Marine Echinoderms Research Articles

MiR-210, not let-7, regulates Akt gene expression against Vibrio splendidus infection in the sea cucumber Apostichopus japonicus

The immune regulatory roles of microRNAs (miRNAs) have recently attracted considerable attention. Bioinformatics prediction revealed that both let-7 and miR-210 provide potential binding sites for the Akt (rac-alpha serine/threonine-protein kinase) gene sequence in the sea cucumber Apostichopus japonicus (termed AjAkt). In this study, we first used a dual-luciferase reporter assay and functional validation techniques to verify the interactions between these two miRNAs (let-7 and miR-210) and AjAkt, and then investigated the functions of the validated miRNA/mRNA pair as part of the innate immune response against Vibrio splendidus infection. We found that AjAkt interacts with miR-210 rather than let-7, and miR-210 negatively regulates the expression of AjAkt. From 8 to 48 h after infection with V. splendidus, opposite trends were observed in the expression levels of miR-210 and AjAkt (mRNA and protein) in coelomocytes, suggesting that the miR-210/AjAkt pair is involved in immune regulation during this period after infection. Both AjAkt silencing and miR-210 overexpression enhanced the phagocytic capacity and reduced the infectivity of A. japonicus after pathogen infection, suggesting that the miR-210/AjAkt pair may regulate the innate immune response of A. japonicus by altering phagocytic capacity. The findings of this study enrich our knowledge of the role of miRNA/mRNA pairs in immune regulation in sea cucumbers and provide insights into the molecular mechanisms of the innate immune response in marine echinoderms.

Ecotoxicity of 3D printing material polylactic acid (PLA) on sea urchin Paracentrotus lividus

In this study, the ecotoxicity of 3D printing material [polylactic acid (PLA)] was investigated with marine echinoderms; sea urchin Paracentrotus lividus. To achieve this goal, (i) fertilization success, spermiyotoxicity, and embriyotoxicity exposed to PLA concentrations (0.001, 0.005, 0.01, 0.1, and 1 g/L) were assessed for 72 h. For this purpose, our study is important to make comprehensive evaluations to ensure the safety of bioplastic formulations and to take measures to regulate the use of additives. At the same time, the additive used to increase the durability of bioplastic materials will also allow us to understand the long-term effects on ecosystems, wildlife, and human health. Our aim is to minimize possible harm and ensure that the overall environmental impact of bioplastics remains positive.

Ecotoxicty of 3D printing material Polylactic Acid (PLA) on sea urchin Paracentrotus lividus

In this study the ecotoxicity of 3D printing material [polylactic acid (PLA) investigated with marine echinoderm; sea urchin Paracentrotus lividus. To achieve this goal, (i) fertilization success, spermiyotoxicity and embriyotoxicity exposed to PLA concentrations (0.001, 0.005, 0.01, 0.1 and 1 g/L) were assessed for 72 h. For this purpose, our study is important to make comprehensive evaluations to ensure the safety of bioplastic formulations and to take measures to regulate the use of additives. At the same time, the additive used to increase the durability of bioplastic materials will also allow us to understand the long-term effects on ecosystems, wildlife and human health. Our aim is to minimize possible harm and ensure that the overall environmental impact of bioplastics remains positive.

Diversity and characterization of culturable fungi associated with the marine sea cucumber Holothuria scabra.

Fungi associated with the marine echinoderm, Holothuria scabra, produces extracellular enzymes and bioactive metabolites, and mycoviruses that could be used for biotechnological and pharmaceutical applications. The species identification based on molecular and morphological characteristics classified the culturable fungi into twenty-three genera belonging to eight orders, Chaetothyriales, Eurotiales, Hypocreales, Mucorales, Mycosphaerellales, Onygenales, Pleosporales and Venturiales, from four classes, Eurotiomycetes, Dothideomycetes, Mucoromycetes and Sordariomycetes of the two phyla Ascomycota and Mucoromycota. The most frequent genera were Aspergillus (relative frequency, 45.30%) and Penicillium (relative frequency, 22.68%). The Menhinick species richness and Shannon species diversity indices were 1.64 and 2.36, respectively, indicating a high diversity of fungi. An enzymatic production test revealed that sixteen isolates could produce proteases and amylases at different levels. The presence of mycoviruses was detected in eight isolates with different genomic profiles. Thirty-two of the 55 isolates produced antimicrobial metabolites which had an inhibitory effect on various microbial pathogens. Most of these active isolates were identified as Aspergillus, Penicillium and Trichoderma. Notably, Aspergillus terreus F10M7, Trichoderma harzianum F31M4 and T. harzianum F31M5 showed the most potent activity against both Gram-positive and Gram-negative bacteria and human pathogenic fungi. Our study represents the first report of the mycobiota associated with the marine echinoderm Holothuria scabra.

