11th Greek Australian Legal and Medical Conference
Crete, Greece 2007

Jellyfish and Marine Envenomations Reports from Antiquity to the Present

Assoc. Professor Peter J Fenner A.M., M.D. (London), F.A.C.T.M., F.R.C.G.P.


Jellyfish stings and envenomation from marine animals is often considered to be a relatively recent phenomenon. However, records exist dating back to the Ancient Greeks, who described jellyfish swarms (vast numbers of jellyfish in one area), stings and envenomation by marine animals throughout the Mediterranean. Swarms of jellyfish have become more common since the opening of the Suez Canal in 1869 that altered the fine ecological balance in the Mediterranean.

Aristotle played an important early role in identifying and describing both marine and land-based animals in Greece and the Aegean Sea and as the “Father of Modern History” was the first to group them into a logical dichotomous classification, as well as adding generally to all aspects of Science. Another major contributor to our information on Science, including marine envenomation in antiquity was Pliny the Elder who, as well as contributing great knowledge was the first to introduce referencing or citing the basis for the information he published.

References to marine envenomation and poisoning date right back to Egyptian times where such knowledge was captured in hieroglyphics on the walls of temples: a perpetual memorial to the great knowledge of our forebears.


Jellyfish have been present in the world’s oceans and seas since time in immemorial. Fossilized jellyfish have been found in Canada dating back to Upper Cambrian times, some 510 million years ago.1 Fossilized jellyfish from the Mediterranean area have, however, only been present since the upper Jurassic period some 150 million years ago.2

The Mediterranean Sea is extensive, some 3,400km in length and with a maximum width of 1600km but an average width of about 160kms. Comparison of a modern map of the Mediterranean with a map of Homer’s Mediterranean Sea from the first century BC shows that the early Greeks had an excellent idea of the extent of the Mediterranean Sea and the surrounding countries (Figure 1).

Figure 1 – Homer’s ‘World’ - http://en.wikipedia.org/wiki/Image:Homer_world_map-en.svg#file

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Marine envenomation studies can be dated back to Aristotle who was born in Northern Greece, the son of a Court Physician to the Macedonian royal family in 384 BC. He originally trained in medicine which gave him a good basis for his later studies, but in 367 he left Northern Greece and went to Athens to study with Plato, who at that time was running his famous school of philosophy. Aristotle proved to be a brilliant pupil but became opposed to some of Plato’s teachings and eventually returned to Macedonia in 338 where he tutored the future Alexander the Great. Later he started a school of his own. In his lifetime he produced numerous works and there are still 30 surviving philosophical treatises in Biology, Physics, Morals, Aesthetics and Politics. He is classified and known as the father of ‘Natural History’. His words are prophetic and apply even today not just to his work but to other more recent medical research work.

“I found no basis prepared; no models to copy... Mine is the first step, and therefore a small one, though worked out with much thought and hard labour. It must be looked at as a first step and judged with indulgence”

Aristotle wrote ‘Historia Animalium” (the history of animals) in which he classified them by their way of life, their actions or their various bodily parts. He first divided them into two types:

  1. those with red blood and
  2. those without red blood,

which is similar to the classification today of vertebrates and invertebrates. He then grouped all these animals into those with similar characteristics and called them genera. He then distinguished species within these genera and even named many species, including 24 crustaceans and annelid worms, 40 molluscs and echinoderms, and 116 fish species, all from the Aegean Sea. He accurately described many vertebrates as oviparous (laying eggs) or viviparous (giving live birth) and he distinguished whales and dolphins (mammals) from fish. Even more astonishing is that he described live birth in sharks, a fact not confirmed again for many centuries.

Those with blood (vertebrates) included 5 genera: -

  1. viviparous
  2. mammals and birds
  3. oviparous quadrupeds
  4. reptiles
  5. amphibians and fishes.

Bloodless animals (invertebrates)

  1. cephalopods
  2. crustaceans
  3. insects (including spiders, scorpions and centipedes)
  4. shelled animals (molluscs and echinoderms) and
  5. zoophytes (‘plant animals’ - i.e. resembling plants) - cnidarians (jellyfish).

His biological key and animal classification system is shown in figure 2.

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Figure 2 – Aristotle’s dichotomous classification of animals

It is a dichotomous classification (aptly, Greek for ‘cut in two’), like the branches of tree trunk. A representation of his ‘tree of life’ , is represented as a massive mosaic on the floor of a church in Otranto, Italy. (Figure 3)

Figure 3 – “Tree of Life” – Church, Otranto, Italy

missing image fileMine is the first step …..

