Search Results (89)

Background/Objectives: Sea urchin gonads (“roe”) are a valuable seafood product and a chemically complex matrix whose composition varies with physiology and environment. We present a biphasic extraction and ¹H NMR workflow to build a reusable reference inventory of polar metabolites and apolar lipid features in Paracentrotus lividus. Methods: Gonads from 37 adults (23 males, 14 females) collected at two sites (Alicante and Jávea–Dénia, Spain; October 2024) were lyophilized, extracted with methanol/chloroform/water, and analyzed by 400 MHz ¹H NMR in buffered aqueous solution (polar) and CDCl₃ (apolar). Polar metabolite identification combined 1D patterns with database matching and ¹H–¹³C HSQC confirmation on representative samples, yielding 71 annotated resonances corresponding to 37 metabolites spanning amino acids, osmolytes/quaternary amines, carbohydrates/aminosugars, and nucleoside/purine-related compounds. Results: Polar fingerprints enabled supervised modelling: PLS-LDA separated sexes with low cross-validated error, and SPA/COSS ranking highlighted glycine, alanine, creatine and osmolyte-associated signals as key discriminants; pathway mapping supported the enrichment of amino-acid and one-carbon/purine networks. Apolar spectra were annotated at the motif level and used for lipid-index estimation, indicating substantial unsaturation but low docosahexaenoic acid (DHA) and modest sex effects. Conclusions: The curated peak lists and reporting framework facilitate reproducible NMR annotation and future comparative studies of P. lividus gonads. Full article

Over the past few decades, demand for sea urchin roe has risen, while wild sea urchin populations have declined. This trend has increased interest in aquaculture techniques and the development of formulated feeds to support ecological restoration and research. Here, we examined the effects of a high-protein formulated feed on gonad development in Paracentrotus lividus, compared to fresh feeds (maize and spinach), across three replicated tanks. We assessed gonad maturation, gamete viability, and larval development, and developed a new histopathological index applicable to both sexes. Formulated feed significantly enhanced gonad maturation, increased gamete production, and led to heavier gonads with higher gonadosomatic indices compared to fresh feeds, which were insufficient to promote maturation within four weeks. Notably, no histological alterations were observed in the gonads. Fertilization trials showed that embryos were produced, but none reached the pluteus stage, indicating decreased embryo viability. Although the formulated feed improved gonad development, it adversely affected water quality, increasing nutrient concentrations and lowering pH. Overall, these findings suggest that high-protein formulated feeds could potentially improve aquaculture production by enhancing gonad maturation and gamete output, but additional measures may be needed to support complete larval development. Full article

The European flat oyster Ostrea edulis and the stony sea urchin Paracentrotus lividus play key ecological roles in Mediterranean coastal ecosystems, supporting biodiversity and ecosystem functions. The decline of their natural populations has prompted several restoration initiatives; however, the rapid spread of the invasive blue crab Callinectes sapidus raises concern about its potential impact on native species and the success of these efforts. This study investigated predation by male and female C. sapidus on different size classes of O. edulis and P. lividus under controlled laboratory conditions. Crabs were offered single or mixed prey species, and consumption was monitored over 24 h. Small (~33 mm shell length) oysters were heavily preyed upon (>62%), whereas medium (~60 mm) and large (~82 mm) individuals were not consumed, although attempted predation on medium individuals was observed. In contrast, P. lividus was only occasionally consumed (<32%) at the smallest size (~13.5 mm diameter). Predation differed slightly between sexes at shorter exposure times but converged after 24 h. These results indicate that C. sapidus poses a serious threat to O. edulis restoration, particularly for small individuals, while its impact on P. lividus appears limited. Incorporating predator assessment and mitigation strategies into restoration planning should become standard practice to strengthen the resilience and effectiveness of Mediterranean restoration efforts. Full article

