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Jellyfish Sting Newsletters: Number 33 - July 2005

Significant Papers Published 

  1. Carrette T, Seymour J. Vascular dopplers: a new way of recording cardiac parameters in envenomed organisms. Toxicon 45;541-544, 2005.

    Measuring cardiac activity in experimental animals for research purposes has great relevance and obvious implications for investigating venom actions and toxicity. Previous techniques have been confined to vertebrate models as traditional heart recording apparatuses require a closed vascular system to be effective. A new technique utilizing a Vascular Doppler placed external to the cardiac muscle was trialled in order to record previously undocumented invertebrate heart activity of envenomed animals. Combined with Avisoft sound collection software, this technique was found to be successful in recording cardiac parameters such as heart rate and extent of contraction in an invertebrate model. This method is advantageous as it is not only inexpensive and easily portable but allows for specific venom actions to be investigated in a wider variety of previously unreportable, but ecologically significant animals.

  2. Uechi G, Toma H, Arakawa T, Sato Y. Biochemical and physiological analyses of a hemolytic toxin isolated from a sea anemone Actineria villosa. Toxicon 45;761-766, 2005.

    A species of venomous sea anemone Actineria villosa was recently found inhabiting the coastal areas of Okinawa, Japan. This marine animal produces various proteinous toxins. The toxin purified from the tentacles of the animals was found to be a protein with a molecular weight of approximately 19 kDa. This newly found hemolytic toxin of A. villosa, was named Avt-I. Incubation of the toxin with sphingomyelin inhibited hemolytic activity by up to 85%, showing that Avt-I may target sphingomyelin on the erythrocyte membrane. The hemolytic activity was stably maintained at temperatures below 45 degrees C, however, a sharp linear decrease in heat stability was observed within the range of 45-55 degrees C. Thus A. villosa produces a toxin with strong hemolytic activity similar in biochemical and physiological properties to other members of actinoporin family previously isolated from related species of sea anemones.

  3. Vera C, Kolbach M, Zegpi MS, Vera F, Lonza JP. Jellyfish sting. An update. Rev Med Chil. 132;233-241, 2004.

    Jellyfish are aquatic organisms, whose number increases under certain conditions of water temperature. The firing of structures known as nematocysts induces the extrusion of the poison, to attack their victims. The poison produces characteristic local and systemic reactions which can sting humans and be fatal.

  4. Radwan FF, Roman LG, Baksi K, Burnett JW. Toxicity and mAChRs binding activity of Cassiopea xamachana venom from Puerto Rican coasts. Toxicon 45;107-112, 2005

    A separation of toxic components from the upside down jellyfish Cassiopea xamachana (Cx) was carried out to study their cytotoxic effects and examine whether these effects are combined with a binding activity to cell membrane receptors. Nematocysts containing toxins were isolated from the autolysed tentacles, ruptured by sonication, and the crude venom (CxTX) was separated from the pellets by ultracentrifugation. For identifying its bioactive components, CxTX was fractionated by gel filtration chromatography into six fractions (named fraction I-VI). The toxicity of CxTX and fractions was tested on mice; however, the hemolytic activity was tested on saline washed human erythrocytes. The LD50 of CxTX was 0.75 microg/g of mouse body and for fraction III, IV and VI were 0.28, 0.25 and 0.12 microg/g, respectively. Fractions I, II and V were not lethal at doses equivalent to LD50 1 microg/g. The hemolytic and phospholipase A2 (PLA2) activities of most fractions were well correlated with their mice toxicity. However, fraction VI, which contains the low molecular mass protein components (< or =10 kDa), has shown no PLA2 activity but highest toxicity to mice, highest hemolytic activity, and bound significantly to the acetylcholine muscarinic receptors (mAChRs) isolated from rat brain. The results suggested that fraction VI contains proteinaceous components contributing to most of cytolysis as well as membrane binding events. Meanwhile, fraction IV has shown high PLA2 that may contribute to the venom lethality and paralytic effects.

  5. Bailey PM, Bakker AJ, Seymour JE, Wilce, JA. A functional comparison of the venom of three Australian jellyfish--Chironex fleckeri, Chiropsalmus sp., and Carybdea xaymacana--on cytosolic Ca2+, haemolysis and Artemia sp. lethality. Toxicon 45;233-242, 2005.

