Jellyfish Species Research Articles

Freshwater jellyfish in northeastern Argentina: a risk to human health.

Although cnidarians are mostly marine organisms, the occurrence of freshwater jellyfish frequently arouses the interest of ecologists, due to their sudden and unusual appearances in natural and artificial water bodies around the world. This study describes a series of cases compatible with cnidarian envenomation that occurred coincidentally in time and space with the presence of Craspedacusta sowerbii Lankester, 1880 jellyfish in the province of Misiones (El Saltito stream) in January 2022. A year later, its presence was confirmed in another watercourse of this province (Cazador stream). Based on these findings, its possible toxicological consequences in humans were evaluated by characterizing the jellyfish extract using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and enzymatic/toxic activities. We revealed the presence of proteolytic enzymes and cytolytic toxin(s), which-by means of activating the inflammatory cascade-could explain the stinging skin lesions observed in the suspected cases described. In addition to recording for the first time the occurrence of this cnidarian in northeastern Argentina, this work provides, for the first time, a toxinological explanation for the clinical observations after contact with the most widespread freshwater jellyfish species in the world, giving support to health professionals in the diagnosis and management of such accidents/envenomation.

Bioaccumulation Patterns of Trace Elements in Jellyfish (Crambionella orsini and Cassiopea andromeda) from Northwestern Coastal Waters of the Persian Gulf

Trace element pollution in the Persian Gulf originates from industrial activities, urbanization, shipping, and oil extraction, leading to accumulation in sediments, water, and marine life such as jellyfish. This study investigated trace element bioaccumulation in two jellyfish species, Crambionella orsini and Cassiopea andromeda, across different locations. Jellyfish samples were collected from the Mahshahr and Dilam ports, and their trace element concentrations were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The study revealed no significant differences in trace element concentrations between C. orsini and C. andromeda. However, levels of copper, iron, manganese, and nickel were significantly higher in specimens from Mahshahr compared to those from Dilam. No significant differences were observed for cadmium, mercury, vanadium, tin, magnesium, and selenium across sites. Lower concentrations of lead, arsenic, zinc, and cobalt were found in C. orsini from Dilam compared to Mahshahr. Additionally, the study found no significant correlation between trace element concentrations in the water and their accumulation in jellyfish bodies. These findings offer valuable insights into the distribution and bioaccumulation of trace elements in jellyfish populations across different marine environments in the Persian Gulf.

Detection of the jellyfish Chrysaora pacifica by RPA-CRISPR-Cas12a environmental DNA (eDNA) assay and its evaluation through field validation and comparative eDNA analyses

Climate-driven environmental changes and anthropogenic activities can result in the proliferation of non-indigenous aquatic species such as jellyfish that may cause envenomation and various ecological disruptions. Here we developed a two-step RPA-CRISPR-Cas12a eDNA assay, consisting of target eDNA amplification followed by a CRISPR-Cas12 reaction, for the early detection of Chrysaora pacifica, a jellyfish species often considered non-indigenous to South Korea. The assay demonstrated high sensitivity, with a detection limit of two copies COI/μL for eDNA derived from C. pacifica, using target specific RPA primers and crRNA sequences. Field validation of the assay using eDNA samples from Jinhae Bay collected over eight months of time-series monitoring, revealed temporal distribution of the jellyfish which correlated with results of digital polymerase chain reaction (dPCR) and eDNA metabarcoding. The C. pacifica eDNA assays were also corroborated (R-square 0.7891) by reports from a citizen science–based jellyfish-monitoring program operated by the National Institute of Fisheries Science, South Korea. Our RPA-CRISPR-Cas eDNA assay can therefore, be an efficient alternative to traditional tools for the early detection of outbreaks of non-indigenous or harmful species in marine ecosystems.

