Molecular monitoring plankton community during jellyfish blooms in the water near the Liaoning Hongyan River Nuclear Power Plant

The Liaoning Hongyan River Nuclear Power Plant is located on the east coast of Liaodong Bay in the Bohai Sea,China,and the safety of the cooling water is often threatened by large-scale jellyfish outbreaks.Thus,monitoring jellyfish growth,migration,and disappearance is essential to the safety of the nuclear power plant.In this study,high-throughput sequencing was used to analyze the community characteristics of mesoplankton in the sea area at the inlet and outlet from April to September 2019.At the same time,the micro-individuals of jellyfish(including oosperm,planula,polyps,or ephyra of jellyfish)in the water were detected by real-time fluorescent quantitative PCR(qPCR).Both the maximum abundance of Aurelia coerulea and Nemopilema nomurai in July were detected by high-throughput sequencing and q PCR.Only three common taxa of plankton(Paracalanus,Calanoida,and Poaceae)were found in the waters near the inlet and outlet,and the beta diversity of plankton in the waters near the inlet and outlet was low in the same period.Based on the plankton community composition in the sea water near the inlet,it could be speculated that jellyfish outbreaks would have a significant impact on the plankton via the predation effect.The maximum mt-16S rDNA copy numbers of A.coerulea and N.nomurai in the samples from the waters of Liaodong Bay were detected in June 2019,and that of N.nomurai showed an increasing trend from north to south,with the jellyfish tending to move to the seawaters near the plant.The results indicate that the optimum monitoring period for jellyfish outbreaks in Liaodong Bay is from the end of May to the end of July.

A model for the transportation and distribution of jellyfish Rhopilema esculentum for stock enhancement in the Liaodong Bay, China

A numerical model for jellyfish Rhopilema esculentum stock enhancement is developed for the first time. The model is based on an operational ocean circulation-surface wave coupled forecasting system for the seas off China and adjacent areas and uses a Lagrangian particle-tracking scheme to track the trajectories of released jellyfish. The Jellyfish are modeled as particles with diel vertical migration and are passively drifted by the current and dispersion due to the sub-grid processes. A comparison between the simulation and survey results demonstrate that the model can capture the primary distribution patterns of the released jellyfish. The model results show that the ocean current and indirect wind impact are the main drivers controlling the jellyfish transport. A connectivity matrix between the release sites and fishing grounds indicates the top of the bay is better than the eastern and western coasts for jellyfish fishing. The matrix also shows that only 45% and 27% of the jellyfish released from Wafangdian(WFD) can enter the fishing ground in 2008 and 2010; thus, the site near WFD is not an advisable location for jellyfish release. A Lagrangian probability density function based on a nine-year tracing experiment validates the results and further provides a "climatology" distribution of the released jellyfish.Several experiments are conducted to examine the sensitivity of the model to random walk schemes and to release conditions. The model requires a random walk but is insensitive to the random walk scheme. The experiments with different habitat depths show that if the jellyfish are fixed on the bottom of the water, most of them will be transported to the center, or even out of the bay, by the bottom circulation.

Investigation of the Biochemical and Histological Changes Induced by Zearalenone Mycotoxin on Liver in Male Mice and the Protective Role of Crude Venom Extracted from Jellyfish <i>Cassiopea Andromeda</i>

Zearalenone (ZEN) is a non steroidal estrogenic mycotoxin produced by Fusarium species of fungi which contaminate human foods and animal feeds worldwide. In this study hepatotoxicity of ZEN was evaluated in mice by oral adminis-tration of single and repeated doses of ZEN mycotoxin (2.7 mg/kg b.w.). The protective effect of crude venom extracted from jellyfish Cassiopea andromeda was also assessed. Mice were divided into four groups (N = 10). G1: receiving the toxin once and sacrificed 48 h later, G2: toxin administered twice for one week, G3: toxin administered twice a week for two weeks, G4: pretreated orally by a single dose of crude venom (1.78 mg/20g) 24 hours prior to administration of ZEN twice a week for two weeks. Each treated group had its corresponding control which received 1% DMSO sa-line.ZEN treatment significantly increased alanine aminotransferase (ALT), aspartateaminotrnsferase (AST) and alka-line phosphatase (ALP) activities after 48 hours and two weeks, while ALT was also significantly increased after one week. Tumor necrosis factoralpha (TNF-α) level was undetected in treated and control groups except the group treated with ZEN for one week. Alphafetoprotein (AFP) level was increased significantly only after two weeks. The activity of antioxidants was significantly increased in all groups. ZEN was also found to modify the serum proteins especially gamma-globulin which showed a significant decrease after 48 h and two weeks. Improvement in liver func-tion occurred in the group pretreated with the crude venom, and AFP and antioxidants returned to normal level, while TNF-α level was also undetected. Gamma globulin was significantly increased. The recovery observed in the group which was pretreated with crude venom may related to bradykinin content of this venom which exhibits a hepatoprotective effect. Histological changes in mouse liver coincided with biochemical changes. In conclusion, this study revealed that ZEN induced liver function and structural changes promising an approach for using a crude venom of jellyfish to enhance liver function.

