Proteomic comparison of the organic matrices from parietal and base plates of the acorn barnacle Amphibalanus amphitrite.

Acorn barnacles are efficient colonizers on a wide variety of marine surfaces. As they proliferate on critical infrastructure, their settlement and growth have deleterious effects on performance. To address acorn barnacle biofouling, research has focused on the settlement and adhesion processes with the goal of informing the development of novel coatings. This effort has resulted in the discovery and characterization of several proteins found at the adhesive substrate interface, i.e. cement proteins, and a deepened understanding of the function and composition of the biomaterials within this region. While the adhesive properties at the interface are affected by the interaction between the proteins, substrate and mechanics of the calcified base plate, little attention has been given to the interaction between the proteins and the cuticular material present at the substrate interface. Here, the proteome of the organic matrix isolated from the base plate of the acorn barnacle Amphibalanus amphitrite is compared with the chitinous and proteinaceous matrix embedded within A. amphitrite parietal plates. The objective was to gain an understanding of how the basal organic matrix may be specialized for adhesion via an in-depth comparative proteome analysis. In general, the majority of proteins identified in the parietal matrix were also found in the basal organic matrix, including nearly all those grouped in classes of cement proteins, enzymes and pheromones. However, the parietal organic matrix was enriched with cuticle-associated proteins, of which ca 30% of those identified were unique to the parietal region. In contrast, ca 30-40% of the protease inhibitors, enzymes and pheromones identified in the basal organic matrix were unique to this region. Not unexpectedly, nearly 50% of the cement proteins identified in the basal region were significantly distinct from those found in the parietal region. The wider variety of identified proteins in the basal organic matrix indicates a greater diversity of biological function in the vicinity of the substrate interface where several processes related to adhesion, cuticle formation and expansion of the base synchronize to play a key role in organism survival.

The goose barnacle Pollicipes pollicipes as a tool for trace metal biomonitoring and health risk assessment for human consumers in northwestern Atlantic coast of Morocco.

The bioaccumulation of trace metals Cd, Cr, Cu, Fe, and Zn in soft tissues of the barnacle Pollicipes pollicipes was investigated seasonally along the Atlantic coast of northwestern Morocco. Average concentrations (µg g-1 dry weight) exhibited a decreasing order: Fe (548.15 ± 132.43) > Zn (430.80 ± 181.68) > Cd (17.46 ± 9.99) > Cu (7.72 ± 1.26) > Cr (3.12 ± 0.80), with the highest levels during wet seasons. The "Metal Pollution Index" and "Individual Multimetal Bioaccumulation Index" revealed a substantial barnacle contamination in industrialized areas. Additionally, Cd and Zn concentrations surpassed permissible guideline limits. While the "Target Hazard Quotient" and "Hazard Index" unveiled no significant health risks associated with barnacle consumption for humans, Cd posed potential risks, particularly for children consuming barnacles from polluted locations. Regarding the "Maximum Safe Consumption", Cd demonstrated potential harm across all sex and age groups. These findings contribute valuable data on the safety of barnacle consumption, marking the initial assessment of such risks in Morocco. The study offers evidence of metal pollution occurrence and proposes the barnacle species as a reliable biomonitor of trace metal bioavailabilities in marine coastal areas. To our knowledge, this investigation is the first comprehensive report of metal contamination biomonitoring using barnacles from Moroccan Atlantic waters.

New genes helped acorn barnacles adapt to a sessile lifestyle.

Barnacles are the only sessile lineages among crustaceans, and their sessile life begins with the settlement of swimming larvae (cyprids) and the formation of protective shells. These processes are crucial for adaptation to a sessile lifestyle, but the underlying molecular mechanisms remain poorly understood. While investigating these mechanisms in the acorn barnacle, Amphibalanus amphitrite, we discovered a new gene, bcs-6, which is involved in the energy metabolism of cyprid settlement and originated from a transposon by acquiring the promoter and cis-regulatory element. Unlike mollusks, the barnacle shell comprises alternate layers of chitin and calcite and requires another new gene, bsf, which generates silk-like fibers that efficiently bind chitin and aggregate calcite in the aquatic environment. Our findings highlight the importance of exploring new genes in unique adaptative scenarios, and the results will provide important insights into gene origin and material development.

