Algal Species Research Articles

Epiphytic Algae on Dominant Macrophytes in Lotic Ecosystems in the Eastern Flanks of Mount Cameroon

Aims: This study was designed to assess quantitative estimates of epiphyte biomass and diversity on the dominant macrophytes in two rivers in the Eastern flanks of Mount Cameroon. Place and Duration of Study: Two sets of water samples were collected at the top 10cm of the rivers for nutrient and chlorophyll a determination. A single preliminary collection of algal epiphytes from partially submerged aquatic macrophytes was carried out from the littoral zone of Ndongo and Limbe rivers, between May and June 2023. Methodology: The sedimentation technique was employed in the study. Three slides were prepared for each aquatic macrophyte sample for microscopic analysis. Identification was done by comparative morphology using relevant journals and textbooks. Results: All variables related to water clarity (TSS, Phytoplankton Chl a, HC) assessed during the study were similar in both rivers. Water clarity based on HC values was below 6 mg/l implying both rivers were clear during the study period. Epiphytic algae identified were recorded from 4 main divisions, namely Bacillariophyta, Chlorophyta, Cyanophyta and Euglenophyta. The highest algal diversity in Ndongo was recorded from Commelina benghalensis (H=3.45) with 41 algal species identified. Justicia in Ndongo river had the lowest algal species richness (24) with an algal diversity of 2.91. Nymphaea had the highest algal diversity (H=3.36) and algal species richness (36) in Limbe river. Algal species richness was the same in the two other plant hosts Commelina benghalensis and Colocasia esculentus (29 species per host). The highest algal chlorophyll a was recorded on Nymphaea (621mg/g dry weight) and Commelina benghalensis (644mg/g) in Limbe and Ndongo respectively. Lowest epiphyte Chlorophyll a was recorded in Justicia secunda in Ndongo (607 mg/g). Conclusion: All macrophytes studied harbored a large algal flora demonstrating their diverse ecological roles carried out in these rivers. Nymphaea lotus and Commelina benghalensis in Limbe and Ndongo rivers had the highest epiphytic algal biomass.

An alternative process for bioethanol production from marine and freshwater algae using yeast for hydrolysis

This research develops a new process for production of bioethanol from marine and freshwater algae based on hydrolysis using yeast rather than the established methods of enzyme and acid hydrolysis. Yeast were isolated and adapted specifically for this process and the effectiveness of this hydrolysis was evaluated. This method was then evaluated within a full ethanol production process involving ozone pretreatment, and both hydrolysis and fermentation using yeast, under different nutrient supplementation regimes. The process effectiveness was evaluated for species of freshwater (Spirogyra hyalina) and marine (Kappaphycus alvarezii) algae. The yeast-based hydrolysis method outperformed acid and enzyme hydrolysis for both species of freshwater and marine algae, with particularly significant results for the freshwater algae. In the whole of process treatment, the yeast-based hydrolysis approach was effective when combined with ozone pretreatment for marine algae, and without any pretreatment for freshwater algae. The highest ethanol yield was achieved through fermentation with a yeast extract supplement present. These results indicate that ozone pretreatment, hydrolysis using yeast, and fermentation with the use of yeast extract as a nutrient are promising methods for economic ethanol production from seawater algae, and for freshwater algae where ozone pretreatment is not required.

The Existence of Macroalgae in Indonesia: Unlocking the Nutritive Potential for Sustainable Beef Production