You, my readers or hearers of my lectures, if you think I have done as much as can fairly be expected of an initial start. . . acknowledge what I have achieved - and will pardon what I have left for others to accomplish,


Pliny the Elder

Another famous early investigator in the ancient marine envenomation field was “Pliny the Elder” who lived from 29AD to 79AD, whose actual name was Gaius Plenius Secondus. He was born in Como in Italy in 23AD and was the author of some 75 books and 160 volumes of unpublished notebooks. It is reported that he used to dictate continuously to a scribe who always accompanied him. He would dictate when he was travelling, he would dictate most of the day – he would even dictate whilst sitting down, attending his basic ablutions!

His most famous surviving work is “Historia Naturalis” (Natural History) which was published in AD77. It consists of 37 books including topics as varied as cosmology, astronomy, geography, zoology, botany, mineralogy, medicine, metallurgy and agriculture. A brilliant first, and something that has been essential in all scientific articles particularly in the current climate of plagiarism, is that he always named the sources of his knowledge, citing nearly 4,000 authors – the start of the referencing system used in scientific articles today. Specific to this discussion are the books 28 to 32 - “Materia Medica”.

In 79AD Pliny first recorded bioluminescence. After rubbing his stick against jellyfish “slime” on the beach, he noticed that it glowed in the dusk light. The jellyfish was originally called ‘Pulmo marinaris’, but is now known as ‘Pelagia noctiluca’ (night light) - a jellyfish that Australians know as ‘the little mauve jelly fish’.

Pliny discovered other bioluminescent clams and jellyfish, and he introduced them to his banquets. After everyone had eaten, he would extinguish the lights. It seemed that the bioluminescent foods made people’s lips glow in the dark, making a fascinating aside – and also making his banquets famous! Also, as Romans rather tended to gorge themselves at these banquets, it seemed that vomiting was a reasonably frequent event, and for convenience people would just vomit underneath the table. Of course with the bioluminescence this made it particularly easy for a host to detect any such vomit underneath the table or anywhere else in the room – presumably the slaves would then be directed to clear it up. Due to Pliny’s influence, Romans also used bioluminescence as cosmetics so they glowed in the dark.

Unfortunately Pliny died investigating the eruption of Mt. Vesuvius in August 79AD. A scientist to the last, he was investigating the causes and effects of the eruption. Unfortunately he was overcome by poisonous fumes emitted during the eruption.

Bioluminescence has proven to be more than just an amusement. It has been researched since the 18th century. In this period jellyfish were squeezed through a cheese cloth, rubbed on a flat surface and subjected to electrical stimuli when they gave off a green glow. Bioluminescence less commonly comes in other colours including yellow, red, cyan or blue. It is a feature possessed by a number of other species including corals, sea cucumbers, bacteria, toadstools, plankton, fungi, and a number of various fish, particularly in deeper darker waters. Probably the most commonly known example is that of glow worms.

Bioluminescence from Aqueora victoria (Forskal 1775) has been used in cell biology, as the protein causing the bioluminescence in this jellyfish will light up specific proteins, and an interesting use has have been to introduce bioluminescence proteins to enable them to detect pollution, particularly in hospital waste water.3

An even more important aspect of bioluminescence is the detection or assessment of cancer cells in humans: an area with some future exciting prospectives.4

Pelagia notiluca – (“Little Mauve Jellyfish”)

Pelagia have been known in the Mediterranean since antiquity. It even features in a Mosaic on floor of a Villa in Palermo, Sicily – the home of Roman magistrate in the 4th century AD (Figure 4).

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Figure 4 - 4thC AD - Pelagia noctiluca mosaic

Present throughout the Mediterranean, as well as many other seas worldwide including the cooler ocean waters off the New South Wales beaches in Australia, it can cause thousands of human stings when it infests beaches. The sting is painful and burning, with little relief from cold packs or ice, which must be placed in polythene bags to prevent them getting wet, as melting ice is fresh water and this causes discharge of remaining stinging cells present on the skin or adherent tentacles, thus increasing the sting and the pain. Even using ice, the skin may blister within hours and this can last several days and cause pigmented scars.5