Impact of warming and acidification of the Mediterranean Sea on statolith formation of the scyphozoan jellyfish Rhizostoma pulmo Macri (1778)

Ocean warming and acidification negatively affect organisms and biogeochemical cycles. To date, emphasis has been placed on the study of the impact on the structures of calcifying species; however, there is limited knowledge about the influence of the increase of these two variables on the solid structures of non-calcifying species as jellyfish. Here, we study the effects that the increase of temperature and acidity would cause on the statoliths of newly released ephyrae of the Mediterranean jellyfish Rhizostoma pulmo. Six combinations of temperature and PCO2 (18, 24 and 30ºC with a PCO2 of 500 and 1000 ppm each), according to the projections of the SSP5-8.5 (IPCC, 2021) scenario for the year 2100, were applied during 32 days to different groups of polyps randomly selected. Statoliths of the released ephyrae were counted and their size was measured. Our results show that, even though neither temperature nor PCO2 increase exerted a representative effect on the amount of statoliths synthesized in newly released ephyra from R. pulmo, it did exert an impact on the size of these structures: warming led to the formation of larger statoliths, while the rise in PCO2 induced the production of smaller structures. Under the simultaneous increase of both variables, acidification attenuated the effects of temperature, but still slightly larger statoliths were synthesized. The size differences observed in these structures could negatively impact the equilibrium system of this jellyfish species, potentially affecting its ability to survive.

Characterization and phylogenetic analysis of the complete mitochondrial genome of Cotylorhiza tuberculata assembled using next-generation sequencing

In this study, the complete mitochondrial genome (mitogenome) of Cotylorhiza tuberculata (Scyphozoa; Rhizostomeae; Cepheidae) was assembled by the next-generation sequencing data. The complete mitogenome spanned 16,590 bp and contained 14 protein-coding genes, two transfer RNA genes, and two ribosomal RNA genes. Total AT% content was 67.7%, comprising A 30.22%, C 16.16%, G 17.05%, and T 36.56%. The gene arrangement exhibited consistency with the known mitogenomes of other jellyfish species. Furthermore, the phylogenetic relationship of C. tuberculata was investigated based on analysis of the 13 common protein-coding genes. Results indicated a close relationship between C. tuberculata and both Cassiopea xamachana and Cassiopea andromeda. These findings provide a valuable reference for advancing understanding of the phylogenetic relationships, taxonomic classification, and phylogeography of jellyfish species.

Microbial Diversity and Screening for Potential Pathogens and Beneficial Bacteria of Five Jellyfish Species-Associated Microorganisms Based on 16S rRNA Sequencing.

Jellyfish, microorganisms, and the marine environment collectively shape a complex ecosystem. This study aimed to analyze the microbial communities associated with five jellyfish species, exploring their composition, diversity, and relationships. Microbial diversity among the species was assessed using 16S rRNA gene sequencing and QIIME analysis. Significant differences in bacterial composition were found, with distinct dominant taxa in each species: Mycoplasmataceae (99.21%) in Aurelia coerulea, Sphingomonadaceae (22.81%) in Cassiopea andromeda, Alphaproteobacteria_unclassified (family level) (64.09%) in Chrysaora quinquecirrha, Parcubacteria_unclassified (family level) (93.11%) in Phacellophora camtschatica, and Chlamydiaceae (35.05%) and Alphaproteobacteria_unclassified (family level) (38.73%) in Rhopilema esculentum. C. andromeda showed the highest diversity, while A. coerulea exhibited the lowest. Correlations among dominant genera varied, including a positive correlation between Parcubacteria_unclassified (genus level) and Chlamydiaceae_unclassified (genus level). Genes were enriched in metabolic pathways and ABC transporters. The most abundant potential pathogens at the phylum level were Proteobacteria, Tenericutes, Chlamydiae, and Epsilonbacteraeota. The differing microbial compositions are likely influenced by species and their habitats. Interactions between jellyfish and microorganisms, as well as among microorganisms, showed interdependency or antagonism. Most microbial gene functions focused on metabolic pathways, warranting further study on the relationship between pathogenic bacteria and these pathways.

