Sea Urchin Gonads Research Articles

Combination of TiO2 nanoparticles and Echinometra mathaeis gonad extracts: In vitro and in vivo scolicidal activity against hydatid cysts

Abstract Echinococcosis (hydatid cyst) is a zoonotic disease in sheep, cattle, pigs, rats, and humans that is caused by larvae of the tapeworm Echinococcus granulosus. Several studies have shown that invertebrates exhibit activity against various parasites, but no studies are available of effects of extracts of the sea urchin Echinometra mathaei on hydatid cysts. Here, E. mathaeis gonad extracts were investigated for their effects on hydatid cysts, in the absence and presence of TiO2 nanoparticles. Different concentrations of E. mathaeis gonad extracts with and without TiO2 were applied for different times and the scolicidal activity of each of these conditions was determined on viable protoscolices. 15 μg/ml gonad extract + TiO2 was sufficient to kill 84% of the protoscolices after 60 min incubation. In vivo studies were performed on mice injected with E. granulosus protoscolices. Gonad extracts and gonad extracts combined with TiO2 were given by oral gavage for a period of 3 months. Combined application of extract and TiO2 increased the treatment efficiency, as shown by the reduction in number, size and volume of the cysts. Thus, sea urchin gonad extracts combined with TiO2 nanoparticles have anti-hydatic and scolicidal effects.

Transcriptome analysis to characterize the genes related to gonad growth and fatty acid metabolism in the sea urchin Strongylocentrotus intermedius.

Sea urchin gonads of both sexes, commonly termed "roe", are highly valued seafood delicacies, and Strongylocentrotus intermedius is considered one of the tastiest sea urchins. In order to produce high-quality gonads for consumption and clarify the mechanism of gonad growth and development of the sea urchin, more genetic information, especially at the transcriptome level, is needed. A more thorough understanding of sea urchin gonad growth and development in both sexes could enable regulation of these processes at several stages with the aim of suppressing gametogenesis in order to produce high-quality gonads for consumption. The adult sea urchins S. intermedius were cultured for 3months, and were sampled for the gonadal transcriptome analysis which has been performed on the RNAs of three male and female adults of S. intermedius in each gonad development stage. Illumina sequencing raw sequence data was deposited in the NCBI Sequence Read Archive (SRA) database (PRJNA532998). It generated 560,196,356 raw reads and 548,956,944 clean reads were acquired, which were assembled into 107,850 transcripts with 44,124 genes. Comparative analysis showed the differentially expressed genes (DEGs) from 114 to 2566. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were used to determine the functional significance of these DEGs. We have selected 9 genes related to growth and 12 genes related to fatty acid biosynthesis and metabolism in sea urchin gonads. These data for sea urchins were intended to provide markers for gonad growth and development that can be accumulated for use in aquaculture applications.

Metabolomic changes and polyunsaturated fatty acid biosynthesis during gonadal growth and development in the sea urchin Strongylocentrotus intermedius

Strongylocentrotus intermedius is an important commercial species of sea urchin distributed in the coastal waters of China. However, the metabolomic changes that accompany its gonadal growth and development stages remain unclear. In this study, we have histologically observed gonad growth stages, analyzed the fatty acid composition, and employed an untargeted metabolomic approach to investigate the metabolites associated with the gonadal growth and development of S. intermedius, as well as the biosynthesis and metabolism of polyunsaturated fatty acids (PUFAs) at different stages and in different sexes. The gonad mass of sea urchin increased from 0.70 ± 0.18 g in January (at the recovering stage) to 8.78 ± 2.89 g in July (the reproductive stage), with the GSI increasing from 4.02 ± 0.88% to 16.86 ± 2.79%. We have analyzed 34 types of fatty acids, such as arachidonic acid, eicosapentaenoic acid, etc., of which PUFAs were the dominant fatty acid class in this species, accounting for >48.55% of the total. In the metabolomic analysis, linolelaidic acid, sciadonic acid, cis-8,11,14,17-eicosatetraenoic acid, adrenic acid, docosapentaenoic acid, and tetracosapentaenoic acid were detected in the differentially expressed metabolites of the unsaturated fatty acids biosynthesis pathway. We found that the most significant functional pathways during gonadal growth and development were “arachidonic acid metabolism”, “alpha-linolenic acid metabolism” and “linoleic acid metabolism”, which are all related to fatty acid metabolism. These results will provide valuable information on the possible presence of both exogenous and endogenous fatty acids in sea urchin gonads and the metabolomic changes in S. intermedius during gonadal growth periods, and will further our understanding of the intermediary metabolism and the molecular bases of growth traits in this species.