Abstract Assessment of the existence of macroalgae and revealing the chemical composition to investigate the potential usage for feed to support sustainable beef production has been conducted in Indonesian prominent livestock production area specifically Lombok, Bali, Yogyakarta, Lampung and Bengkulu. These regions host numerous seaweed production centres, while others hold the capacity to develop into seaweed cultivation zones. To assess the existence, utilisation, and accessibility of macroalgae in each region, observations and interviews were conducted. Subsequently, dominant macroalgae species were sampled and subjected to proximate analysis to determine their nutritional profiles. The results showed that the dominant macroalgae observed included red algae (Rhodophyta) like Eucheuma sp., Gracilaria sp., and Acanthophora sp., green algae (Chlorophyta) such as Ulva sp. and Caulerpa sp., and the brown alga (Phaeophyta) Sargassum sp. The dominant macroalgae found in all five observation sites with high abundance were Sargassum sp., Gracilaria sp., and Eucheuma cottonii. Ulva sp. and Eucheuma spinosum were present at four sites, while Acanthophora sp. and Caulerpa sp. were found at three sites. The dry matter content of the macroalgae ranged from 9.92% to 17.01%, with the highest values observed in the Eucheuma group (14.11%-17.01%). This was followed by Sargassum sp. (12.55 ± 2.40%), Ulva sp. (12.28 ± 2.33%), and Gracilaria sp. (11.09 ± 3.79%). Caulerpa sp. exhibited the lowest dry matter content (9.92 ± 1.29%). The crude protein (CP) content varied both within and between groups of algae species and observation sites. Gracilaria sp. exhibited the highest CP content (13.55 ± 0.16%), followed by Caulerpa sp. (11.87 ± 2.22%), Sargassum sp. (8.98 ± 0.42%), and Ulva sp. (6.98 ± 0.94%). The mineral content of the macroalgae was noticeably high, which is reflected in the low organic matter content. Ulva sp. had the highest organic matter content (80.17%), followed by Sargassum sp. (70.55%), Gracilaria sp. (66.53%), Caulerpa sp. (47.61%), and Eucheuma cottonii (43.50%). The readily available seaweed in this study tend to exhibit moderate to high protein and mineral content, making it a promising partial replacement or supplement for conventional feed, potentially contributing to sustainable beef production. Gracilaria sp., the most readily available seaweed, high in nutrient content with the potential to partially replace conventional feed protein sources. Its abundance of vitamins and minerals may enrich the overall value of the feed.

A traits-based approach to assess aquaculture’s contributions to food, climate change, and biodiversity goals

Aquaculture has the potential to support a sustainable and equitable food system in line with the United Nations Sustainable Development Goals (SDG) on food security, climate change, and biodiversity (FCB). Biological diversity amongst aquaculture organisms can drive diverse contributions to such goals. Existing studies have assessed the performance of a limited number of taxa in the general context of improving aquaculture production, but few explicitly consider the biological attributes of farmed aquatic taxa at the FCB nexus. Through a systematic literature review, we identify key traits associated with FCB and evaluate the potential of aquaculture to contribute to FCB goals using a fuzzy logic model. The majority of identified traits are associated with food security, and two-thirds of traits linked with food security are also associated with climate change or biodiversity, revealing potential co-benefits of optimizing a single trait. Correlations between FCB indices further suggest that challenges and opportunities in aquaculture are intertwined across FCB goals, but low mean FCB scores suggest that the focus of aquaculture research and development on food production is insufficient to address food security, much less climate or biodiversity issues. As expected, production-maximizing traits (absolute fecundity, the von Bertalanffy growth function coefficient K, macronutrient density, maximum size, and trophic level as a proxy for feed efficiency) highly influence a species’ FCB potential, but so do species preferences for environmental conditions (tolerance to phosphates, nitrates, and pH levels, as well as latitudinal and geographic ranges). Many highly farmed species that are typically associated with food security, especially finfish, score poorly for food, climate, and biodiversity potential. Algae and mollusc species tend to perform well across FCB indices, revealing the importance of non-fish species in achieving FCB goals and potential synergies in integrated multi-trophic aquaculture systems. Overall, this study provides decision-makers with a biologically informed assessment of desirable aquaculture traits and species while illuminating possible strategies to increase support for FCB goals. Our findings can be used as a foundation for studying the socio-economic opportunities and barriers for aquaculture transitions to develop equitable pathways toward FCB-positive aquaculture across nuanced regional contexts.

