MARINE STINGS OR BITES
and Hazardous Marine Life
(Caution: This is NOT a medical advice page)
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A marine sting or bit is from any form of marine life - here in
the Keys its salt-water creatures that create the injury. Most of the time in the Keys, for recreational swimming, diving
and snorkeling, the stings come primarily from jellyfish and sea lice, though
the following are common marine animals that can cause bite or sting injury:
|Jellyfish (not all types sting)
||Portuguese man of war (a type of jellyfish)
|| Stingray (not all rays have stingers)
||Coral - especially fire coral
- View the bottom of this page for pictures and more
information on these creatures -
Common symptoms are: Pain, Stinging, Swelling,
Redness, Numbness, Rash, Itching, and Open Wounds (as
when you get bit)
What can you do to prevent these?
- Wear Water Shoes - we make everyone on our boat do this when we're out
exploring the sandbars and islands. Protect your feet.
- Don't run into the water or dive headfirst - OK, just use common sense
with diving in, and don't run so fast you'll fall down onto sharp things.
- If you don't know what it is -- DON'T TOUCH IT! The other part of
this is to learn what things are, and what things sting and bite and which
- Do not swim with open wounds
- Don't wear bright shiny clothing, jewelry or equipment - this is primarily
true in murky water of low visibility. On the reef in the daytime, where fish
can see what you are, it's not as much of a problem but a little shiny lure
hanging around your neck could still prompt a fish to go for it.
- Don't hang your body parts over the side of the boat while chumming the
water! A couple of kids have lost toes around Boot Key Harbor because of
this. This is especially true at dusk and night. - and certainly don't swim
- Avoid swimming or hanging your body parts in the water during feeding
times of dawn and dusk, and avoid night time swimming. (Snorkelers and Divers
on reefs can of course enjoy the life after dark, but this is a bit different
than just flailing around in the darkness anywhere).
- Use the oily lotions before you get in the water to ward off stings from sea lice
- Push floating seaweed away from you - it harbors sea lice during that
season (mother's day to father's day generally)
JELLYFISH, HYDROIDS, MAN OF WAR, ANEMONES AND SEA LICE:
These all have tentacles (some so small you couldn't see them) that stick to
the skin and fire a little poisonous stinger called a nematocyst. This
microscopic little barb injects the prey with a poison (mostly an irritant to
humans, but it can get bad depending on what got you). They do this to paralyze
little fish and creatures in order to eat them. For us it stings and hurts. The
nasty sting from a man of war can be immediate and painful like a blow torch
passed over your skin, while the more subtle stings of sea lice can first take a
few minutes to develop a very slight itch, then proceed on later to a
"drive-you-nuts" itching under the skin. Most exhibit redness and swelling -
some more than others. The toxin from the nematocysts is a protein and can be
broken down like other proteins using heat, vinegar or meat tenderizers. If the
tentacles are still on your skin DO NOT RUB OR MOVE THEM AROUND! - you'll fire
more of the nematocysts and make it worse. First inactivate the stingers by
pouring vinegar or alcohol over it, then gently lift it from the skin. If none
is available and you're in the water then try to gently flush it from your skin
in the water with movement, trying not to make it worse. Wash the site gently
with soap and water. If you're on a boat try to get vinegar or meat tenderizer
on it right away. If you can heat up the vinegar on the boat then get it as hot
as you can without risking a burn to the skin. Then pour it over the stings. If
you have a hot shower on board then take as hot a shower as you can stand
without burning the skin, then do the hot/warm vinegar or meat tenderizer
afterwards. I recently got very bad sea lice stings (Sea Lice are
microscopic photoplankton that have nematocysts to sting you. They are NOT
jellyfish larvae that get under your skin) and found that meat tenderizer - made
into a paste and gently rubbed all over the site - worked much better than
vinegar, but it got quite messy when it flaked off.
SCORPION FISH, LIONFISH, STONEFISH, CATFISH, STINGRAYS AND SEA URCHINS:
These all produce venom. The hot water technique described above will help
break down the venom. Immerse the area in as hot of water as you can stand
(don't burn yourself) for 60-90 minutes. Any pieces of spines or fins should be
gently removed while you are wearing gloves, or use small tweezers and pickups.
I have to tell you from personal experience, that while perhaps uncivilized, it
works - Peeing on a sea urchin sting provides immediate relief from the burning!
