Box Jelly Fish | Chironex | Irukandji
BOX JELLYFISH INFORMATION
Information supplied by Phuket Aquarium
written by Prof. Peter Fenner and Dr Lisa-Ann Gershwin.
Synopsis of Jellyfish Hazards
Two quite different types of dangerous box jellyfish occur throughout the
world's oceans, particularly in the tropics. They are separated quite
easily by the number of tentacles attached to each corner of the body, as well
as by the type of sting they give. Not all box jellyfish are dangerous,
but a good rule of thumb is to consider it as potentially dangerous until you
know that it is safe.
1. Multi-tentacled Box
Square, box shaped body with a branched "arm" hanging from each corner, each
with multiple tentacles (total up to 60 tentacles). There are at least two types
of multi-tentacled box jellyfish in Thailand, one smaller with branches in a
single row, and the other larger with branches in three dimensions. The
Australian species Chironex fleckeri is an example of a multi-tentacled
box jellyfish, and is widely considered the "world's most venomous animal", able
to kill healthy adults and children in as little as 2 minutes through massive
envenomation. As a general guideline, an adult multi-tentacled box jelly may
have up to 120-180 metres of tentacle, requiring as little as 1.2 metres to kill
a child, or 3-5 metres to kill an adult; some sort of barrier between the
jellyfish and skin is an essential part of safety. Multi tentacled box jellyfish
are generally found in shallow coastal environments, particularly on sandy
beaches near mangroves and river mouths. They are found throughout the tropics
of the world; they are commonest in the warmer months but may be found at any
time of year in any conditions.
2. Single-tentacled Box
Rectangular box-shaped body with specimens from 1cm to 15cm tall (depending
on species), with an unbranched "arm" hanging from each corner with one
tentacle, each with a single tentacle only (total 4 tentacles). Throughout the
world there are currently many types of single-tentacled box jellyfish that
cause severe symptoms known as the "Irukandji syndrome", with more still being
found; Carukia barnesi is a common Australian example. Irukandji syndrome
has been confirmed throughout the recreational oceans and seas of the world,
e.g. Australia, Thailand, Japan, Hawaii, Florida, Caribbean, Tahiti, India and
others, as far north as North Wales in the UK and as far south as Melbourne in
Australia. An initially minor skin sting results in severe symptoms after a
delay in onset of about 5-40 minutes. The symptoms include: severe lower back
pain, nausea, vomiting, profuse sweating, difficulty breathing, cramps, spasms,
coughing and a feeling of "impending doom"; these are not usually deadly, but
are severely distressing and may promote drowning. Some species can also cause
severe hypertension (high blood pressure), which may be deadly to previously
well patents, through stroke or heart attack. In Australia, Irukandji jellyfish
are typically found along protected beaches, as well as reefs, islands and open
ocean, particularly during periods of mild, onshore breezes. They are more
abundant during warmer months, but may be found in any location, any time of
year and in any conditions.
3. Other types of Jellyfish
Other types of jellyfish such as blue bottles, Portuguese man-o-war, blubbers,
sea lice, lion's mane, sea nettles, mauve stingers and others are common in the
Thai region but are of less serious medical concern than box jellyfish and
Irukandjis, and are not generally considered life threatening in this region.
However, it is not uncommon for people unfamiliar with jellyfish identification
to fear all jellyfish; this can be easily overcome with education.
History of marine stinger knowledge in
A colleague (Dr John Williamson) visited
Phuket, on the Andaman Sea, west Thailand, with Dr Robert Hartwick PhD, in
August 1985. Exploration of the local coastline, fishing villages, and
excursions with native fishermen in their boats revealed several jellyfish but
no multi-tentacled box jellyfish (also called 'chirodropids') were seen. Local
fisher folk immediately recognised photos of box jellyfish, and of human stings,
and a village fisherman's wife proudly displayed leg scars from a sting 3 years
previously which could have been a chirodropid. The fishermen knew the
"summertime" chirodropids as "munga fi" (see case report below), which
translated approximately info "fire jelly", and they associated hot, still
weather and calm water with the risk of stings. Almost every fisherman admitted
to "munga fi" stings at some time in his life. No deaths were known or admitted.
Later in Bangkok, at the Department
of Dermatology, Siriraj Hospital, Dr. Williamson learned that the presentation
of patients with mainly chronic scarring - almost definitely from
"box-jellyfish" stings - sustained in the Bangkok area, was a regular
occurrence. A senior Bangkok scuba diving instructor, Lieutenant Colonel (Ret.)