Paracentrotus lividus roe enhancement by a short-time rearing in offshore cages using two agar-based experimental feed

In this study, we tested the effect of two agar-based biocomposites (differing for the fish meal source), on the Paracentrotus lividus gonad cycle progression and biochemical composition, in an offshore pilot scale trial. The purpose of this study was to identify a feeding regime for P. lividus that would allow adequate gonadal growth without accelerating the gamete maturation, in order to extend the market period. The purpose was pursued through the use of agar as a binding agent in the manufacturing of biocomposites to be used as feed for P. lividus and the realization of special offshore cages. The gonad index, histology, biochemical composition of fatty acids (FA) and free amino acids (FAA) and volatile molecule fingerprint were evaluated. Both the gonad index and the histological analysis showed a slower gametogenesis progression in the gonads of caged sea urchins with respect to the field collected ones, consistent with our previous results obtained testing a similar feed composition in a recirculating system. The amount and the relative proportions of FA and FAA in the gonads of wild and cultured gonads were similar, while the analysis of the volatile substances of the gonads of the sea urchin conducted using the electronic nose, shows that they vary as a result of the different feeding treatments. These results show that P. lividus sea urchins can be housed, under this feeding regime during the recovery phase of the gonads, without acceleration of the maturation of the gametes and thus in conditions to allow the extension of the market period. Moreover, the here tested agar-based biocomposites make it possible to reduce the management costs of the rearing system as they need to be replaced only once a week, and its environmental impact as they guarantee a limited nutrient dispersion in the water.

Lipid and fatty acid profiles of gametes and spawned gonads of Arbacia dufresnii (Echinodermata: Echinoidea): sexual differences in the lipids of nutritive phagocytes

Sea urchin gonads contain nutritive phagocytes (NP) that store nutrients such as protein, lipid and carbohydrates for use during the production of gametes. While there is some information on the role of protein, particularly major yolk protein (MYP), during gametogenesis, very little is known about the role of lipids and their component fatty acids. We compared the lipid and FA profile of mature Arbacia dufresnii gonads (intact), with gonads that had been induced to spawn (spawned) and their associated gametes. The total lipid concentration decreased in females from the intact to the spawned gonads, and with a minimum value in the eggs, whilst male intact and spawned gonads had similar lipid concentrations, with significantly lower lipid concentration only in the sperm. Sex was the main factor affecting FA profile in the gonads (intact, spawned) and gametes of A. dufresnii, with differences in both the variety of FA, their total concentration and proportion. Interestingly, sexual differences in FA profile of the gonads are due not only to the presence of mature gametes, but also due to the NP and gametes remaining after spawning. As male and female sea urchins have the same basic gonad wall and NP structure, and the same echinoferrin based system for deposition of the MYP in the NP, our study reveals an unexplored biochemical complexity in the lipids and fatty acids of the NP within sea urchin gonads that has implications for future research.

Effect of three diets on the gametogenic development and fatty acid profile of Paracentrotus lividus (Lamarck, 1816) gonads

In this study, the effects of three diets were investigated to enhance Paracentrotus lividus production for commercial purposes. P. lividus were fed ad libitum for 80 days with: diet A—fresh Codium tomentosum Stackhouse, 1797; diet B—formulated using a jellified mix of macroalgae and vegetables, including C. tomentosum (20%), Coralina sp. Linnaeus, 1758 (17%), cabbage Brassica oleracea var. capitata Linnaeus, 1753 (30%), carrot Daucus carota Linnaeus, 1753 (30%) and agar (3%) as a gelling agent. Diet C consisted of maize Zea mays Linnaeus, 1753 (56%) and New Zealand spinach Tetragonia tetragonoides (Pallas, 1781) Kuntze, 1891 (44%). Their effects on the gonadal and somatic growths, gonadosomatic index (GI) and gametogenesis were evaluated, as well as on the total lipid content and fatty acid composition of sea urchin's gonads. Diet A provided high values of eicosapentaenoic acid (EPA). Gonads of sea urchins fed with diet A were found mostly in growth and maturation stages of gametogenesis and showed the lowest lipid content. Sea urchins fed with diet B presented their gonads in the reabsorption stage and had the highest values of omega-3 polyunsaturated fatty acids (PUFAs). Sea urchins fed with diet C were in the early stages of gametogenesis and had the highest values of lipid content, plus omega-6 PUFAs. Once as an ingredient in a balanced mix with vegetables, C. tomentosum can be a key factor to the development of new promising high-quality and low-cost feed for P. lividus roe enhancement.