Copula lucentia sp. nov., a new box jellyfish (Cnidaria: Cubozoa: Carybdeida) from Western Mediterranean Sea

A new species of box jellyfish, Copula lucentia sp. nov., is described from El Campello, Spain, and compared to the holotype of Copula sivickisi that was successfully recovered after being lost for almost 60 years. So far, the only cubozoan species recorded in the Western Mediterranean was Carybdea marsupialis. The genus Copula just included the type species (Copula sivickisi) reported from different localities in the Pacific, Atlantic, and Indian Oceans. Morphologically, this new species possesses the typical characteristics of the genus Copula (four adhesive pads on the apex and a vertical keyhole-shaped rhopalial niche ostium) but it can be differentiated from the C. sivickisi holotype by the velarial canal pattern. In C. lucentia sp. nov., the velarial canal roots taper towards the velarial rim and each root bears one to two narrow triangular canals with sharp tips, resembling a bird beak. In contrast, the velarial canal roots of C. sivickisi bear two short, broad canals that increase breadth towards the velarial rim and split up into three- to six-lobed, finger-like canals with rounded tips, giving the canal pattern a paw-like appearance. Molecular analyses of mitochondrial cytochrome c oxidase subunit I (COI) and nuclear 16S ribosomal DNA genes confirm the distinction of the new species and show that there are even more Copula species than expected, but which will not be focused on here. This study highlights not only that there are species yet to be discovered in the Mediterranean Sea but that a revision of the genus Copula is necessary.

Redescription of the commercially harvested jellyfish, Crambionella orsini and Lobonemoides gracilis (Cnidaria: Scyphozoa) from Sri Lanka

ABSTRACT Two types of edible jellyfish, namely ‘ball-type’ and ‘white-type’, were reported to be commercially harvested respectively from the southeast and northwest coasts of Sri Lanka, but their taxonomic identity was unknown. Therefore, medusae collected in the ‘Waya-jel-Survey’, together with specimens from museums, were examined, comparing their morphomeristic data with information from the literature. As per results, the ‘ball-type’ and ‘white-type’ jellyfish species were recognized respectively as Crambionella orsini (Vanhöffen 1888) and Lobonemoides gracilis Light 1914 for the first time from Sri Lanka, with a detailed account of morphological features. Among the four valid species of the genus Crambionella, C. orsini is distinguished by the presence of 16 velar lappets per octant, without tubercles. The two congeners of L. gracilis, namely L. robustus Stiasny 1920 and L. sewelli Rao 1931, were synonymized to L. gracilis, making Lobonemoides monospecific, thus L. gracilis is recognized by the presence of papillae on the exumbrella; 1–6 elongated velar lappets between two successive rhopalia; and the window-like openings and long, spindle-shaped appendages on the oral arms. Likewise, the present study re-describes C. orsini and L. gracilis providing a basic component for efficient management of jellyfish fishery resources in Sri Lanka as well as in other Asian countries.

Dynamic population modeling of bacterioplankton community response to gelatinous marine zooplankton bloom collapse and its impact on marine nutrient balance

The diverse microbial community in the ocean, encompassing various metabolic types, interacts with the wide array of compounds in the dissolved organic matter (DOM) pool, thereby influencing the ocean’s biogeochemical state and, consequently, the global climate. Our understanding of the interactions between specific DOM constituents and microbial consortia remains limited, necessitating further refinement to achieve a mechanistic comprehension of the relationship between the DOM field and the microbial metabolic network. Attaining this level of understanding is crucial for accurately predicting the marine ecosystem’s response to natural and anthropogenic perturbations. To address this gap, we developed a bacterial population model based on the von Foerster equation. This model aims to describe the complex microbial-mediated degradation of gelatinous zooplankton (hereinafter ‘jellyfish’) detritus, as an important, but largely overlooked source of DOM in the ocean. By considering microbial growth and decay, as well as DOM uptake, and nutrient release, the model is able to describe the microbial community’s life cycle, and the biochemical transformations of the jellyfish-derived organic matter. We fitted the model to results of laboratory microcosm experiments conducted to simulate scenarios experienced by ambient microbiomes during decay of two different jellyfish species in the northern Adriatic Sea. By interpreting the fitted parameters, we highlight the differences in the microbial response to different jellyfish species, namely how these affect the microbial community composition and the release of nutrients. This model has been specifically designed for integration with ocean circulation models to create a comprehensive physical-biogeochemical ocean model. Such an extended model can be utilized for multi-scale simulations to assess the system’s response to jellyfish and jellyfish-derived organic matter. Given that jellyfish blooms may become more prevalent under future ocean scenarios, this modeling approach is essential for understanding their potential impact on marine ecosystems.

