Hypnea Spinella Research Articles

Lipid Characterization of Beach-Cast Seaweeds from Gran Canaria Island: Potential Use in Human and Animal Nutrition

Macroalgal wracks can be considered unpleasant for beach users and, consequently, they are usually collected from most touristic beaches and discarded. However, seaweeds are an important source of bioactive lipid compounds, such as phospholipids, glycolipids, and n-3 polyunsaturated fatty acids (n-3 PUFA), displaying multiple health-promoting properties, including antioxidant and antimicrobial activities. The aim of this study is to characterize the lipid composition of twelve marine seaweed species (two green, six red, and four brown species) from macroalgal wracks of Gran Canaria Island, and to evaluate their potential use for several purposes, including human and animal nutrition. Lipid content, lipid classes, and fatty acid profiles of isolated specimens from the macroalgal wracks were determined. Lipid contents ranged between 0.27 and 3.17% of dry weight, with all species showing high phytosterols proportions and balanced omega-6/omega-3 (n-6/n-3) ratios. In addition, Cymopolia barbata, Asparagopsis sp., and Hypnea spinella seem to be an attractive source of both mono- and di-galactosyl-diacylglycerols, while A. stellata, Jania sp., and Lobophora sp. are relatively rich in n-3 LC−PUFA. Finally, both green algae showed the most favorable values for the nutritional indicators of cardiovascular health promotion. Overall, the macroalgal species analyzed could be considered as interesting sources for human and animal nutrition.

Rhodophyta DNA Barcoding: Ribulose-1, 5-Bisphosphate Carboxylase Gene and Novel Universal Primers.

Red algae (Rhodophyta) are a heterogeneous group of marine algal species that have served as a source of high-value molecules, including antioxidants and scaffolds, for novel drug development. However, it is challenging to identify Rhodophytes through morphological features alone, and in most instances, that has been the prevailing approach to identification. Consequently, this study undertook the identification of red algae species in Kenton-on-Sea, South Africa, as a baseline for future research on red algae biodiversity and conservation. The identification was achieved by designing, analysing, and using a set of universal primers through DNA barcoding of the rbcL gene. The PCR products of the rbcL gene were sequenced, and 96% of the amplicons were successfully sequenced from this set and matched with sequences on BOLD, which led to these species being molecularly described. Amongst these species are medicinally essential species, such as Laurencia natalensis and Hypnea spinella, and potential cryptic species. This calls for further investigation into the biodiversity of the studied region. Meanwhile, the availability of these primers will ease the identification process of red algae species from other coastal regions.

Seaweed flora of the St. Martin’s Reef, Bangladesh

St. Martin’s Reef (SMR) about 14 km west of the St. Martin’s Island, Teknaf, Cox’s Bazar, Bangladesh was not known during last over 50 years of seaweed researches. Recent six collections made with the assistance of Bangladesh Navy revealed 8 seaweeds species which are Pterocladiella maribagoensis Boo and Geraldo, Hypnea spinella (C. Agardh) Kützing, Peyssonnelia polymorpha (Zonars.) Schmitz, Jania pumila Lamx., Jania ungulata f. brevior (Yendo) Dawson (Rhodophyta); Caulerpa racemosa var. clavifera (Turner) Bosse, Bryopsis plumosa (Huds.) C. Ag. and Halimeda tuna (Lin.) Lamx. (Chlorophyta). Of these six seaweeds such as Pterocladiella maribagoensis Boo et Geraldino, Hypnea spinella (C. Agardh) Kützing, Jania pumila Lamx., Jania ungulata f. brevior (Yendo) Dawson, Bryopsis plumosa (Huds.) C. Ag. and Halimeda tuna (Lin.) Lamx have been newly recorded and described from the SMR in Bay of Bengal (Bangladesh territory). Presence of Peyssonnelia polymorpha and Bryopsis plumosa in the collections and physical and chemical water environments recorded indicated it as a true newly forming reef. The present illustrated account is however may be considered as base-line information on seaweed flora of the new SMR in the North-east Bangladesh coast. A total of six seaweeds have been newly recorded making the total seaweeds to 215 mostly from the SMI and nearby SMR. Bangladesh J. Plant Taxon. 30(1): 153-163, 2023 (June)