Background an Objectives: The Mediterranean sea urchins Paracentrotus lividus and Arbacia lixula co-occur on shallow rocky reefs but display contrasting ecological and physiological traits. We compared their gonadal metabolomes to identify species-specific metabolic strategies. Methods: High-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy to intact gonadal tissues, combining multivariate chemometric modelling with targeted integration, boxplot-based univariate analysis and pathway analysis. Results:A. lixula showed an osmolyte- and redox-oriented phenotype with elevated betaine, taurine, sarcosine, trimethylamine (TMA), trimethylamine N-oxide (TMAO), carnitine, creatine, malonate, methylmalonate, uridine and xanthine. In contrast, P. lividus exhibited an amino-acid-enriched anabolic profile dominated by lysine, glycine and glutamine, together with higher levels of formaldehyde, methanol and 3-carboxypropyl-trimethylammonium. Pathway analysis indicated that A. lixula metabolites mapped onto glycine/serine–threonine metabolism and the folate-linked one-carbon pool, whereas P. lividus metabolites were enriched in glyoxylate/dicarboxylate, nitrogen and amino-acid pathways. These contrasting osmolyte–C₁ versus nitrogen–amino-acid strategies are compatible with species-specific host–microbiota metabolic interactions inferred from published microbiome data. Conclusions: Overall, our results support a framework in which A. lixula adopts a resilience-oriented osmolyte strategy and P. lividus an efficiency-oriented anabolic strategy, highlighting HR-MAS NMR metabolomics as a powerful approach to investigate adaptive biochemical diversity in marine invertebrates. Full article

Climate-induced ocean warming poses a major threat to marine invertebrate reproduction, including the sea urchin Paracentrotus lividus, a species of considerable ecological, economic, and scientific interest. Its gonads, highly valued as a culinary delicacy, support local fisheries and aquaculture industries, making reproductive health a critical factor for both conservation and commercial viability. The present study reported the effects of elevated seawater temperatures, mimicking marine heatwave (MHW) conditions, on gonadal maturation and fertilization success on P. lividus. Here, adult specimens at the mature stage of gametogenesis were exposed to control (18 °C) and elevated temperature regimes (24 °C) over a six-week period, and key reproductive metrics were assessed, including histological analysis. Morphological analysis showed very evident gonadal retraction, nearly devoid of germ cells, both for males and females, with a significant decrease in the gonadal index. In addition, histological analysis revealed consistent damage to the gonads, with a significantly increase in histopathological index in specimens kept at 24 °C. These findings reinforce the temperature sensitivity of P. lividus reproduction, suggesting that recurrent heatwaves could severely impair its reproductive output and population dynamics with potential cascading effects on benthic community structure in a long-term ocean warming predicted to intensify. Full article

Sea urchin eggs are surrounded by a network of extracellular matrix, consisting of the jelly coat (JC) and vitelline layer (VL). While the voluminous JC evokes acrosomal reaction in the approaching sperm, the tight VL ensheathing the plasma membrane of the subjacent microvilli is known to be the subcellular site where ‘sperm receptors’ reside. In this study, we have examined the roles of JC and VL at fertilization in a combinatorial approach utilizing two different pretreatments of the eggs: (i) incubation with dithiothreitol (DTT) in alkaline seawater to remove JC and VL, (ii) masking the egg extracellular matrix with a carbohydrate-binding protein concanavalin A (Con A). Surprisingly, the results showed that the DTT-denuded eggs still engulfed sperm at fertilization, even more effectively than intact eggs, as multiple sperm entered. On the other hand, Con A appeared to interfere with sperm entry in a dose-dependent manner and to delay the onset of the Ca²⁺ wave in intact eggs after the cortical Ca²⁺ release, representing sperm–egg fusion. This prolonged time lag in triggering the Ca²⁺ wave at fertilization was associated with compromised dynamics of the subplasmalemmal actin filaments in Con A-pretreated eggs. By using Alexa Fluor 633 Con A and BPA-C8-Cy3, respectively, we also report unprecedented fluorescent labeling of the egg JC and the spontaneous ‘acrosomal protrusion’ on the head of Paracentrotus lividus sperm diluted in natural seawater. Combined with electron microscopy observations of intact and denuded eggs, our results suggest that the glycoconjugate on the egg surface contributes to the fertilization signal transduction, affecting the Ca²⁺ wave via actin cytoskeletal changes and sperm entry. Full article