    Cnidarian venoms produce a wide spectrum of envenoming syndromes in humans ranging from minor local irritation to death. Here, the effects of Chironex fleckeri, Chiropsalmus sp., and Carybdea xaymacana venoms on ventricular myocyte cytosolic Ca2+, haemolysis and Artemia sp. lethality are compared for the first time. All three venoms caused a large, irreversible elevation of cytosolic Ca2+ in myocytes as measured using the Ca2+ sensitive fluorescent probe Indo-1. The L-type Ca2+ channel antagonist verapamil had no effect on Ca2+ influx whilst La3+, a non-specific channel and pore blocker, inhibited the effect. Haemolytic activity was observed for all venoms, with C. xaymacana venom displaying the greatest activity. These activities are consistent with the presence of a pore-forming toxin existing in the venoms which has been demonstrated by transmission electron microscopy in the case of C. fleckeri. The venom of C. fleckeri was found to be more lethal against Artemia sp. than the venom of the other species, consistent with the order of known human toxicities. This suggests that the observed lytic effects may not underlie the lethal effects of the venom, and raises the question of how such potent activities are dealt with by envenomed humans.

  6. Ramasamy S, Isbister GK, Seymour JE, Hodgson WC. The in vivo cardiovascular effects of an Australasian box jellyfish (Chiropsalmus sp.) venom in rats. Toxicon 45;321-327, 2005.

    Using a new technique to extract venom from the nematocysts of jellyfish, the in vivo cardiovascular effects of Chiropsalmus sp. venom were investigated in anaesthetized rats. Chiropsalmus sp. venom (150 microg/kg, i.v.) produced a transient hypertensive response (44+/-4 mmHg; n=6) followed by hypotension and cardiovascular collapse. Concurrent artificial respiration or pretreatment with Chironex fleckeri antivenom (AV, 3000 U/kg, i.v.) did not have any effect on the venom-induced hypertensive response nor the subsequent cardiovascular collapse. The cardiovascular response of animals receiving venom after the infusion of MgSO4 (50-70 mM @ 0.25 ml/min, i.v.; n=5) alone, or in combination with AV (n=5), was not significantly different from rats receiving venom alone. Prior administration of prazosin (50 microg/kg, i.v.; n=4) or ketanserin (1 mg/kg, i.v.; n=4) did not significantly attenuate the hypertensive response nor prevent the cardiovascular collapse induced by venom (50 microg/kg, i.v.). In contrast to previous work examining C. fleckeri venom, administration of AV alone, or in combination with MgSO4, was not effective in preventing cardiovascular collapse following the administration of Chiropsalmus sp. venom. This indicates that the venom of the two related box jellyfish contain different lethal components and highlights the importance of species identification prior to initiating treatment regimes following jellyfish envenoming.

  7. Ramasamy S, Isbister GK, Seymour JE, Hodgson WC. Pharmacologically distinct cardiovascular effects of box jellyfish (Chironex fleckeri) venom and a tentacle-only extract in rats. Toxicol Lett 155;219-226, 2005.

    The present study investigated the in vivo cardiovascular effects of Chironex fleckeri venom and tentacle extract (devoid of nematocysts). In anaesthetised rats, venom (10 microg/kg, i.v.) produced a transient pressor response (23+/-4 mmHg) followed, in two of five animals, by cardiovascular collapse. Tentacle extract (100 microg/kg, i.v.) produced a more prolonged hypertensive effect (31+/-3 mmHg) without cardiovascular collapse. Prazosin (50 microg/kg, i.v.) did not have any significant effect on the cardiovascular effects produced by venom. However, prazosin significantly attenuated the pressor response produced by tentacle extract. Ketanserin (1 mg/kg, i.v.) did not have any significant effect on the cardiovascular response of the anaesthetised rat to venom (10 microg/kg, i.v.; 25+/-1 mmHg). Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed to compare the two jellyfish samples used in the present study.

  8. Noguchi K, Sakanashi M, Matsuzaki T, Nakasone J, Sakanashi M, Koyama T, Hamadate N, Sakanashi M. Cardiovascular effects and lethality of venom from nematocysts of the box-jellyfish Chiropsalmus quadrigatus (Habu-kurage) in anaesthetized rats. Toxicon 45;519-526, 2005.