Alterations in mitochondrial structure and function in response to environmental temperature changes in Apostichopus japonicus

Global temperatures have risen as a result of climate change, and the resulting warmer seawater will exert physiological stresses on many aquatic animals, including Apostichopus japonicus. It has been suggested that the sensitivity of aquatic poikilothermal animals to climate change is closely related to mitochondrial function. Therefore, understanding the interaction between elevated temperature and mitochondrial functioning is key to characterizing organisms’ responses to heat stress. However, little is known about the mitochondrial response to heat stress in A. japonicus. In this work, we investigated the morphological and functional changes of A. japonicus mitochondria under three representative temperatures, control temperature (18 °C), aestivation temperature (25 °C) and heat stress temperature (32 °C) temperatures using transmission electron microscopy (TEM) observation of mitochondrial morphology combined with proteomics and metabolomics techniques. The results showed that the mitochondrial morphology of A. japonicus was altered, with decreases in the number of mitochondrial cristae at 25 °C and mitochondrial lysis, fracture, and vacuolization at 32 °C. Proteomic and metabolomic analyses revealed 103 differentially expressed proteins and 161 differential metabolites at 25 °C. At 32 °C, the levels of 214 proteins and 172 metabolites were significantly altered. These proteins and metabolites were involved in the tricarboxylic acid (TCA) cycle, substance transport, membrane potential homeostasis, anti-stress processes, mitochondrial autophagy, and apoptosis. Furthermore, a hypothetical network of proteins and metabolites in A. japonicus mitochondria in response to temperature changes was constructed based on proteomic and metabolomic data. These results suggest that the dynamic regulation of mitochondrial energy metabolism, resistance to oxidative stress, autophagy, apoptosis, and mitochondrial morphology in A. japonicus may play important roles in the response to elevated temperatures. In summary, this study describes the response of A. japonicus mitochondria to temperature changes from the perspectives of morphology, proteins, and metabolites, which provided a better understanding the mechanisms of mitochondrial regulation under environment stress in marine echinoderms.

Screening of in-vitro Antidiabetic Potentials from the Protein Extracts of Stomopneustes variolaris

Diabetes mellitus (DM) is one of the serious endocrine disorders caused by insufficient production or inefficacy of the insulin and it is the immense cause of death throughout the world. However, finding for novel antidiabetic drugs from natural resources is still fascinating, because of their safe effect on DM. The marine environment provides a pool of unique and novel bioactive compounds due to its extremely diverse environmental conditions and biota. Stomopneustes variolaris is a marine echinoderm, belongs to family Stomopneustidae and they have toxins in their bodies as a defence mechanism which often has medicinal value. The present investigation aimed to evaluate the antidiabetic potentials of protein extracts from the spines, shell, and tissue of Stomopneustes variolaris. The spine, shell, tissue shows significant variation in protein content and the highest concentration of protein was found in tissue extract. The studies of haemoglobin glycation reveal that the haemoglobin glycation was increased with increasing concentration of the glucose. The highest haemoglobin glycation was reported in 20mg/ml glucose concentration at 24hr incubation period. The Glucose Adsorption Capacity of spine, shell and tissue extracts shows a strong positive correlation such as r = 0.9930, r = 0.9931 and r = 0.9969 corresponding to increased glucose concentration. The inhibition percentage of physiological haemoglobin glycation was depended on the glucose concentration. The protein extract of Stomopneustes variolaris spine (86.19 ± 0.28) showed the highest percentage of physiological haemoglobin glycation inhibition at 40mg/ml glucose concentration. The % of Glucose dialysis retardation index (GDRI) was decreased with increasing time incubation in all the tested protein extracts. The spine extract of Stomopneustes variolaris (37.26 ± 0.4) showed the highest percentage of GDRI at 30min incubation period. The maximum percentage of glucose uptake by yeast was observed with the spine extract (46.4±0.25) of Stomopneustes variolaris. The in-vitro α-amylase inhibitory activities of Stomopneustes variolaris spine, shell, and tissue were found as 51.11±0.79%, 41.81±0.31% respectively.