A highly specific and ultrasensitive approach to detect Prymnesium parvum based on RPA-CRISPR-LbaCas12a-LFD system

BackgroundHarmful algal blooms (HABs), caused by the rapid proliferation or aggregation of microorganisms, are catastrophic for the environment. The Prymnesium parvum is a haptophyte algal species that is found worldwide and is responsible for extensive blooms and death of larval amphibians and bivalves, causing serious negative impacts on the ecological environment. For the prevention and management of environmental pollution, it is crucial to explore and develop early detection strategies for HABs on-site using simple methods. The major challenge related to early detection is the accurate and sensitive detection of algae present in low abundance. ResultsHerein, recombinase polymerase amplification (RPA) was combined with clustered regularly interspaced short palindromic repeats and Cas12a protein (CRISPR-LbaCas12a) systems, and the lateral flow dipstick (LFD) was used for the first time for early detection of P. parvum. The internal transcribed spacer (ITS) of P. parvum was selected as the target sequence, and the concentration of single-strand DNA reporters, buffer liquid system, reaction time, and amount of gold particles were optimized. The RPA-CRISPR-LbaCas12a-LFD approach demonstrated highly specificity during experimental testing, with no cross-reaction against different microalgae used as controls. In addition, the lowest detection limit was 10,000 times better than the lowest detection limit of the standalone RPA approach. The feasibility and robustness of this approach were further verified by using the different environmental samples. It also observed that P. parvum are widely distributed in Chinese Sea, but the cell density of P. parvum is relatively low (<0.1 cells/mL). SignificanceThe developed approach has an excellent specificity and offers 10,000 times better sensitivity than the standalone RPA approach. These advantages make this approach suitable for early warning detection and prevention of HAB events in environmental water. Also, the outcomes of this study could promote a shift from traditional laboratory-based detection to on-site monitoring, facilitating early warning against HABs.

Application of MALDI-MS for characterization of fucoidan hydrolysates and screening of endo-fucoidanase activity

Brown macroalgae synthesize large amounts of fucoidans, sulfated fucose-containing polysaccharides, in the ocean. Fucoidans are of importance for their recently discovered contribution to marine carbon dioxide sequestration and due to their potential applications in biotechnology and biomedicine. However, fucoidans have high intra- and intermolecular diversity that challenges assignment of structure to biological function and the development of applications. Fucoidan-active enzymes may be used to simplify this diversity by producing defined oligosaccharides more applicable for structural refinement, characterization, and structure to function assignment for example via bioassays. In this study, we combined MALDI mass spectrometry with biocatalysis to show that the endo-fucoidanases P5AFcnA and Wv323 can produce defined oligosaccharide structures directly from unrefined macroalgal biomass. P5AFcnA released oligosaccharides from seven commercial fucoidan extracts in addition to unrefined biomass of three macroalgae species indicating a broadly applicable approach reproducible across 10 species. Both MALDI-TOF/TOF and AP-MALDI-Orbitrap systems were used, demonstrating that the approach is not instrument-specific and exploiting their combined high-throughput and high-resolution capabilities. Overall, the combination of MALDI-MS and endo-fucoidanase assays offers high-throughput evaluation of fucoidan samples and also enables extraction of defined oligosaccharides of known structure from unrefined seaweed biomass.

The role of cis-zeatin in enhancing high-temperature resistance and fucoxanthin biosynthesis in Phaeodactylum tricornutum.

