Epifaunal composition and fractal dimensions of intertidal marine macroalgae in relation to emersion

2006 ◽  
Vol 86 (6) ◽  
pp. 1297-1304 ◽  
Author(s):  
Garnet J. Hooper ◽  
John Davenport
Keyword(s):  
Algal Species ◽  
Harpacticoid Copepod ◽  
Structural Complexity ◽  
Fractal Dimensions ◽  
Marine Macroalgae ◽  
Subtidal Zone ◽  
Epifaunal Community ◽  
Faunal Communities ◽  
Abundance And Diversity ◽  
Tidal Emersion

The effect of tidal emersion on the epifauna of three common British intertidal macroalgae, Cladophora rupestris (Chlorophyceae), Laminaria digitata (Phaeophyceae) and Fucus serratus (Phaeophyceae) was investigated. Tidally-induced migration of intertidal fauna is well documented, but the aim of this study was to determine the effect of algal complexity on the degree of change in epifaunal community structure between tidal states. The structural complexity of each algal species was determined by measuring the fractal dimension (D) of algal outlines (1.76, 1.23 and 1.11 respectively for the three species). In the case of L. digitata, a weighted value for D was used to take account of the varying morphologies of the holdfast, stipe and blade. The hypotheses tested were: (i) that increased algal fractal complexity is associated with increased abundance and diversity of associated epifaunal communities; (ii) that community composition is significantly reduced during emersion in intertidal algae (due to faunal migration); and (iii) that the degree of migration due to the receding tide is significantly reduced in more geometrically complex algae. Overall, faunal communities associated with C. rupestris were significantly more abundant and diverse than those associated with the other algal species investigated. No significant migration away from seaweeds was observed for any faunal taxon from any of the algal species studied during emersion. However, harpacticoid copepod abundance increased significantly on L. digitata at low tide. It is likely that these copepods were associated with the holdfast or underside of the lamina for protection from desiccation and the elements. This suggested an advantage associated with inhabiting low shore macroalgae during emersion compared with migration into the subtidal zone.

DNA metabarcoding reveals fine scale geographical differences of consumed algae in the Galápagos marine iguanas (Amblyrhynchus cristatus)

2021 ◽  
pp. 1-10
Author(s):  
Sten Anslan ◽  
Denisse Dalgo ◽  
Timm Reinhardt ◽  
Nicolás Peñafiel ◽  
Juan Guayasamin ◽  
...  
Keyword(s):  
Algal Species ◽  
Marine Macroalgae ◽  
Rbcl Gene ◽  
Ribulose Bisphosphate Carboxylase ◽  
Geographical Differences ◽  
Bisphosphate Carboxylase ◽  
Amblyrhynchus Cristatus ◽  
Dna Metabarcoding ◽  
Feeding Activities ◽  
Marine Iguanas

Abstract Galápagos marine iguanas are primarily associated with the marine environment and show special nutritional adaptations. They are the only lizards worldwide that forage on marine macroalgae. Until now, consumed algae have been identified by direct observations during their feeding activities and microscopic identification in faeces samples. In this study, we use a novel DNA metabarcoding approach to identify consumed algal species from the faeces of marine iguanas. We developed primers for the ribulose-bisphosphate carboxylase (rbcL) gene and applied a metabarcoding approach to 25 individual faeces samples collected in four representative sites of two subspecies (Amblyrhynchus cristatus mertensi and A. c. godzilla), found in the San Cristóbal Island. We detected 18 consistently occurring macroalgal operational taxonomic units (OTUs). Most of the OTUs were assigned to Rhodophyta (red algae) and only one OTU to Chlorophyta (green algae). Despite the number of consumed algal species did not differ between two subspecies (OTU richness; P = 0.383), diet overlap level between A. c. mertensi and A. c. godzilla was low (Schoener index = 0.345), suggesting that both subspecies consumed different algal species in their natural environment. Further studies are needed to understand whether the difference of consumed algae reflects disparities in the abundance of algal species between sites, or whether iguanas of the two genetically differentiated subspecies prefer distinct algal species.