A.B. "Dusty" Rhodes, continues to report jellyfish stings and sightings in the
Gulf of Siam and in the Andaman Sea, including one night time sighting of a
chirodropid in the Andaman Sea.
Studies in Thailand suggest that a
locally occurring plant "phakbung-thale" (Ipomoea pes-caprae (L.) Roth)
which is found in abundance along the warmer seashores of both
hemispheres, and which has been and is used by Thai fisherman to both prevent
and treat jellyfish stings (Wasuwat 1970; Applied Scientific Research Institute
of Thailand 1977), may have a valid pharmacological basis (Pongprayoon et al
A review of Thai literature dealing with jellyfish stings in the Gulf of
Siam and Andaman Sea revealed anecdotal reports of a few deaths following jelly
fish stings (Siriraj Hospital Gazette 1985 and J. Nakorn Rachasema Hospital 1991
- in Thai and not listed in Medline).
In December 1995, two deaths were
described after jellyfish envenomation at Langkawi Island, on the west coast of
Malaysia on its border with Thailand (Fenner & Williamson 1996). The victims;
rapid demise and the characteristic skin markings suggested that the causative
jellyfish was a multi-tentacled box jellyfish.
A 26 year old British tourist was swimming off Chaweng Beach on the Thai Island
of Koh Samui on October 20, 1999. It was early evening and the sea was
calm. He suddenly came out of the water and was observed by his friends waling
unsteady and asking for water to drink. He then, within minutes, collapsed,
stopped breathing and was pulseless with dilated non reactive pupils on arrival
at a nearby local hospital. The physician, one of the reporters, noted extensive
welts across his neck, chest and back with the typical appearance of recent
jelly fish stings. Efforts of resuscitation were not successful.
A 25 year old male from Australia and a 23 year old female, from Switzerland
died in August after being stung in waters of Koh Pha Ngan, officials said. The
25 year old (male) died on 9 August 2002 after receiving massive stings to his
legs while swimming of the islands Hat Rin Nok beach. He died before arriving at
a beach-side clinic, a hospital official said. Late afternoon wading in
waist-deep water he was stung on both legs, stopped breathing - pulseless within
5 minutes. Resuscitation commenced immediately asystolic ECG on arrival at the
local hospital 15 minutes later.
Bangkok Pater Report:
Island warns of
deadly jellyfish after tourist deaths - Wed Aug 21 12.33 2002 AM ET
BANGKOK, Thailand - Officials on a popular resort island in
southern Thailand have laid nets in the sea to prevent poisonous
jellyfish from nearing the shore after two foreign tourists were
fatally stung while swimming.
Sean Tyrrel, 25 of
Australia and Mounya Den, 23, of Switzerland died earlier this month
after being stung in waters off Koh Pha Ngan, officials said
Tyrrell died on
Aug. 9 after receiving massive stings to his legs while swimming off
the island's Hat Rin Beach. He died before arriving at a beachside
clinic a hospital official said.
A day later, Dena died
from similar stings to her legs after being taken by speedboat to
Ban Don Inter Hospital on the nearby island of Koh Samui.
The victims' hometowns
were not immediately available.
The deaths on the
island, which is known for hosting all-night rave parties, have
prompted local authorities to warn tourists against swimming in the
sea during the monsoon season, when the deadly jellyfish are
frequently washed toward the beach by rough seas.
"We have set up a sign
board on the beach warning tourists to refrain from swimming where
the jellyfish are rampant, and laid nets in the areas to prevent the
lethal jellyfish from coming close to the beach," Hat Rin local
administrator Prasob Tauychareon told The Associated Press.
The victims were the
first to die from jellyfish stings in several decades, he said.
3 April 2008 (Thursday), Klong
Dao beach, Koh Lanta, Southwest Thailand.
11 year old girl dies after being stung by jellyfish while paddling on lilo
about 20m out from the beach in the morning around 10 am. Later that day a
sign was erected on the beach saying: Watch out for Jellyfish, be careful
when you are swimming.
History of marine stinger knowledge in
Whilst deaths and life threatening
stings from marine stingers have been known and tracked in Australia since
1884, two issues have been pivotal.