Phaeodactylum tricornutum a prominent source of industrial fucoxanthin production, faces challenges in its application due to its tolerance to high-temperature environments. This study investigates the physiological responses of P. tricornutum to high-temperature stress and its impact on fucoxanthin content, with a specific focus on the role of cis-zeatin. The results reveal that high-temperature stress inhibits P. tricornutum's growth and photosynthetic activity, leading to a decrease in fucoxanthin content. Transcriptome analysis shows that high temperature suppresses the expression of genes related to photosynthesis (e.g., psbO, psbQ, and OEC) and fucoxanthin biosynthesis (e.g., PYS, PDS1, and PSD2), underscoring the negative effects of high temperature on P. tricornutum. Interestingly, genes associated with cis-zeatin biosynthesis and cytokinesis signaling pathways exhibited increased expression under high-temperature conditions, indicating a potential role of cis-zeatin signaling in response to elevated temperatures. Content measurements confirm that high temperature enhances cis-zeatin content. Furthermore, the exogenous addition of cytokinesis mimetics or inhibitors significantly affected P. tricornutum's high-temperature resistance. Overexpression of the cis-zeatin biosynthetic enzyme gene tRNA DMATase enhanced P. tricornutum's resistance to high-temperature stress, while genetic knockout of tRNA DMATase reduced its resistance to high temperatures. Therefore, this research not only uncovers a novel mechanism for high-temperature resistance in P. tricornutum but also offers a possible alga species that can withstand high temperatures for the industrial production of fucoxanthin, offering valuable insights for practical utilization.IMPORTANCEThis study delves into Phaeodactylum tricornutum's response to high-temperature stress, specifically focusing on cis-zeatin. We uncover inhibited growth, reduced fucoxanthin, and significant cis-zeatin-related gene expression under high temperatures, highlighting potential signaling mechanisms. Crucially, genetic engineering and exogenous addition experiments confirm that the change in cis-zeatin levels could influence P. tricornutum's resistance to high-temperature stress. This breakthrough deepens our understanding of microalgae adaptation to high temperatures and offers an innovative angle for industrial fucoxanthin production. This research is a pivotal step toward developing heat-resistant microalgae for industrial use.

Improved breeding and seed production of climbing perch (Anabas testudineus) in controlled tanks and cage systems

The climbing perch (Anabas testudineus) is a valuable fish species with significant potential for aquaculture. However, a low survival rate was observed at its early development stages, requiring an optimized protocol for sustainable aquaculture production. This paper presents an improved breeding and seed production technology for climbing perch. Mature climbing perch were induced to spawn using salmon gonadotropin-releasing hormone analog (sGnRHa) at a dose of 30 µg/kg-1 body weight of the breeder. The female broodfish spawn 9–10 hours after hormone injection. Developmental stages were defined based on the morphological features of the embryos from the first cleavage to the hatching stage. The first cleavage began at approximately 18–20 minutes after fertilization. Newly hatched larvae were observed within 18–20 h at 30°C, having an average larval size of 0.389±0.042 mm (total length). Successful breeding entails a selection of suitable algal species, an optimal aquaculture environment, regular feeding rates, consistent monitoring of larval development, and effective management of water quality. Survival rates from the larval stage to fry were achieved at 84.69% and 77.60%, respectively, while the survival rate to the fingerlings stage was 72.51%. Therefore, by implementing an optimized protocol, aquaculture practitioners can maximize the production potential of climbing perch while ensuring sustainable cultivation practices. The findings from this research contribute to the advancement of climbing perch aquaculture by providing valuable insights for the successful cultivation and increased economic profitability of A. testudineus species in hatchery productions.

Production of fermentable glucose from the hydrolysis process of cellulose algae waste using fungal cellulases

Kappaphycus alvarezii is the most widely cultivated algae species globally because of its main use in carrageenan production. Waste resulting from carrageenan production still contains high levels of cellulose, which is potentially convertible into fermentable sugar. However, the commercial viability of sugar conversion from algae waste is limited by the high cost of the hydrolysis required to break down the algae waste. This study aims to develop a new hydrolysis method, through the adoption of fungal algal cell disruption to produce a fermentable sugar. The fungus Trichoderma reseei was developed as a new pretreatment method. It was chosen for its superior inherent properties, including low chemical input and environmental friendliness. This study develops a method for fungal pretreatment of algae processing waste. We investigated the effects of substrate concentration, inoculum size, and reaction time on sugar production using full factorial design. The results showed that substrate concentration, inoculum size, and reaction time affect sugar production. This study demonstrates that sugar production from algae proccessing waste can reach more than 70% under optimum conditions. These results indicate the potential of microbial cellullase as an economically friendly pretreatment for sugar production from algae processing waste.