Effect of protein and lipid levels in diets for adult sea urchin Paracentrotus lividus (Lamarck, 1816)

Paracentrotus lividus gonads are considered a prized seafood delicacy due to its organoleptic features. The increasing market demand for sea urchin depleted several wild stocks, thus aquaculture can play an important role in supplying high-quality animals. Nevertheless, the success of this activity largely depends on the development of nutritionally balanced diets capable of producing excellent gonads. In this study, four extruded diets formulated with low or high protein (30 and 50% dry matter (DM), LP and HP, respectively) and lipid (6 and 11% DM, LL and HL, respectively) levels were fed to wild-caught individuals (4.5 cm diameter) for 15 weeks. Twelve homogeneous groups of 15 individuals were randomly distributed by mesh cages (45 urchins/m2) within 250 L tanks in a recirculating aquaculture system (RAS) at 18 °C and a 12 L:12 D photoperiod regime. Sea urchins fed the LP/LL diet were compared to wild specimens with similar maturation stage.All experimental diets were well accepted by sea urchins and resulted in similar final body weight (42–43 g). No significant differences were observed in specific growth rate or protein efficiency ratio among diets. The HP diets led to a decrease of dry matter and energy intake resulting in the lowest feed conversion ratio (FCR). Weight gain, whole body composition and nutrient gain remained similar among dietary treatments. The gonad somatic index (GSI) varied between sex but was similar among dietary treatments (19–23%) and was higher than values observed in wild specimens (6–7%). Females had significantly higher total concentration of carotenoids than males, irrespectively of the dietary treatments. Dietary treatments and sex did not affect gonad texture (firmness and resilience) or colour parameters (brightness, redness, yellowness, chroma or hue angle), but affected gonad composition. Total carotenoid content in gonads was not affected by diets and resulted in lower values compared to wild specimens. These had higher levels of echinenone, β-cryptoxantin and β-carotene and showed higher redness and firmness values when compared to the LP/LL diet, irrespectively of the sex. Gonad lipid content and n-3 PUFA were higher in female than in male, whilst protein content showed an opposite trend, suggesting some sex related differences in the metabolic use of nutrients.This study clearly shows that it is possible to enhance sea urchin gonad yield in relation to wild animals in a RAS at 18 °C. All diets were effective in promoting gonad growth, but the diet with the lowest protein (30% DM) and lowest lipid (6% DM) level resulted in the highest gonad yield in both sexes.

De novo transcriptomic analysis of gonad of Strongylocentrotus nudus and gene discovery for biosynthesis of polyunsaturated fatty acids.

Strongylocentrotus nudus is an important cultured sea urchin species in north China, because its gonad is rich in unsaturated fatty acids, particularly long polyunsaturated fatty acids (LC-PUFAs). These PUFAs play pleiotropic and crucial roles in a wide range of biological process. However, the genes contributing to biosynthesis PUFAs have not been elucidated yet, and the molecular mechanism relative to the difference in PUFA composition between male and female gonad as been revealed but the corresponding has not been understood. In this paper, solexa sequencing based transcriptomic approach was used to identify and characterize the key genes relative to PUFA synthesis and further conducted different expressed genes between male and female gonad. A total of 130,124 transcripts and 189330 unigenes were de novo assembled from 64.32Gb data. Next, these unigenes were subjected to functional annotation by mapping to six public databases, and this process revealed a lot of genes involving in lipid metabolism. In addition, three types of fatty acids front-end desaturase and three species of very long fatty acids elongase were identified and the pathway for PUFA biosynthesis was hypothesized. Last, comparative analysis revealed the higher expression level of Δ5 desaturase, Δ6 desaturase, ELOVL-4, -6 and -7 in male gonad compared with female. This results could plausible explain the differ in composition of PUFAs between male and female gonad of sea urchin.