Interspecific fastening tissue between Hypnea pannosa and Hypnea spinella (Cystocloniaceae, Rhodophyta)

ABSTRACT There have been frequent reports in several macroalgae of fusions between algal structures. However, most of these reports have documented the (intraspecific) adhesion of portions of the same thallus. The different adhesion structures have been termed anastomoses, and include ring-shaped cells, adherent discs, tentacle cells and pseudo-laterals. Hypnea pannosa and H. spinella are seasonally highly persistent and abundant species in the Mexican Tropical Pacific, with a wide distribution in the region. When the species grow together in the rocky intertidal zone, they produce contact points between their thalli, which hold them together. The fusions between the branches and axes of these species result in a fastening tissue that is distinct from all those previously described. Here we describe the anatomical changes that occur at the contact points between the branches and axes of the two species using optical microscopy, scanning electron microscopy and transmission electron microscopy. The adhesion structures resulted in significant morphological and anatomical changes to the superficial cortical cells, with a new type of interspecific fastening tissue growing outside of the contact points. We characterize this new type of interspecific fastening tissue, consider its origin and structural complexity, and compare it to other connecting structures reported. Additionally, we discuss the consequences of this new type of tissue and its possible ecological significance.

JENIS-JENIS MAKROALGA EPIFIT PADA BUDIDAYA (Kappaphycus alvarezii) DI PERAIRAN TELUK GERUPUK LOMBOK TENGAH

Abstract:Epiphytes are organisms that attach to other organisms to support their growth and development. One type of epiphytes that has a negative impact on the host is algae (macroalgae). This algae is a competing organism for cultivation algae (Kappaphycus alvarezii). This research was conducted From May to October 2017 in Gerupuk Bay, Central Lombok. The aim of the research is to find out the types of macroalgae epiphytes on macroalgae kappaphycus alvarezii. This research was conducted using exploratory methods by taking seaweed samples overgrown with epiphytes, the research data obtained were descriptive analisys. As supporting data, environmental parameters are measured including temperature, pH, salinity, DO, phosphate, and NH4. Based on the results of exploration found 13 species of epiphytic algae in kappaphycus alvarezi cultivation, namely: Chaetomorpha linum, Chaetomorpha linum, Cladophora dalmatica, Acanthophora spicifer, Batrachospermum sp, Callithamnion sp., Caulachantus ustulatus, Ceramium sp, Hypnea spinnosa, Hypnea spinella, Hypnea sp, Polysiphonia brodiaei , Spyridia filamentosa. The type of epiphytes found that grows in both cultivation methods and some others are found only in one method. Meanwhile, data on environmental parameters are in the optimal range for macroalgae growth.This data is expected to be used as a consideration for the cultivateddevelopment in the Gerupuk Bay cultivation center. Keywords : Macroalgae, Epiphytes, Aquaculture, Kappaphycus alvarezii

Komunitas Makroalga di Perairan Tayando-Tam, Maluku Tenggara

<strong>Community of Macroalgae in Tayando-Tam Waters, Southeast Maluku.</strong> Macroalgae is one of the most important economically valuable resources to be developed for food and medicine. This study aims to determine the structure of macroalgae communities by examining the diversity, density, dominance and environmental conditions of its waters. The research was conducted in Tayando-Tam waters, Southeast Moluccas at five stations in September 2015. The study was conducted by transect along 200 meters from the coast to the open shore, observation stations in 50x50 cm quadrant size. The macroalgae community in Tayando-Tam waters is generally in good condition although there is one station that has a moderate dominance value due to a current limiting factor. The macroalgae obtained in five stations are 37 species, dominated by Acanthophora muscoides species, Hypnea spinella, and Halimeda opuntia. Water conditions are still in the optimal range for macroalgae growth.