    Haemodynamic effects of saline-extracted venom from nematocysts isolated from Chiropsalmus quadrigatus (Habu-kurage) were studied in anaesthetized rats. Intravenous administration of venom (0.2-5 microg protein/kg) produced immediately dose-dependent hypertension and bradycardia. Femoral blood flow transiently increased but calculated femoral vascular conductance decreased. Changes caused by 1 microg/kg of venom were reproducible, and were not affected by prazosin, atropine or BQ123 (ET(A) receptor antagonist) but were significantly attenuated by nicardipine. At doses over 2 microg/kg, hypotension and a decrease in pulse pressure were observed subsequent to transient hypertension. In 5 of 8 rats received 5 microg/kg venom and 6 of 6 rats at 10 microg/kg, death due to irreversible cardiac arrest occurred within 30 min after intravenous injection. However, during nicardipine infusion, venom (10 microg/kg) exerted only modest effects and the rats survived. Heating venom (50 degrees C for 10 min) before injection practically abolished the haemodynamic effects of 10 microg/kg venom, indicating its thermolability. Data show that C. quadrigatus venom has both vasoconstrictor and cardiodepressive effects in rats, and suggest that a calcium channel blocker can protect against the cardiovascular and lethal effects of the venom.

  9. Hopkin M. Box jellyfish show a keen eye. May 9, 2005.

    Box jellyfish are best known as near-invisible marine killers and a scourge of tropical holidaymakers, but it seems they should also be known for their oddball eyes.

    Zoologists have discovered that the jellyfish use a remarkable sophisticated eye to produce a blurred image. The jellyfish don’t have a brain to deal with any incoming visual information; they rely instead on a simple ring of nerves to coordinate behaviour. Researchers think that the mass of imagery and light beaming into a box jellyfish’s 24 eyes may provide the type of information the creature needs, without it having to filter or process any of these data.

    Box jellyfish, also known as cubozoans owing to their cubic shape, are unusual in the jellyfish world because they are active predators. Unlike other species that drift along and eat whatever their tentacles ensnare, box jellyfish behave more like a fish, swimming towards interesting objects and skirting obstacles. To help it perform these feats, a box jellyfish has a cluster of six eyes at each of its four corners.

  10. Silfen R, Vilan A, Wohl I, Leviav Am. Mediterranean jellyfish (Rhopilema nomadica) sting. Burns 29;868-870, 2003.

    The steady increase in reports on jellyfish poisoning may be related to the dramatic increase in temperature of the world’s oceans over the past four decades. Most jellyfish species become active at water temperatures above 20 oC and above, which usually occur in late summer. Although jellyfish stings lead to only mild symptoms in most cases, some victims seek medical help for acute pain that is resistant to the usual analgesics, or for, late worrying symptoms. The Mediterranean jellyfish (Rhopilema nomadica) poisoning is a painful urticarial eruption leaving post-inflammatory hyperpigmentation.

  11. Four lay press reviews were also published.

    1. Skin and Allergy News, June 2003, 34. First aid for venomous marine stings: Think heat. Venoms induce lysis of the red blood cell membrane, and heat application reduces the hemolysis. A review of the Hawaiian studies discussing this option was reported in earlier issues here from the Hawaiian Medical Journal.

    2. Smithsonian, June 2005, 80-87. Killers in Paradise. A review of recent Chironex and Irukandji experiments.

    3. National Geographic, July 2005, 54-57. Deadly jellyfish of Australia. A review of Chironex.

    4. New York Times, Zimmer Carl. Plain, simple, primitive? Not the jellyfish. Page D1, June 21, 2005. A review of recent genetic research in jellyfish shows that they have a remarkably sophisticated collection of genes including many that give rise to complex human anatomy.

  12. Marchini B, De Nuccio L, Mazzei M, Mariottini GL. A fast centrifuge method for nematocyst isolation from Pelagia noctiluca Forskal (Cnidaria: Scyphozoa). Riv Biol. 97(3);505-15, 2004.

    Nematocyst isolation from surrounding tissue is an important step to characterize Cnidarian venom. Although several protocols have been used to extract venoms from cnidarian tissues, the complete isolation of nematocysts from tissue is still difficult. The goal of the present work was to evaluate the effectiveness of three different media, Percoll, Ficoll and Methylcellulose in isolating nematocysts from Pelagia noctiluca tentacles by centrifugation. The complete sedimentation of nematocysts and tissue fragments to the bottom of the test tubes was observed in Ficoll and Methylcellulose suspensions. The best result was obtained using a discontinuous density gradient of Percoll: three types of nematocysts were concentrated in three different fractions along the density gradient. Protein assay and preliminary chromatographic analyses confirmed these results.