Fisherman's Hospital in Marathon FL recommends that you follow up with a
Doctor in these situations:
- You have a sign of an infection (redness, swelling, pain, drainage, fever)
- Uncontrolled bleeding
- If you have not had a tetanus shot in 5 years
- Any problem with the wound that bothers you should be reported to your
MORE INFO & PICTURES
Many of the photos below are supplied by "(C) Paul Humann/New World
Publications" - For more information about marine life books and guides for
viewers, to go to
. This is a really good website that has lots of photos and a learning center
where you can get more detailed information on reefs and marine life. It even
has a kids corner, and a complete catalogue with all of their books and guides.
Check it out.
HYDROIDS - Stings
Brushing against these delicate white or
silvery tentacles can be painful. This is one of the most common injuries to
divers on reefs - stinging hydroids. They may be very small, from 1 to 5
inches, and come in different shapes. Mild to severe stinging occurs with
possible welts on the skin. It's not serious and will go away. Try vinegar,
or a 50% solution of rubbing alcohol (isopropyl alcohol). Apply a
hydrocortisone cream or lotion to the area twice daily. Don't rinse the area
with fresh water! (causes more firing of nematocysts and stinging), and
don't rub the area with your hand. Do NOT apply an ice pack. All of these
will only make it worse.
White Ball Hydroid
Plate Fire Coral
FIRE CORAL - Stings
stuff really burns after you touch it! That's why they call if fire coral.
It has a light reddish brown appearance and can take different forms. It can
also vary from a light beige to a mustard color. The plate fire coral shown
at the left is distinctive, and the tips are often lighter than the main
formation. It frequently grows on many of the heavier corals. this type
tends to be in shallow areas close to the surface. The fire coral tentacles
are quite small but can give the coral a "fuzzy" texture. It also encrusts
around other structures such as the bottle shown below, or encrusts over
other dead coral. It often will cover large areas of steel or concrete on
shipwrecks and underwater structures. This encrusting fire coral takes on
many different shapes so it's harder to identify. I've gotten stung
myself by simply hauling in the anchor rode on a small boat - it must have
dragged through fire coral and I got stung just by handling the line. The
sting is similar to the hydroids - use vinegar or 50% rubbing alcohol, and
apply hydrocortisone cream twice daily. The same Don'ts apply: Don't
rinse with fresh water, rub it in, or apply ice packs.
Encrusting Fire Coral
We just took a
"tourist" friend out snorkeling recently and he found a floating sponge
encrusted with fire coral. He grabbed it and squeezed it as hard as he could
to "feel" the sponginess. What he got was painfully intense burning and
welting that lasted a few days.
Fire Coral Tentacles - Closeup
Fire Coral Formation
SHARP CORALS - Things that Cut
The small flower coral shown above is razor sharp and
easily cuts if you rub up against it. The branches of the Staghorn coral at
left have sharp pointy tips that can puncture dive suits and penetrate
deeply, where than can break off and embed in the flesh. One of the more
common reasons for snorkelers to get coral cuts is when they swim over coral
heads that are very close to the surface. Any wave surges or boat wakes can
slam them hard into the coral. OUCH! These types of cuts become easily
infected in a tropical environment. The wounds should be cleaned with soap
and water and inspected to ensure that no coral pieces remain embedded. An
antiseptic or topical antibiotic is applied and the wound bandaged.
This is a small worm that grazes on the surface of corals
or algae. It sometimes hides under rocks. They're fun to watch. the
segmented body has two rows of bright white tufts along its length - these
white tufts are what hurts! They cause an intense burning sensation and tend
to stick to your skin like little fiberglass. strands
Bristleworm closeup - Venomous bristles in the white tufts
When stung, you must remove all the bristles you can see. You
can try to pick them off gently with tweezers (don't rub or scrape!). Once
you have those off then dry the area - use a hairdryer or something if you
have one. Gently apply sticky tape to the area and peel it very slowly away.
Hopefully most of the remaining bristles will stick to the tape. Apply the
vinegar or alcohol (discussed previousl) for some pain relief. The meat
tenderizer or diluted ammonia solution (sometimes found in your own urine)
also works. If you really welt up you might try some hydrocortisone cream.
Longspined Sea Urchin
|SEA URCHINS - Things that stick and sting
Not all urchins have as long and sharp of spines as the one
shown on the left. Some, such as pencil urchins, have short stubby spines
and are easy to hold in your bare hand. The longspined ones though are
extremely sharp and VERY brittle. They'll break off in your skin immediately
and sting like heck! Don't touch or mess with unless you know how. For
someone with the experience it is possible to pick them up and let them walk
on your hand by their lower walking spines, which aren't as sharp or long -
but if you mess up you'll pay the price. These can be EXTREMELY painful.