The detection of tetrodotoxins (TTXs) in European shellfish led the European Union to request a risk assessment from the European Food Safety Authority (EFSA). EFSA set a reference limit of 44 µg TTX equivalents kg⁻¹ and called for more data on TTX occurrence, especially in gastropods, which can accumulate in TTXs but remain poorly studied. Recently, preliminary monitoring has revealed the recurrent presence of TTXs in mussels in three areas along the North–Central Adriatic coast of Italy, while research on non-bivalve organisms has not yet been carried out. This study presents a preliminary survey, conducted from January 2023 to March 2025, on the presence of TTXs in gastropods, echinoderms, and arthropods collected from this area. A method in Hydrophilic Interaction Liquid Chromatography coupled with tandem Mass Spectrometry (HILIC-MS/MS) for detecting TTXs in bivalve mollusks was first tested through an international proficiency test, then optimized for the other invertebrates, the object of this study. TTX levels in all gastropods and arthropod samples were undetectable, while traces (~5 µg kg⁻¹) were found in one echinoderm sample (Paracentrotus lividus), marking the first reported occurrence of TTX in this species. Sea urchins are widely consumed in Italy; therefore, this finding is of particular importance from a public health perspective and deserves further investigation. Some gastropod genera or species sampled (e.g., Nassarius, Rapana venosa) have been identified as TTX carriers in other regions; therefore, the negative results obtained in this study may be related to seasonal or geographic variability. These results provide valuable data to EFSA’s call for monitoring emerging risks, particularly as climate change may increase TTX prevalence in European waters as well as worldwide. Full article

Background: The edible gonads of the sea urchin Paracentrotus lividus are highly valued, yet sex cannot be determined externally, limiting selective harvest and quality control. Objective: We aimed to test whether headspace solid-phase microextraction gas chromatography–mass spectrometry combined with chemometrics can discriminate sex from gonadal volatilomes. Methods: Gonads from 29 individuals (21 females, 8 males) were profiled by this technique. Spectral data were modeled with Partial Least Squares–Linear Discriminant Analysis (PLS–LDA), Variable Importance in Projection scores highlighted key features, and Mann–Whitney tests assessed univariate differences. Tentative identifications were assigned by library match and curated for potential environmental artifacts. Results: Chemometric modeling yielded a clear female–male separation. Female gonads were enriched in low-odor-threshold oxygenates—aldehydes (hexanal, heptanal) and alcohols (1-penten-3-ol, 1-octen-3-ol)—together with diet-linked monoterpenes (e.g., D-limonene), consistent with PUFA LOX/HPL pathways and macroalgal inputs. Male gonads were dominated by saturated/branched hydrocarbons and long-chain alcohols with limited direct odor impact. Minor aromatic hydrocarbons (e.g., styrene; 1,3-bis(1,1-dimethylethyl)-benzene) were retained as environmental/artifact markers and excluded from biological interpretation. Conclusions: HS-SPME gas chromatography–mass spectrometry volatilomics coupled with PLS–LDA effectively distinguishes the sex of P. lividus gonads and rationalizes reported sensory differences. The marker set offers a basis for future non-destructive sexing workflows, pending confirmation with retention indices, authentic standards, and GC-olfactometry. Full article

