Search Results (26)

Marine envenomations are common non-infectious hazards for travelers. Lionfish, venomous fish native to Indo-Pacific waters, have become an invasive species in the Atlantic Ocean and threat to native marine ecosystems. Various control measures have been implemented in response to rapidly expanding lionfish populations, including licensed culling by recreational divers. We herein review lionfish envenomation through framing with a case that occurred during a diving trip to Curacao for the purpose of lionfish spearfishing. Following initial management in Curacao with hot water immersion, wound care, and antibiotic prophylaxis, the patient continued to have persistent swelling, bruising, and pain to the puncture site and was referred to our outpatient clinic for further evaluation. In addition to reviewing clinical syndromes and approach to management for common marine envenomations that may be encountered in the post-travel setting, we situate this case within the broader ecological context of expanding invasive species ranges with climate change and rising sea temperatures. Pre-travel providers should counsel patients at high risk for marine envenomations on preventative measures, along with how and when to seek care following exposure. Post-travel providers should be familiar with the immediate and long-term sequelae of non-infectious envenomations and intoxications, including marine exposures. Larger national and multinational collaborations are required to mitigate the effects of climate change and international marine movement on invasive species, especially those that incur risk to marine and human health alike. Full article

Jellyfish stings are the most common type of marine life injuries. However, at present, the treatment measures against jellyfish stings are mostly empirical and supportive, with uncertain therapeutic outcomes, and there is a lack of specific antidotes based on the toxic mechanism of jellyfish venom in clinical practice. In our previous study, polyphenol epigallocatechin-3-gallate (EGCG) was found to neutralize the toxicity of jellyfish Nemopilema nomurai venom (NnV) in vivo and in vitro. Herein we further demonstrated that EGCG exerted its antagonistic effect against NnV through inhibiting the oxidative stress, pro-apoptotic proteins, and systemic inflammatory responses. Subsequently, we constructed a polyethylene glycol (PEG)-EGCG/tetracycline hydrochloride (HTC) co-loaded micellar nanocomplex in order to enhance the stability and bioavailability of EGCG in vivo, which successfully integrated the membrane-repair function of PEG, the enzyme inhibitory effect of HTC and the antioxidant properties of EGCG. Notably, this micellar nanocomplex demonstrated significant protective effects against both functional damage and pathological alterations in a non-lethal NnV-envenomed mouse model. When administered 1 h after NnV envenomation, EGCG (40 mg/kg), HTC and PEG-EGCG (containing 40 mg/kg EGCG) only partially improved abnormal blood biochemical indicators and moderately alleviated histopathologic damage, and PEG-EGCG/HTC containing merely 8 mg/kg EGCG completely mitigated the toxic reactions in envenomed mice. In the preventive regimen, the administration of EGCG, HTC or PEG-EGCG 30 min before exposure showed no significant improvement in abnormal blood biochemical indicators and histopathologic damage, while PEG-EGCG/HTC could still significantly improve the functional impairments and histopathologic damage of the heart and liver in NnV-envenomed mice. These findings suggest the clinical translational potential of PEG-EGCG/HTC against jellyfish envenomation. Full article

Aquatic envenomations may cause severe tissue injury, neurologic morbidity, and even mortality among those whose leisure and/or occupational activities expose them to marine and freshwater animals. The Motoro ray, or Potamotrygon motoro (also known as an ocellate river stingray) is endemic to freshwater tributaries throughout Brazil, and is a frequent source of severe envenoming of local fisherman and those residing near waterways. Local wound management including immersion in warm water, wound cleaning and debridement, as well as antibiotics are mainstays of treatment, as are local anesthetics (e.g., nerve blocks) and systemic opioid analgesics; however, high-quality evidence supporting such interventions is lacking. We present a case of a Canadian who was envenomed by his pet Motoro ray, and describe his clinical presentation and evolution of symptoms over the subsequent months. With the ever-increasing trade of exotic wildlife, clinicians, public health authorities, and those within the broader wildlife regulatory ecosystem should be attuned for unanticipated adverse consequences, such as those described herein. We further situate this case within the existing published literature around this particular species of ray, which is not typically considered an ornamental fish. Full article

