Species Of Marine Molluscs Research Articles

Nematicidal Potentiality of Four Marine Molluscans' Defensive Secretions From the Red Sea Against Syphacia obvelata (Nematoda: Oxyuridae) In Vitro.

The continuous requirement to substitute safe and affordable alternatives for helminth medications, as well as address the resistance of some used drug classes, introduced bioactive products derived from marine animals into the field of competition; however, almost all the previous research only focused on their impact on bacterial and protozoal infection. In the present work, we investigated the potential in vitro nematocidal effect of the aqueous extract of defense secretions for four species of marine mollusks: two cephalopods, namely the cuttlefish Sepia pharaonis and the common Octopus Octopus vulagris and two gastropods, the sea hare Aplysia argus and the sea slug Berthillina citrina, against the adult murine pinworm Syphacia obvelata. Data showed dose and time efficacy in all examined extracts. The sea slug's skin acid secretion has the highest impact, causing death in the cultivated worms, followed by the ink of the sea hare, the common octopus and the cuttlefish, where LC90 after 10 h of exposure were 250, 290, 316, and 391 µg/mL, respectively. Comparatively with the control and albendazole-treated groups, the skin acid secretion of the sea slug caused the highest levels of the antioxidant enzymes SOD, Cat and GSH-PX; however, albendazole prompted the highest level of GSH-PX enzyme in all experimental groups.

Spatial metabolomics shows contrasting phosphonolipid distributions in tissues of marine bivalves

Lipids are an integral part of cellular membranes that allow cells to alter stiffness, permeability, and curvature. Among the diversity of lipids, phosphonolipids uniquely contain a phosphonate bond between carbon and phosphorous. Despite this distinctive biochemical characteristic, few studies have explored the biological role of phosphonolipids, although a protective function has been inferred based on chemical and biological stability. We analyzed two species of marine mollusks, the blue mussel Mytilus edulis and pacific oyster Crassostrea gigas, and determined the diversity of phosphonolipids and their distribution in different organs. High-resolution spatial metabolomics revealed that the lipidome varies significantly between tissues within one organ. Despite their chemical similarity, we observed a high heterogeneity of phosphonolipid distributions that originated from minor structural differences. Some phosphonolipids are ubiquitously distributed, while others are present almost exclusively in the layer of ciliated epithelial cells. This distinct localization of certain phosphonolipids in tissues exposed to the environment could support the hypothesis of a protective function in mollusks. This study highlights that the tissue specific distribution of an individual metabolite can be a valuable tool for inferring its function and guiding functional analyses.

The new Checklist of the Italian Fauna: marine Mollusca

The mollusc fauna of the Mediterranean Sea is still considered as the best-known marine mollusc fauna in the world. The previous modern checklists of marine Mollusca were produced by joint teams of amateurs and professionals. During the last years the Italian Society of Malacology (Società Italiana di Malacologia – S.I.M.) maintained an updated version of the Mediterranean checklist, that served as the backbone for the development of the new Italian checklist. According to the current version (updated on April 1st, 2021), 1,777 recognised species of marine molluscs are present in the Italian Economic Exclusive Zone, including also the Tyrrhenian coasts of Corsica and the continental shelf of the Maltese archipelago. The new checklist shows an increase of 17% of the species reported in the 1995 Checklist. This is largely (yet not solely) due to the new wave of studies based on Integrative Taxonomy approaches. A total of 135 species (7.6%) are strictly endemic to the Italian waters; 44 species (2.5%) are alien and correspond to the 28% of the Mediterranean alien marine molluscs. All eight extant molluscan classes are represented. The families represented in the Italian fauna are 307, an increase of 14.6% from the first checklist, partly due to new records and partly to new phylogenetic systematics. Compared with the whole Mediterranean mal-acofauna, the Italian component represents 71% in species and 61% in families, which makes it a very remarkable part of the Mediterranean fauna.&nbsp

Projecting global mariculture production and adaptation pathways under climate change.