Direct anti-tumoral effects of sulfated fucans isolated from echinoderms: a possible role of neuropilin-1/β1 integrin endocytosis and focal adhesion kinase (FAK) degradation.

Hypercoagulability, a major complication of metastatic cancers, has usually been treated with heparins from natural sources, or with their synthetic derivatives, which are under intense investigation in clinical oncology. However, the use of heparin has been challenging for patients with risk of severe bleeding. While the systemic administration of heparins, in pre-clinical models, has shown primarily attenuating effects on metastasis, their direct effect on established solid tumors has generated contradictory outcomes. We investigated the direct antitumoral properties of two sulfated fucans isolated from marine echinoderms, FucSulf1 and FucSulf2, which exhibit anticoagulant activity with mild hemorrhagic potential. Unlike heparin, sulfated fucans significantly inhibited tumor cell proliferation (by ~30-50 percent), and inhibited tumor migration and invasion in vitro. We found that FucSulf1 and FucSulf2 interacted with fibronectin (FN) as efficiently as heparin, leading to loss of prostate cancer and melanoma cell spreading. The sulfated fucans increased the endocytosis of β1 integrin and neuropilin-1 (NRP-1) chains, two cell receptors implicated in FN-dependent adhesion. The treatment of cancer cells with both sulfated fucans, but not with heparin, also triggered intracellular focal adhesion kinase (FAK) degradation, with a consequent overall decrease in activated FAK levels. Finally, only sulfated fucans inhibited the growth of B16-F10 melanoma cells implanted in the dermis of syngeneic C57/BL6 mice. FucSulf1 and FucSulf2 arise from this study as candidates for the design of possible alternatives to long-term treatments of cancer patients with heparins, with the advantage of also controlling local growth and invasion of malignant cells.

EchoAI: A deep-learning based model for classification of echinoderms in global oceans

IntroductionIn response to the need for automated classification in global marine biological studies, deep learning is applied to image-based classification of marine echinoderms.MethodsImages of marine echinoderms are collected and classified according to their systematic taxonomy. The images belong to 5 classes, 38 orders, 145 families, 459 genera, and 1021 species, respectively. The deep learning model, EfficientNetV2, outperforms the competing model and is chosen for developing the automated classification tool, EchoAI. Then, the EfficientNetV2-based tool, EchoAI is applied to each taxonomic level.ResultsThe accuracy for the test dataset was 0.980 (class), 0.876 (order), 0.738 (family), 0.612 (genus), and 0.469 (species), respectively. Online prediction service is provided.DiscussionThe EchoAI model and results are facilitated for investigating the diversity, abundance and distribution of species at the global scale, and the methodological strategy can also be applied to image classification of other categories of marine organisms, which is of great significance for global marine studies. EchoAI is freely available at http://www.csbio.sjtu.edu.cn/bioinf/EchoAI/ for academic use.

Functions of lysin motif (LysM)-containing protein in antibacterial responses of sea cucumbers, Apostichopus japonicus

The lysin motif (LysM)-containing protein is one of widespread pattern-recognition receptors in prokaryotes and eukaryotes. Numerous LysM-containing gene sequences are present in gene databases; however, few have been well characterized, especially in echinoderms. In this study, the full-length cDNA of a novel LysM-containing gene was obtained from the sea cucumber Apostichopus japonicus, named AjLysM-1, using polymerase chain reaction (PCR) combined with rapid amplification of cDNA ends. We prepared and expressed recombinant AjLysM-1 protein (rAjLysM-1) and determined its pathogen-recognition ability by enzyme-linked immunosorbent and immunofluorescence assays. We also analyzed the tissue expression pattern and response to immune challenges of AjLysM-1 using quantitative real-time reverse transcription-PCR and in situ hybridization. The AjLysM-1 protein was predicted to be an intracellular non-secreted LysM-containing protein, highly homologous to the same protein in other marine echinoderms. AjLysM-1 transcripts were highest expressed in coelomocytes and were strikingly induced by challenge with representative bacterial and fungal polysaccharides. rAjLysM-1 showed weak binding to mannan, Pseudoalteromonas nigrifaciens, and Shewanella baltica, implying that AjLysM-1 might provide inadequate defense against Gram-negative bacteria and fungi. Notably, rAjLysM-1 also interacted with tyrosine protein kinase and filamin-B, indicating that it could be involved in focal adhesion in A. japonicus. These findings improve our understanding of the functions of LysM-containing proteins in marine echinoderms.