Macroalgal foraging preferences of juvenile green turtles (Chelonia mydas) in a warm temperate/subtropical transition zone

Understanding resource use and foraging requirements is important for the recovery of threatened and endangered marine turtles. Throughout their range, an increasing number of juvenile green turtles (Chelonia mydas) has been observed foraging and sheltering within man-made structures. These “artificial habitats” are ecologically important as they support the growth of attached macroalgae, a primary food resource of juvenile green turtles. A population of juvenile green turtles in the Trident Basin at Port Canaveral, Florida, USA (28.41°N, 80.59°W), has historically exhibited strong site fidelity. The purpose of this study was to compare the foraging of juvenile green turtles with the availability of macroalgal resources. Foraging (lavage) samples from 94 juvenile green turtles during a 2-year study period from September 2008 through April 2010 were analyzed with the data from two previous studies (1997 and 2002) to determine the patterns of foraging habits through time. Turtles predominantly foraged on species of red (Rhodophyta) and green (Chlorophyta) macroalgae; however, opportunistic foraging on flotsam and invertebrates was common. Selection for certain rhodophytes (i.e., Gelidiopsis planicaulis, Grateloupia filicina, and Hypnea spinella) and chlorophytes (i.e., Cladophora liniformis, Ulva flexuosa, U. lactuca, and U. prolifera) varied by sampling period. Temperature-driven changes in the macroalgal species composition drove inter-annual differences in foraging content between 2002 and 2010. In addition, after an extended cold event, foraging samples from several turtles contained macroalgae not present in the Basin which suggested that turtles moved out of the Basin to forage during this time or newly emigrated. Establishing baseline resource utilization is instrumental for identifying the quality and function of natural and artificial habitats supporting juvenile green turtles, as their populations continue to recover around the globe.

Circling and touching: two new behaviours in the courtship of the Picasso triggerfish Rhinecanthus aculeatus (Linnaeus, 1758)

The reproduction of Rhinecanthus aculeatus (Linnaeus, 1758), a tropical Indo-Pacific reef fish, occurs around the full and new moon (Kuwamura 1997). Spawning begins 16 to 45 min before the sunrise. The courtships begin 7 to 27 min before the spawning. A specific behaviour of the courtships is when the male places its rostrum against the caudal peduncle of the female (Kuwamura 1997). Observations have been recorded in the lagoon of Tiahura [shallow sandy area (0.5 - 2 m deep) with algae Hypnea spinella (C.Agardh) Kutzing, 1847 - Moorea, French Polynesia; 17°29′27′ S, 149°53′32″O] in March and April 2015. Fifteen R. aculeatus (five males and ten females) lived in this area where the males have territories, which included the subterritories of the females. During video-recorded courtships, in addition to the behaviour described by Kuwamura (the nuzzling), two new behaviours have been observed: circling and touching. During the circling, the male and the female swim to the surface in progressively larger circles (Fig. 1). The circling behaviour has been observed in other Balistidae such as Pseudobalistes flavimarginatus (Ruppell, 1829) and Balistapus undulatus (Park, 1797) (Lobel and Johannes 1980). During the touching, the abdomens of the male and the female’s touch each other without gametes emission (Fig. 2). The touching has been reported for Xanthichthys mento (Jordan and Gilbert 1882) (Kawase 2003). Although Balistidae present different reproductive strategies, they have common reproduction features, such as the time and the day of hatching and spawning (Kawase 2003). Our observations are innovative because the courtship of R. aculeatus is more complicated than previously described. This result suggests, thus, that Balistidae have also some common courtship behaviour features. These behaviours may facilitate the release of gametes, as with the nuzzling (Kuwamura 1997) or can convince the partner to mate. We do not know if these patterns are phylogenetically related. But as the egg care strategy of Balistidae (biparental vs maternal) appears to be related to the distribution of food and breeding sites, more than by the phylogeny (Kuwamura 1997), more studies on this topic will be useful to better understand the establishement of these behaviours.