Pelagia is unique in a number of ways. It is the only jellyfish that has ever been published in a medical journal as having caused a life-threatening sting through allergy. The initial contact with a jellyfish produces a local toxic reaction when the toxins are injected under the skin causing pain. Some toxins when they are absorbed systemically can cause further symptoms, although this does not usually happen with Pelagia. However, a case of life-threatening allergic reaction to Pelagia occurred some 20 years back, when a woman who had been previously stung by Pelagia with no problems, was stung again.6 This time, within minutes she started to get throat swelling with trouble breathing and her airway became totally blocked and her pulse became impalpable within minutes. Fortunately there were a number of people around her, who happened to be her security guards, and they started immediate cardiopulmonary resuscitation. Also, being security guards they had radios and called for immediate radio backup. A medical team was there very quickly and she was resuscitated successfully. This is the only one reported case of a life-threatening allergic reaction, and it was actually of interest as it occurred to the Greek Prime Minister’s wife some years back.

The impact of the Suez Canal

In 1869 the French engineer Lessops completed the Suez Canal. Whilst this was a major economic boost to shipping it also proved to be somewhat of an ecological disaster for the Mediterranean.

Possibly, for the first time ever, jellyfish in the Red Sea were able to migrate through the Canal and into the Mediterranean, where the various conditions proved ideal for improved growth and expansion. Also, their natural predators did not seem to achieve the same benefits and consequently some introduced jellyfish species, particularly Rhopilema, proliferated.

There is no clear explanation of why it happened at that time. Although people generally believe that this was the first Suez Canal, it was the first that allowed major shipping to traverse from the Mediterranean to the Red Sea and vice versa. Lessops had dug this new Canal, north from the Red Sea, following 2 lakes to a mid point before heading direct towards the Mediterranean following a previous Canal that had been started in 500BC by Darius, the Persian Conqueror of Egypt. Darius did not complete the canal as his expert advisors felt that the Red Sea was higher than the Mediterranean, and work stopped. The Ptolomies following Darius finished his Canal by 250BC. It was 50 metres wide and served ocean going vessels between the Mediterranean and the Red Sea – and in fact probably Cleopatra rode upon it in a royal barge a few years BC.

This canal that had also been dug along the route of an even earlier canal that started in 600BC, and even that leg had followed a vastly older canal that had been opened for shipping round about 1500BC, shown on temple carvings in Egypt with the Queen of Egypt sailing on the canal leaving for Africa on a barge.7 From other engravings and history it appeared that this particular canal had followed an even older Canal. Egyptian history, blending into myth over a period of 4,000 years, tells of older canals…

As stated, with the opening of the Suez Canal in 1869, marine species in the Red Sea migrated through to the Mediterranean where they found the conditions excellent and with few predators allowing these newly-introduced jellyfish to proliferate, where over time they destroyed a number of the fish stocks and other wildlife. ‘Swarms’ of both the new and the old jellyfish can cause major problems periodically in the Mediterranean Sea.8

Jellyfish in the Mediterranean are usually deep water, sea going creatures. However, they can be carried ashore by wind and currents, reaching beaches where people swim and cause many painful stings. These ‘swarms’ of jellyfish cause major losses to tourism and fisheries – particularly the latter affecting fish stocks, and cause major fish shortages, a major staple food in the Mediterranean. The swarms also cause blockage of the cooling vents for ships’ engines and power stations, causing overheating, shut down, and even permanent damage. Swarms of Rhopilema, the introduced species from the Red Sea, and the local Pelagia noctiluca seem to have been increasing in the past 20 years in the south east Mediterranean. They have 2 annual peaks: June to August, which corresponds almost exactly with the tourist season, and a secondary peak in the winter of January to March season. They occur in very high densities which may be several kilometres long with millions of species from the surface through to 20 to 30 metres in depth. Up to a quarter of a million stings may occur in a bad season, many of which are minor stings and do respond to cold treatment, whereas others are more painful and cause severe blistering.

Venomous Fish

Whilst discussing venomous fish Aristotle’s name comes to the fore again. His “Historia Animalium” includes many medical treatments, including the use of cattle’s milk, chicken’s eggs, mammals’ horns and sea sponge and stingray barbs (he actually refers to stingray as Trigon). Again, he obviously studies the species extensively, as his information was amazing.

“All fishes, with the exception of the flat selachians, lie down side by side, and copulate belly to belly. Fishes, however, that are flat and furnished with tails-as the ray, the trygon (stingray) and the like – copulate, not only in this way, but also, where the tail from its thinness is no impediment, by mounting of the male upon the female, belly to back…

However, the earliest recorded use of a marine organism in specific treatment is in ‘Materia Medica’ where Pliny the Elder recommended that the sting unit of a sting ray be ground up and used for the treatment of both toothache and obstetrics. While this may seem a little bizarre the compound toxins and peptides from a number of venomous marine animals form the basis for many modern medical treatments, as the effect of one venom can possibly be successfully used to counter other medical conditions.