  13. Oiso N, Fukai K, Ishii M, Ohgushi T, Kubota S. Jellyfish dermatitis caused by Porpita pacifica, a sign of global warming? Contact Dermatitis 52;232-233, 2005.

    The jellyfish was found out of its usual habitat.

  14. Nevalainen TJ, Peuravuori HJ, Quinn RJ, Llewellyn LE, Benzie JA, Fenner PJ, Winkel KD. Phospholipase A2 in cnidaria. Comp Biochem Physiol B Biochem Mol Biol. 139(4);731-735, 2004.

    Phospholipase A2 (PLA2) is an enzyme present in snake and other venoms and body fluids. PLA2 catalytic activity in tissue homogenates of 22 species representing the classes Anthozoa, Hydrozoa, Scyphozoa and Cubozoa of the phylum Cnidaria were measured. High PLA2 levels were found in the hydrozoan fire coral Millepora sp. (median 735 U/g protein) and the stony coral Pocillopora damicornis (693 U/g) that cause skin irritation upon contact. High levels of PLA2 activity were also found in the acontia of the sea anemone Adamsia carciniopados (293 U/g). Acontia are long threads containing nematocysts and are used in defense and aggression by the animal. Tentacles of scyphozoan and cubozoan species had high PLA2 activity levels: those of the multitentacled box jellyfish Chironex fleckeri contained 184 U/g PLA2 activity. The functions of cnidarian PLA2 may include roles in the capture and digestion of prey and defense of the animal. The current observations support the idea that cnidarian PLA2 may participate in the sting site irritation and systemic envenomation syndrome resulting from contact with cnidarians.

  15. Greenwood PG, Garry K, Hunter A, Jennings M. Adaptable defense: A nudibranch mucus inhibits nematocyst discharge and changes with prey type. Biol Bull. 206;113-120, 2004

    Nudibranchs that feed on cnidarians must defend themselves from the prey’s nematocysts or risk their own injury or death. While a nudibranch’s mucus has been thought to protect the animal from nematocyst discharge, an inhibition of discharge by nudibranch mucus has never been shown. The current study investigated whether mucus from the aeolid nudibranch Aeolidia papillosa would inhibit nematocyst discharge from four species of sea anemone prey. Sea anemone tentacles were contacted with mucus-coated gelatin probes, and nematocyst discharge was quantified and compared with control probes of gelatin only. Mucus from A. papillosa inhibited the discharge of nematocysts from sea anemone tentacles. This inhibition was specifically limited to the anemone species on which the nudibranch had been feeding. When the prey species was changed, the mucus changed within 2 weeks to inhibit the nematocyst discharge of the new prey species. The nudibranchs apparently produce the inhibitory mucus rather than simply becoming coated in anemone mucus during feeding. Because of the intimate association between most aeolid nudibranchs and their prey, an adaptable mucus protection could have a significant impact on the behavior, distribution, and life history of the nudibranchs. An important fact is that the blockade disappeared after cnidarian contact lapsed.

Letters to the Editor 

  1. Burnett JW. Dysphonia: a new addition to jellyfish envenomation syndromes. Wildnerness and Environmental Medicine 16;117-118, 2005.

    A young healthy male developed dysphonia (numbing plus sounds without words) lasting only 30-45 min. after swishing small Physalia physalis medusae in his mouth while swimming freestyle off Ft. Lauderdale, Florida in January, 2004.


  1. Russ Hoare from Quicksilver in Port Douglas, Australia writes that his report on a new, spotted large jellyfish seen there has been resurrected and will be published. They have seen this year a large wave of Physalia there similar to the one several years ago. It is not an annual occurrence.

  2. Kathleen Shea of Colorado was stung by an unknown jellyfish, said to be a ? box jellyfish, and had significant muscle pain. The sting occurred near her mouth which she brushed with her left arm. She had trouble speaking in the first few hours. She thought her voice aberration for a few hours was due to muscle spasticity, pain and disorientation.

  3. Neil Pacey of Mussman, Australia developed generalized hives after a jellyfish lodged in his hair while on the Great Barrier Reef. For a year he has had chronic hives occurring mostly at night. The acute phase passed in a few hours after significant facial edema with a bit of respiratory difficulty persisting.