A Check List of Algae from Chilika Lake, Orissa

A total of one hundred and two species of algae belonging to five divisions e.g. Cyanophyta, Chlorophyta, Bacillariophyta, Dinophyta and Rhodophyta were recorded from the Chilika lake during 2000-2001 of which fifty eight species belonging to four divisions were reported for the first time. Enteromorpha usneoides recorded in the Southern sector of the lake for the first time shows new and extended distribution range of Entromorpha species in India. A checklist of algal species found in Chilika lake has been given.

Blue-Green Algal Flora on Archaeological Monuments of India

Forty-six blue-green algal species belonging to fifteen genera, e.g. Gloeocapsopsis, Gloeothece, Myxosarcina, Chroococcidiopsis, Lyngbya, Phromidium, Plectonema, Nostoc, Calothrix, Tolypothrix, Chtorogloeopsis, Fischerella, Hapalosiphon, Westiellopsis and Stigonema occurred on the exposed surfaces of various archaeological monuments from different regions of India. All these blue-green algal species have been isolated and maintained in the culture collection at the Department of Botany, Utkal University.

Nutritional values, antioxidant, and cytotoxic activities of selected edible marine macroalgae: a comparative study

AbstractThe objective of this study is to assess the chemical composition, nutritional values, and bioactivities of four macroalgae from the Egyptian Red Sea coasts using standard methods. Of these, three Rhodophyceae species, Digenea simplex (D. simplex), Laurencia papillosa (L. papillosa), and Galaxaura oblongata (G. oblongata), and one Phyaeophyceae species, Turbinaria decurrens (T. decurrens), were selected. The results of proximate and chemical composition analyses based on the algal dry weight (DW) showed that carbohydrate content was the highest, ranging from 32.47 ± 1.03% to 45.5 ± 1.23%. Other algal constituents, including ash, protein, moisture, sulfate, lipid, phenolics, and flavonoids, have contents that depend on the algal species. Besides, HPLC analysis revealed that each algal extract contained varying amounts of nine phenolic acids. Atomic absorption spectrometry, the HPLC-Pico-Tag method, the ion chromatography technique, and GC/MS analyses were used to determine the chemical profiles of the elemental, amino acid, halide, and fatty acid of each algal extract. Bioactivities revealed that both the •DPPH and ABTS assays showed that all the algae studied had a significant ability to scavenge free radicals in a dosage-dependent way. They also had strong selective cytotoxic activity against HEPG-2 and HCT-116 cell lines, but only weak activity against MCF-7 and A549 cell lines. Finally, our findings suggested that the selected algae might be efficiently used as nutraceuticals and functional foods, indicating an increase in their proliferation.

Fault-Tolerant Phototaxis of a Modular System Inspired by Gonium pectorale Using Phase-Based Control

In this study, we proposed a model for modular robots in which autonomous decentralized modules adaptively organize their behavior. The phototaxis of Gonium pectorale, a species of volvocine algae, was modeled as a modular system, and a fault-tolerant modular control method of phototaxis was proposed for it. The proposed method was based on the rotation phase of the colony and adaptively adjusted an internal response-related parameter to enhance the fault tolerance of the system. Compared to a constant parameter approach, the simulation results demonstrated a significant improvement in the phototaxis time for positive and negative phototaxis during module failures. This method contributes to achieving autonomous, decentralized, and purposeful mediation of the modules necessary for controlling modular robots.

Dimethylsulfoniopropionate (DMSP) Increases Longevity and Mitochondrial Function in Caenorhabditis elegans: Implications for the Role of the Global Sulfur Cycle in Terrestrial Ecosystems.