Dietary habits of grazers influence their suitability as biological controls of fouling macroalgae inex situmariculture

The dietary habits of the sea urchin Salmacis sphaeroides and the gastropod Trochus maculatus in ex situ mariculture were examined. Fouling algal assemblages on terracotta tiles were exposed to the grazers and compared. Except for Day 0, the assemblages on Days 2, 13 and 27 differed significantly across treatments. S. sphaeroides rapidly consumed most algae, leaving an assemblage dominated by turf algae and bare tile. T. maculatus primarily fed on green filamentous algae, resulting in an even distribution of other algal functional groups, while control tiles were dominated by green filamentous algae. Using three representative fouling algae species (Bryopsis corymbosa, Hypnea spinella and Lobophora variegata), the consumption rates of both grazers and dietary preferences of S. sphaeroides were examined through a single-diet and a choice experiment respectively. The single-diet experiment revealed differential algal consumption rates for S. sphaeroides (H. spinella = B. corymbosa > L. variegata) and T. maculatus (B. corymbosa > H. spinella = L. variegata). The choice experiment showed that S. sphaeroides preferred H. spinella over the other two species. These experiments highlighted the importance of understanding the dietary habits of grazers as this has direct implications on their effectiveness as biological controls of fouling macroalgae in mariculture.

Antioxidant Substances and Trace Element Content in Macroalgae from a Subtropical Lagoon in the West Coast of the Baja California Peninsula

Macroalgae play an important role in the ecology of the marine environment. They form the base of the food webs, and represent the major food source for a variety of organisms. In order to assess their potential nutritional value, the antioxidant and trace element content (vitamin C, total polyphenols, zinc, iron, cooper, selenium, cadmium and lead) of eight macroalgae species, three red (Hypnea spinella, Gracilaria textorii and G. vermicullophyla), four green (Caulerpa sertularioides, Codium simulans, C. amplivesiculatum and Ulva lactuca) and one brown (Dictyota flabellata ) macroalgae, were determined. The concentration ranges found were as follows: zinc, 19.1-7.4; iron, 638.4-89.2; copper, 3.9-0.9; selenium, 0.32-10; cadmium, 4.33-0.02, and lead 8.8-0.39 mg kg -1 dry weight. Green macroalgae showed higher concentrations of iron and zinc. Total polyphenol content ranged from 29.6 to 70.3 mg 100 g-1 dry weight; brown macroalgae showed higher polyphenol concentration. C. simulans and C. amplivesiculatum had higher vitamin C content (3.16 ± 0.52 mg g -1 and 6.08 ± 0.69 mg g -1 dry weight, respectively) than the other species. Comparison with several commonly consumed vegetables and fruits suggest that these macroalgae are likely a good alternative source of antioxidants and micronutrients for consumers.

Comparative performances of juvenile abalone ( Haliotis tuberculata coccinea Reeve) fed enriched vs non-enriched macroalgae: Effect on growth and body composition

Abalone Haliotis tuberculata coccinea Reeve (1846), is a target species for diversification of European aquaculture production. Taking into account that sustainable, eco-friendly production methods are to be a part of future expansion of the abalone industry, growth performance of juvenile abalone reared in an integrated culture system was evaluated and compared with that of abalone fed non-enriched macroalgae. Four macroalgae treatments, three monospecific: Ulva rigida (UN), Hypnea spinella (HN) and Gracilaria cornea (GN) and a composite one (MN), were produced out of fishpond wastewater effluents, while other four control treatments consisted of the same species reared in fresh seawater (U; H; G; M). Seaweeds reared in fishpond wastewater effluents increased their protein content from 11–17% to 29–34%. Lipids consisted mainly of saturated fatty acids (SFA) (43–60%), palmitic acid being the most abundant fatty acid (40–47%). Highest EPA percentage was found in red algae H. spinella (6.9%), being ten times higher than that of U. rigida (0.7%). All the algae tested contained very low levels of arachinodic acid (0.1–1.6%) and docosahexaenoic acid (0.5–3%). Protein levels in foot muscle (74–76%) did not differ significantly (P < 0.05) among treatments. Survival was generally high, ranging from 85 to 100%. Weight gain (17–561%) and SGR (0.2–2.3%) were positively related to protein content; whereas, protein efficiency ratio (PER) (0.5–3.7) was negative correlated. PE ratios increased by 82–159% (DW) as a function of the enrichment among the different diets. Food conversion ratio (FCR) (7–188) improved according to the increase in PER. Overall, biofilter-produced macroalgae showed a significantly higher dietary value compared to the control treatments. Similarly, animals fed the mixed diets performed significantly better than those fed a single algal diet. Feeding G. cornea led to the lowest growth performance probably due to the lowest feed intake. The results clearly indicate that H. tuberculata coccinea growout can efficiently take place in an integrated-culture system suggesting that on-farm seaweed-abalone production could be part of future development of the abalone industry in the Canary Islands.