Nghiên cứu một số đặc điểm sinh học sinh sản cầu gai đen Diadema setosum (Leske, 1778)

Reproductive characteristics of black sea urchin Diadema setosum was studied during the period of April 2016 to April 2017. A total of 632 specimens of black sea urchin were collected from the intertidal reef at Hon Son, Kien Giang province, Viet Nam. Monthly data collection showed that the reproductive cycle of black sea urchin was seasonal dependence. The highest gonadosomatic index (GSI) of black sea urchin was found in June (16.10±7.70), but no differ significantly with those GSI occurring from April to July. The lowest GSI was found during the period of September to December and remain low until March next year. The data suggested that spawing season of animal may occur from May to August yearly. Length-weight relationship of black sea urchin (n=632) was W = 0.48L2.84 with the value of regression co-efficient r2 = 0.93. Histology analysis also confirmed that most of the gonad (>70%) of black sea urchin collected from April to July reached the maturity stage (stage IV) and 5 different stages development of the gonad were also observed. These are resting, recovery, growing, pre-matured and matured stages. The absolute fecundity is GSI and size dependence of black sea urchin. The absolute fecundity was estimated about of 7.1 million eggs/ind. (72.9 g). The gonad of black sea urchin begin to develop when shell diameter of black sea urchin is greater than 2.5 cm.

Odor-Active Volatile Compounds from the Gonads of the Sea Urchin <i>Mesocentrotus nudus</i> in the Wild in Miyagi Prefecture, Tohoku, Japan

Background and Aims: Mesocentrotus nudus is commercially harvested from shallow rocky bottoms in northern Japan. The gonads are targeted as an edible product. The objective of this study was to identify odor-active volatile organic compounds (VOCs) from the gonads of adult M. nudus collected at a fishing ground in Miyagi Prefecture, Tohoku, Japan. Methods and Results: Gas chromatography-mass spectrometry analysis and gas chromatography-sniffing techniques identified 42 compounds categorized as alcohols, aldehydes, aromatic hydrocarbons, esters, halomethanes, hydrocarbons, ketones, sulfur-containing compounds, and nitrogen-containing compounds. GC-sniffing analysis characterized four compounds with preferable odors of sea urchin gonads; limonene, propyl acetate, acetone, dibromochloromethane. On the other hand, the analysis characterized three compounds with unpreferable odors; methyl mercaptane, dimethyl sulfide, and s-methyl thioacetate. Several VOCs from the gonads were derived from seaweeds, terrestrial plants, and fish flesh as food because M. nudus is omnivorous. Conclusion: This is the first study to identify VOCs from edible sea urchin gonads in the wild in Japan. These VOC data comprise a typical standard in order to evaluate a higher quality of sea urchin gonads.

Effects of sea urchin (Diadema setosum) gonad extracts on gene expression of FOXP3 and the production of cytokine on Salmonella typhi-induced mice

The gonad of the sea urchin, Diadema setosum, is highly nutritious and has demonstrated importance for the regulation of inflammation response. However, no previous research has evaluated the capacity of sea urchin gonads to regulate inflammatory response. Our objectives were to examine the effect of gonad extracts of D. setosum on expression of mRNA FoxP3 gene and the production of cytokine (Interferon-gamma (IFN-y) and Interleukin-10 (IL-10) in mice after the induction of lipopolysaccharide (LPS) using Salmonella typhi. Fifteen male mice were divided into two groups (intervention and control), before and after intraperitoneal injection of S. typhi. The intervention group was treated with two dosages of the extracted gonad (100 and 200 mg/kg of body weight). The control group was fed with natural diet only. We found that the expression of gene FoxP3 and production of cytokine exhibited a short decrease after 24 hours of LPS induction and then returned to pre-induction levels. Notably, the expression of FoxP3 and production of IFN-y in the control group continued to decline significantly until day 7. Conversely, the production of IL-10 continued to increase significantly. We conclude that the gonad extract of D. setosum is effective for the regulation of immune response and it has strong potential to be developed as a dietary supplement for acute and chronic inflammation.