Bacterial community succession in response to dissolved organic matter released from live jellyfish

Jellyfish blooms have increased worldwide, and the outbreaks of jellyfish population not only affect the food web structures via voracious predation but also play an important role in the dynamics of nutrients and oxygen in planktonic food webs. However, it remains unclear whether specific carbon compounds released through jellyfish metabolic processes have the potential to shape bacterial community composition. Therefore, in this study, we aimed to investigate the compositional succession of the bacterioplankton community in response to the dissolved organic matter (DOM) released by the live Scyphomedusae Cyanea lamarckii and Chrysaora hysoscella collected from Helgoland Roads of the North Sea. The bacterial community was significantly stimulated by the DOM released form live jellyfish and different dominant phylotypes were observed for these two Scyphomedusae species. Furthermore, the bacterial community structures in the different DOM sources, jellyfish-incubated media, Kabeltonne seawater, and artificial seawater (DOM-free) were significantly different, as revealed by automated ribosomal intergenic spacer analysis fingerprints. Catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH) revealed a rapid species-specific shift in bacterial community composition. Gammaproteobacteria dominated the community instead of the Bacteroidetes community for C. lamarckii, whereas Gammaproteobacteria and Bacteroidetes dominated the community for C. hysoscella. The significant differences in the bacterial community composition and succession indicate that the components of the DOM released by jellyfish might differ with jellyfish species.

An Improved Jellyfish Algorithm for Multilevel Thresholding of Magnetic Resonance Brain Image Segmentations

Image segmentation is vital when analyzing medical images,especially magnetic resonance(MR)images of the brain.Recently,several image segmentation techniques based on multilevel thresholding have been proposed for medical image segmentation;however,the algorithms become trapped in local minima and have low convergence speeds,particularly as the number of threshold levels increases.Consequently,in this paper,we develop a new multilevel thresholding image segmentation technique based on the jellyfish search algorithm(JSA)(an optimizer).We modify the JSA to prevent descents into local minima,and we accelerate convergence toward optimal solutions.The improvement is achieved by applying two novel strategies:Rankingbased updating and an adaptive method.Ranking-based updating is used to replace undesirable solutions with other solutions generated by a novel updating scheme that improves the qualities of the removed solutions.We develop a new adaptive strategy to exploit the ability of the JSA to find a best-so-far solution;we allow a small amount of exploration to avoid descents into local minima.The two strategies are integrated with the JSA to produce an improved JSA(IJSA)that optimally thresholds brain MR images.To compare the performances of the IJSA and JSA,seven brain MR images were segmented at threshold levels of 3,4,5,6,7,8,10,15,20,25,and 30.IJSA was compared with several other recent image segmentation algorithms,including the improved and standard marine predator algorithms,the modified salp and standard salp swarm algorithms,the equilibrium optimizer,and the standard JSA in terms of fitness,the Structured Similarity Index Metric(SSIM),the peak signal-to-noise ratio(PSNR),the standard deviation(SD),and the Features Similarity Index Metric(FSIM).The experimental outcomes and the Wilcoxon rank-sum test demonstrate the superiority of the proposed algorithm in terms of the FSIM,the PSNR,the objective values,and the SD;in terms of the SSIM,IJSA was competitive with the others.