Effects of increased CO2 levels on growth, photosynthesis, ammonium uptake and cell composition in the macroalga Hypnea spinella (Gigartinales, Rhodophyta)

The red seaweed Hypnea spinella (Gigartinales, Rhodophyta), was cultured at laboratory scale under three different CO2 conditions, non-enriched air (360 ppm CO2) and CO2-enriched air at two final concentrations (750 and 1,600 ppm CO2), in order to evaluate the influence of increased CO2 concentrations on growth, photosynthetic capacity, nitrogen removal efficiency, and chemical cellular composition. Average specific growth rates of H. spinella treated with 750 and 1,600 ppm CO2-enriched air increased by 85.6% and 63.2% compared with non-enriched air cultures. CO2 reduction percentages close to 12% were measured at 750 ppm CO2 with respect to 5% and 7% for cultures treated with air and 1,600 ppm CO2, respectively. Maximum photosynthetic rates were enhanced significantly for high CO2 treatments, showing P max values 1.5-fold higher than that for air-treated cultures. N–NH +4 consumption rates were also faster for algae growing at 750 and 1,600 ppm CO2 than that for non-enriched air cultures. As a consequence of these experimental conditions, soluble carbohydrates increased and soluble protein contents decreased in algae treated with CO2-enriched air. However, internal C and N contents remained constant at the different CO2 concentrations. No significant differences in data obtained with both elevated CO2 treatments, under the assayed conditions, indicate that H. spinella is saturated at dissolved inorganic carbon concentrations close by twice the actual atmospheric levels. The results show that increased CO2 concentrations might be considered a key factor in order to improve intensively cultured H. spinella production yields and carbon and nitrogen bioremediation efficiencies.

Characterization of polysaccharides from Hypnea spinella (Gigartinales) and Halopithys incurva (Ceramiales) and their effect on RAW 264.7 macrophage activity

Red algae have been reported to be an important source of polysaccharides with potential immunomodulatory properties. The objective of this study was to characterize the polysaccharides from Halopithys incurva and Hypnea spinella and to evaluate their effect on the synthesis of cytokines by murine cell line RAW 264.7 macrophages. Polysaccharides were obtained by N-cetylpyridinium bromide precipitation and characterized by Fourier transform-infrared spectroscopy. Their effect on the activity of RAW 264.7 macrophages was examined by quantification of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and nitric oxide (NO) production using enzyme-linked immunosorbent assays. The activation of the cytokine IL-6 and NO increased linearly as the concentration of polysaccharides from H. incurva and Hy. spinella increased. In general, the activation of IL-6 and NO was tenfold greater when macrophages were exposed to polysaccharides from H. incurva than when exposed to polysaccharides from Hy. spinella. In contrast, TNF-α concentration did not increase when macrophages were exposed to increasing polysaccharide levels. These results indicate that polysaccharides are strong cytokine IL-6 inducers.

Does biofouling influence Kappaphycus alvarezii (Doty) Doty ex Silva farming production in Brazil?