They used to be very prevalent in the Florida Keys in the 70's and 80's, but
you don't see many of them around here anymore, though they are starting to
come back. We always caution divers to keep their hands at their sides
(don't dive or snorkel using hand motions - use your fins) so they don't
stick themselves. They come out of their hiding cracks at night so the risk
is higher then. When you're walking in shallows look ahead so you don't step
on urchins. The smaller ones with less pointy spines don't hurt if you
gently pick them up, but if you step on them they can penetrate right
through your water shoes. I can tell you from personal experience that
urine is the quickest remedy available - even if it does gross out the
ladies - it works immediately. You can't really get the spines out. Remove
any visible pieces with tweezers but don't try to dig out the embedded ones.
Immerse the area in as hot of water as you can stand (or as hot of vinegar)
without burning yourself. Once dry you should use an topical antiobiotic to
guard against infection. Spines may work themselves out so don't bandage it
tightly. Eventually the spine will break down and dissolve naturally. If you
get one in a joint it becomes more serious and can even involve surgery. I
did get a small one in my knuckle joint once, but eventually it did break
down, the pain went away, and I have full use of the joint.
Most of the sponges on the reef are harmless. The one
shown at left though is the exception. It is a Caribbean species that causes
extreme irritation and will make you miserable for a long time. It's been
called the "Dread Red Sponge", the "Irritating Sponge", and the
"Do-Not-Touch-Me Sponge" (pretty self explanatory name). It gets big
and has an irregular shape. It's a dark reddish brown and rather bland
aesthetically. It has numerous tiny spicules that will stick to your skin
and burn for days. The same applies with the other stings: Use the
vinegar or alcohol and don't rub or scrape. You can also try the same trick
used with the bristleworm tufts: dry the area and use sticky tape to
gently and slowly peel away the tiny spicules. Use the hydrocortisone twice
daily. If it gets really bad, and you develop an allergic reaction, you
might have to be treated with Benadryl or other antihistamine. If
you've rubbed up against this sponge with clothing or gloves then be very
careful in handling them. The little spicules are easy to transfer this way.
You can soak the material in the vinegar solution, then wash them.
Bulb Tentacle Sea Anemone
Sea anemones sting. That's how they
paralyze small fish, then digest them in their tentacles. There are many
different varieties, but the small soft looking tentacles are typical of
most. Do not touch.
Caribbean Sea Wasp
These rise into the shallows at night and get close to shore
JELLYFISH - Float and Sting
One of the most common dangerous jellyfish in the Caribbean
Cassiopeia - Upside Down Jellyfish
(This is how they swim)
some people say it's a mild sting
Moon Jelly (Aurelia)
Very common in season in the Florida Keys. Some people
claim they are harmless, but they do sting.
Lion's Mane Jellyfish
Largest jellyfish in the world. The sting even causes
blisters. - Nasty stuff.
These frequently wash up on beaches. It's important to
caution kids not to "pop" them with their bare feet - the stinging burn from
this would be intense. These are nasty (but pretty) jellyfish.
I'm including this here because I don't know where else to
put them, and they sting like a mild jellyfish sting. Sea lice are
microscopic and you can't see them. They hang around in sea weed on the
surface, among other things, so try not to let the seaweed drag across your
skin. These things are like chiggers for the northerners that know about this
- and they'll concentrate around areas of your clothing that are tight to
the skin. You get bunches of stings at once and they'll drive you nuts with
itching. They start like a very subtle itch and then get worse until you see
the red welts that will appear. It's a microscopic zooplankton that stings
you. It is not a jellyfish larvae and does not get under your skin. It's a
sting. Hot water, hot vinegar, meat tenderizer paste - the meat tenderizer
worked the best on me with a recent case of very bad sea lice stings (see
can use an oily lotion before you get in the water to help keep them off
you. The season is generally between mothers day and fathers day here in the
Keys. You can't predict when you'll get them - just have to take your
chances. Some days are fine and others not.
SEA LICE WELTS - Left & Right
These things drive you NUTS with itching. - Spring 2003
JELLYFISH: The ones shown here will sting you. The Portuguese
Man-of-War jellyfish look like a blue/purple gas filled balloon floating on the
surface - these are nasty. They trail their tentacles underneath and can reach
60' in length. I got a Man-of-War sting (several) across my face one night while
swimming in the dark. It felt literally like someone passed a blowtorch over my
face, and really welted up. Our daughter got one when she was about six all
across her legs. It was so extensive that we took her to the hospital because we
were afraid that because of her very small size for even six that she might have
an allergic reaction or go into an allergic shock reaction (anaphylactic shock).