Protease and DNase Activities of a Very Stable High-Molecular-Mass Multiprotein Complex from Sea Cucumber Eupentacta fraudatrix.

Only some human organs, including the liver, are capable of very weak self-regeneration. Some marine echinoderms are very useful for studying the self-regeneration processes of organs and tissues. For example, sea cucumbers Eupentacta fraudatrix (holothurians) demonstrate complete restoration of all organs and the body within several weeks after their division into two parts. Therefore, these cucumbers are a prospective model for studying the general mechanisms of self-regeneration. However, there is no data available yet concerning biomolecules of holothurians, which can stimulate the processes of organ and whole-body regeneration. Investigation of these restoration mechanisms is very important for modern medicine and biology because it can help to understand which hormones, nucleic acids, proteins, enzymes, or complexes play an essential role in self-regeneration. It is possible that stable, polyfunctional, high-molecular-weight protein complexes play an essential role in these processes. It has recently been shown that sea cucumbers Eupentacta fraudatrix contain a very stable multiprotein complex of about 2000 kDa. The first analysis of possible enzymatic activities of a stable protein complex was carried out in this work, revealing that the complex possesses several protease and DNase activities. The complex metalloprotease is activated by several metal ions (Zn2+ > Mn2+ > Mg2+). The relative contribution of metalloproteases (~63.4%), serine-like protease (~30.5%), and thiol protease (~6.1%) to the total protease activity of the complex was estimated. Metal-independent proteases of the complex hydrolyze proteins at trypsin-specific sites (after Lys and Arg). The complex contains both metal-dependent and metal-independent DNases. Mg2+, Mn2+, and Co2+ ions were found to strongly increase the DNase activity of the complex.

Population Characteristics of the Upper Infralittoral Sea Urchin Arbacia lixula (Linnaeus, 1758) in Eastern Mediterranean (Central Greece): An Indicator Species for Coastal Water Quality

The black sea urchin (Arbacia lixula, Linnaeus, 1758) is a non-edible marine echinoderm of high ecological importance with the potential to affect marine ecological communities. A. lixula were sampled monthly for one year from the supralittoral fringe at two locations in the Pagasitikos Gulf, in the north-western Aegean Sea. Morphometric characteristics exhibited significant spatiotemporal variation. The population in closer proximity to treated sewage effluent outflow exhibited significantly higher biometric relationships resulting in possible improved physiological conditions. Spatial distribution exhibited a clumped pattern of dispersion, consisting of predominantly six age classes. The dominant cohort was the four-year age class, comprising 31.2% of the total population. Significant negative allometric relationships were exhibited between all morphometric characteristics. The maximum approximate age of the total A. lixula population was estimated at 15.27 years. The von Bertalanffy growth equation for the entire population was estimated as: test diameter = 62.881×1−e−0.196×Age+1.147. The gonadosomatic index indicated a seasonal cycle with a peak in late spring. The approximate age of sexual maturity was estimated at 4.45 years. We observed a significantly higher number of females than expected at the site in closer proximity to the treated sewage effluents (32% of total female number).

Применение технологии сверхкритической экстракции для получения полиненасыщенных кислот из морской звезды (Lysastrosoma anthosticta Fisher, 1922)

Introduction. Starfish (Asteroidea) are marine echinoderms with more than 160 species. Starfish are a valuable source of protein and fats. The present research featured the chemical composition of starfish, which can be used as a commercial source of lipids.
 Study objects and methods. The study defined the optimal parameters for extracting the lipid fraction of Lysastrosoma anthosticta with supercritical carbon dioxide, as well as the qualitative composition of the obtained extracts.
 Results and discussion. The yield of fatty acids obtained with supercritical carbon dioxide co-solvent was 1.8 times higher than that obtained with standard extraction according to the Folch method. The content of impurities was lower than in the samples with chloroform-methanol system. The polyunsaturated fatty acids isolated from L. anthosticta mainly belonged to ω-3 (18.0%), ω-6 (11.7%), ω-7 (21.2%), ω-9 (10.1%), and ω-11 (6.5%). The rest was saturated fatty acids, mainly palmitic (14%) and myristic (6%). The qualitative composition of the lipid fraction did not depend significantly from the isolation method. However, the supercritical extraction increased the product yield, extraction rate, and the quality of the extraction residue. Supercritical carbon dioxide left a dry residue, which had no typical smell and was brittle enough for grinding. Such residue can presumably be used to produce protein concentrate.
 Conclusion. Supercritical extraction with chloroform can be recommended to isolate fatty acids from marine organisms at 60°C and 400 bar.