Genomic and single-cell analyses reveal genetic signatures of swimming pattern and diapause strategy in jellyfish

Jellyfish exhibit innovative swimming patterns that contribute to exploring the origins of animal locomotion. However, the genetic and cellular basis of these patterns remains unclear. Herein, we generated chromosome-level genome assemblies of two jellyfish species, Turritopsis rubra and Aurelia coerulea, which exhibit straight and free-swimming patterns, respectively. We observe positive selection of numerous genes involved in statolith formation, hair cell ciliogenesis, ciliary motility, and motor neuron function. The lineage-specific absence of otolith morphogenesis- and ciliary movement-related genes in T. rubra may be associated with homeostatic structural statocyst loss and straight swimming pattern. Notably, single-cell transcriptomic analyses covering key developmental stages reveal the enrichment of diapause-related genes in the cyst during reverse development, suggesting that the sustained diapause state favours the development of new polyps under favourable conditions. This study highlights the complex relationship between genetics, locomotion patterns and survival strategies in jellyfish, thereby providing valuable insights into the evolutionary lineages of movement and adaptation in the animal kingdom.

New records of two jellyfish species Rhizostoma luteum (Quoy and Gaimard 1827) and Cotylorhiza tuberculata (Macri 1778) in the Moroccan northwest Mediterranean coast

During monitoring visits to the beaches of Fnideq, M'Diq, Cabo-Negro, and Martil, two jellyfish species along the Moroccan Northwest Mediterranean coast have been observed. Rhizostoma luteum (Quoy JRC, Gaimard JP. Observations zoologiques faites à bord de l'Astrolabe, en mai 1826, dans le Détroit de Gibraltar. Annales des Sciences Naturelles, 1827) was recorded at Fnideq in January 2014, and Cotylorhiza tuberculata (Macri S. Nuove osservazioni intorno la Storia naturale del polmone marino, 1778) was recorded between M'Diq and Cabonegro beach in August 2015. Although their occurrence in the Mediterranean Sea is less frequent compared to the outbreaks of Pelagia noctiluca (Forskål P. Descriptiones animalium, avium, amphibiorum, piscium, insectorum, vermium: quae in itinere orientali observavit. ex officina Mölleri; 1775), these findings represent the first documented records of Rhizostoma luteum and Cotylorhiza tuberculata in this region, contributing valuable insights to the existing knowledge of jellyfish distribution in the Mediterranean.

‘Jelly to Joule’: Direct laser writing of sustainable jellyfish-based ‘graphenic silicon’ anodes for environmentally remediating high-performance lithium-ion batteries

The ramifications of global climate change and resource scarcities have made it imperative to re-examine the definition of sustainable energy-storage systems. It is crucial to recognize that not all renewable resources are inherently sustainable, and their full impact on the environment must be assessed. With the proliferation of invasive jellyfish species wreaking havoc on marine ecosystems and economies worldwide, utilizing overabundant jellyfish as a carbon source presents an opportunity to create energy-storage systems that are both financially beneficial and environmentally remediating. Accordingly, a comprehensive approach to sustainability also requires eco-friendly solutions throughout the entire lifecycle, from material sourcing to battery production, without compromising high-performance requirements. Currently, most electrode syntheses for lithium-ion batteries (LIBs) employed are energy-intensive, multiple-steps, complex, and additive-heavy. In response, this work pioneers the straightforward use of low-energy laser irradiation of a jellyfish biomass/silicon nanoparticle blend to encapsulate the silicon nanoparticles in-situ within the as-forming conductive carbonized matrix, creating sustainable and additive-free composite anodes. The self-standing anode is directly synthesized under ambient conditions and requires no post-processing. Here, a laser-synthesized conductive three-dimensional porous carbon/silicon composite anode from raw jellyfish biomass for LIBs is presented, displaying outstanding cyclic stability (>1000 cycles), excellent capacity retention (>50% retention after 1000 cycles), exceptional coulombic efficiency (>99%), superb reversible gravimetric capacity (>2000 mAh/g), and high rate performance capability (>1.6 A/g), paving a new path to future sustainable energy production.