Some of these more dangerous jellyfish, including the Man-of-War, produce severe
burning, possible scarring, and even shock and paralysis of your breathing
muscles. Moon Jellies aren't as bad but they'll still sting, even though some
publications call them harmless. These are very common here in the Keys. The
stinging reaction varies a lot from person to person. Most snorkel boats here in
the Keys carry vinegar with them to treat the tourists. At night when they float
by just below the surface they glow a blue/purple color in the shape of the 4
leaf design in their center, and around their edges. It's very surreal and you
can sometimes see hundreds of these aliens floating in the darkness, going by
your anchored boat. Here in the Keys there is a small jellyfish, the comb jelly,
about 2-3" long, that looks like a little "baggie" - slightly oblong and
pleated. These are completely harmless and will not sting at all. Not as common
here in the Keys are Caribbean Sea Wasps and Sea Nettles, but they are very
nasty. The Sea Wasp rises up to shallower water from the depths at night and
you'll find them frequently close to shore. Its sting is also very severe
resulting in possible paralysis of limbs and breathing difficulty. Sea Nettles
are similarly nasty and it has very long tentacles like a Man-Of-War. It is one
of the most common jellyfish in the Caribbean. The upside down jellyfish, or
Cassiopeia, are said to sting only mildly, but I have no personal experience
with them. They are common here in the Keys - especially in the canals. Another
"Nasty" jellyfish, which I have never seen here in the Keys, is the Lion's Mane,
which is pale orange and one of the largest jellyfish in the world - clusters of
more than 150 tentacles that extend 20 feet or more. These will even cause
Pouring vinegar over the sting is the quickest and most effective method to
treat it. Do this before you try to rub or wash the area to neutralize any
remaining nematocysts that haven't fired. If you can heat up the vinegar, so
much the better. The isopropyl alcohol will work, but not as well. Some have
suggested making a paste out of baking soda, but I have never tried this. Do NOT
wash off the tentacles with fresh water because this will cause them to fire and
sting more. Use the vinegar, then gently pull off any visible tentacles with
tweezers. Meat tenderizer paste will work too. Peeing on it (urine) will only
make it worse by causing the nematocysts to fire. Do not rub or scrape them.
After it's cleaned and dried you can try the hydrocortisone on it twice daily.
If it's a bad sting from one of the "Nasty" jellyfish, and/or on a small child,
then watch them for shock including breathing problems. Most of the garden
variety stings though are just a nuisance, maybe less than a bee sting and
certainly not as bad as a wasp sting.
Oregon Coast Aquarium - live images of our moon
jelly exhibit (the lights are turned off at night). The animal on display is the
Oregon moon jelly, Aurelia labiata.
Common here in the Keys - graceful and elegant
Stingray City - Grand Cayman Island
Stingrays often get a bum rap and are really harmless -
unless you accidentally step on them or try to hurt them. These divers are
feeding the rays by hand. The problem with stingrays is usually when you're
walking through the surf or shallow water. If they don't sense you coming
and you step on them they'll instinctively thrust their barb into you just
out of self defense. Otherwise they're not a problem.
This closeup of the stingray tail shows the barb at the base
of the tail. It's used much like a knife and can be thrust deeply into you -
but only out of self defense. It's a poisonous barb that can leave parts of
the stinger or sheath in you. It's more serious than some of the other
marine stings because it makes a deeper and larger wound. Rinse this
wound with fresh water (unlike stings from nematocysts), then immerse the
area in as hot of water as you can tolerate without burning yourself. You
may need to do this for 30-90 minutes and repeat when the pain comes back.
Remove all visible portions of the stinger or sheath and wash with soap and
water. Try to flush the wound as much as possible. Bandage it lightly and
apply topical antiobiotics if there is any sign of an infection. This might
rate seeing a doctor.
This small ray also has a stinger, but is similarly
harmless unless provoked.
Some rays like the Manta ray, don't even have any stingers. They are very graceful in
Spotted Eagle Ray
The stingers on these rays are very short and close to
the tail - hard to see but there.
These suckers are just plain ugly, and very hard to spot.
The natural camouflage blends right in with the reef. It usually sits
motionless on a coral head or the bottom, and there are several varieties of
Scorpionfish. The poisonous spines are like hypodermic needles and will
inject a very toxic venom. Each spine has a long groove that connects to a
venom sack at the base of the fin - kind of like a fish version of a
rattlesnake. These wounds are excruciatingly painful but generally not
considered deadly. Immerse it in the hottest water you can stand (break down
the toxin). Inspect it to gently remove any remnants of the spine or sheath.