Fish venom biology reaches far beyond addressing risks of human envenomation. The critical understanding of venom composition and the drivers that modulate it will enable scientists to deliver a span of novel bioresources with multiple potential biotechnological applications. The lesser weever fish (Echiichtys vipera), common in the surf of sandy beaches in Portugal, is a noteworthy case study due to frequent envenomation episodes during summer, albeit the lack of information regarding its venom system and the composition of its venom. We collected about one hundred animals from Costa da Caparica (W Portugal) as beach trawl (arte xávega) by-catch. Histology showed a similar essential microanatomical structure of glands in both venomous spines (dorsal and opercular) and no obvious gender differences. Transversal sections across the spines showed a T-shaped supportive bone structure that harbor masses of large, glandular cells that bear large sacculi. The structure is surrounded by a retractable layer of skin, thicker in the opercular spines comparatively to dorsal. The lack of muscular tissue near the glands and missing venom delivery ducts in the spines suggest that venom secretion in this species is holocrine, i.e., that venom is delivered through rupture of the skin and underlying glandular tissue upon mechanical pressure. Proteomics of the venomous spines (dorsal and opercular) showed a different proteomic signature between males and females, pointing to intersexual variation and suggesting that other biotic and abiotic factors might influence venom composition (maturation stage or geographic distribution). Additionally, protein homology matches performed against known toxins from marine venomous fishes indicated the presence of novel unexplored toxins in this species besides expected cytolysins. Our focus in the future is to identify, isolate and characterize the individual components of this venom. We anticipate new insights on the intraspecific adaptation of fish venom systems to specific ecological needs and advocate for sustainable bioprospecting for novel proteins with high biotechnological potential. Full article

Nemopilema nomurai is a species of common large toxic jellyfish in China seas, and its tentacle tissues contain various types of nematocysts. However, the correlation between the morphology and function of nematocysts still remains unclear. In this study, we first obtained two monomorphic nematocysts with high-purity from N. nomurai, namely Anisorhizas and O-isorhizas, by density gradient centrifugation: the Anisorhizas is small and rod-shaped and the O-isorhizas is larger and spherical. Upon deionized water stimulation, O-isorhizas exhibited a stronger discharge capability than Anisorhizas. The nematocyst contents of Anisorhizas (AnC) and O-isorhizas (OnC) were extracted separately, and their composition and bioactivities were analyzed simultaneously. The protein bands by SDS-PAGE revealed similar distributions in AnC and OnC, except that the protein band distribution in OnC was more extensive. OnC showed stronger cytotoxicity, hemolytic activity, metalloprotease activity, and serine protease activity than AnC. In contrast, AnC exhibited a higher antioxidant activity and significant proinflammatory activity. Both AnC and OnC exhibited antimicrobial activities against certain marine pathogenic Vibrios. These results suggest that O-isorhizas, with the larger capsule capability, stronger discharge ability and toxicity, likely plays a major role in inducing toxic effects and tissue damage, while Anisorhizas, being smaller and less toxic, may undertake preferentially other functions, such as synergistic predation, environmental stress adaptation, and energy balance maintenance. This study provides insights into the morpho-functional relationship between various types of nematocysts, and also lays a foundation for further exploration of the functional diversity of nematocysts and the mechanisms underlying jellyfish envenomation. Full article

Accurate detection of residual jellyfish venom is crucial for species identification and clinical management post-envenomation. We developed a highly specific immunoassay for Nemopilema nomurai venom using polyclonal antibodies (titer: 1:256,000). The established i-ELISA exhibited linear detection (0–20 ng/mL) with low variability (intra-plate CV: 0.77–2.78%; inter-plate CV: 2.25–5.17%). The kit demonstrated remarkable thermal stability (<15% signal decay after 6 days at 37 °C; detectable positivity through Day 9), suggesting >1-year shelf life at 4 °C. It showed significantly higher sensitivity for N. nomurai venom than venoms from Rhopilema esculentum, Chrysaora quinquecirrha, Cyanea melanaster, scorpions, or bees (p < 0.01). Validation in murine/human skin envenomation models and serum from systemically intoxicated mice confirmed the reproducibility and stability of residual toxins. This study developed a highly sensitive, specific, reproducible, and stable i-ELISA for Nemopilema nomurai venom, providing a methodological basis for creating diagnostic kits for marine envenomation. Full article