Isotopic evidence for the dietary difference between Rhizostomeae Nemopilema nomurai and Semaeostomeae Cyanea nozakii

Blooms of the Rhizostomeae Nemopilema nomurai and the Semaeostomeae Cyanea nozakii have become more prominent in the coastal waters of China since the end of the 20th century. However, the trophic ecology of these jellyfish species remain incompletely understood. In this study, the trophic characterizations of N. nomurai and C. nozakii populations were assessed using stable isotope analysis (SIA), with a focus on the important bloom area offshore of the Yangtze Estuary. Our results indicated obvious trophic differences between two scyphomedusae. The higher trophic position of the C. nozakii population in the coastal planktonic food web was reflected by its relatively large δ15N value compared to that of N. nomurai. The MixSIAR model indicated that small copepods (<1000 μm) and seston were important food sources for N. nomurai, and showed a stable dietary, irrespective of N. nomurai size. Conversely, C. nozakii exhibited a more diverse diet composition, and gelatinous organisms also were an important part of the diet of C. nozakii. Moreover, a pronounced ontogenetic shift in the diet of C. nozakii was observed, consisting of an increase in the proportion of zooplanktonic prey (excluding seston) in the C. nozakii diet with diameter. This study provides isotopic evidence of the substantial difference in trophic ecology between N. nomurai and C. nozakii, which resulted from the variations in SI values and diet compositions. Inconsistent size-based variation patterns were observed in trophic ontogenetic shifts within the N. nomurai and C. nozakii groups, highlighting a need for further investigation. These results will give insights into the characteristics of trophic ecology and functional roles of Rhizostomeae and Semaeostomeae, and indicate the need for a more careful consideration of the representations of Rhizostomeae and Semaeostomeae in coastal ecosystems, so as not to underestimate the knowledge of taxon-specific ecological effects on energy flow.

ВЗАИМОДЕЙСТВИЕ ЛИПОПОЛИСАХАРИД-СВЯЗЫВАЮЩИХ БЕЛКОВ С РАЗЛИЧНЫМИ ФОРМАМИ ЛИПОПОЛИСАХАРИДОВ

Lipopolysaccharide-binding proteins from two common jellyfish species Aurellia aurita and Ropelema asamushi were isolated and purified, and the interaction of lipopolysaccharides (LPS) of various structural types with LBP was studied. By inhibiting the interaction, it was found that both proteins specifically bind to the lipid and core fragments of the LPS molecule. There are two types of binding sites in LBP with Kd = 3,28 × 10-6 M and Kd = 0,13 × 10-6 M (for the protein from A. aurita) and Kd = 3,66 × 10-6 M and Kd = 0,27 × 10-6 M (for protein from R. asamushi). It has been shown by dynamic light scattering that the binding of LBP to R-LPS leads to the dissociation of LPS micelles. The sizes of LPS aggregates decrease from 200 nm to 25–30 nm in the composition of LPS–LSB complexes. The data of electrokinetic measurements indicate the neutralization of the negative charge of Rd-LPS (-42,2 mV) in the LPS-LSB-R. asamushi complex up to -4,4 mV. S-LPS micelles from E. coli do not disaggregate upon binding to LBP, which is apparently due to the shielding of lipid A by O-specific chains in the S-LPS molecule. The binding of LPS to LBP may affect their endotoxic properties.