Structural Complexity and Distance from Source Habitat Determine Invertebrate Abundance and Diversity

Biotropica ◽  
2011 ◽  
Vol 43 (6) ◽  
pp. 738-745 ◽  
Author(s):  
Roger P. Mormul ◽  
Sidinei M. Thomaz ◽  
Alice M. Takeda ◽  
Rômulo D. Behrend
Keyword(s):  
Structural Complexity ◽  
Invertebrate Abundance ◽  
Abundance And Diversity

scholarly journals Antifungal Efficacy of Marine Macroalgae against Fungal Isolates from Bronchial Asthmatic Cases

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 3032 ◽  
Author(s):  
Suresh Mickymaray ◽  
Wael Alturaiki
Keyword(s):  
Antifungal Activity ◽  
Fungal Pathogens ◽  
Fungal Infections ◽  
Algal Species ◽  
Marine Macroalgae ◽  
Minimum Fungicidal Concentration ◽  
Asthmatic Patients ◽  
The Cost ◽  
Algal Extracts ◽  
Airway Colonization

Fungal sensitization is very common in bronchial asthmatic cases, and the connection with airway colonization by fungi remains uncertain. Antifungal therapy failure is a significant fraction of the cost and morbidity and mortality in the majority of the asthmatic cases. Hence, the present study aimed to investigate the antifungal activity of five marine macroalgae—Acanthaophora specifera, Cladophoropsis sp., Laurencia paniculata, Tydemania sp., and Ulva prolifera—which were tested on selected fungal pathogens isolated from 15 sputum of 45 bronchial asthmatic patients. The highest antifungal activity was observed in ethanol fractions of L. paniculata followed by U. prolifera, Cladophoropsis sp., A. specifera, and Tydemania sp. The minimum fungicidal concentration and minimum inhibitory concentration values of the ethanolic fractions of algal species were found to be 125–1000 µg/mL and 125–500 µg/mL, respectively. The algal extracts contained terpene alcohol, diterpene, steroids, sesquiterpene, and sesquiterpene alcohol, as determined by GC–MS/MS analyses. The present study shows that the marine macroalgae containing bioactive compounds had excellent inhibitory activity against a variety of fungal pathogens, which may be useful for combating fungal infections and recovering from chronic asthmatic states.

scholarly journals Associations between Benthic Cover and Habitat Complexity Metrics Obtained from 3D Reconstruction of Coral Reefs at Different Resolutions

2020 ◽  
Vol 12 (6) ◽  
pp. 1011 ◽  
Author(s):  
Atsuko Fukunaga ◽  
John H. R. Burns ◽  
Kailey H. Pascoe ◽  
Randall K. Kosaki
Keyword(s):  
Fractal Dimension ◽  
Coral Reefs ◽  
Habitat Structure ◽  
Coral Cover ◽  
Three Dimensional ◽  
Structural Complexity ◽  
Coralline Algae ◽  
Crustose Coralline Algae ◽  
Surface Areas ◽  
Abundance And Diversity

Quantifying the three-dimensional (3D) habitat structure of coral reefs is an important aspect of coral reef monitoring, as habitat architecture affects the abundance and diversity of reef organisms. Here, we used photogrammetric techniques to generate 3D reconstructions of coral reefs and examined relationships between benthic cover and various habitat metrics obtained at six different resolutions of raster cells, ranging from 1 to 32 cm. For metrics of 3D structural complexity, fractal dimension, which utilizes information on 3D surface areas obtained at different resolutions, and vector ruggedness measure (VRM) obtained at 1-, 2- or 4-cm resolution correlated well with benthic cover, with a relatively large amount of variability in these metrics being explained by the proportions of corals and crustose coralline algae. Curvature measures were, on the other hand, correlated with branching and mounding coral cover when obtained at 1-cm resolution, but the amount of variability explained by benthic cover was generally very low when obtained at all other resolutions. These results show that either fractal dimension or VRM obtained at 1-, 2- or 4-cm resolution, along with curvature obtained at 1-cm resolution, can effectively capture the 3D habitat structure provided by specific benthic organisms.

scholarly journals SCREENING OF THE ANTIOXIDANT ACTIVITY OF CRUDE EXTRACTS IN 86 ALGAE SPECIES FROM EL JADIDA COAST (MOROCCO)

2019 ◽  
pp. 54-61 ◽  
Author(s):  
Fatima Chibi ◽  
Halima Rchid ◽  
Wafa Arsalane ◽  
Rachid Nmila
Keyword(s):  
Antioxidant Activity ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Algal Species ◽  
Marine Macroalgae ◽  
Rapid Screening ◽  
Fucus Spiralis ◽  
El Jadida ◽  
Promising Source ◽  
Layer Chromatography