The commercial cultivation of Kappaphycus alvarezii is the main source of raw material for the carrageenan industry. Brazilian commercial farming uses floating rafts that serve as substrata for fouling organisms that may affect production of the carrageenophyte seedlings. The aim of this work was to identify and quantify the biofouling on floating rafts at Sepetiba Bay, Rio de Janeiro State (23° 02′ 25″ S and 43° 53′ 39″ W), and to evaluate seedling damage caused by epibionts and endobionts. Samples were collected from August 2006 to August 2007. In each assessment, organisms contained in random sampling areas of 18 quadrats of 0.10 m2 (n = 18) were removed from floating rafts. K. alvarezii seedling samples were collected to verify the presence of epibionts or endobionts (n = 30). Twenty-four taxa belonging to seven groups of animals and three groups of seaweed were found. The percentage occurrence estimated 13 dominant organisms and amphipod tubes: e.g., Chondracanthus tedii, Cladophora vagabunda, Gracilariopsis tenuifrons, Hypnea spinella, Hypnea musciformis, Hincksia mitchelliae, Spyridia spp., Ulva spp., Bowerbankia sp., Bugula neritina, Botryllus sp., Haplosclerida sp., and Perna perna. Richness, equitability, diversity, and total biomass varied significantly during the study period (p 0.05).

Acclimation of Red Sea macroalgae to solar radiation: photosynthesis and thallus absorptance

Thallus absorptance, daily courses of maximal quantum yields of chlorophyll fluores- cence of photosystem II (Fv/Fm) and electron transport rates (ETR) were determined in 3 macroalgae (Hypnea spinella, Rhodophyta; Sargassum vulgare, Phaeophyta; and Ulva lactuca, Chlorophyta) collected from a low nutrient supply (LNS) ecosystem (Red Sea, Gulf of Aqaba, Eilat, Israel). In addi- tion, U. lactuca grown previously in high nutrient supply (HNS) fishpond effluents was used to eval- uate the effect of nutrient enrichment on photosynthesis. Short-term (2 d) and mid-term (5 d) effects of both photosynthetically active radiation (PAR) and full solar irradiance (PAB: PAR+UVA+UVB) at 3 solar irradiance treatments (no neutral filters, no NF; 2 neutral filter layers, 2NF; and 4 neutral filter layers, 4NF simulating levels of irradiance at 5, 10 and 20 m depth respectively) were evaluated in algae incubated with running seawater. Significant effects of time (variation throughout the day) and irradiance (number of neutral filters) on both Fv/Fm and ETR were observed. Photoinhibition occurred at noon under the no NF (up to 40% decrease) and 2NF (up to 30% decrease) treatments; however, full recovery in all treatments was reached in the afternoon (dynamic photoinhibition) except in H. spinella. The highest maximum ETR was observed in the no NF treatment despite its strongest photoinhibitory effect. The decrease in Fv/Fm at noon was similar to or higher under the PAB than under the PAR treatment alone, depending on the species. Photoinhibition was lower and the maxi- mum ETR was higher in HNS than in LNS U. lactuca, indicating positive effects of nutrient supply on both photosynthesis and photoprotection. The maximum ETRs exhibited by different algae may be related to their zonation in the field and the resulting energy supply.

Macroalgae blooms and δ15N in subtropical coastal lagoons from the Southeastern Gulf of California: Discrimination among agricultural, shrimp farm and sewage effluents

Macroalgae blooms of Gracilaria vermiculophylla, Hypnea spinella and Spyridia filamentosa have been found in coastal lagoons in the SE Gulf of California. Agriculture, livestock, shrimp and poultry farms and sewage contribute anthropogenic nitrogen to the systems. The δ15N of these sources, water column and macroalgae were studied in order to identify the N supply for macroalgae blooms. δ15N of three species of macroalgae (4.3–13.6‰) were enriched compared to the water column (δ15N–NO3- 3.7–6.8‰), probably because of fractioning from the macroalgae. δ15N of POM (1.4–10.3‰) was similar to the water column but the relationship was unclear. Depending on the site, macroalgae showed different δ15N values since some sites receive more or less influence from one given source of the associated watershed, which is reflected in the different δ15N values of the macroalgae of the same system and in the relative contributions of the sources.