Jellyfish detection algorithm based on multi-gradient flow feature fusion

Jellyfish detection is a challenge in the field of underwater biological identification. Although early works have solved some of the problems of jellyfish detection, there are still shortcomings. Earlier jellyfish datasets were not as extensive, necessitating heavy reliance on data augmentation. Moreover, the detection capability is limited, especially in scenarios involving jellyfish gatherings and occlusions. To overcome these limitations, we establish a high-quality dataset with more jellyfish species and propose a more robust real-time detection algorithm. Our algorithm primarily consists of a multi-gradient flow backbone and a feature fusion module GFPN. Additionally, we have designed a receptive field expansion module SPPFCSPC_G. The entire network employs the FReLU activation function, while the bounding box regression utilizes the WIOU loss function. Our methods demonstrate accuracy and run-time performance in comparison with the state-of-the-art yolo series algorithms. Results show that our algorithm achieves the highest Precision, Recall and mAP50, exceeding the baseline yolov5 by 1.1%, 4.1%, and 4.5%, and outperforming the latest yolov8 by 0.9%, 1.3%, and 2.5%. Importantly, our method effectively addresses aggregation, occlusion, and deformation issues commonly encountered in jellyfish detection.

Biodiversity of Gelatinous Organisms in the Western Adriatic Sea and Identification of Their Echo Traces in Acoustic Data

The abundance of gelatinous organisms, such as salps and jellyfish, in the Adriatic Sea has significantly increased over the past decade. Environmental factors play a key role in driving this shift in abundance through rising temperatures and a consequent decrease in oxygen levels in the water, for which jellyfish have higher tolerance levels. Additionally, fisheries may contribute to the proliferation of jellyfish by diminishing their natural predators and food competitors. Pelagic trawl catch data from 2015 to 2023 acquired during MEDIAS acoustic surveys in the western Adriatic Sea were reviewed to extract information concerning the abundance and distribution of salps and jellyfish. These data were subsequently analyzed and compared with satellite environmental information to identify potential correlations. When considering environmental information related to the month of the survey, the results show two significant relationships: one between the abundance of Aequorea aequorea and average salinity and another one between the abundance of Rhizostoma pulmo and bottom temperature. Furthermore, when considering environmental data from the month preceding the survey, a relationship between the overall abundance of gelatinous organisms, salps and jellyfish together, and surface temperature was identified. Additionally, an analysis was conducted on specific hauls that almost exclusively yielded jellyfish, with the aim of identifying their echo traces. Although it was not possible to allocate one jellyfish species to a specific echo trace due to the frequent co-occurrence of more than one species, a general indication of typical backscatter for these species, with a higher response at 70 kHz, was consistently observed in all cases examined.

Biodiversity and distribution patterns of blooming jellyfish in the Bohai Sea revealed by eDNA metabarcoding

BackgroundThe mass occurrence of scyphozoan jellyfish severely affects marine ecosystems and coastal economies, and the study of blooming jellyfish population dynamics has emerged in response. However, traditional ecological survey methods required for such research have difficulties in detecting cryptic life stages and surveying population dynamics owing to high spatiotemporal variations in their occurrence. The environmental DNA (eDNA) technique is an effective tool for overcoming these limitations.ResultsIn this study, we investigated the biodiversity and spatial distribution characteristics of blooming jellyfish in the Bohai Sea of China using an eDNA metabarcoding approach, which covered the surface, middle, and bottom seawater layers, and sediments. Six jellyfish taxa were identified, of which Aurelia coerulea, Nemopilema nomurai, and Cyanea nozakii were the most dominant. These three blooming jellyfish presented a marked vertical distribution pattern in the offshore regions. A. coerulea was mainly distributed in the surface layer, whereas C. nozakii and N. nomurai showed a upper-middle and middle-bottom aggregation, respectively. Horizontally, A. coerulea and C. nozakii were more abundant in the inshore regions, whereas N. nomurai was mainly distributed offshore. Spearman’s correlation analysis revealed a strong correlation between the eDNA of the three dominant blooming jellyfish species and temperature, salinity, and nutrients.ConclusionsOur study confirms the applicability of the eDNA approach to both biodiverstiy evaluation of blooming jellyfish and investigating their spatial distribution, and it can be used as a supplementary tool to traditional survey methods.