Under pressure: Assessing the ecological boundaries of the epipelagic goose barnacle Lepas anatifera using ocean gliders and laboratory experiments.

Epipelagic barnacles have been considered good bioindicators since they are abundant and broadly distributed but with apparent tolerance restrictions to temperature and salinity, and also bioaccumulate pollutants. However, Lepas anatifera was found attached to the oceanic gliders, thriving through drastic and unreported environmental fluctuations. This study aimed to assess the resistance and oxidative stress responses of L. anatifera collected from gliders and attached to floating litter to temperature, salinity, and pressure. Barnacles withstood all tested pressure, temperature, and salinity ranges, except the extreme salt concentration. The activities of antioxidant enzymes - catalase and superoxide dismutase - were significantly increased under high temperature, high pressure, and low salinity. Malondialdehyde levels significantly increased only under high pressure. In conclusion, L. anatifera can be considered resistant organisms to extreme environmental changes. However, the instauration of oxidative stress under certain circumstances makes them vulnerable to predicted future trends in marine environments.

The Darwin wasp Camera thoracica (Szpligeti, 1916) (Ichneumonidae) as a natural enemy of the dreaded Brazilian wandering spider Phoneutria nigriventer (Keyserling, 1891) (Ctenidae).

Wandering spiders (genus Phoneutria) hold a prominent position as some of the worlds most medically significant venomous arachnids, especially in Brazil. In this study, we record and illustrate for the first time, the Darwin wasp Camera thoracica (Szpligeti, 1916) as a natural enemy of the ctenid Phoneutria nigriventer (Keyserling, 1891). Furthermore, we provide a description of the previously unknown male wasp, update and standardize the description of the female, and provide biological notes.

Rapid discovery of a new antifoulant: From in silico studies targeting barnacle chitin synthase to efficacy against barnacle settlement.

Due to the adverse environmental impacts of toxic heavy metal-based antifoulants, the screening of environmentally friendly antifoulants has become important for the development of marine antifouling technology. Compared with the traditional lengthy and costly screening method, computer-aided drug design (CADD) offers a promising and efficient solution that can accelerate the screening process of green antifoulants. In this study, we selected barnacle chitin synthase (CHS, an important enzyme for barnacle settlement and development) as the target protein for docking screening. Three CHS genes were identified in the barnacle Amphibalanus amphitrite, and their encoded proteins were found to share a conserved glycosyltransferase domain. Molecular docking of 31,561 marine natural products with AaCHSs revealed that zoanthamine alkaloids had the best binding affinity (-11.8 to -12.6 kcal/mol) to AaCHSs. Considering that the low abundance of zoanthamine alkaloids in marine organisms would limit their application as antifoulants, a marine fungal-derived natural product, mycoepoxydiene (MED), which has a similar chemical structure to zoanthamine alkaloids and the potential for large-scale production by fermentation, was selected and validated for stable binding to AaCHS2L2 using molecular docking and molecular dynamics simulations. Finally, the efficacy of MED in inhibiting cyprid settlement of A. amphitrite was confirmed by a bioassay that demonstrated an EC50 of 1.97 µg/mL, suggesting its potential as an antifoulant candidate. Our research confirmed the reliability of using AaCHSs as antifouling targets and has provided insights for the efficient discovery of green antifoulants by CADD.

Reducing Gut Dissolution of Zinc Oxide Nanoparticles by Secondary Microplastics with Consequent Impacts on Barnacle Larvae.