Dimethylsulfoniopropionate (DMSP) is a compound synthesized by marine phytoplankton that contributes to the oceanic sulfur cycle. Interestingly, DMSP has also been found in algal species and several terrestrial plants, forming part of the global sulfur cycle. However, compared to its role in the marine environment, the impact of DMSP on terrestrial ecosystems remains relatively unexplored. In this study, DMSP was shown to promote longevity and prevent age-associated functional decline in Caenorhabditis elegans (C. elegans), a soil-dwelling organism. DMSP decreased mitochondrial content and improved mitochondrial function in C. elegans at the old stage, which was via enhancing autophagy flux. It was demonstrated that DMSP significantly increased the expression of autophagy and mitophagy genes during aging. Furthermore, DMSP protected against Parkinson's disease (PD) induced by α-synuclein (α-syn) aggregation via autophagy. Mechanistic studies showed that DMSP directly activated nuclear translocation of the Skinhead-1 (SKN-1) transcription factor from the cytoplasm. Moreover, SKN-1 was involved in DMSP-induced autophagy and played a key role in lifespan extension and α-syn clearance in C. elegans. In conclusion, DMSP delays physiological aspects of aging in C. elegans, providing insights into the interplay between the global sulfur cycle and terrestrial organisms.

Connecting Species-Specific Extents of Genome Reduction in Mitochondria and Plastids.

Mitochondria and plastids have both dramatically reduced their genomes since the endosymbiotic events that created them. The similarities and differences in the evolution of the two organelle genome types have been the target of discussion and investigation for decades. Ongoing work has suggested that similar mechanisms may modulate the reductive evolution of the two organelles in a given species, but quantitative data and statistical analyses exploring this picture remain limited outside of some specific cases like parasitism. Here, we use cross-eukaryote organelle genome data to explore evidence for coevolution of mitochondrial and plastid genome reduction. Controlling for differences between clades and pseudoreplication due to relatedness, we find that extents of mtDNA and ptDNA gene retention are related to each other across taxa, in a generally positive correlation that appears to differ quantitatively across eukaryotes, for example, between algal and nonalgal species. We find limited evidence for coevolution of specific mtDNA and ptDNA gene pairs, suggesting that the similarities between the two organelle types may be due mainly to independent responses to consistent evolutionary drivers.

A Botanical Tour in the Sikkim State, Eastern Himalayas

The paper gives an account of the collections of Angiosperms and other lower group of plants made and studied by the author from the Sikkim State of the Eastern Himalayas during 1955. The area under study lies between 27°10'-28°5' N and 88°30'-89° E and includes the Lachen and Lachung river valleys, the upper Tista river valley and the neighbouring mountain slopes and meadows of the Northern Sikkim and the mountain ranges and meadow on way to Nathu La from Gangtok and Jelap La from Rongli, covering an altitude between 1400 and 4400 m. During the period under study, nearly 5000 specimens comprising 471 species of flowering plants, 6 species of Gymnosperms, 38 species of Pteridophytes and 14 species of algae, were collected. Notes on several medicinal and economic plants growing in wild condition, based on the data collected from the villagers and forest guards, are also incorporated in the paper.

Greening up the fight against emerging contaminants: algae-based nanoparticles for water remediation

AbstractNanoparticles are commonly used for different purposes, including as photocatalysts, biosensors, antibacterial, antifungal, and anticancer agents. Recently, the synthesis of nanoparticles via biological techniques has become popular due to cost efficiency, sustainability, and the least secondary pollutants generation. Plants, algae, and microorganisms are primarily used to synthesize bio-nanoparticles. Algae-based nanoparticles have gained more attention due to their catalytic activity against emerging organic contaminants such as dyes, phenols, and organosulfur compounds. Nevertheless, a systemic evaluation of the potential of algae-based nanoparticles in environmental remediation is yet to be conducted. This paper reviews recent progress in the biosynthesis of algae-based nanoparticles and the potential use of algae-based nanoparticles in environmental remediation. Furthermore, the review examines the factors that affect the properties and behaviors of algae-based nanoparticles. Additionally, the review briefly discusses other medical and industrial applications as well as advantages over physically and chemically synthesized nanoparticles. Challenges associated with the production process and usage of algae-based nanoparticles are also discussed, including the difficulty of predicting the properties of nanoparticles and adapting to large-scale processes. Overall, algae-based nanoparticles have several advantages, including their high stability and surface activity due to the presence of surface functional groups from algae species used for the synthesis of algae-based nanoparticles. However, further research is required to address the knowledge gaps and potential key research areas. Graphical Abstract