Severe fundus lesions induced by ocular jellyfish stings: A case report

BACKGROUND Globally,although the jellyfish population has increased in recent years,ocular jellyfish stings remain an uncommon ophthalmic emergency,and have been rarely reported.According to a few previous reports,ocular jellyfish stings may cause anterior segment disorders,and most of these injuries were self-limited and spontaneously resolved within 24 to 48 h.CASE SUMMARY A brother and sister both presented with severe fundus complications several years after ocular jellyfish stings and both had prolonged blurred vision.To our knowledge,such fundus lesions induced by jellyfish stings have not been reported previously.CONCLUSION The fundus status of patients following ocular jellyfish stings should be carefully monitored in cases of irreversible ocular damage.

Intraguild predation by polyps of three scyphozoan jellyfish:Nemopilema nomurai,Aurelia coerulea,and Rhopilema esculentum

Jellyfish blooms occur worldwide and have resulted in serious problems in tourism,fisheries,coastal industries,and the marine ecosystem.The life cycle of scyphozoan jellyfish consists of a pelagic medusa stage and a benthic polyp stage.Success of asexual reproduction of the polyps determines directly the number of medusae;thus,the polyp stage is the key to understanding the population dynamics of medusae.Nemopilema nomurai,Aurelia coerulea,and Rhopilema esculentum are three scyphozoan jellyfish commonly inhabit in Chinese coastal waters.Polyps of A.coerulea are easily visible,while those of N.nomurai and R.esculentum remain yet to be found in the wild.However,distribution of the medusa indicates that the polyps of all three species may occur together.To evaluate the distribution pattern of polyps of the three species and explore intraguild predation by the polyps,we conducted a laboratory experiment that considered the attachment sequence and size relationship of calyx diameter of the polyps.We found that the polyps of A.coerulea preyed on polyps of the other two species in all treatments,except when polyps of R.esculentum were bigger than those of A.coerulea.The polyps of R.esculentum preyed on the polyps of N.nomurai only when polyps of R.esculentum attached first and were bigger than those of N.nomurai.Colonies of N.nomurai polyps were rarely found in the places inhabited by A.coerulea polyps.In addition,A.coerulea polyps are known to inhabit at depths of less than 20 m in coastal sea,thus,we speculate that N.nomurai polyp colonies might occur at depths of more than 20 m.Therefore,our finding that polyps of A.coerulea aggressively preyed on polyps of other species may help understand other such systems of jellyfish bloom in the world.

Using LA-ICP-MS to analysis elemental composition of statoliths of Scyphozoan jellyfish

Scyphozoan jellyfish outbreak events are drawing increasing attentions during the past decade.Elemental compositions of statoliths are helpful to understand jellyfish life history and blooming mechanisms,but very rare endeavor has been focused on the Scyphozoan class.In this work,we explored the feasibility of element analysis of Aurelia aurita(a representative Scyphozoan jellyfish outbreak species in China)which may be used as proxies of environment parameters during jellyfish living and moving.Statolith crystals of Aurelia aurita were found to be a gathering of hexahedron type trigonal needle with size of 10-50μm long,and 5-10μm in diameter.By using laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS)downhole profiling method,elements such as Ca,Sr,Mg,Na and P were found to be above the limit of detection and limit of quantification.The epidermis of statocyst could significantly impact the element analyses,so the real statolith element signal section needs to be selected based on elements and Ca profiles together with care.By laser ablated a signal spot repeatedly,the analytical uncertainty was about 3%-4%for Sr/Ca content ratio and Mg/Ca content ratio,but above 10%for other element/Ca content ratios(n=3).Based on the analysis of statolith from temperature-control cultured jellyfish,Sr/Ca content ratios among different statoliths of the same jellyfish were about 6%(n=14),demonstrating biological processes/vital effects causing small variations compared with analytical uncertainties.Therefore,Sr/Ca content ratios may be used as a potential proxy to reveal the living environment variations the Scyphozoan jellyfish has experienced,such as temperature history,which is helpful to understand jellyfish bloom mechanisms.