Stingrays are actually very gentle creatures, and often referred to as ‘the pussycat of the sea’. In the Grand Cayman Islands divers swim amongst large numbers of stingrays and actually play with them touching their fins. However, one of the most common causes of envenomation in a stingray occurs because of one of its “normal” habits. A stingray will burrow itself into the sand lying flat on the bottom awaiting its prey. Unfortunately there is a reflex action when the flaps or wings of the stingray are touched, it causes an immediate whipping forwards of the tail. In the tail, actually facing away from the body, are 1-9 or so barbs. The reflex producing the forward whip of the tail changes the direction of these barbs so that instead of facing backwards, they are actually being driven forwards under a high power. If they encounter the integument of a victim they can puncture it with ease as the barbs are strong enough to penetrate through thin rubber or even the leather of protective boots. When the barb is driven into the victim, it may cause one of major problems. The barb has a serrated edge and may cause jagged tears, deep cuts and even death from exsanguination.

The barb may also jam into deeper tissues such as bones and joints, where it can cause chronic infection, as when it punctures the lining of the barb (which contains toxins) becomes stripped off the barb and remains in the integument of the victim lining the tract following the barb - which may be broken off in the skin or withdrawn whole. This remaining tissue contains venom that can cause muscle necrosis, chronic infection and even osteomyelitis. It caused the death of a very fit 12 year old in Innisfail back in 1988 when in a bizarre set of circumstances the boy, who was sitting in the centre of the boat was struck by the tail of a stingray that leapt up in front of the boat. One barb went into his knee and broke off, the other went into his chest and was withdrawn whole. The tract of the chest envenomation was followed but it appeared to have glanced off the ribs going harmlessly into subcutaneous tissues.9

Unfortunately, however, it had actually penetrated his chest and gone straight into his heart. Whilst this produced sudden chest pain, no other symptoms were experienced, as the hole sealed over very quickly as the barb was withdrawn. As the boy appeared completely fit with a normal chest xray the morning after envenomation, he was allowed home. However, the remaining venom in the tract caused muscle necrosis and five days later he suddenly collapsed and could not be resuscitated. A post mortem proved that the barb had actually gone directly into his heart and withdrawn: remaining venom caused muscle necrosis, creating a small hole in the heart with cardiac tamponade and instant death.9

Wading fishermen are at the highest risk of envenomation as they tend to walk through shallow water. The technique of avoiding stingray is to shuffle through the water when the noise frightens the stingray away, thus preventing envenomation.

Other ‘venomous fish’

Include the Siganid, Rabbit fish and Weaver fish. Stings from the latter are particularly common in the Mediterranean and in Europe with a small dorsal barb just protruding from the sand, puncturing the skin of people walking on the sand or wading in shallow oceans just off shore.

Scorpion fish have small dorsal venomous barbs and envenomation is common amongst women who become envenomated whilst scaling fish caught by their husbands. Envenomation causes severe local pain which spreads moving up to the draining lymph nodes – the groins in the legs and the axilla in the arms and can cause nausea, vomiting and palpitations.5

The current recommended treatment includes placing the effected stung area in hot water – usually about 42-43 degrees centigrade. This is slightly higher that the temperature coming out of a car engine but often such hot water is only available in the radiators of cars or even the telltales on outboard engines or coolant pipes on the inboard engines of boats. Before placing the affected area in hot water, which can be withstood for 15 minutes or so, place the other limb in first to test it is not too hot and cause burning or scalding. It is often necessary to continue this treatment for some time and recurrent top-ups are often required. However, all victims comment on the efficacy of the heat treatment for localised pain.5

Finally, treatment of a penetrating barb needs one of three antibiotics - which can be difficult to achieve in Australia. One is doxycycline which is fairly easily available but the other two are ciprofloxacin that needs a special authority, and 3rd generation cephalosporins, only available as intravenous medication given in hospital.5

Poisonous fish

Poisonous fish can occur in the Mediterranean in the warmer months although they are mainly concentrated in the Red Sea. These are puffer fish and similar species, and contain tetrodotoxin that in sufficient dose can cause fatality. In Japan puffer fish are eaten as a delicacy, specially prepared by trained chefs who remove the liver, abdominal organs and the skin, as these are areas of intense local concentration, whereas the meat contains lower concentrations that just cause numbness and tingling of the lips: unfortunately this process does not work completely, with some 10+ deaths occurring in Japan each year.5 The identification and avoidance of poisoning has been known since time immemorial, as it only occurs from fish having no scales. A warning is actually recorded in the Bible - Deuteronomy 14, verses 9-10.

