerance to 25 to 40 psu, with little change in physiology, which favors the occurrence of this species in diverse environments. However, 15, 20, 45 and 50 psu were the most damaging and led to loss of biomass, depigmentation of apices, and the highest concentrations of antioxidant metabolites. The 50 psu treatment caused the greatest changes in general, greatly reducing a biomass and chlorophyll content, and facilitating the presence of endophytes.

Resumen Mensualmente entre junio 2010 y agosto 2011 en la ensenada de Turpialito, Golfo de Cariaco, Venezuela, se recolectaron macroalgas e identificaron, y ejemplares de Echinometra lucunter con diámetro de testa 41.04 ± 6.60 mm para examinar el contenido estomacal y el índice de llenado. Se identificaron 65 especies de macroalgas, pertenecientes a los Phylla Rhodophyta, Heterokontophyta y Chlorophyta. La mayor biomasa anual la presentaron Halimeda opuntia (56.5 g.m-2), Acanthophora spicifera (15.94 g.m-2), Sargassum vulgare (15.28 g.m-2) y Centroceras clavulatum (12.26 g.m-2). Los ítems alimenticios más frecuentes fueron las macroalgas filamentosas: Sphacelaria sp. (546) y Herposiphonia sp. (441) y la foliácea Dictyota sp. (410), y entre los invertebrados esponjas (155), moluscos bivalvos (70) y crustáceos cirrípedos (65). El ID osciló entre 0.8 y 6.0% (2.6 ± 1.21 %), con máximos en diciembre 2010 (6.0 ± 2.21 %), abril (4.3 ± 0.34 %) y junio 2011 (4.0 ± 1.79 %), con oscilaciones mensuales asociadas a los períodos de surgencia y estratificación. El conocimiento de las características principales de la dieta, es necesaria para proponer planes de cultivo y de conservación de la especie.

Abstract Echinometra lucunter is relatively abundant in the Venezuela coast, however no details are known about its diet. We compare the stomach contents and repletion index of E. lucunter with macroalgae available in their environment (June 2010-August) and the nutrient cycle at the Golfo de Cariaco. Seventy-one species of macroalgae were identified: Rhodophyta (45), Heterokontophyta (11) and Chlorophyta (15). The mean testa diameter was 41.04 ± 6.60 mm. The food preferences included filamentous, siphonal and calcaeous macroalgae; main food items were the filamentous macroalgae Sphacelaria sp. and Herposiphonia sp., and foliose Dictyota sp., including invertebrates such as sponges, bivalves and barnacle crustaceans. The repletion index was 0.8 - 6.0 % (2.6 ± 1.21 %), maximum values were associated to primary productivity cycle, i.e. December 2010 (6.0 ± 2.21 %), April (4.3 ± 0.34 %), June 2011 (4.0 ± 1.79 %). Food preferences could be associated to the upwelling season and productivity cycle. Rev. Biol. Trop. 63 (Suppl. 2): 233-242. Epub 2015 June 01.

Foram coletadas amostras de algas marinhas de 19 espécies (sendo 4 pertencentes ao filo Chlorophyta, 5 ao filo Phaeophyta e 10 ao filo Rhodophyta) em dois locais do litoral catarinense. Os extratos etanólicos foram submetidos ao teste de letalidade para larvas de Artemia salina com objetivo de realizar uma triagem das espécies. Dos 26 extratos testados, 25 apresentaram toxicidade significativa em pelo menos uma das 3 concentrações testadas. O grupo de algas vermelhas (Rhodophyta) foi o que obteve maior porcentagem de extratos com resultados estatisticamente significativos pelo método do qui-quadrado e também menores valores de CL50, com destaque para Acanthophora spicifera, Hypnea musciformis e Pterocladiella capillacea. Observaram-se diferenças entre as espécies de um mesmo gênero (Codium decorticatum e Codium isthmocladium) e também a influência de fatores ambientais (Hypnea musciformis) na toxicidade dos extratos.