The jellyfish fishery in Mexico

Jellyfish has been captured in Asia for 1700 years, and it has been considered a delicacy. Since the 70s important jellyfish fisheries have developed in several parts of the world, with catches increasing exponentially, reaching 500,000 tons per year in the mid-nineties. In Mexico, only the cannonball jellyfish Stomolophus meleagris is captured commercially. Most of the capture of this jellyfish species is obtained within the Gulf of California, specifically in the state of Sonora. The total reported capture in 2010 was 16,581 metric t and 14,220 in 2011. With these capture volumes jellyfish was ranked as the third most important fishing resource in the state of Sonora. The fishing season in Sonora is from April to May;a total of 4 or 5 weeks, and the catch per unit effort is around 3 tons by trip. Currently, there are nine jellyfish marketing companies, with about 20 processing plants distributed along the coast of Sonora, primarily in Guaymas, Kino Bay, and Puerto Penasco. Although the process is simple, the large amounts of jellyfish required and the need to optimize production costs make jellyfish processing an intense activity that employs hundreds of people during the fishing season, becoming an alternative employment for the people who depend on the fishing industry.

Countermeasures for Constructing Provincial Modern Agricultural Industrial Park:Taking Jellyfish Industry,the Leading Industry of Yingkou City as an Example

At present,modern agricultural industrial park with large-scale planting and breeding base as a platform has become an innovative measure to promote the development of regional modern agriculture and an important starting point for the implementation of rural industry revitalization,and it has been highly valued by local governments.Yingkou City has established and developed a modern agricultural industrial park with jellyfish as the leading industry.This will effectively fill the gap in this work in Yingkou City and boost the development of the jellyfish industry.This study provides strong support for the promotion of the city card of"China's Hometown of Jellyfish".

Study on Jellyfish Outbreaks and Their Monitoring and Control Technology in the Yellow Sea and the Northern East China Sea

Jellyfish outbreaks have become a new type of marine ecological disasters,and have great influence on the structure and function balance of marine ecosystems,fishery resources,production safety of coastal power plants,marine landscape and tourism.In recent years,the Yellow Sea and the northern East China Sea are the high risk areas of jellyfish outbreaks.In this paper,the research results of jellyfish outbreaks in the Yellow Sea and the northern East China Sea are summarized,and the species composition,distribution,life-history characteristics and hazards of jellyfish outbreaks are described.Meanwhile,the possible causes of jellyfish outbreaks are analyzed,and the monitoring and control technology of jellyfish disasters are discussed.It will provide a scientific basis for the monitoring,management,and emergency disposal of jellyfish disasters.

Changes in the small-jellyfish community in recent decades in Jiaozhou Bay, China

We used long term monitoring data to evaluate changes in abundance and species dominance of small-jellyfish (collected with zooplankton net whose bell diameter was less than 5 cm) between 1991 and 2009 in the Jiaozhou Bay, China. Zooplankton samples were vertically towed with conical plankton net from near-bottom to surface, identified microscopically, and mapped in time-space using Grapher 7.0 and Surfer 8.0. Results show that the abundance of small-jellyfish throughout the bay had been increasing during 2001-2009 on average of 15.2 ind./m 3 , almost 5 times higher than that between 1991 and 2000. The occurrence of peak abundance shifted from spring to summer after 2000, and two peaks appeared in spring and summer, respectively, after 2005. Both the abundance and the frequency of blooms of small-jellyfish increased after 2000 in the bay. In addition, the biodiversity of jellyfish has increased significantly in recent years with a change in dominant species. Several new dominant species appeared after 2000, including Rathkae octopunctata in winter, Phialidium hemisphaericum in spring, summer, and autumn, Phialucium carolinae in spring, and Pleurobrachia globosa in summer and autumn, while some previous dominant species throughout the 1990s (Eirene ceylonensis, Zanclea costata, Lovenella assimilis, and Muggiaea atlantica) were no longer dominant after 2000. The abundance of small-jellyfish was positively correlated with the density of dinoflagellates, and the abundance of zooplankton. We believe that the changes in smalljellyfish abundance and species composition were the result of eutrophication, aquaculture and coastal construction activities around the bay. Concurrently, seawater warming and salinity decrease in recent decades promoted the growth and reproduction of small-jellyfish in the bay.