Two creeping Ceramium species (Ceramiaceae, Rhodophyta) from the Florida Keys: C. reptans sp. nov. and recircumscription of C. codii (Richards) Mazoyer

Tae Oh Cho and Suzanne Fredericq. 2006. Two creeping Ceramium species (Ceramiaceae, Rhodophyta) from the Florida Keys: C. reptans sp. nov. and recircumscription of C. codii (Richards) Mazoyer. Phycologia 45: 495–504. DOI: 10.2216/05-44.1On the basis of comparative morphology, a new creeping Ceramium species with incomplete and narrow nodal cortication, C. reptans sp. nov. is described from the Florida Keys, USA, where it co-occurs epiphytically with C. codii on the same host, Hypnea spinella. Ceramium reptans sp. nov. is recognized by a prostrate axis producing unbranched upright axes dorsally; five periaxial cells per axial cell; three cortical cells cut off per periaxial cell, with the first acropetal cortical cell becoming the pseudoperiaxial cell that extends longitudinally parallel to the level of neighboring periaxial cells, a second acropetal and third basipetal horizontal cortical cell; and cruciately divided tetrasporangia in whorls bulging from a single node appressed to the contiguous node below on upright axes, 3–6 segments below the apex. Ceramium codii, described from Bermuda, is recognized by a prostrate axis producing unbranched, upright axes dorsally, four periaxial cells per axial cell, three cortical cells cut off per periaxial cell with the basipetal cortical cell cut off horizontally on the prostrate axis, and 1–2 tetrahedrally divided tetrasporangia produced per periaxial cell. Among the described creeping Ceramium species; C. codii, C. bisporum, C. cingulatum, C. cingulum, C. dorsiventrale, C. incospicuum, C. jolyi, C. luetzelburgii, C. procumbens, C. poeppigianum, C. punctiforme, C. serpens, and C. tenerrimum var. brevizonatum f. repens, none has the characteristic pseudoperiaxial cells of C. reptans. Ceramium codii may not be a widespread species as is widely reported in the literature.

Habitat related variation in UV tolerance of tropical marine red macrophytes is not temperature dependent.

Because tropical marine macrophytes experience high ultraviolet-B radiation (UVBR: 280-320 nm) it is assumed that they have high UV tolerance. This was investigated by examining the relative UV sensitivity of five Caribbean red macrophytes. Furthermore, the possibility of temperature dependence of UV effects was examined over a tropical temperature range. Algal fragments of intertidally occurring Gelidiopsis planicaulis (Taylor) Taylor, Wurdemannia miniata (Duby) Feldman and Hamel, and Hypnea spinella (Agardh) Kützing, and the subtidal species Bryothamnion triquetrum (Gmelin) Howe and Heterosiphonia gibbesii (Harvey) Falkenberg were repeatedly subjected to artificial UVBR and ultraviolet-A radiation (UVAR: 320-400 nm) at 22, 26 and 30 degrees C, whereas exposure to photosynthetically active radiation (PAR) served as control. Growth rates, optimal quantum yield of PSII and accumulation of DNA damage were monitored for 10 days, whereas the relative abundance of the D1 reaction centre binding protein and the presence of UV absorbing compounds were investigated in some samples. UVAR and UVBR significantly depressed growth rates of all species. UVBR exposure caused accumulation of DNA damage and resulted in stronger growth reduction than UVAR. UVBR and UVAR caused a depression of optimal quantum yield and a lower D1 abundance. However, the former recovered fast and acclimated to the UV treatments. Some species produced UV absorbing compounds in response to UVAR. UV exposure caused less pronounced effects in intertidally occurring species than in subtidal species. UV effects on growth, the accumulation of DNA damage and UV induced depression of optimal quantum yield were independent of temperature in most species. We conclude that high UVBR in tropical regions may depress in situ growth rates of these intertidal and subtidal red macrophytes.