Jellyfish stings represent a significant global marine hazard, causing injuries from localized skin damage to fatal systemic complications. While skin reactions are the most common symptom, heart toxicity (cardiotoxicity) is the primary cause of death. A growing body of evidence shows that the immune system’s response worsens this venom-induced heart damage. However, current research remains disproportionately focused on cutaneous inflammatory responses, leaving systemic immunopathological processes—especially those potentiating cardiotoxicity—poorly understood. Moreover, few jellyfish toxins (like those from the Chironex fleckeri) have been thoroughly studied, and the molecular mechanisms of heart injury remain largely unknown. This review introduces a novel pathophysiological classification of jellyfish envenomation into three distinct categories—immunotoxicity-dominant, cardiotoxicity-dominant, and dual-mechanism synergistic—based on clinical and mechanistic profiles. By synthesizing current knowledge on venom components and their multi-system interaction, we aim to identify actionable therapeutic targets and propose mechanism-driven treatment strategies. This refined classification offers a foundation for future clinical decision-making and the development of targeted therapies, potentially improving patient outcomes through more personalized envenomation management. Full article

Cone snails are a large group of marine gastropods that produce a complex mixture of toxic compounds to hunt prey and defend against predators. The majority of the venom comprises small toxic peptides named conotoxins, which target membrane receptors. In contrast, a smaller part of the venom contains larger proteins and conoproteins, which are thought to be involved in conotoxin maturation and the envenomation process, respectively. Interestingly, many species of cone snails contain conoporins, which are similar to actinoporins—pore-forming toxins found in sea anemones. These actinoporin-like proteins (ALPs) have recently been detected in many molluscan species, and only a few have been experimentally characterized. Due to being highly expressed in the venom gland of many cone snail species, conoporins are thought to play an important part in the envenomation process. Despite this, the exact function of conoporins is currently unknown. We propose several hypotheses aiming to elucidate their biological role. Full article

Envenomation by marine animals poses a significant health concern globally, affecting both local residents and tourists in coastal regions. The primary objective of this review is to critically evaluate the existing scientific literature to determine the most effective first-aid treatment for envenomations caused by marine animals, specifically whether hot-water immersion (HWI) or ice-pack treatment (IPT) provides the best immediate care. This comprehensive review covers a wide range of marine envenomations, from jellyfish stings to stingray injuries. While our focus is primarily on the efficacy of HWI and IPT, we also explore the role of cold-water treatment as a result of its relevance and similarity to ice-pack applications. In addition, we examine other treatments mentioned in the literature, such as medications or vinegar, and highlight their findings where applicable. To provide a clear and structured overview, we summarised the articles in separate tables. These tables categorise the type of research conducted, the marine species studied, the region of origin of the marine species, and the key findings of each study. Our analysis of the available evidence indicates a general consensus in the scientific community on the effectiveness of HWI or IPT for envenomation by marine animals. However, when treating those injuries, it is crucial to consider all factors since there is no universally superior treatment due to the diverse nature of marine habitats. Full article

Jellyfish stings are the most common marine animal injuries worldwide, with approximately 150 million envenomation cases annually, and the victims may suffer from severe pain, itching, swelling, inflammation, arrhythmias, cardiac failure, or even death. Consequently, identification of effective first aid reagents for jellyfish envenoming is urgently needed. Here, we found that the polyphenol epigallocatechin-3-gallate (EGCG) markedly antagonized the hemolytic toxicity, proteolytic activity, and cardiomyocyte toxicity of the jellyfish Nemopilema nomurai venom in vitro and could prevent and treat systemic envenoming caused by N. nomurai venom in vivo. Moreover, EGCG is a natural plant active ingredient and widely used as a food additive without toxic side effects. Hence, we suppose that EGCG might be an effective antagonist against systemic envenoming induced by jellyfish venom. Full article

Bites from venomous marine annelid ‘bloodworms’ (e.g., Glycera spp.) do not appear to have been described in the medical literature despite being seemingly well-known to bait diggers and fishermen. The few laboratory study reports describe their venom composition and physiological effects in vitro to be primarily proteolytic enzymes and neurotoxins apparently used for predation and defense. Herein, we present the report of a symptomatic envenoming suffered by a marine ecologist bitten while performing her field research. The local effects included a rapid onset of pain, swelling, and numbness at the bite site “as if injected with local anesthetic”. Additional signs and symptoms appearing over a two-week period were consistent with both delayed venom effects and potentially secondary infection. The late signs and symptoms resolved during a course of antibiotic treatment with doxycycline prescribed as a precaution and lack of resources to consider a wound culture. Comments about annelid bites sporadically appear in the popular literature, especially pertaining to the fishing industry, under names such as ‘bait-diggers hand’. While these bites are not known to be dangerously venomous, they seem to produce painful local symptoms and possibly increase the risk of marine bacterial infections that could be associated with more serious outcomes. More cases need to be formally described to better understand the natural history of these types of envenomation. Full article