Short-term variation of abundance of the purple sea urchin, Paracentrotus lividus (Lamarck, 1816), subject to harvesting in northern Portugal

Paracentrotus lividus is a common and intensely harvested sea urchin at several European locations, including the Mediterranean Sea and the Atlantic coast of the Iberian Peninsula. The increasing human pressure on this resource due to the growing demand and market value of sea urchin gonads as seafood raises concerns on the ecological sustainability of present fisheries, which are showing a technological improvement and an expansion towards previously non-harvested areas. We examined the abundance of P. lividus of both commercial and non-commercial size before, during and after the harvesting season (from October to April) in the rocky shallow subtidal habitat along the northern Portuguese coast. The abundance of commercial (≥50 mm in test diameter) P. lividus individuals increased in the harvesting season, but drastically dropped by about 90% in the after-harvesting period. Such a pattern was consistent among three rocky shores spanning about 65 km of coast. The multivariate population structure and most size classes of non-commercial sea urchins did not differ depending on the period. The only exception was Class 4 (test diameter between 30 and 40 mm), which was more abundant in the harvesting than in the before- and, further, the after-harvesting period, but only at one shore. Very small (Class 1, test diameter below 10 mm) urchins were never found. The present findings suggest that human harvesting may cause considerable reductions in the abundance of target P. lividus, but that such an effect would not be evident concomitantly with harvesting, but in the subsequent period. Even if just under a precautionary principle, protection strategies focused on sea urchin populations and the harvesting period are advisable to contribute to maintain a sustainable local fishery of P. lividus populations that are likely to be negatively affected also by other natural and anthropogenic perturbations.

Antioxidant peptides derived from the hydrolyzate of purple sea urchin (Strongylocentrotus nudus) gonad alleviate oxidative stress in Caenorhabditis elegans

The papain hydrolyzate prepared from purple sea urchin (Strongylocentrotus nudus) gonad exerts significant antioxidant activity. Through ultrafiltration, gel filtration and high performance liquid chromatography, the active fractions from the hydrolyzate were screened by alleviating paraquat-induced oxidative stress in Caenorhabditis elegans, and the peptide components were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Two antioxidant peptides SnP7 (AAVPSGASTGIYEALELR, 1805.03 Da) and SnP10 (NPLLEAFGNAK, 1173.34 Da) exhibit significant antioxidant capacity, which reduce reactive oxygen species (ROS) level and the expression of superoxide dismutase-3 (SOD-3) and heat shock protein-16.2 (HSP-16.2) in oxidation-damaged nematodes. Further studies indicated that SnP7 and SnP10 induce DAF-16 nuclear translocation and the expression of stress-related genes such as sod-3. RNA interference (RNAi) suggested that peptide-induced enhancement of resistance is dependent on DAF-16. Taken together, S. nudus antioxidant peptides might act through activate DAF-16 signaling pathway, and induce the expression of DAF-16 target genes that enhance antioxidant potential of organisms.

Higher Dietary Arachidonic Acid Levels Improved the Growth Performance, Gonad Development, Nutritional Value, and Antioxidant Enzyme Activities of Adult Sea Urchin (Strongylocentrotus intermedius)

The gonads of sea urchins (Strongylocentrotus intermedius) are characterized by high levels of arachidonic acid (ARA, 20:4n-6) and eicosapentaenoic acid (EPA, 20:5n-3). However, to our knowledge, little information is available regarding the physiological response of adult sea urchins to dietary ARA. In the present study, four dietary feeds were formulated with graded ARA (0, 0.5%, 1%, and 2% dry diet). Each diet was randomly allocated to three cages during a 56-day feeding experiment. The results showed that the sea urchin weight gain rate (WGR) and the gonadosomatic index (GI) significantly increased as ARA was equal to or above 1.0% of dry diet (P 0.05), but was significantly lower than those fed with kelp (P < 0.05). These results suggested that relatively higher levels of ARA (1% dry diet) significantly promoted growth, gonad development, activities of antioxidant enzymes, as well as nutritional values (TEAA, TEAA/TNEAA, and PUFA) of adult S. intermedius.

Carotenoid composition of a New Zealand (Evechinus chloroticus) and an Australian (Heliocidaris erythrogramma) sea urchin in relation to gonad colour

Sea urchins are commercially harvested for their edible gonads, also known as roe or uni. Most species, particularly those from the Northern hemisphere are reported to exhibit limited variation in gonad colour, which is proposed to be due to carotenoid pigments. The commercially harvested species from New Zealand, Evechinus chloroticus, and from Australia, Heliocidaris erythrogramma, however, exhibit considerable gonad colour variation, ranging from a culinary desirable light yellow/orange to an undesirable brown. Gonads from E. chloroticus and H. erythrogramma were characterized spectrophotometrically and the carotenoid content extracted and analysed by reversed-phase high-performance liquid chromatography. The main carotenoid found in the gonads of both species was 9′-cis-echinenone, with lower levels of all-trans-echinenone, lutein and isozeaxanthin. Carotenoid composition contributed to the yellow/orange colour components of the gonads, but was not correlated with the darker roe coloration observed in some E. chloroticus individuals. Our results highlight important considerations relating sea urchin gonad coloration to carotenoid content and as such will provide useful information for the future aquaculture and processing of these two species.