Levantamento Taxonômico das Macroalgas da Zona das Marés de Costões Rochosos Adjacentes ao Terminal Marítimo Almirante Maximiano Fonseca,Baía da Ilha Grande, RJ.

Taxonomic survey of the intertidal seaweeds of the rocky shores near the oil terminal Almirante Maximiano Fonseca, Ilha Grande Bay, RJ The oil terminal “Almirante Maximiano Fonseca” is a potential source of oil contamination to Ilha Grande Bay, Rio de Janeiro, Brazil. Knowledge of the marine communities around the oil terminal is essential for monitoring purposes. A taxonomic survey of the intertidal seaweed from two rocky shores near the oil terminal (Foca and Enseada) was made. Samplings were done on August and November 1999, February and April 2000. Sixty three species were identified: 13 Chlorophyta, 15 Phaeophyta and 35 Rhodophyta. The algal flora was similar to those described for other localities of the southern littoral of Rio de Janeiro State. Ulva lactuca, Bryopsis pennata, Colpomenia sinuosa, Jania capillacea, Amphiroa fragilissima, Gelidium pusillum, Hypnea spinella, Centroceras clavulatum, Ceramium diaphanum, Laurencia papillosa and Polysiphonia scopulorum var. villum were the most frequent species, being considered characteristic of the local intertidal communities. We recommend that biological aspects of these species should be investigated, by “in situ” and bioassays approaches, in order to assess their potential as bioindicators of oil pollution. We also suggest the study of the structure of the intertidal communities on a broader spatial-temporal scale, as a means of identifying the effects of oil spills from the terminal routine operations on the local biota.

Temperature responses of macroalgae from the tropical island Hainan (P.R. China)

SUMMARYThe temperature tolerances of 24 tropical macroalgae collected on Hainan Island (P.R. China) were investigated. For some isolates, growth response curves were also determined. The upper survival temperatures (USTs, 32–37°C) of these tropical west Pacific strains are similiar to those of tropical Atlantic species. With regard to their lower survival temperatures (LSTs) the species investigated show high variations: 12 species have LSTs between 16 and 7°C (Hypnea musciformis (Wulfen) Lamx. var esperi J, Ag., Centroceras clavulatum (C. Ag) Mont., Falkenbergia hillebrandii (Bornet) Falkenberg, Gelidiopsis intricata (Ag.) Vickers, Halymenia maculata J. Ag., Hypnea cenomyce J. Ag., Hypnea spinella (C. Ag.) Kütz., Gracilaria changii (Xia et Abott) Abott, Chang et Xia, Dictyopteris repens (Okam.) Boerg., Laurencia cartilaginea Yamada, Gelidium pusillum (Stackh.) Le Jol., Laurencia sp.). Their LSTs and temperature requirements for growth (range: 15–30 °C, optimum: 25–30 °C) are mostly similar to those of tropical west Atlantic and amphi‐Atlantic (sub)tropical macroalgae as well as to tropical isolates of species with an Atlantic tropical to warm‐temperate distribution. The remaining 12 species have LSTs between 6 and 1 °C (Ulva conglobata Kjellm., Ulva fasciata Delile, Padina boryana Thivy, Dictyosphaeria cavernosa (Forssk.) Boerg., Boodlea composita (Harv.) Brand, Boergesenia forbesii (Harv.) Feldm., Cladophora vagabunda (L.) van den Hoek, Enteromorpha compressa (L,) Grev., Enteromorpha intestinalis (L.) Link, Gracilaria tenuistipitata Chang et Xia, var liui Chang et Xia, Monostroma nitidum Wittr. and Valonia aegagropila C. Ag.). Their LSTs are mostly similar to those of Atlantic macroalgae with a tropical to (warm‐) temperate distribution. The results are discussed with respect to the factors which may have triggered the development of the temperature requirements of the various species.