The environmental impact of sunscreen is a growing concern, yet the combined effects of its components on marine animals are poorly understood. In this study, we investigated the combined effects of sunscreen-extracted zinc oxide nanoparticles (nZnO) and microplastics (MPs) on the development of barnacle larvae, focusing on the different roles played by primary microplastics (PMPs) and secondary microplastics (SMPs) generated through the phototransformation of PMPs. Our findings revealed that a lower concentration of nZnO (50 µg/L) enhanced molting and eye development in barnacle larvae, while a higher concentration (500 µg/L) inhibited larval growth. Co-exposure to PMPs had no significant effect on larval development, whereas SMPs mitigated the impact of nZnO by restricting the in vivo transformation to ionic Zn. Accumulated SMPs reduced gut dissolution of nZnO by up to 40%, lowering gut acidity by 85% and buffering the in vivo dissolution of nZnO. We further identified a rough-surfaced Si-5 fragment in SMPs that damaged larval guts, resulting in decreased acidity. Another Si-32 resisted phototransformation and had no discernible effects. Our study presented compelling evidence of the impacts of SMPs on the bioeffect of nZnO, highlighting the complex interactions between sunscreen components and their combined effects on marine organisms.

The fluid dynamics of barnacle feeding.

Sessile barnacles feed by sweeping their basket-like cirral fan through the water, intercepting suspended prey. A primary component of the diet of adult barnacles is copepods that are sensitive to fluid disturbances and capable of escaping. How do barnacles manage to capture copepods despite the fluid disturbances they generate? We examined this question by describing the feeding current architecture of 1 cm sized Balanus crenatus using particle image velocimetry, and by studying the trajectories of captured copepods and the escapes of evading copepods. We found that barnacles produce a feeding current that arrives both from behind and the sides of the barnacle. The flow from the sides represents quiescent corridors of low fluid deformation and uninterrupted by the beating cirral fan. Potential prey arriving from behind are likely to encounter the cirral fan and, hence, capture here is highly unlikely. Accordingly, most captured copepods arrived through the quiet corridors, while most copepods arriving from behind managed to escape. Thus, it is the unique feeding flow architecture that allows feeding on evasive prey. We used the Landau-Squire jet as a simple model of the feeding current. For the Reynolds number of our experiments, the model reproduces the main features of the feeding current, including the lateral feeding corridors. Furthermore, the model suggests that smaller barnacle specimens, operating at lower Reynolds numbers, will produce a fore-aft symmetric feeding current without the lateral corridors. This suggests an ontogenetic diet shift from non-evasive prey to inclusion of evasive prey as the barnacle grows.

The first record larvae of the genus Peltogaster (Rhizocephala: Peltogastridae) with eyes and unilobed male aesthetasc.

The complete larval development of Peltogaster lineata Shiino, 1943 (Rhizocephala: Peltogastridae), including five nauplii and one cypris stage, is described and illustrated using SEM. The development took 3.5-4 days at a water temperature of 22-23 °C. Peltogaster lineata has the peltogastrid type of development. Nauplii possess a large and clearly reticulated flotation collar, six pairs of dorsal shield setae with the U-shaped second pair, long segmented frontolateral horns each with two subterminal setae, and a long seta at the antennal basis. The attachment disc in female cyprids has a flap-like extension at the posterior margin. Cyprids of both sexes possess two sensory setae at the attachment disc. The large male aesthetasc is unilobed, the female subterminal aesthetasc terminates into two thin long filamentous processes. Larvae of P. lineata have distinctly visible nauplius eyes.

Effective drying processes for Taikor (Garcinia pedunculata Roxb.) fruit by ultrasound-assisted osmotic pretreatment: Analysis of quality and kinetic models.