Venoms are complex mixtures of biologically active molecules that impact multiple physiological systems. Manufacture of antivenoms (AVs) therefore requires potency testing using in vivo models to ensure AV efficacy. As part of ongoing research to replace small animals as the standard model for AV potency testing, we developed an alternate in vivo method using the embryonated egg model (EEM). In this model, the survival of chicken embryos envenomated in ovo is determined prior to 50% gestation, when they are recognized as animals by animal welfare legislation. Embryos were found to be susceptible to a range of snake, spider, and marine venoms. This included funnel-web spider venom for which the only other vertebrate, non-primate animal model is newborn mice. Neutralization of venom with standard AV allowed correlation of AV potency results from the EEM to results from animal assays. Our findings indicate that the EEM provides an alternative, insensate in vivo model for the assessment of AV potency. The EEM may enable reduction or replacement of the use of small animals, as longer-term research that enables the elimination of animal use in potency testing continues. Full article

Box jellyfish are extremely potent venom-producing marine organisms. While they have been found worldwide, the highest health burden has been anticipated to be the tropical Indo-Pacific of Southeast Asia (SEA). At least 12 Cubozoan species have now been documented in Thai waters, and many of them inflict acutely lethal strings, especially those under the order Chirodropida. Our previous study has successfully differentiated species of box jellyfish using DNA sequencing to support the morphological study. In this study, we specifically designed polymerase chain reaction (PCR) primers for the 16S ribosomal RNA (rRNA) gene and the mitochondrial DNA cytochrome oxidase subunit I (COI) gene of lethal Thai Chironex species. The SYBR green-based real-time PCR panel was performed for rapid species identification. The sensitivity and specificity of the panel were determined by testing samples of different species. Moreover, we applied the panel to the tentacle sample from a real patient, which helped confirm the animal-of-cause of envenomation. Our results show a success for species identification of box jellyfish using 16S rRNA and COI PCR panel, which revealed congruence between molecular and morphological identification. Furthermore, the panel worked very well with the unknown samples and jellyfish tissue from the real envenomation case. The results demonstrated that molecular panels were able to identify three species of Chironex box jellyfish both rapidly and accurately, and can be performed without having a complete specimen or morphological study. Full article

Conotoxins form a diverse group of peptide toxins found in the venom of predatory marine cone snails. Decades of conotoxin research have provided numerous measurable scientific and societal benefits. These include their use as a drug, diagnostic agent, drug leads, and research tools in neuroscience, pharmacology, biochemistry, structural biology, and molecular evolution. Human envenomations by cone snails are rare but can be fatal. Death by envenomation is likely caused by a small set of toxins that induce muscle paralysis of the diaphragm, resulting in respiratory arrest. The potency of these toxins led to concerns regarding the potential development and use of conotoxins as biological weapons. To address this, various regulatory measures have been introduced that limit the use and access of conotoxins within the research community. Some of these regulations apply to all of the ≈200,000 conotoxins predicted to exist in nature of which less than 0.05% are estimated to have any significant toxicity in humans. In this review we provide an overview of the many benefits of conotoxin research, and contrast these to the perceived biosecurity concerns of conotoxins and research thereof. Full article

Biological fouling organisms on fish cages represent a major issue and costly factor in marine finfish aquaculture. Cnidarians have been identified as one of the most problematical groups, contributing significantly to the occlusion and structural stress of the cage nets, but also dramatically affecting farmed species health in aquaculture facilities worldwide. Recently, significant relationships were established in different Spanish aquaculture facilities between hydrozoans and juvenile fish affected by gill injuries and mortality episodes. Community composition, growth rate and reproductive potential of biofouling were monitored on fish cages over two seasonal periods of fry cages farming, located in southern Spain (SW Alboran Sea), with a special focus on cnidarians. Biomass and community composition of biofouling changed with time and between studied periods, with a marked seasonality in colonization periods and taxonomic composition, particularly for the colonial hydrozoans. The hydroids Ectopleura larynx and Pennaria disticha were found at the highest densities. P. disticha was responsible for major biomass contribution to total hydroid biomass with the fastest growth rates. In addition, actinulae larvae of E. larynx were identified in zooplankton samples at high densities especially during periods of fry introduction in sea cages (when fish are highly vulnerable). These results corroborate evidence of the detrimental influence of fouling cnidarians in Mediterranean finfish aquaculture due to a direct harmful impact on fish health. Investigations on population dynamics, reproductive biology and envenomation potential of fouling hydrozoans should be regarded as key component of best monitoring practices to ensure good farmed fish welfare, maximization of aquaculture production and overall marine spatial planning. Full article