Immunosafe(r)-by-design nanoparticles: Molecular targets and cell signaling pathways in a next-generation model proxy for humans.

Nanotechnology research covers a wide field of studies pointing to design and shape complex matter in a scale between 1 and 100nm, with unique size-depending properties and applications. The value and potential of engineered nanoparticles in human diagnostics and therapies essentially relay on their safety and biocompatibility. Entering a cell, in fact, these particles take complex interactions with the surrounding biological environment, dramatically changing their own identity. The formation of a custom-made protein corona is the first signal of their interplay with the cell defensive mechanisms, and a major issue in their application in medicine. Preliminary in-depth studies in model organisms have been developed to assess immunological safety and competence in facing the host immune system and its defensive response. New affordable animal models are emerging in pilot nano-response and safety studies. Sea urchins, benthic marine Echinoderms, have a wide and very efficient immune system working with innate defense mechanisms and are widely used in immune studies. Nano-safety studies have been showing that the sea urchin Paracentrotus lividus displays an excellent sensing system and high defensive capability, joined to the availability of easily accessible immune cells. As in mammals, nanoparticle recognition and interaction activate specific signaling pathways, metabolic rewiring and homeostasis maintenance. In this chapter, we point to the value of planning new research and developing nano-immune studies using an easy nonmammalian next-generation model, able to unravel new specific response mechanisms to nanoparticles.

A new subfamily of ionotropic glutamate receptors unique to the echinoderms with putative sensory role.

Chemosensation is a critical signalling process in animals and especially important in sea cucumbers, a group of ecologically and economically important marine echinoderms (class Holothuroidea), which lack audio and visual organs and rely on chemical sensing for survival, feeding and reproduction. The ionotropic receptors are a recently identified family of chemosensory receptors in insects and other protostomes, related to the ionotropic glutamate receptor family (iGluR), a large family of membrane receptors in metazoan. Here we characterize the echinoderm iGluR subunits and consider their possible role in chemical communication in sea cucumbers. Sequence similarity searches revealed that sea cucumbers have in general a higher number of iGluR subunits when compared to other echinoderms. Phylogenetic analysis and sequence comparisons revealed GluH as a specific iGluR subfamily present in all echinoderms. Homologues of the vertebrate GluA (aka α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, AMPA), GluK (aka kainate) and GluD (aka delta) were also identified. The GluN (aka N-methyl-d-aspartate, NMDA) as well as the invertebrate deuterostome subfamily GluF (aka phi) are absent in echinoderms. The echinoderm GluH subfamily shares conserved structural protein organization with vertebrate iGluRs and the ligand binding domain (LBD) is the most conserved region; genome analysis indicates evolution via lineage and species-specific tandem gene duplications. GluH genes (named Grih) are the most highly expressed iGluRs subunit genes in tissues in the sea cucumber Holothuria arguinesis, with Griha1, Griha2 and Griha5 exclusively expressed in tentacles, making them candidates to have a chemosensory role in this species. The multiple GluH subunits may provide alternative receptor assembly combinations, thus expanding the functional possibilities and widening the range of compounds detected during aggregation and spawning in echinoderms.

An annotated and illustrated checklist of the porcelain crabs of Panama (Decapoda: Anomura).