Samples of 19 macroalgae species (4 Chlorophyta, 5 Phaeophyta and 10 Rhodophyta) have been collected from two points of Santa Catarina's coast. The ethanolic extracts were avaluated with the brine shrimp assay in order to perform a screening for potential toxicity. A total of 25 extracts presented significant results in one or more of the tested concentrations. The phylum Rhodophyta presented more statistically significant results with the chi-square test, as well as lower values of LC50. The extracts of Acanthophora spicifera (from Canasvieiras and Ilha do Francês), Hypnea musciformis and Pterocladiella capillacea (both from Ilha do Francês) presented LC50 below 50 mg/mL. Differences between the species of same genus (Codium decorticatum and Codium isthmocladium) and the influence of environmental factors (Hypnea musciformis) were observed.

Se estudió la abundancia espacial y temporal de dinoflagelados epífitos asociados a la ciguatera durante dos ciclos anuales (marzo 1999 a marzo 2000, y marzo 2001 a marzo 2002) en la costa del noroeste de Cuba. Recolectamos 14 especies de macroalgas (Phaeophyta, Chlorophyta y Rhodophyta) y obtuvimos 1340 muestras. Identificamos siete especies de dinoflagelados potencialmente nocivas, cinco de ellas nuevos registros para el fitobentos cubano: Prorocentrum belizeanum Faust, P. concavum Fukuyo, P. mexicanum Tafall, Coolia monotis Meunier, y Ostreopsis lenticulares Fukuyo. El análisis de ANOVA/MANOVA mostró diferencias espaciales significativas: la abundancia celular más baja se encontró cerca de la desembocadura del río y la más alta en el área más profunda. Prorocentrum lima (Ehrenberg) Dodge, se encontró principalmente sobre las Phaeophyta seguido de las Chlorophyta y Rhodophyta. Gambierdiscus toxicus se encontró principalmente sobre las Phaeophyta seguido de las Rhodophyta y Chlorophyta. Todas las especies halladas en el área del estudio estaban sobre Padina spp. (Phaeophyta). No se encontró ninguna especie de dinoflagelado sobre Acanthophora spicifera (Rhodophyta). Las condiciones ambientales en verano (temperatura, nutrientes, transparencia de agua y la baja velocidad del viento) favorecen el desarrollo de las macroalgas, siendo un substrato adecuado para el desarrollo de dinoflagelados potencialmente nocivos, y posiblemente el vector principal para la extensión de la ciguatera en la costa noroeste cubana.

The spatial and temporal abundance of epiphytic dinoflagellates associated with ciguatera was studied over two annual cycles (March 1999 to March 2000 and March 2001 to March 2002) in the northwestern coast of Cuba. From 14 species of macroalgae (Phaeophyta, Chlorophyta, and Rhodophyta), 1340 samples were obtained identifying seven species as potentially noxious; five of them are new reports for Cuba’s phytobenthos: Prorocentrum belizeanum Faust, P. concavum Fukuyo, P. mexicanum Tafall, Coolia monotis Meunier, and Ostreopsis lenticularis Fukuyo. ANOVA/MANOVA analysis showed significant spatial differences: lower cell abundance near the shoreline adjacent to a river inlet and higher cell abundance in the deepest area. Prorocentrum lima (Ehrenberg) Dodge 1975 was found mainly on Phaeophyta followed by Chlorophyta and Rhodophyta. Gambierdiscus toxicus was found mainly on Phaeophyta followed by Rhodophyta and Chlorophyta. All the species reported in the study area were mainly on Padina spp. (Phaeophyta). Acanthophora spicifera (Rhodophyta) did not host dinoflagellate species. Environmental conditions in summer (higher temperature, more nutrients, greater water transparency, and low wind intensity) are suitable for macroalgae development, which serves as a substrate for potentially harmful dinoflagellates, and possibly the main vector for spreading ciguatera along the coast of Cuba. Rev. Biol. Trop. 54(2): 299-310. Epub 2006 Jun 01.