Transmitters such as serotonin, dopamine, noradrenaline, and acetylcholine act as regulators or triggers of numerous processes in the early embryo, including in sea urchins. However, the identity of these mechanisms relative to mature nervous systems remains controversial. The aim of this study was to comprehensively characterize the transcriptomic basis of these as well as glutamatergic, GABAergic and histaminergic systems by comparing publicly available RNA-Seq data across four sea urchin species (Mesocentrotus franciscanus, Lytechinus variegatus, Paracentrotus lividus, Strongylocentrotus purpuratus) during early development (egg to early gastrula). Transcript abundance was normalized using the geometric mean of housekeeping genes (GHG) to facilitate comparative analysis and to use the universal significance threshold. We detected mRNA transcripts encoding numerous components (enzymes, receptors, transporters) for all seven transmitter systems from the earliest stages, suggesting a complex signaling potential prior to neurogenesis. The expression of multiple mRNAs of receptors for the same transmitter indirectly supports our earlier notion of the possibility of simultaneous regulation of different processes by this transmitter even in the single-cell embryo. Notably, transcripts for key synthesis enzymes (TPH, DBH) were often low, indicating limited de novo synthesis, while transcripts for degradation enzymes (MAO, AChE) were abundant. Consistent expression across species was observed for specific receptors such as HTR6, D1-like dopamine, β-adrenergic receptors and the α7 subunit of nicotinic AChR. However, the expression profiles of many components, particularly glutamatergic receptors and metabolic enzymes, showed considerable interspecies variability. These findings indicate that multiple transmitter systems are transcriptionally represented early in development, suggesting substantial molecular overlap with mature systems, while the diversity between species points to possible evolutionary plasticity. This comparative transcriptomic dataset provides a basis for targeted functional studies of the role and interactions of these pre-nervous transmitter pathways in orchestrating embryogenesis. Full article

This study evaluated the performance of a recirculating aquaculture system (RAS) integrated with macroalgae (Ulva ohnoi) cultivation and sea urchin (Paracentrotus lividus) feeding, in a multi-trophic aquaculture approach. This system aimed to enhance sustainability through water bioremediation by macroalgae and valorization of the algal biomass as echinoderms feed. Over a 180-day trial, biomass production of U. ohnoi remained stable, with daily growth rates ranging from 7.4 to 24.4%. Statistical analyses (PCA and GAM) indicated no significant linear or non-linear relationship between macroalgae growth and environmental parameters (temperature, radiation, photoperiod). A theoretical estimate of nutrient production showed fairly stable values that do not statistically explain biomass production variation, highlighting the species’ adaptability. Sea urchins fed with fresh U. ohnoi showed regular growth, supporting the nutritional suitability of this macroalgae. For fish (Sparus aurata), no significant differences in growth or feed conversion ratio were observed between systems with and without algae. Parasitological monitoring revealed lower parasite loads and egg deposition in tanks in recirculation with U. ohnoi during certain periods, suggesting a potential role of macroalgae in reducing monogenean propagation. These findings underscore the feasibility of integrating Ulva cultivation into RAS, contributing to circular aquaculture models with improved sustainability and resource efficiency. Full article

The sea urchin Paracentrotus lividus is a good model in ecotoxicology, but adults living along the Italian coasts have a limited reproductive period. In this species, natural or human-driven pressures may lead to limited gamete availability for ecotoxicological surveys. This study investigates the quality of early developmental stages of wild and cultured sea urchins to be used in ecotoxicology, avoiding field collection of mature specimens. Adult sea urchins were cultured in the laboratory for 2 years. Every 45 days, fertilization and larval quality were checked and compared to those from adults sampled in the wild. Fertilization was never affected, differently from development, which was impaired in the larvae obtained from sea urchins reared for more than one year. Fertilization and embryotoxicity were performed using copper nitrate in wild and cultured sea urchins. Fertilization did not differ up to ten months, while similar embryotoxicity was only found up to 5 months. This study promotes rearing sea urchins in ‘ready-to-spawn’ conditions for ecotoxicology surveys by recommending 10- and 5-month rearing times to assess fertilization and embryo toxicity, respectively. Here, we provided a baseline in marine ecotoxicology to obtain gametes on demand, irrespective of reproductive period and other pressures that may impact gamete availability. Full article

This study assesses sediment toxicity in the historically contaminated Orbetello Lagoon (southern Tuscany) using Paracentrotus lividus embryo development bioassays. Elutriates from 15 sites were analysed for trace metals, organic matter, and ammonium. Despite elevated mercury concentrations, toxicity did not consistently correlate with metal levels. Instead, Principal Component Analysis (PCA) identified ammonium as a key driver of developmental toxicity, suggesting that it significantly influences both biological effects and metal bioavailability. These results demonstrate that ammonium, often overlooked, can confound sediment toxicity assessments and should be integrated into risk evaluation frameworks for coastal systems affected by legacy pollution. Full article