Relationship between bacteria and phytoplankton during the giant jellyfish Nemopilema nomurai bloom in an oligotrophic temperate marine ecosystem

Bacterial abundance, phytoplankton community structure and environmental parameters were investigated to study the relationships between bacteria and phytoplankton during giant jellyfish Nemopilema nomurai blooms in the central Yellow Sea during 2013. N. nomurai appeared in June, increased in August, reached a peak and began to degrade in September 2013. Results showed that phosphate was possible a key nutrient for both phytoplankton and bacteria in June, but it changed to nitrate in August and September. Phytoplankton composition significantly changed that pico-phytoplankton relative biomass significantly increased, whereas other size phytoplankton significantly decreased during jellyfish bloom. In June, a significantly positive correlation was observed between chlorophyll a concentration and bacterial abundance(r=0.67, P<0.001, n=34).During jellyfish outbreak in August, there was no significant correlation between phytoplankton and bacteria(r=0.11, P>0.05, n=25), but the relationship(r=0.71, P<0.001, n=31) was rebuilt with jellyfish degradation in September. In August, small size phytoplankton occupied the mixed layer in offshore stations, while bacteria almost distributed evenly in vertical. Chlorophyll a concentration significantly increased from(0.42±0.056) μg/L in June to(0.74±0.174) μg/L in August, while bacterial abundance just slightly increased. Additionally, the negative net community production indicated that community respiration was not entirely determined by the local primary productivity in August. These results indicated that jellyfish blooms potentially affect coupling of phytoplankton and bacteria in marine ecosystems.

Comparative study of the hemolytic and cytotoxic activities of nematocyst venoms from the jellyfish Cyanea nozakii Kishinouye and Nemopilema nomurai Kishinouye

Two species of jellyfish, Cyanea nozakii Kishinouye and Nemopilema nomurai Kishinouye, have occurred offcoastal areas of the northeastern China Sea, Yellow Sea, and Bohai Sea in recent years. They influence marine ecosystem safety and fishery production, and also pose a risk to human health. The current study examined the hemolytic and cytotoxic activities of crude venoms extracted from the nematocysts of C. nozakii and N. nomurai. The results showed that there were more nematocysts on tentacles from C. nozakii than on tentacles of the same length from N. nomurai. The protein concentration per nematocyst extracted from N. nomurai was higher than that from C. nozakii. Both nematocyst venoms showed dose-and timedependent hemolytic activity on erythrocytes from chicken, pigeon, and sheep, with sheep erythrocytes being the most sensitive, with EC 50 values of 69.69 and 63.62 μg/m L over a 30-min exposure with N. nomurai and C. nozakii nematocyst venoms, respectively. A cytotoxic assay of both jellyfish venoms on A431 human epidermal carcinoma cells resulted in IC 50 values of 68.6 and 40.9 μg/mL after 24-h incubation, respectively, with venom from C. nozakii showing stronger cytotoxic activity than that from N. nomurai. The results of current study indicate that nematocyst venom from C. nozakii had stronger hemolytic and cytotoxic activities than that from N. nomurai and, thus, C. nozakii might be more harmful to the health of humans and other species than are N. nomurai when they appear in coastal waters.

Screening of Extraction Methods for Glycoproteins from Jellyfish (Rhopilema esculentum) Oral-Arms by High Performance Liquid Chromatography

In order to select an optimum extraction method for the target glycoprotein (TGP) from jellyfish (Rhopilema esculentum) oralarms, a high performance liquid chromatography (HPLC)–assay for the determination of the TGP was developed. Purified target glycoprotein was taken as a standard glycoprotein. The results showed that the calibration curves for peak area plotted against concentration for TGP were linear (r = 0.9984, y = 4.5895x+47.601) over concentrations ranging from 50 to 400 mgL-1. The mean extraction recovery was 97.84% (CV2.60%). The fractions containing TGP were isolated from jellyfish (R. esculentum) oral-arms by four extraction methods: 1) water extraction (WE), 2) phosphate buffer solution (PBS) extraction (PE), 3) ultrasound-assisted water extraction (UA-WE), 4) ultrasound-assisted PBS extraction (UA-PE). The lyophilized extract was dissolved in Milli-Q water and analyzed directly on a short TSK-GEL G4000PWXL (7.8 mm×300 mm) column. Our results indicated that the UA-PE method was the optimum extraction method selected by HPLC.