First, multi-tentacled box
jellyfish were originally identified in Australia in the 1940's, and linked
as the causal agent to fatalities in 1955. However, it wasn't until the
1960's that Jack Barnes, a physician in Cairns, began advising the public to
wear protective clothing to minimise their exposure to risk. For decades,
this protective clothing was pantyhose; in the early 1980's, lycra body
suits were introduced. Both work well (see below for more information).
However, protective clothing was, in general, not popular with beach-goers.
In 1982, a company called UniNet began installing 'stinger nets', in
response to request from the tourism industry. Today, about 30 stinger nets
are installed at popular beaches throughout northern Queensland where
Chironex occur. There has never been a life threatening multi-tentacled
box jellyfish sting inside the nets; in addition, the nets provide a safer
place to swim than in unprotected areas, and they act as a positive,
reassuring education device to the recreational public. Indeed, deaths in
Queensland have reduced from 1 per 4 years before the nets to 1 per 12 years
since the nets, whereas in Northern Territory where nets are not used,
deaths have increased from 1 in 4 years to 1 in 3 years. Because of the
nets, Chironex have been considered well managed in Queensland for
over 20 years, allowing the tourism industry to flourish.
Second, the symptoms of
Irukandji syndrome were first identified in Australia in the 1940's, but
were not linked to species of jellyfish as the causal agent until 1961.
However, the general public and tourism industry was not widely aware of
Irukandjis and the illness they cause until 2002, following two highly
publicised tourist fatalities in North Queensland. The negative publicity
resulting from the fatalities caused a conservatively-estimated loss to
tourism of about $65 Million. In response, the state government initiated
the Queensland Government Irukandji Task Force, for the purpose of
overseeing research and public safety. Through the Task Force, excellent
contributions to the scientific knowledge and management strategies were
produced toward reducing risk from marine stingers. As an outgrowth of the
Task Force, the Whitsunday region assembled a local Marine Stinger
Management Committee in 2005; in two years of pro-active effort at raising
awareness about the utility of protective clothing, life threatening stings
reduced from a historical average of 30-ish per year to 7 per year to 4 per
Best Practice Prediction
In general, multi-tentacled box jellyfish are commonest in the warmer
months (November to May in Australia), particularly along shallow, sandy
beaches near mangroves and river mouths, and particularly along the southern
ends of bays. However, they have been found all months and in just about all
Multi-tentacled box jellyfish
often swarm in shallow, protected conditions, e.g. calm, early morning seas.
Presence of schools of small prawns and fish often coincide with Box
Jellyfish swarms, because multi-tentacled box jellyfish follow their food.
Whilst "early season" box jellies are typically too small to be a health
threat (they become deadly at about 8cm body size), it is important to keep
in mind that large specimens are often found with small specimens, so the
detection of a high risk condition is based on presence of box jellyfish,
not presence of large box jellyfish.
In general, single-tentacled box
jellyfish typically swarm on flat-calm days with a mild, 5-10 know onshore
breeze. In Australia, we typically see swarms of Irukandjis between
between Christmas and New Year, and somewhat lesser swarms around Easter
time, but usually only for 1-2 days in any given location. However, it is
important to note that even when swarms are not present, occasional stings
do occur in all conditions.
It has been demonstrated by many
different researchers over the past 50 years that a very strong correlation
exists between Irukandjis and 'salps and jelly buttons'. Salps are a type of
colonial invertebrate that are easily recognised as chains of jellyfish,
with the individuals stuck together in a herringbone pattern. Jelly buttons
are any of a number of types of small clear jellyfish that produce a 'sea
lice' type of nuisance sting. Both salps and jelly buttons are more numerous
than Irukandjis, and may be effectively used as predictors of the relative
risk of Irukandjis. On the highest risk Irukandji days, it is common to see
salps and jelly buttons washing up at the tide line, and also to feel a
higher than usual "sea lice" sort of stinging irritation feeling to the
Best Practice Prevention
The primary strategy for prevention of life-threatening jellyfish stings
in Australia is providing a barrier between jellyfish and human skin. For
multi-tentacled box jellyfish, the most successful method currently in use
is stinger nets; for single-tentacled box jellyfish, the most successful
method currently in use is protective clothing. It should be noted, however,
that protective clothing works equally well for all types of jellyfish sting
prevention. The reason for the different strategies is that multi-tentacled
box jellyfish are more of a 'beach problem', where Irukandjis are a 'reef,
island and beach problem'/ Thus, the nets work well for beaches, but not so
well for reefs and island; but whereas divers and snorkelers do not mind
wearing protective clothing, beach-goers tend to be less willing. Thus, the
biggest challenge in the Queensland marine stinger problem is currently
beach Irukandji stings.