Copper-based nanoparticles (as Cu₂O) are a key component in marine antifouling paints and, as coatings degrade, release nanoparticles that can affect a wide range of non-target organisms. This study investigates the impact of Cu₂O nanoparticles on the early development of urchins Arbacia lixula, Paracentrotus lividus and Sphaerechinus granularis, and benchmarks their toxicity against similarly sized Cu and CuO nanoparticles and ionic copper. Concentration-dependent toxicity was noted for all forms of copper at concentrations in the 1 to 5000 µg L⁻¹ range. EC₅₀ values after Cu₂O exposure indicated that A. lixula (99 µg L⁻¹) was generally more sensitive than the other two species, with EC₅₀ values of 371 µg L⁻¹ and 606 µg L⁻¹ noted for S. granularis and P. lividus, respectively. The same trend across species was noted for both Cu and CuO, although these nanoparticles generally showed higher EC₅₀ values, indicating lower toxicity compared to Cu₂O. LC₅₀ values qualitatively parallel the corresponding EC₅₀ values, with Cu₂O consistently the most toxic, while Cu was less harmful, and CuO did not reach LC₅₀ at any concentration. Again, greatest lethality was noted in A. lixula. While copper ion release from Cu was much greater than from CuO and Cu₂O, the latter showed similar or greater toxicity to developing embryos compared to Cu. This indicates that copper ions are not the sole driver of toxicity of Cu₂O, but there may also be a contribution derived from Cu₂O redox activity within cells or at membranes that negatively impact oxidative stress defence mechanisms and metabolic pathways. Full article

Paracentrotus lividus is a widely distributed species in the Mediterranean Sea and North-East Atlantic Ocean, where it plays an important ecological and commercial role. The growing demand for its delicious gonads has rapidly led to the overexploitation of the natural populations around Sardinia (western Mediterranean). The present research aimed at understanding the population genetics of the species within the area, and at gathering data on the juveniles produced in an experimental ‘conservation hatchery’ facility. A multilocus approach was used, combining mitochondrial genes (COI and Cytb) and microsatellite markers. Overall, both the microsatellites and mitochondrial results indicate that the hatchery-produced juveniles were less genetically diverse and significantly divergent from the wild populations, most likely because of a bottleneck effect due to the insufficient number of parental breeders used. As concerns the wild populations, despite the high harvesting pressure, they still have a good quantity of genetic variation. A weak overall differentiation was found, suggesting extensive gene flow among the sites. However, the differentiation in the pairwise comparisons between the wild Sardinian samples was found to be significant with regard to the mitochondrial sequences, to be further investigated with additional studies. These data provide the scientific knowledge necessary to inform future management actions and to improve future aquaculture protocols. Full article

The study of ecotoxicity induced by vanadium (V) represents an area of increasing interest due to the growing use of V in both the industrial and pharmaceutical areas. This leads to its introduction into water environments, marking a developing problem, especially since rising global temperatures appear to intensify its toxic properties. Cytotoxicological approaches carried out on whole marine embryos represent a valid research tool since they grow directly in contact with the pollutants and are equipped with highly responsive cells to stressors. Here, we discuss the detrimental impact on Paracentrotus lividus sea urchin embryos resulting from the combination of V and higher temperatures, reflecting the effects of climate variation. The results demonstrate the remodeling of embryonic architecture at the morphometric level, revealing developmental delays and anomalies. These malformations involve variations in the total skeletal mass due to the almost total absence of the skeleton, with the exception of small calcareous aggregates. Furthermore, both a modulation in total tissue remodeling enzymatic activities and a variation in the amount of three MMP-like gelatinases (MMP-2, -9, and -14) were observed. This research demonstrates that climate change significantly increases the harmful effects of V, emphasizing the necessity for comprehensive toxicity assessments in environmental evaluations. Full article