The sustainability of global seafood supply to meet increasing demand is facing several challenges, including increasing consumption levels due to a growing human population, fisheries resources over-exploitation and climate change. Whilst growth in seafood production from capture fisheries is limited, global mariculture production is expanding. However, climate change poses risks to the potential seafood production from mariculture. Here, we apply a global mariculture production model that accounts for changing ocean conditions, suitable marine area for farming, fishmeal and fish oil production, farmed species dietary demand, farmed fish price and global seafood demand to project mariculture production under two climate and socio-economic scenarios. We include 85 farmed marine fish and mollusc species, representing about 70% of all mariculture production in 2015. Results show positive global mariculture production changes by the mid and end of the 21st century relative to the 2000s under the SSP1-2.6scenario with an increase of 17%±5 and 33%±6, respectively. However, under the SSP5-8.5scenario, an increase of 8%±5 is projected, with production peaking by mid-century and declining by 16%±5 towards the end of the 21st century. More than 25% of mariculture-producing nations are projected to lose 40%-90% of their current mariculture production potential under SSP5-8.5 by mid-century. Projected impacts are mainly due to the direct ocean warming effects on farmed species and suitable marine areas, and the indirect impacts of changing availability of forage fishes supplies to produce aquafeed. Fishmeal replacement with alternative protein can lower climate impacts on a subset of finfish production. However, such adaptation measures do not apply to regions dominated by non-feed-based farming (i.e. molluscs) and regions losing substantial marine areas suitable for mariculture. Our study highlights the importance of strong mitigation efforts and the need for different climate adaptation options tailored to the diversity of mariculture systems, to support climate-resilient mariculture development.

Nutritional evaluation of some economically important marine and freshwater mollusc species of Bangladesh

Molluscs are the most important resources among all the seafood items in South-East Asian countries. However, very little information available on nutritional value of molluscs in these regions. In this study, we evaluated the 7 economically important species of molluscs in terms of proximate composition, amino acids profile, fatty acids profile, cholesterol and heavy metal contents in the bivalves (mussels, oysters, clams and cockles) and univalve (snail) collected from freshwater and marine environments of Bangladesh. The results of the proximate analyses revealed that significantly higher amount of crude protein contents were present in marine water oysters, clams and cockles (59.3 ± 0.3 to 75.4 ± 0.2%) than the freshwater mussels and snail (36.9 ± 0.4 to 49.6 ± 0.6%) on dry matter basis. However, carbohydrate contents were significantly higher in freshwater mussels and snail (30.2 ± 0.9 to 57.3 ± 0.2%) compared to the marine water bivalves (8.1 ± 0.4 to 20.2 ± 0.6%). Crude lipid contents were ranged from 2.5 ± 0.2 to 11.2 ± 0.1% and ash from 11.4 ± 0.1 to 16.8 ± 0.6% among the bivalves and snail species. The amino acid contents were comparatively higher in marine water bivalves than their freshwater counterparts. Saturated fatty acid contents were found to be higher in marine water bivalves than the freshwater mollusc species. The results also show that the omega-3 (eicosapentaenoic acid, EPA and docosahexaenoic acid, DHA) fatty acids were comparatively higher in oysters, clams and cockles in marine water than those in freshwater mussels and snail. However, omega-6 fatty acids like linoleic acid (LA), α- linolenic acid (ALA) and arachidonic acid (ARA) were higher in freshwater mussels and snail than in the marine bivalves. The n-3/n-6 ratio were significantly higher in oysters and cockle species than the other groups of bivalves and snail. The index of atherogenicity and index of thrombogenicity of the mollusc species ranged from 0.74 ± 0.1 to 1.74 ± 0.2 and 0.5 ± 0.1 to 2.6 ± 0.2, respectively. The results show that marine water bivalves contained higher amount of potassium, sodium, iron, chlorine especially oyster species contained significantly higher iodine than the freshwater bivalves and snail. However, freshwater mussels and snail showed significantly higher amount of zinc contents than the marine bivalves. The heavy metal contents such as arsenic, chromium and mercury were absent or present in very tiny amounts among the mollusc species. Significantly higher amount of cholesterol was present in marine bivalves and freshwater snail species than the freshwater mussels. Overall, the results indicate that marine bivalves can be good sources of high quality protein and lipid especially EPA and DHA. On the other hand, freshwater mussels and snails also could be good sources of protein, LA and ARA but scarcity of EPA and DHA.