The present study aimed to analyze and establish an effective combination of ultrasound and immersion pretreatment processes for drying Taikor (Garcinia pendunculata Roxb.) fruits. Taikorslices were first immersed in 10 % sucrose, fructose, and glucose solution. Then, the immersed slices were treated in an ultrasonic bath at 30 °C for 10, 20, and 30 min. Drying operations were carried out at 50, 60, and 70 °C, with a fixed relative humidity of 30 %. The Page, Newton, Henderson and Pabis, and Weibull distribution models were fitted to the obtained drying data to determine the best kinetic model that effectively describes the drying properties ofTaikor. After drying operations, changes in quality parameters, e.g., ß-carotene, vitamin C, B vitamins, color, antioxidant activities, and microbial loads, were measured to obtain the best drying temperature and the most effective pretreatment combination with minimum loss of nutrients of the sample. Among different kinetic models, both Page and Weibull distribution models showed the best R2 values of 0.9867 and 0.9366, respectively. The chemical properties were preserved to the greatest extent possible by drying at 50 °C with glucose pretreatment. The color parameters were better preserved by fructose pretreatment. Sonication time also had profound effect on the quality parameters of dried Taikor slices. However, higher temperature drying required a shorter time for drying and exhibited better performance in microbial load reduction. This study's findings will help to establish an effective drying condition forGarcinia pedunculatafruits.

The first record of a Konservat-Lagerstätten in which early post-settlement stages of fossil archaeobalanids (Cirripedia: Balanomorpha) are preserved.

A diverse sessile barnacle fauna from a Miocene shallow-water deposit at Dolnja Stara vas in Slovenia is described. It includes the first descriptions of early post settlement juveniles of Actinobalanus sloveniensis attached to mangrove leaves. These represent three distinct growth phases, the earliest being interpreted as being less than 24 h post settlement, the others being 1 to 2 days post settlement. An assessment of their taphonomy is provided. Associated adult balanomorphs are attached to a variety of organic substrates, including mangrove leaves and branches, fragments of the conifers ?Taxodioxylon, Carapoxylon, pine cones, molluscs, and cetacean bones. The barnacles include A. sloveniensis, Amphibalanus venustus, and Perforatus perforatus-many with opercula retained within the shells. A. venustus retains some of the original shell color. This is the second record of barnacle-plant associations from the Central Paratethys from Kamnik and Trbovlje. The paleoecology and paleogeography of the site are discussed.

Thermal performance study of a PV-driven innovative solar dryer with and without sensible heat storage for drying of Garcinia Pedunculata.

Uneven drying is the key drawback of a conventional multi-tray dryer. Therefore, an improved active solar dryer with and without integrated sensible heat storage (SHS) was proposed. A unique feature of this dryer is its movable walls from the sides of the dryer to transform it to an indirect or mixed-mode as and when necessary. Garcinia Pedunculata (GP) is a local seasonal medicinal fruit in Northeast India. Drying kinetics of GP, the dryer performance and economic analysis of dryer were evaluated in the indirect solar dryer without SHS (Exp. I), mixed-mode solar dryer without SHS (Exp. II), indirect solar dryer with SHS (Exp. III), mixed-mode solar dryer with SHS (Exp. IV), and open sun drying (OSD). The dryer's average efficiencies were 18.12%, 22.37%, 21.74%, and 24.46% for Exp. I, Exp. II, Exp. III, and Exp. IV, respectively. The moisture content of GP was reduced to 12.09% in wet basis (w.b.) from 87.99% (w.b.). The overall drying time for Exp. I, Exp. II, OSD, Exp. III and Exp. IV were 31, 26, 53, 28, and 10 h, respectively. From the eleven drying models, the Two-Term model was the best-fitted model for Exp. I, Exp. II, OSD and Exp. III, and Midilli and Kucuk model was for Exp. IV. The final product's fragrance and colour are better for Exp. IV. Developing this dryer for Exp. I, Exp. II, Exp. III and Exp. IV, the price required was around 25,000, 27,000, 26,000, and 28,000 INR (1 US$ = 74.57 INR), respectively, while the economic payback periods are 1.6 years, 0.9 year, 1.4 years, and 0.59 year, respectively.

Daphnepedunins G and H, anti-HIV macrocyclic 3,4-seco-daphnane orthoesters from Daphne pedunculata.