Spatial variations in trace element concentrations of the sea urchin, Paracentrotus lividus, a first reference study in the Mediterranean Sea

A study on Trace Elements (TE) from sea urchin gonads has been conducted in the western Mediterranean Sea. Contamination data were used to determine a Trace Method Pollution Index (TEPI). TE concentrations varied considerably depending on the location of the sampling stations. The results showed that five trace elements (Zn, Fe, As, Al, Cu) are ubiquitous. The geographical area considered (Corsica) represents an important range of environmental conditions and types of pressure that can be found in the western Mediterranean Sea. TEPI was used to classify the studied sites according to their degree of contamination and allowed reliable comparison of TE contamination between local and international sites. TE contamination of the western Mediterranean Sea displayed a north-to-south gradient, from the Italian coasts down through the insular Corsican coasts to the north African littoral. Due to the increasing environmental pressure on the Mediterranean Sea, a regular monitoring of TE levels in marine organisms is necessary to prevent any further environmental deterioration.

Markers of oil exposure in cold-water benthic environments: Insights and challenges from a study with echinoderms

In spite of increasing naval activities and petroleum exploration in cold environments, there is currently a paucity of tools available to monitor oil contamination in boreal marine life, especially in sedentary (non-fish) species that dominate benthic communities. This research aimed to identify biotic sources of variation in biomarkers using subarctic echinoderms, and to identify suitable biomarkers of their exposure to hydrocarbons. The focal species included the sea star Asterias rubens, the brittle star Ophiopholis aculeata, the sea urchin Strongylocentrotus droebachiensis, and the sea cucumber Cucumaria frondosa, which are among the most abundant echinoderms in the North Atlantic and Arctic Oceans. The latter two species are also commercially exploited. A series of 96-h acute exposures of the water-accommodating fraction (WAF) of used lubricating oil (ULO) were performed in different seasons (i.e. distinct reproductive stages). Digestive and reproductive tissues were analyzed for baseline and response levels of glutathione peroxidase (GPx) and ethoxyresorufin-O-deethylase (EROD). GPx activity was detected in the pyloric caecum, stomach, and gonad of sea stars, the intestine and gonad of sea cucumbers, and the gonad of brittle stars and sea urchins. No seasonal variation in baseline GPx activity occurred. Upon exposure to the ULO WAF, sex-based differences were elicited in the GPx activity of sea star stomachs (lower in females than males). EROD activity was present in the pyloric caeca of sea stars, and the gonads of brittle stars and sea urchins. An interaction between season and sex on baseline EROD activity was measured in the gonads of sea urchins. Ovaries exhibited significant seasonal variation in EROD activity and had greater activity than testes during the spawning and post-spawning seasons. Seasonal variation in EROD activity also occurred in sea star pyloric caeca and brittle star gonads. Furthermore, testes of sea urchins exposed to the ULO WAF exhibited suppressed EROD activity compared to baseline levels. The nearly universal presence of GPx activity highlights its potential as a useful biomarker, while EROD activity was much more limited. Findings suggest a complex relationship between temporal and biotic factors on both the baseline and response levels of enzymatic activity, emphasizing the need to consider sex and sampling season in studies of biomarkers of hydrocarbon exposure in boreal indicator species that display annual reproductive cycles.