On two rare species of Plio-Pleistocene marine molluscs of the Mediterranean Basin

On two rare species of Plio-Pleistocene marine molluscs of the Mediterranean Basin

An ecosystem services perspective for the economic value of seafood production supported by seagrass ecosystems: An exercise in Derawan Island, Indonesia

Seagrass meadows provide provisioning services that play a vital role in food security and human wellbeing, especially on the small island. However, the utilisation value is uncalculated as support for seafood production and livelihoods for the community, because they are considered as alternative uses, so that seagrass ecosystem services are underestimated and undervalued. This paper aims to show the economic value provided by seagrass ecosystem services in providing seafood, both as a primary or secondary source. Through field survey and effect on production (EOP) analysis shows that capture fisheries and other marine biota collecting, both crustacean and mollusc species associated with the seagrass ecosystem are utilised directly by coastal communities in Derawan Island, Indonesia. Estimates of the economic value of fish and marine biota employed in the seagrass ecosystem area are US$ US$ 13,488.80 and US$ 35,744.69 per hectare per year, respectively, or a total of US$ 49,233.49 per hectare per year. This value demonstrates the potential importance of seagrass ecosystems. Unfortunately, these benefit values have not been fully understood by the communities, so that many people ignore the function of seagrass ecosystem services as provisioning services, although in the scarcity the utilisation of the seagrass ecosystem is quite intensive. Hence, the precautionary principle and suggesting conservation actions in a participatory manner is challenging to implement.

An Effective Microinjection Method and TALEN-Mediated Genome Editing in Pacific Abalone.

Pacific abalone, Haliotis discus hannai, is an economically important marine mollusk species and an important model animal for studies on ecological, fertilization and developmental biology. While embryonic injection and genome editing have been wildly used in gene function study and trait improvement in many species, they have not been developed in abalones. In this study, we reported an effective method to inject exogenous materials in H. discus hannai unfertilized eggs. The injected eggs could be fertilized at a ratio of 52.6% ± 5.9% and hatch at a ratio of 14.6% ± 1.6%. On the base of this, we further developed an efficient genome editing approach in this species with the transcription activator-like effector nuclease (TALEN) technique. Two TALEN pairs targeting the coding sequence of the abalone nodal gene were assembled and tested. While one of the TALEN pairs showed no detectable mutation efficacy, the other one generated mutations in 50% of the targeted loci. The mutation includes small insertions and deletions and base pair replacements like that reported in other species when the TALEN method was applied. Overall, this is the first study to demonstrate site-specific genome editing in abalone. This work can serve as a reference for future studies focusing on the functional genomics in mollusks.

Nutritional profiling of selected species of edible marine molluscs from the south-west coast of India

The current study determined the nutritional parameters of selected species of edible marine molluscs viz., Indian squid Uroteuthis (Photololigo) duvaucelii, veined octopus Amphioctopus marginatus, spineless cuttlefish Sepiella inermis and edible oyster Crassostrea bilineata (=madrasensis) from the Arabian Sea and estuarine systems of the south-west coast of India. The selected species demonstrated balanced essential to non-essential amino acids ratio (1.04-1.52). U. (P.) duvaucelii exhibited greater quantities of sulfur comprising amino acids (0.102 g 100 g-1 wet weight) and lysine (1.566 g 100 g-1). Among polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were found to be prominent in edible portion of the molluscs studied (7.6-10.3 and 8.7-17.4% respectively). A. marginatus exhibited significantly greater n-3/n-6 PUFA (~7, p<0.05) than other molluscs. Lower thrombogenicity and atherogenicity indices (<0.45 and <0.85, respectively) make the mollusc studied during the present investigation valuable food items for cardioprotection and anti-platelet aggregation. Higher content of vitamin D3 (489 IU) and vitamin K1 (1.84 μg 100 g-1) in C. bilineata signified their importance in preventing osteoporosis. The results reveal that these species are good sources of essential elements and toxic metals were below threshold limits of recommended standards for human consumption.

Sample checklist of Gastropoda and Bivalvia in Cham Islands, Vietnam.

BackgroundCham Islands (Cu Lao Cham) is a group of 8 small islands in the Quang Nam province, Central Vietnam. There is only one study that mentioned the diversity of marine molluscs in this area. However, the data on species composition have not been digitised and not stored or shared for other purposes. Our paper aims to share the checklist of marine mollusc species (Bivalvia and Gastropoda) species that we collected from the littoral zone of Cham Islands in May 2017. This is the first digitised and online data of marine molluscs in Vietnam. It is very important for researchers in various fields such as the structure and function of ecology and biodiversity monitoring.New informationThis study provides a checklist of the marine bivalves and snails in the Cham Islands of Vietnam. Moreover, this first widely shared data of biodiversity in Vietnam can trigger biodiversity data papers in this data-poor country.The data of this study will be important inputs for better understanding biodiversity on the Cham Islands and Vietnam as well as for forming the basis for monitoring, exploitation and conservation of biodiversity in this area.In total, 145 taxa were recorded, 46 bivalve taxa and 99 snail taxa, from which 128 were identified to the species level and 17 were identified to the genus level. There are 116 new species records for the Cham Islands.The specimens are currently deposited in the Institute of Ecology and Biological Resources (IEBR), Vietnam Academy of Science and Technology (VAST).