Daphnepedunins G (1) and H (2) with unusual macrocyclic 3,4-seco-daphnane orthoester structure were isolated from Daphne pedunculata. Their structures were determined by physicochemical and spectroscopic analyses combined with synthetic methods, including methyl esterification, derivatization reaction using a chiral anisotropic agent, and biomimetic conversion. Compounds 1 and 2 along with their methyl esters 1a and 2a were evaluated for anti-HIV activity, among which 1a and 2a exhibited potent activity with IC50 values of 1.08 and 1.17 µM, respectively.

Comparative genomics reveals the dynamic evolutionary history of cement protein genes of barnacles from intertidal to deep-sea hydrothermal vents.

Thoracican barnacles are a diverse group of marine organisms for which the availability of genome assemblies is currently limited. In this study, we sequenced the genomes of two neolepadoid species (Ashinkailepas kermadecensis, Imbricaverruca yamaguchii) from hydrothermal vents, in addition to two intertidal species. Genome sizes ranged from 481 to 1054 Mb, with repetitive sequence contents of 21.2% to 50.7%. Concordance rates of orthologs and heterozygosity rates were between 82.4% and 91.7% and between 1.0% and 2.1%, respectively, indicating high genetic diversity and heterozygosity. Based on phylogenomic analyses, we revised the nomenclature of cement genes encoding cement proteins that are not homologous to any known proteins. The major cement gene, CP100A, was found in all thoracican species, including vent-associated neolepadoids, and was hypothesised to be essential for thoracican settlement. Duplicated genes, CP100B and CP100C, were found only in balanids, suggesting potential functional redundancy or acquisition of new functions associated with the calcareous base. An ancestor of CP52 genes was duplicated dynamically among lepadids, pollicipedids with multiple copies on a single scaffold, and balanids with multiple sequential repeats of the conserved regions, but no CP52 genes were found in neolepadoids, providing insights into cement gene evolution among thoracican lineages. This study enhances our understanding of the adhesion mechanisms of thoracicans in underwater environments. The newly sequenced genomes provide opportunities for studying their evolution and ecology, shedding light on their adaptation to diverse marine environments, and contributing to our knowledge of barnacle biology with valuable genomic resources for further studies in this field.

Cytotoxic xanthones from Garcinia pedunculata fruits.

Eight previously undescribed and seven known xanthones were isolated from the fruits of Garcinia pedunculata Roxb. The structures were identified by a variety of spectroscopic methods as well as by comparison with the literature. The isolates showed appreciable cytotoxicity against three human tumor cell lines (HepG2, A549, and MCF-7). Pedunculaxanthone G exhibited inhibitory activities with IC50 values of 12.41, 16.51, and 15.45 µM against the cancer cell lines and induced cell apoptosis in HepG2 cells.

Impacts of ocean acidification and warming on the release and activity of the barnacle waterborne settlement pheromone, adenosine.

The effects of ocean acidification (OA) and warming on the physiological processes of many marine species have been well documented. However, far less is known about the impacts of these global variables on chemical communication. In this study, we identified the barnacle waterborne settlement pheromone (BWSP) of Balanus albicostatus as adenosine (Ado). Our results showed that neither elevated temperature (30 °C vs. ambient 26 °C) nor elevated pCO2 (1000 µatm vs. ambient 400 µatm) significantly affected the release of Ado from B. albicostatus adults. Exposure to elevated temperature and OA did not impair larval cue perception for settlement in B. albicostatus; however, OA inhibited settlement under elevated temperature in the absence/presence of BWSP, and elevated temperature induced larval settlement only in the presence of BWSP under ambient pCO2 condition. These results provided important insights into barnacle aggregation behavior in changing oceans and may help to predict the consequences of climate change on barnacle populations.

Tricks of the puppet masters: morphological adaptations to the interaction with nervous system underlying host manipulation by rhizocephalan barnacle Polyascus polygeneus.