The present study is the first exhaustive checklist of porcelain crabs (Porcellanidae) distributed on the Pacific and Atlantic (Caribbean) coasts of Panama, based on literature records and material collected between 2006 and 2019. The Panamanian porcellanid fauna is currently composed of a total of 76 species, with 26 species reported from the Caribbean coast, 45 species reported from the Pacific coast, and five species reported from both sides of the Central American Isthmus (Isthmus of Panama). In other words, the Caribbean and Pacific coasts of Panama each harbour, respectively, 31 and 50 species of porcellanid crabs. However, this total includes two problematic porcellanid records from Panama, viz. Clastotoechus nodosus (Streets, 1872) and Petrolisthes brachycarpus Sivertsen, 1933, as well as a putatively undecribed taxon reported as Pachycheles sp. The following four species are recorded for the first time from Panama, viz. Euceramus panatelus Glassell, 1938, Pachycheles riisei (Stimpson, 1859) [also being new for Mexico], Petrolisthes dissimulatus Gore, 1983 and P. tonsorius Haig, 1960. In addition, Minyocerus kirki Glassell, 1938 is newly recorded from Colombia, extending its previously known distributional range significantly southwards. Most species are illustrated in colour, several for the first time, based on material from Panama or other localities. At least 20 further species (16 in the Atlantic, 5 in the Pacific, and 1 in both oceans) are suspected to occur in Panamanian waters, based on their records from the neighbouring Costa Rica and/or Colombia, or their wide distribution in the Caribbean Sea or the tropical eastern Pacific. The presence of several cryptic or pseudocryptic species (at least some of them presumably undescribed), especially in the taxonomically challenging Petrolisthes galathinus (Bosc, 1802) species complex, or the eventual species splitting within some taxa currently seen as transisthmian, will likely further increase the total number of species present in Panama. The porcellanid fauna of Panama is also ecologically remarkably diversified. Most Panamanian porcelain crabs are free-living under rocks, in crevices of rocks, dead coral heads, coralline algae, coral rubble etc., or on mud, among mangrove roots. Euceramus panatelus lives in possibly self-dug burrows in soft mud or muddy sand, whereas its congener E. transversilineatus (Lockington, 1878) may occasionally be found in association with holothuroids. At least 15 further porcellanid species occurring in Panama live in permanent or facultative associations with a variety of other marine organisms, including sponges, cnidarians (octocorals), echinoderms (sea urchins, sea stars, sea cucumbers), polychaetes (parchment worms) and other decapod crustaceans (hermit crabs), making them one of the most attractive groups for studies of symbiosis-related behaviour and evolution.

Very Stable Two Mega Dalton High-Molecular-Mass Multiprotein Complex from Sea Cucumber Eupentacta fraudatrix.

In contrast to many human organs, only the human liver can self-regenerate, to some degree. Some marine echinoderms are convenient objects for studying the processes of regenerations of organs and tissues. For example, sea cucumbers Eupentacta fraudatrix can completely restore within several weeks, the internal organs and the whole body after their division into two or three parts. Therefore, these cucumbers are a very convenient model for studying the general mechanisms of regeneration. However, there is no literature data yet on which biomolecules of these cucumbers can stimulate the regeneration of organs and the whole-body processes. Studying the mechanisms of restoration is very important for modern biology and medicine, since it can help researchers to understand which proteins, enzymes, hormones, or possible complexes can play an essential role in regeneration. This work is the first to analyze the possible content of very stable protein complexes in sea cucumbers Eupentacta fraudatrix. It has been shown that their organisms contain a very stable multiprotein complex of about 2000 kDa. This complex contains 15 proteins with molecular masses (MMs) >10 kDa and 21 small proteins and peptides with MMs 2.0–8.6 kDa. It is effectively destroyed only in the presence of 3.0 M MgCl2 and, to a lesser extent, 3.0 M NaCl, while the best dissociation occurs in the presence of 8.0 M urea + 0.1 M EDTA. Our data indicate that forming a very stable proteins complex occurs due to the combination of bridges formed by metal ions, electrostatic contacts, and hydrogen bonds.

Reproductive cycle and gonadal development of the Atlantic sea urchin Arbacia punctulata in the Gulf of Mexico: changes in nutritive phagocytes in relation to gametogenesis