Nutritional and Medicinal Properties of Microbial Oil

Plant and animal oils and fats currently dominate the edible oil market, but a new sustainable alternative of lipids from single-celled organisms has become advantageous in human nutrition and pharmacy. Single-cell oils (SCOs) are lipids biosynthesized and accumulated in the lipid bodies of oleaginous species of bacteria, yeasts, molds, and algae. The review has investigated SCOs’ composition, with a detailed review of the described beneficial impact in medicine, cosmetics, pharmacy, and nutrition. Although microbial oil has been known for more than 100 years, it was not applied until the 21st century, when commercial SCO production for human use started and administrative regulations governing their use were completed. This article discusses the applications of SCOs, which can be easily found in microorganisms, in the pharmaceutical, cosmetic, and food industries. In addition, some aspects of 15- or 17-carbon-atom-long fatty acids were also pointed out. Furthermore, some challenges for heterotrophic single-cell oil synthesis and improvements in its extraction efficiency have also been concluded, which can further contribute to their broadened use in pharmacy, medicine, cosmetics, and food applications.

The State of Knowledge of CCA Diversity in the Caribbean Coral Reefs

Crustose coralline algae (CCA) are a diverse and ecologically important species found in most of the world’s oceans. The current lack of taxonomic knowledge and relative abundance compromises our ability to predict species diversity numbers and, thus, their ecological roles and impacts on coral reefs. To gather a better understanding of the state of knowledge of crustose coralline algae taxonomy in the Caribbean, 107 different research papers, and other primary and secondary literature were studied; any source with taxonomical information, species identification, or genetic markers for identification was recorded. All Genebank codes were collected and sorted by supposed species marker and then ran through the National Center of Biotechnology Information. The location these genetic markers were gathered from was compared to the natural habitat range of the species, based on the Algaebank habitat description. Of the supposed 83 described species of crustose algae in the Caribbean, based on morphological characteristics, only 24 total were confirmed by DNA markers. This leaves at least 59 species of CCA to be confirmed in the Caribbean Sea with molecular markers. This indicates the importance of DNA barcode survey studies to assess the accurate diversity of this group in the region. With this limited knowledge apparent, it should be seen that a CCAs phylogenetic and taxonomical review must be done. An in-depth assessment should be conducted on CCA collections to identify the Caribbean species correctly and thus know their biodiversity in local habitats.

The effects of turbulence on the growth of three different diatom species

The effects of turbulence on phytoplankton growth have received considerable attentions. However, the complexity of turbulence poses a significant challenge to its systematic characterization in the laboratory, resulting in relatively limited data on the effects of turbulence on several algal species. Here, a laboratory turbulence simulation system was set up to systematically investigate the growth of three common diatom species (Thalassiosira pseudonana, Skeletonema costatum, and Phaeodactylum tricornutum) under stationary and turbulent conditions (at 60, 120, 180 rpm), and measurements were taken for the algal biomass, algal photosynthetic activity, and nutrients consumption. By comparing the growth of three algae species under different turbulence exposure intensities, this study found that different algae exhibit varying sensitivities to turbulence, and therefore have different shear thresholds. Meanwhile, cell morphology is the key factor influencing the different shear threshold values observed in the three diatom species. Additionally, turbulence could impact algal aggregation and light availability, and dramatically improve nutrient uptake by phytoplankton. Our study will provides theoretical support for future endeavors in using turbulence to cultivate phytoplankton or combat algal blooms.