Objective: This work aimed to screen the antioxidant activity of marine macroalgae from the Moroccan Atlantic coast (region of El Jadida). Methods: Evaluation of the antioxidant activity of different collected species, lyophilized and extracted with a solvent mixture chloroform/methanol (2/1; v/v) was conducted according to two techniques, first by thin layer chromatography (tlc) then by spectrophotometry, using a free radical 2,2-diphenyl-1-picrylhydrazyl (dpph). The sampling on a distance of 110 km allowed to harvest 86 algal species (16 brown algae, 47 red algae, 14 green algae and 9 algae being identified). Results: The analysis by thin layer chromatography reveals an antioxidant activity in nearly half of harvested algal species (52.32 %). This activity varies depending on the concentration of the extract and in function of incubation time in the presence of dpph. The monitoring of the kinetics of degradation of dpph by spectrophotometer in the presence of extracts which were active by tlc allowed to confirm the results and select the most active algal species based on the percentage of remaining dpph in the medium after 120 min of reaction: Fucus spiralis (17.02 %), Cyctoseira ericoides (12.16 %) (Phaeophyceae), and Gracilaria multipartita (36%), Halopitys incurvus (5%) (Rhodophyceae). Conclusion: The results show that the methodology adopted in this work is reliable and can be used for rapid screening of antioxidant property in plants and the species: Fucus spiralis, Cyctoseira ericoides, Gracilaria multipartita, and Halopitys incurvus can be a promising source of natural compounds endowed with high antioxidant potential.

Texture Analyses Show Synergetic Effects of Biomechanical and Biochemical Stimulation on Mesenchymal Stem Cell Differentiation into Early Phase Osteoblasts

2013 ◽  
Vol 20 (1) ◽  
pp. 219-227 ◽  
Author(s):  
So Hee Park ◽  
Ji Won Shin ◽  
Yun Gyeong Kang ◽  
Jin-Sook Hyun ◽  
Min Jae Oh ◽  
...  
Keyword(s):  
Stem Cell ◽  
Fractal Dimension ◽  
Cell Differentiation ◽  
Early Phase ◽  
Human Mesenchymal Stem Cells ◽  
Structural Complexity ◽  
Fractal Dimensions ◽  
Stem Cell Differentiation ◽  
Control Group ◽  
Mesenchymal Stem Cell Differentiation

AbstractWe investigated the structural complexity and texture of the cytoskeleton and nucleus in human mesenchymal stem cells during early phase differentiation into osteoblasts according to the differentiation–induction method: mechanical and/or chemical stimuli. For this, fractal dimension and a number of parameters utilizing the gray-level co-occurrence matrix (GLCM) were calculated based on single-cell images after confirmation of differentiation by immunofluorescence staining. The F-actin and nuclear fractal dimensions were greater in both stimulus groups compared with the control group. The GLCM values for energy and homogeneity were lower in fibers of the F-actin cytoskeleton, indicating a dispersed F-actin arrangement during differentiation. In the nuclei of both stimulus groups, higher values for energy and homogeneity were calculated, indicating that the chromatin arrangement was chaotic during the early phase of differentiation. It was shown and confirmed that combined stimulation with mechanical and chemical factors accelerated differentiation, even in the early phase. Fractal dimension analysis and GLCM methods have the potential to provide a framework for further investigation of stem cell differentiation.

scholarly journals The power of 3D fractal dimensions for comparative shape and structural complexity analyses of irregularly shaped organisms

2017 ◽  
Vol 8 (12) ◽  
pp. 1650-1658 ◽  
Author(s):  
Jessica Reichert ◽  
André R. Backes ◽  
Patrick Schubert ◽  
Thomas Wilke
Keyword(s):  
Structural Complexity ◽  
Fractal Dimensions

Do the abundance, diversity, and community structure of sediment meiofauna differ among seagrass species?

2015 ◽  
pp. 1-11
Author(s):  
Jian-Xiang Liao ◽  
Hsin-Ming Yeh ◽  
Hin-Kiu Mok
Keyword(s):  
Ecosystem Engineer ◽  
Structural Complexity ◽  
Nematode Species ◽  
Small Scale ◽  
Seagrass Species ◽  
Thalassia Hemprichii ◽  
Halophila Ovalis ◽  
Deposit Feeders ◽  
Benthic Environment ◽  
Abundance And Diversity

The structural complexity of macrophytes that provide various microhabitats is related to local infaunal abundance and diversity. Seagrass is considered an ecosystem engineer that alters the benthic environment and enables certain distinct meiofauna to thrive in sediments. The effects of seagrass species in a mixed-species seagrass bed at Haikou, Taiwan were examined. Analysing quantitative samples obtained from patches ofThalassia hemprichii, Halodule uninervis, Halophila ovalisand adjacent unvegetated sediments inspected the community structures of meiofauna and marine nematodes. The abundance and diversity of crustaceans and nematodes were substantially higher in habitats in which seagrass grew than in those comprising unvegetated sediments. Both the compositions of higher meiofaunal taxa and nematode species were distinct between seagrass habitats and unvegetated areas. Several nematode species existed exclusively in patches of individual seagrass species, whereas no nematode specifically occurred in unvegetated areas. Regarding the trophic types of nematodes, non-selective deposit feeders were prevalent in the present study, whereas selective deposit feeders and epistrate feeders were relatively dominant in seagrass habitats. Sediments underneath various patches of seagrass species harbour dissimilar nematode communities, even with similar sediment parameters and at a small-scale distance.

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