Apply topical antibiotics once it is cleaned if there is any indication of
The spines along its dorsal fin are poisonous - and can
be raised defensively.
|Lionfish (left) - These are not
supposed to be around here in the Keys, but they've recently been
introduced, so keep your eyes out for them. They won't bother you, but the
spines are very poisonous if you decide to chase and catch them.
Closeup of Grouper Teeth
OK - you'd expect sharks and barracuda for
biting fish -- but Groupers & Snappers? - Yep. Usually what happens here is
that snorkelers or divers will be hand feeding the fish and get their
fingers nipped in the process. This is especially true when they go into a
frenzy during fish feeding. Have you ever looked at the 2 sharp fanglike
teeth in snappers? The Grouper's teeth are small but their jaws are
massively strong and will crush your finger. Wash the wounds with soap and
water, and use a disinfectant and/or topical antibiotic.
|The Jewfish at left is very timid, but
can get massive in size - maybe like a small Volkswagen! They can drag a
diver to their death. Of course spearing such a fish with a line fixed to
the diver is utterly stupid, and illegal anyway (here in the Keys). You can
get your arm stuck just by feeding them though. If you offer them food, when
they open their mouth a huge suction is created and will suck your entire
arm into their mouth. When they close their mouth you're now locked inside
and can't get away - let's hope you didn't do this snorkeling! About the
only way I've heard to get loose is to fight them - maybe squeezing their
eyes until they let you go. - we hope. In this case discretion seems the
better part of valor - just don't feed them to begin with.
|Moray Eels: There are varieties
of eels - all of which are ordinarily harmless unless you go poking your
hands into dark holes (like searching for lobster?), or try to hand feed
them and they miss the bait. When an eel intentionally bites with their
razor sharp teeth, they'll grab on then twist their bodies around to rip the
flesh right off you. They have three sets of teeth - each side and one down
the middle. The teeth can be curved backwards like a snakes to make it
impossible to pull yourself straight out. They're normally out at night but
you can see them on the Keys reefs sometimes in the day. They'll even swim
right between your legs, but don't generally bother you. Eels have extremely
poor eyesight so don't try to hand feed them. The bite would be painful but
is not poisonous. Clean out the wound and apply a topical antibiotic. If it
ripped a big chunk of your flesh off you might require hospitalization.
Enjoy looking at them but don't feed them and keep your hands where you can
Goldentail Moray Eel
|Barracuda: OK - here's what you
see the most on Keys reefs, and what new divers and snorkelers fear. These
guys are just like big puppy dogs and won't bother you. I don't want to land
one in a boat on a hook and line though - those razor sharp teeth can severe
an entire limb. In the water they just look mean because they have to pump
water through their gills to breath - this makes them look like they're
baring their teeth at you like a growling dog - they're not. If you slowly
swim over to one they'll eventually just move out of your way while giving
you a "menacing" sideways glance. Leave them alone and they're harmless. In
murky water where they can't really see very well you should avoid shiny
jewelry or toes hanging in the water because they'll see the flash and think
its a small meal. This is not a problem in clear water in the daytime. If
you did get bit it could be serious because of the surgical like strike -
you might even have to apply a tourniquet to stop the bleeding. If it's that
bad, stop the bleeding, treat for shock, and get to a doctor. This is more
likely for fishermen than it is for snorkelers or divers.
There are all kinds of varieties of sharks.
Any shark bite could be nasty, but the truth is that they are not a problem
for snorkelers and divers. Sharks are very cautious and they're even hard to
approach if you try. Swimming at night, in murky water (including surf
lines) or chummed water can be a different story though. Most of the
beachfront shark bites are because they couldn't see it was really a person
- they took one bite to find out, then spit them back out. Some consolation
though if it was you that got bit! Avoid feeding times of dawn and dusk for
swimming and NEVER swim in a fish mud (huge school of fish).
OK - here it is - what you've been waiting for - JAWS!
Ocean going sharks like the hammerhead are not commonly
seen on Keys reefs.
To read the shark joke we tell tourists
before taking them out snorkeling,
CLICK HERE and scroll down to the SHARK ATTACK story.
Treatment of shark bites of course depends
on the severity. Clean it, control bleeding, and treat for shock (and gather
up spare body parts on ice for re-attachment if needed) :-)
These are commonly seen on Keys reefs and are harmless.
If they do bite though they clamp on and won't release - but you really have
to bug them to do this. A couple years ago here in Marathon a teenage
tourist boy was harassing a small 2 footer and swam down to yank on its
tail. The shark reflexed backwards and locked on to this bruiser kids
shoulder and wouldn't let go. They took him to the hospital where they had
to kill the shark to get if off. The kid was minimally damaged. Poor shark!
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