Investigation into the hemolytic activity of tentacle venom from jellyfish Cyanea nozakii Kishinouye

Cyanea nozakii Kishinouy e( C. nozakii), a giant cnidarian of the class Scyphomedusae, order Semaeostomeae and family Cyaneidae, is widely distributed in the East China Sea, the Yellow Sea and the Bohai Sea, and is abundant from late summer to early autumn. Venom produced by C. nozakii during mass agglomerations can contaminate seawater resulting in death of the halobios and seriously damage commercial fisheries. Swimmers and fishermen commonly suff er painful stings from this jellyfish, resulting in local edema, tingling, breathing difficulties, depressed blood pressure and even death. Such eff ects arise from the complex mixture of biologically active molecules that make up jellyfish venom. In the present study, the hemolytic activity of venom from tentacles of C. nozakii and factors aff ecting its activity were assayed. The HU 50( defined as the amount of protein required to lyse 50 % of erythrocytes) of the venom against dove and chicken erythrocytes was 34 and 59 μg/m L, respectively. Carboxylmethyl chitosan and glycerol could increase hemolytic activity at concentrations greater than 0.06% and 0.2 mol/L, respectively.

Study on the Carry Capacity of Edible Jellyfish Fishery in Liaodong Bay

Jellyfish fishing is a special type of fishery that mainly exists in some countries of East and Southeast Asia. China has the largest jellyfish fishery yield in the world with an annual harvest of around 300 thousand tons. Liaodong Bay is the most important jellyfish fishery ground in China. However, due to the high benefits of jellyfish fishery, which leads to illegal and out-of-season jellyfish fishing occurring each year in Liaodong Bay. Illegal jellyfish fishery in Liaodong Bay is a typical example of the tragedy of the commons. The key problem is that fishermen seek to an illegally initiate jellyfish fishing as early as possible. In this paper, basing on the data of edible jellyfish's biology and ecology, we mainly analyzed the history of jellyfish fishery in China, especially in Liaodong bay, and then we calculated the carry capacity of edible jellyfish in Liaodong Bay which is about 300 thousand tons one year. This number is equal to the recent annual yield of edible jellyfish in China. Furthermore, basing on the carry capacity and reasonable quotas price analysis, we set up a Jellyfish fishing quotas and deficit quotas buyback system which could be a suitable and effective solution for jellyfish fishery management and development in Liaodong Bay at the underlying roots. Although China is the first country with edible jellyfish aquaculture, the annual yield of jellyfish aquaculture is only one fifth of jellyfish fishing. So, there is a very bright developing prospect about edible jellyfish aquaculture in China.

A new record of the freshwater jellyfish Craspedacusta sowerbii Lankester,1880(Hydrozoa)in Southeastern Anatolia(Turkey)

We report the first record of the invasive freshwater jellyfish Craspedacusta sowerbii Lankester in Kralk1z1 Dam Lake,Southeastern Anatolia,Turkey.The medusa was found only in August,2008 when average surface water temperatures were 26.9℃.

Isolation and characterization of venom from nematocysts of jellyfish Rhopilema esculentum Kishinouye

The present work is the first report of the biochemical characterization of the venom from nematocysts of the jellyfish Rhopilema esculentum Kishinouye.The nematocysts were isolated by autolysis and centrifugation and separated by flow cytometry.Four types of nematocysts were identified:mastigophores,euryteles,and atrichous and holotrichous isorhiza.SDS-PAGE and amino acid analyses demonstrated that most of the proteins in the nematocyst extract were between 10 kDa and 40 kDa,and that glutamic acid was the main amino acid.A hemolytic activity assay showed that the activity of the nematocyst venom (RNV) was strongest in Tris-HCl buffer (50 mmol/L,pH 7.8,5% glycerol,0.5 mmol/L EDTA,0.1 mol/L NaCl).The hemolytic activity was related to protein concentration and the HU50 against chicken erythrocytes was 0.91 μg/mL.

Rowing jellyfish contract to maintain neutral buoyancy

Jellyfish are easily carried by ocean currents,yet m ost studies on jellyfish focus on the kinematics in a quiescent fluid.In this experimental and theoretical study,we film six species of rowing jellyfish in a range of background flow speeds at the Georgia Aquarium.Each species has a unique contraction frequency,which is independent of both the body orientation and the background flow speed.Our m athem atical model reveals that jellyfish contract to offset their sinking.This behavior is invariant:Despite the background flow conditions,jellyfish contract as if they are oriented upright in a quiescent fluid.This study indicates that jellyfish operate in open loop without feedback from their environment.