Background: Rhizocephalan interaction with their decapod hosts is a superb example of host manipulation. These parasites are able to alter the host's physiology and behavior. Host-parasite interaction is performed, presumably, via special modified rootlets invading the ventral ganglions. Methods: In this study, we focus on the morphology and ultrastructure of these special rootlets in Polyascus polygeneus (Lützen & Takahashi, 1997), family Polyascidae, invading the neuropil of the host's nervous tissue. The ventral ganglionic mass of the infected crabs were fixed, and the observed sites of the host-parasite interplay were studied using transmission electron microscopy, immunolabeling and confocal microscopy. Results: The goblet-shaped organs present in the basal families of parasitic barnacles were presumably lost in a common ancestor of Polyascidae and crown "Akentrogonida", but the observed invasive rootlets appear to perform similar functions, including the synthesis of various substances which are transferred to the host's nervous tissue. Invasive rootlets significantly differ from trophic ones in cell layer composition and cuticle thickness. Numerous multilamellar bodies are present in the rootlets indicating the intrinsic cell rearrangement. The invasive rootlets of P. polygeneus are enlaced by the thin projections of glial cells. Thus, glial cells can be both the first hosts' respondents to the nervous tissue damage and the mediator of the rhizocephalan interaction with the nervous cells. One of the potential molecules engaged in the relationships of P. polygeneus and its host is serotonin, a neurotransmitter which is found exclusively in the invasive rootlets but not in trophic ones. Serotonin participates in different biological pathways in metazoans including the regulation of aggression in crustaceans, which is reduced in infected crabs. We conclude that rootlets associated with the host's nervous tissue are crucial for the regulation of host-parasite interplay and for evolution of the Rhizocephala.

Sacculina-Induced Morphological Feminization in the Grapsid Crab Pachygrapsus crassipes.

Rhizocephalan barnacles (Thecostraca: Cirripedia) are parasitic crustaceans that lack appendages, segmentation, and a digestive system in adults, while instead infiltrating their hosts with a nutrient-absorbing system of rootlets. Sacculinids, belonging to the Rhizocephala order, are known for their various parasitization-induced effects on their decapod hosts, such as parasitic castration, reduction in the growth of secondary sexual characteristics, feminization of male crabs, and alteration of host behavior. In this study, we conducted field surveys in Japan at Manazuru Town (Kanagawa) on the Pacific coast, and on Sado Island and Noto Peninsula on the Sea of Japan side, and found that sacculinid-parasite-ratios on the grapsid crab Pachygrapsus crassipes were particularly high on the Sea of Japan coast. Molecular phylogenetic analysis revealed that the Manazuru population forms a single clade with Sacculina yatsui, and both Sado and Noto populations form a single clade with S. confragosa. We further demonstrated that external morphologies of male P. crassipes parasitized by sacculinids were changed to female phenotypes. This host-parasite interaction will be a useful model for understanding molecular mechanisms underlying rhizocephalan-driven morphological and behavioral feminization and castration.

Evaluation of natural resveratrol multimers as marine antifoulants.

In the current study we investigate the antifouling potential of three polyphenolic resveratrol multimers (-)-hopeaphenol, vaticanol B and vatalbinoside A, isolated from two species of Anisoptera found in the Papua New Guinean rainforest. The compounds were evaluated against the growth and settlement of eight marine microfoulers and against the settlement and metamorphosis of Amphibalanus improvisus barnacle cyprids. The two isomeric compounds (-)-hopeaphenol and vaticanol B displayed a high inhibitory potential against the cyprid larvae metamorphosis at 2.8 and 1.1 µM. (-)-Hopeaphenol was also shown to be a strong inhibitor of both microalgal and bacterial adhesion at submicromolar concentrations with low toxicity. Resveratrol displayed a lower antifouling activity compared to the multimers and had higher off target toxicity against MCR-5 fibroblasts. This study illustrates the potential of natural products as a valuable source for the discovery of novel antifouling leads with low toxicity.