New records of alien and cryptogenic marine bryozoan, mollusc, and tunicate species in Libya

New records of alien and cryptogenic marine bryozoan, mollusc, and tunicate species in Libya

Proteinaceous secretion of bioadhesive produced during crawling and settlement of Crassostrea gigas larvae

Bioadhesion of marine organisms has been intensively studied over the last decade because of their ability to attach in various wet environmental conditions and the potential this offers for biotechnology applications. Many marine mollusc species are characterized by a two-phase life history: pelagic larvae settle prior to metamorphosis to a benthic stage. The oyster Crassostrea gigas has been extensively studied for its economic and ecological importance. However, the bioadhesive produced by ready to settle larvae of this species has been little studied. The pediveliger stage of oysters is characterized by the genesis of a specific organ essential for adhesion, the foot. Our scanning electron microscopy and histology analysis revealed that in C. gigas the adhesive is produced by several foot glands. This adhesive is composed of numerous fibres of differing structure, suggesting differences in chemical composition and function. Fourier transformed infrared spectroscopy indicated a mainly proteinaceous composition. Proteomic analysis of footprints was able to identify 42 proteins, among which, one uncharacterized protein was selected on the basis of its pediveliger transcriptome specificity and then located by mRNA in situ hybridization, revealing its potential role during substrate exploration before oyster larva settlement.

Complex patterns of temperature sensitivity, not ecological traits, dictate diverse species responses to climate change

Despite widespread interest in describing and forecasting the impacts of climate change on species distributions, poor understanding of the climate variables that shape distributions and conflicting perspectives on the role that species traits play in mediating shifts have limited our ability to interpret and project changes in species distributions. Using standardized survey data along the northeast US continental shelf, we assessed the historical exposure and sensitivity of 81 species of marine chordates, arthropods, and molluscs to 24 sea surface temperature (SST) variables in two seasons. By comparing temperature trends in geographies available to species against temperature trends in geographies used by them we were able to identify which variables species track consistently through space and time. Logistic regression analyses were then used to assess whether species traits affected the likelihood of niche tracking while accounting for the season and temporal window in which temperatures were summarized and methodological constraints that might have limited our ability to detect tracking responses. A slight majority of species (52%) clearly shifted their distributions to track at least one temperature variable through space and time. Tracking rates were much lower on a per variable basis (5.1% of 3432 variables), despite widespread exposure to changing temperatures (89.2% of 3432 variables). None of the twelve ecological traits we investigated – including traits related to dispersal ability, ecological specialization, reproductive capacity, and commercial harvest – accounted for differences in tracking responses across species even after accounting for differences in climate exposure. Our results suggest widespread behavioral or physiological flexibility among our study species, or ongoing genetic adaptation to changing temperatures. They also suggest that divergent selection on climate sensitivities of close relatives may limit the utility of ecological traits for predicting distributional responses to future climate change.

Ubiquity of the neurotoxin β-N-methylamino-L-alanine and its isomers confirmed by two different mass spectrometric methods in diverse marine mollusks

In recent years, the neurotoxin β-N-methylamino-L-alanine (BMAA) has been reported in some marine mollusk species. To further discover BMAA in marine animals, a total of 59 samples belonging to 3 phyla, 22 families, and 43 species, were collected from Dalian, Rongcheng, and Zhoushan cities, China, in April 2017. All samples were quantified by a hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) analysis of underivatized extract, and ten samples were also analyzed by a liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) analysis using a precolumn AQC (6-aminoquinolyl-N-hydroxysuccinimidyl carbamate)-derivatization method. Results indicated that 48 mollusk samples contained BMAA with concentrations above the limit of detection (0.31 μg g−1 wet weight), and the isomers of BMAA, β-amino-N-methylalanine (BAMA) and 2,4-diaminobutyric acid (DAB) were universally present in most samples. However, N-(2-aminoethyl) glycine (AEG) was not found in any sample. Comparison of both analytical methods showed that BMAA and BAMA were not completely separated by the HILIC column although they still could be identified by specific transitions. In contrast the C18 column provided good separation for the AQC-derivatives of BMAA and all of its isomers. Development of analytical methods and stable isotope tracing of BMAA should be carried out in the future.