Macro and trace elements in Paracentrotus lividus gonads from South West Atlantic areas

Sea urchin represents one of the most valuable seafood product being harvested and explored for their edible part, the gonads or roe. This species is generally considered a sentinel organism for ecotoxicological studies being widely used in monitoring programs to assess coastal aquatic environments quality, because is directly exposed to anthropogenic contaminants in their habitat. In this context, the aim of this study is to evaluate the concentrations of macro (Cl, K, P, Ca, S) and trace (Zn, Br, Fe, Sr, I, Se, Rb, Cu, Cr, Ni, As, iAs, Cd, Pb, Hg) elements in Paracentrotus lividus gonads from three South West Atlantic production areas subjected to distinct environmental and anthropogenic pressures. In all studied areas, the elements profile in sea urchin gonads was Cl > K > P > Ca > S > Zn > Br > Fe > Sr > I > Rb > Cu > Se > Cr > Ni, suggesting an element guide profile with special interest for sea urchin farming development. Concerning toxic elements, the profile was the following: As > Cd > Pb > Hg > iAs. The results evidenced higher levels of Pb and Hg in open areas. Distinct area characteristics and anthropogenic pressures of production areas evidence the importance of biomonitoring contaminants, particularly toxic elements. In general, the levels of these elements were below maximum levels in foodstuffs (MLs) which pose a minimal health risk to consumers.

The effects of 3 different microalgae species on the growth, metamorphosis and MYP gene expression of two sea urchins, Strongylocentrotus intermedius and S. nudus

As a result of the increase in demand for sea urchin gonads, which are considered a gourmet food, the sea urchin aquaculture industry has gradually expanded in some South American and Asian countries. This study investigated the growth, metamorphosis and MYP gene expression of larvae of two species of sea urchin (Strongylocentrotus intermedius and Strongylocentrotus nudus) fed with four microalgal diets: Chaetoceros muelleri, Dunaliella tertiolecta, Isochrysis galbana, and a mixture of the three. The larvae fed the C. muelleri and mixture diets were successfully raised to competence for metamorphosis and showed better stomach growth, development rates and metamorphosis rates than the larvae that were fed D. tertiolecta or I. galbana. The results also suggest that the larvae could accumulate long-chain polyunsaturated fatty acids (LC-PUFAs), such as docosahexaenoate (DHA; 22:6n-3), eicosapentaenoate (EPA; 20:5n-3) and arachidonate (ARA; 20:4n-6), either by the assimilation and retention of dietary fatty acids or by synthesis from α-linolenic acid (18:3n-3) and linoleic acid (18:2n-6). Moreover, an accumulation of n-6 and n-3 LC-PUFAs and higher ARA/EPA ratios in the larvae appeared to be associated with improved larval performance. The results also showed that the MYP gene expression levels in the larvae fed the C. muelleri and mixed diets were significantly higher than in the D. tertiolecta and I. galbana groups. In addition, the trend of the MYP gene expression in the different stages was 6-arm stage > 8-arm stage > 4-arm stage > fertilized eggs > prismatic stage. These results provide suggestions for diet selection for sea urchin larvae and the fatty acid composition of diets for urchin larvae, and they provide a reference for further study of the effects of diets on the gene expression of MYP in larvae.

The effect of Sea urchin (Diadema setosum) gonad extract on IgM and IgG antibodies production in BALB/c mice infected by Salmonella typhi

Background: Salmonella typhi infection decreases of the immune system and influences the adaptive antibodies among malnourished children. The gonad of Diadema setosum (D. setosum) is one of food sources from marine biota that contains high-quality nutrients and potentially can be used as a dietary supplement for typhoid fever condition.Objective: This study aimed to determine the effect of gonad D. setosum extract on the production of antibody IgM and IgG in an animal model.Method: This experimental study was used BALB/c mice before and after infected Salmonella typhi through intraperitoneally at 0.2 mL x the unit 103 CFU/mL. The level of IgM and IgG production was measured by Enzyme Linked Immune Sorbent Assay (ELISA). Experimental animals were divided into 2 groups. The control group was only fed with standard diets, while at the intervention group received the extract of D. setosum gonad in two doses (100 and 200 mg/kg body weight).Results: Production of IgM antibodies in the control group significantly increased twofold (p=0.001) whereas the intervention group received the extracts of D. setosum gonad (200 mg/kg body weight) could suppress the increase in IgM antibody production and indicate the highest increase of IgG antibody significantly (p&lt;0.05) at day 7.Conclusion: The gonad of Diadema setosum extracts (200 mg/kg body weight) could suppress the increase in IgM antibody productions and indicate the highest increase of IgG antibody titers in mice infected with Salmonella typhi. The role of anti-microbial substances of the gonad of Diadema setosum, is potential to be utilized as dietary supplement to increase body immune system among patients infected by Salmonella typhi.