ABSTRACTThe annual reproductive cycle comprises steady gametogenic activities that synchronize gonadal maturation and spawning rhythms, which are important for aquatic organisms including marine echinoderms (Echinodermata, Echinoidea). In this study, we report the annual reproductive cycle, gonadal development, and changes in nutritive phagocytes (NPs, which accumulate nutrients in germ cells) in relation to gametogenesis of the Atlantic sea urchin (Arbacia punctulata, an edible echinoid) in the Gulf of Mexico. Monthly changes in gonadal development and maturation were observed morphologically and histologically. We calculated gonadosomatic index (GSI) and compared the stages of gonadal development in order to determine the NPs index, and characteristics of germ cells (eggs and sperm) during the annual reproductive cycle. According to GSI and histological analyses, gametogenic activities were classified into four stages of both sexes: mature (June–August), spent (September–November), recovery (December–March), and growing (April–May). The GSI values in both sexes were high during summer months. In males, testicular lobules were densely packed with sperm from June to August. In females, however, mature eggs first appeared in some ovaries in May, numerically increased from June to July, and decreased in August. During gametogenesis, on the other hand, NPs in both testes and ovaries were depleted from June to August. Collectively, our results suggest that the Atlantic sea urchin spawns during summer months in the Gulf of Mexico. This is the first report, to the best of our knowledge, on gonadal development and changes in NPs during the annual reproductive cycle of any Arbacia species in the Gulf of Mexico.

Assessing bioaccumulation potential of personal care, household and industrial products in a marine echinoderm (Holothuria tubulosa)

A bioaccumulation study of 16 emerging contaminants including preservatives, UV-filters, biocides, alkylphenols, anionic surfactants and plasticizers, in Holothuria tubulosa Gmelin, 1791 specimens was developed. Water and sediments from their coastal habitat were also analyzed. Sediment-water distribution coefficients (log Kd) were in the range 0.78 to 2.95. A rapid uptake and bioaccumulation of pollutants was found. Compounds were detected in intestine and gonads of H. tubulosa after only eight days of exposure. Field-based bioconcentration (BCF) and biota-sediment accumulation factors (BSAF) were calculated. Log BCF > 1 were obtained for most of the compounds studied, indicating their tendency to accumulate in tissue of H. Tubulosa. BCF values decrease as follow: Triclocarban > anionic surfactants > benzophenone 3 > non-ionic surfactants > bisphenol A > parabens. These data provide a detailed accounting of the distribution patterns of some emerging contaminants in organisms at the lower trophic level, representing a potential source of contaminants for organisms in higher levels of the food chain.

Methyl Benzoate Increases High Density Lipoprotein Level In Diet-Induced Hypercholesterolemia In Animal Model Of Sprague-Dawley Rat

Background and Aims: Methyl benzoate was isolated from Acanthaster planci, an invasive marine echinoderm that can be found in Bidong archipelago of Terengganu, Malaysia. The effect of methyl benzoate in reducing the risk of hypercholesterolemia in Sprague-Dawley was investigated by feeding 625 μM of methyl benzoate via oral gavage daily for 28 days.

Bioaccumulation of perfluoroalkyl substances in marine echinoderms: Results of laboratory-scale experiments with Holothuria tubulosa Gmelin, 1791

Bioaccumulation of six perfluoroalkyl substances (PFAS) was assessed using the marine echinoderm Holothuria tubulosa Gmelin, 1791. Batch experiments were conducted to establish the relationship between concentrations in water, sediment and biota over 197 days. The sample treatment for the determination of compounds involves steps of lyophilization, solvent extraction and clean-up of the extracts with dispersive sorbents. PFAS were then analysed by liquid chromatography–tandem mass spectrometry. During contaminant exposure, detectable levels of compounds were found in all samples collected. Mean concentrations of selected PFAS were higher in sediments than in water samples. This fact is explained by the strong adsorption of these compounds into sediments. Sediment-water distribution coefficients (log Kd) were in the range 0.11 (PFBuA) to 2.46 (PFOA). Beside this, PFAS accumulation was observed in Holothuria tubulosa organisms. The uptake of PFAS was very rapid, reaching the maximum between 22 and 38 days of assay. Bioaccumulation factors (mean log BAF: 1.16–4.39) and biota sediment accumulation factors (mean log BSAF: 1.37–2.89) indicated a high bioaccumulation potential for the target compounds. Both parameters increased with perfluoroalkyl chain length (R2 > 0.93; p < 0.05). In organ-specific distributions of PFAS, greater concentrations were found in intestine than in gonads. Also, male specimens showed higher concentration levels than female (student t-test: tcal = 2.788, ttab = 2.262; p < 0.05). These data provide a detailed accounting of PFAS fate and distribution in the marine environment highlighting accumulation at lower trophic levels, a potential source for contamination in higher organisms.