“These ye shall eat of all that are in the waters: all that have fins and scales shall ye eat: And whatsoever hath not fins and scales ye may not eat; it is unclean unto you”

These fish were even known to the Ancient Egyptians. In the tomb of the Pharaoh Ti, Egyptian fish that can be identified in the Tomb of Pharaoh Ti along with Egyptian fishers using a large jar or wickerwork/ rush container from a tied reed canoe, are shown trying to catch Tilapia, Clarias catfish, a Mormyrid), a dolphin, a puffer fish and 2 unknown spp.

Other marine animals

Aristotle’s name occurs yet again as we look at the biology of other Mediterranean marine animals. ‘Aristotle’s Lantern’ is actually the bony mouth structure of a sea urchin (echinoderm – prickle-skinned marine animals). This structure is described in Historia Animalum who investigated its structure.

Aristotle - Further Knowledge

Aristotle also described in Historia Animalum his investigations into”beings that are the work of nature” –the origin of systematic sorting, taking apart (“dissecting”), identifying, and classifying.

Aristotle made many other startling revelations in other areas that proved to be both accurate for his lifetime, as well quite prophetic. In his second book on meteorology he describes: -

The earth is circular, since things gravitate towards the centre, and because the shadow cast by the earth during eclipses.

He also recorded the Bathymetry of certain seas, recognising that the seas and the continents are slowly changing through time

“The Sea of Azov is slowly filling and will eventually become land”

This is actually a shallow north section of the Black Sea which to this day is becoming shallower and soon, within the next century will become total land.

Aristotle also described in his Meteorology book components of the water cycle: -

“Now the sun, moving as it does, sets up processes of change and becoming and decay, and by its agency the finest and sweetest water is every day carried up and is dissolved into vapour and rises to the upper region, where it is condensed again by the cold and so returns to the earth.”

And finally also gives a warning which sounds very much like global warming these days: -

“The same parts of the earth are not always moist or dry, but they change according as rivers come into existence and dry up. And so the relation of land to sea changes too and a place does not always remain land or sea throughout all time, but where there was dry land there comes to be sea, and where there is now sea, there one day comes to be dry land. But we must suppose these changes to follow some order and cycle. The principle and cause of these changes is that the interior of the earth grows and decays, like the bodies of plants and animals. . . .

But the whole vital process of the earth takes place so gradually and in periods of time which are so immense compared with the length of our life, that these changes are not observed, and before their course can be recorded from beginning to end whole nations perish and are destroyed.”

Aristotle and contemporary Greeks at that time were at the forefront of civilization and investigation into everything. We follow them in awe.


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  2. Gaillard C., Goy, J., et al. New jellyfish taxa from the upper Jurassic lithographic limestones of Cerin (France): Taphonomy and Ecology. Palaeontology 2006; 49 (6):1287.
  3. Emmanuel E., Perrodin Y., Keck G., Blanchard J.M., Vermande P. Ecotoxicological risk assessment of hospital wastewater: a proposed framework for raw effluents discharging into urban sewer network. J Hazard Mater. 2005 Jan 14;117(1):1-11.
  4. Hsieh C.L., Xie Z., Yu J., Martin W.D., Datta M.W., Wu G.J., Chung L.W. Non-invasive bioluminescent detection of prostate cancer growth and metastasis in a bigenic transgenic mouse model. Prostate. 2007 May 15:67(7):685-91.
  5. Williamson J., Fenner P., Burnett J., Rifkin J. Eds. Venomous and poisonous marine animals: A medical and biological handbook. 1996; Sydney, Australia, NSW University Press.
  6. Togias A.G., Burnett J.W., Kagey-Sobotka A., Lichtenstein L.M. 1985. Anaphylaxis after contact with a jellyfish. J Allergy Clin Immunol. 75:672-675.
  7. Kinross L. Between two seas. New York: William Morrow & Company, Inc. 1969.
  8. MacKenzie D. Jellyfish swarms threaten Mediterranean beach bums. New Scientist 2007; 11:31.
  9. Fenner P.J., Williamson J.A., Skinner R.A. Fatal and non-fatal stingray envenomation. MJA 1989; 151:621-625.