The unpredictability of scyphozoan jellyfish blooms

The study of jellyfish blooms has gained attention in the recent decades because of the importance of forecasting and anticipating them and avoiding their interference with human activities. However, after thirty years of scientific effort (monitoring systems, empirical laboratory and field studies, modeling, etc.), the occurrence of blooms remains unpredictable, and their consequences unavoidable. Climate change, eutrophication, overfishing, coastal construction, and species translocation have been suggested as stressors that increase them, but robust evidence to support these claims is limited. The widespread belief that jellyfish blooms are “increasing in number” has been challenged in recent years. Among the gelatinous zooplankton, the bloom forming species are concentrated in the class Scyphozoa, and the number of species with at least one recorded bloom has increased during the last decade. The analyses of long-term time series show seasonality in the dynamic of each blooming jellyfish species population, but the blooms vary in intensity and there are years of an unexplained absence of jellyfish. In this review, we focus on the current state of knowledge, uncertainties and gaps in the critical points that can strongly influence the intensity of the bloom or even lead to the absence of the medusa population. These points include ephyrae, planulae and scyphistoma natural, predatory or fishing mortality, the molecular pathway of strobilation, benthic population dynamics, planula settlement and ephyra to medusa transition success. Some of these points account for certain empirical laboratory evidence under controlled conditions, and are difficult to be studied on the field, but the different sources of non-typically recorded variability need to be addressed to improve our understanding of jellyfish population dynamics.

The effectiveness and applications of drones for monitoring jellyfish

ABSTRACT Jellyfish populations experience fluctuations referred to as ‘bloom and busts’, with numbers rapidly increasing followed by their sudden disappearance. When jellyfish numbers are blooming, they have a complicated relationship with their surrounding environment (predators, competitors, but also a food source), and with humans (sting swimmers, but also source of income and food). As a result, it is important to have a precise and efficient tool for monitoring jellyfish populations. In this extended abstract, we will review studies that have used drones to monitor and track different species of jellyfish, identify the advantages and limitations across these studies, and suggest methods to be adopted when using drones to monitor jellyfish.

Characterization of Collagen from Jellyfish Aurelia aurita and Investigation of Biomaterials Potentials.

Marine collagen sources are potent alternatives due to abundant yield, low pathogen infection risk, high biocompatibility, and any religious and ethical restrictions compared to terrestrial collagen sources. In this research, we aim to investigate the biomaterials potential of the collagen from Aurelia aurita, which is a native jellyfish species in the Marmara Sea. Spectroscopic techniques were used to investigate the structure of jellyfish collagen (JCol) from acid-soluble fraction and compared to Jellagen® from Rhizostoma pulmo. MALDI-TOF showed the main peak of Jellagen® at 276,765.161Da and jellyfish collagen at 276,761.687Da. SDS-PAGE indicated α1 and α2 bands at about 122kDa and 140kDa, respectively. In FTIR and Raman spectra, the locations of amide bands of both species were almost the same. The pI of JCol was determined as 4.46. The particle size decreased abruptly at 43oC from 890 to 290nm. Water, organic and inorganic ratios of collagen were determined at 7.14%, 63.59, and 29.27 respectively. In DSC, the denaturation temperature (Td) of JCol was found at 43.7oC and found to be higher than that of the collagens from jellyfishes that have been reported so far in the literature. Biocompatibility testing by metabolic assay revealed significantly higher fibroblast proliferation on collagen film than on the Tissue Culture Plate. To conclude, Aurelia aurita collagen would be a suitable source of collagen when biomaterials are needed to have high biocompatibility and unique macromolecular properties such as high denaturation temperatures.