Quite simply, Irukandjis most
frequently sting the chest and upper arms, because they swim at the surface
and most swimmers and bathers bob at the surface; multi-tentacled box
jellies typically sting the legs, because they swim near the bottom. A
full-body lycra suit covers up about 75-80% of the body's skin surface, but
also serves to cover the parts most frequently stung. Furthermore, lycra
suits provide excellent sun protection, and can be removed at the end of the
day, leaving the wearer and the corals with less greasiness from sunscreen.
Numerous types of "jellyfish
repellents" have been marketed throughout the years. There is
insufficient evidence that these actually work to prevent a life threatening
envenomation. In general, jellyfish stinging cells operate on a hair-trigger
mechanism. Therefore, a chemical means of repelling a jellyfish may be
ineffective because one it touches the skin, the sting still occurs;
similarly, inhibiting the hair trigger may be ineffective because it is a
mechanical process. Thus the only method considered safe by marine stinger
safety experts is providing a physical barrier between the jellyfish and
Best Practice First Aid
Like all first aid treatment, the highest priority is saving human life.
With multi-tentacled box jellyfish stings, loss of consciousness and cardiac
standstill may occur in as little as 2 minutes, so it is of the utmost
importance to stay with the person, get help on the way, and commence CPR
(Cardiopulmonary resuscitation) if necessary. With single-tentacled box
jellyfish, the initial sting will often seem quite minor, but severe
systemic symptoms develop after a delay of 5-40 minutes. Thus, the priority
for multi-tentacled box jellyfish stings is to maintain life; stopping
additional envenomation with vinegar is a secondary priority; with
single-tentacled box jellyfish, there is ample time to see if symptoms
develop, and early vinegar can make a huge difference. Vinegar stops the
stinging cells that haven't fired yet from firing; this inhibition process
is permanent and instant, and works with any type of undiluted household
vinegar. Hot water or ice should NOT be used; freshwater causes massive
discharge of stinging cells, thus increasing envenomation, and heat dilates
capillaries, thus potentially worsening the effect of the sting by
increasing the amount and speed of venom uptake.
FIRST AID TREATMENT FOR
MULTI-TENTACLED BOX JELLYFISH STINGS (e.g. Chironex)
1. Remove from water, if
2. Send others for
help; do not leave the victim
3. If the patient is
unconscious, commence CPR (cardiopulmonary resuscitation) immediately
4. If the patient is
conscious, douse stung area liberally with vinegar for 39 seconds
5. Check consciousness
regularly - victims will often scream with pain - if they become quiet
they may be going unconscious.
6. Be prepared to give
CPR if necessary
7. Get to medical aid
as quickly as possible.
NOTE: Commence CPR
prior to vinegar if the patient is already unconscious; strings to the
rescuer will be minor in comparison to the high likelihood of loss of life
in the patient if CPR is delayed
FIRST AID TREATMENT FOR
SINGLE-TENTACLED BOX JELLYFISH STINGS (e.g. Irukandji)
1. Douse liberally with
vinegar as soon as a sting is suspected, even if minor
2. Do not re-enter the
water for 30-40 minutes, to see if symptoms develop
3. Phone for / or get to
medical aid as quickly as possible if systemic symptoms develop.
Importance of Research in
prediction, prevention & treatment
Many important advancements have been made in recent years toward
improvements and insights in prediction, prevention and treatment of marine
stingers and their stings. This research is very active in Australia, and a
strong collaborative research program is now up and running between Thailand and
The most active areas of research at
this time in Australia are into the ecology of the Cjorpmex and
Irukandjis, in order to refine our understanding of their prediction, and on
developing better offshore treatments for Irukandji stings (e.g., dive
operators, island resorts)
In Thailand, the current research
focus is on identification of the species present, and on understanding their
ecology, i.e. being able to predict and detect them with greater accuracy. There
is an excellent chance that the antivenom used in Australia for Chironex-type
box jellyfish will also be effective for Thailand box jellyfish, and that the
magnesium treatment used by hospitals for Irukandji envenomation will also be
effective for Thai Irukandjis. However, it must be cautioned for Chironex-type
box jellyfish that death typically happens faster than antivenom can be
delivered to the victim; thus prevention remains the primary focus.