Evolutionary radiation of cytotoxic effects in bivalve and gastropod haemolymph

A comparative immunological survey of cytotoxic properties of whole and cell-free haemolymph (plasma) was performed on four species of marine molluscs. Diverse target cells were used: auto- and heterologous mollusc haemocytes, starfish Asterias rubens coelomocytes, trematode Himasthla elongata rediae, and human erythrocytes. While all the four mollusc species were found to contain cytotoxic factors in their plasma, functional features of these molecules in bivalve and gastropod species are essentially different. Cell-free haemolymph of two clams, Mya arenaria and Mytilus edulis, contains pre-synthetized cytolytic complexes capable of immediate and generalized activation, leading to destruction of a broad range of target cells. On the contrary, two gastropod species, Buccinum undatum and Littorina littorea, possess haemolytic factors which display high specificity of recognition of receptor molecules on the target cells and slow cytolytic reaction. Overall, molecular strategies of cytolytic cascade activation in Bivalvia and Gastropoda can be described as low- and highly selective, respectively.

µ-Conotoxins Modulating Sodium Currents in Pain Perception and Transmission: A Therapeutic Potential.

The Conus genus includes around 500 species of marine mollusks with a peculiar production of venomous peptides known as conotoxins (CTX). Each species is able to produce up to 200 different biological active peptides. Common structure of CTX is the low number of amino acids stabilized by disulfide bridges and post-translational modifications that give rise to different isoforms. µ and µO-CTX are two isoforms that specifically target voltage-gated sodium channels. These, by inducing the entrance of sodium ions in the cell, modulate the neuronal excitability by depolarizing plasma membrane and propagating the action potential. Hyperexcitability and mutations of sodium channels are responsible for perception and transmission of inflammatory and neuropathic pain states. In this review, we describe the current knowledge of µ-CTX interacting with the different sodium channels subtypes, the mechanism of action and their potential therapeutic use as analgesic compounds in the clinical management of pain conditions.

Perna canaliculus and the Intestinal Microbiome.

Natural medicines are often an attractive option for patients diagnosed with chronic conditions. Three main classes of bioactives that have been reported from marine mussel extracts include proteins, lipids and carbohydrates. Commercially, the most relevant species of marine mollusks belong to two genera, Perna and Mytilus. Specifically, the Perna canaliculus species has been repeatedly demonstrated to harbor anti-inflammatory compounds such as omega-3 polyunsaturated fatty acids (ω-3 PUFAs) that can ameliorate pro-inflammatory conditions, or proteins that can promote thrombin inhibitory activity. Recent clinical studies have posited that extracts from green-lipped mussels may lead to prebiotic activity in the intestinal microbiome that in turn has been reported to improve symptoms of osteoarthritis of the knee. Prebiotics have been reported to favorably interact with the intestinal microbiome through the proliferation of beneficial bacteria in the gut, suppressing exogenous and endogenous intestinal infections and promoting homeostasis by balancing local pro- and anti-inflammatory actions. Bioactive compounds from Perna canaliculus are functional foods and, in this regard, may positively interact with the intestinal microbiome and provide novel therapeutic solutions for intra-intestinal and extra-intestinal inflammatory conditions.

Morfogénesis del gametotito del helecho Thyrsopteris elegans (Filicales: Thyrsopteridaceae)

An annotated checklist of species of marine molluscs from Golfo Dulce, Bahia Coronado and Golfo de Nicoya. Costa Rica, obtained at 20-200 m during the Victor Hensen cruise, includes 157 species: 108 Gastropoda and 49 Pelecypoda. The checklist includes station and depth data for all species.

Possible impacts of zoosporic parasites in diseases of commercially important marine mollusc species: part I. Perkinsozoa

AbstractThe phylum Perkinsozoa includes well-known parasites of commercially important species of molluscs in aquaculture, such as

Possible impacts of zoosporic parasites in diseases of commercially important marine mollusc species: part II. Labyrinthulomycota

AbstractThe phylum Labyrinthulomycota comprises diverse marine fungus-like protists that are an abundant and widespread component of the marine microbiota. Despite their ubiquity in marine ecosystems, relatively little is known about the ecology of any of the pathogenic species in the Labyrinthulomycota. Most are thought to exist as saprobes, but many species have been documented as pathogens of marine metazoans and metaphytes. The best studied labyrinthulomycotan pathogen in molluscs is Quahog Parasite Unknown (QPX), which causes mortality events in both wild and cultured hard clams,