Dangerous reef organisms
Dangerous reef organisms hot buttons for dangerous reef-organisms section of BIOLOGY OF CARIBBEAN CORAL REEFS website hot button for irritating chemicals section of BIOLOGY OF CARIBBEAN CORAL REEFS website hot button for bites section of BIOLOGY OF CARIBBEAN CORAL REEFS website hot button for sharp spines/bristles section of BIOLOGY OF CARIBBEAN CORAL REEFS website hot button for poisonous flesh section of BIOLOGY OF CARIBBEAN CORAL REEFS website hot button for stings section of BIOLOGY OF CARIBBEAN CORAL REEFS

There aren't many Caribbean-reef orgnanisms that will kill you dead, but there are certainly quite a few that can hurt you. CLICK ON an icon to learn about what you should avoid.

NOTE it goes without saying that a good and careful SCUBA diver will be swimming well above the reef and will not be touching anything. For this reason, most dive-boat operators frown on their customers wearing gloves


Sharp spines/bristles

Perhaps the commonest source of spine-punctures in swimmers, snorkelers, and SCUBA-divers is from sea urchins, especially the long-spined Diadema ones. These can be painful, but much more dangerous are spine-wounds from various fishes, including scorpionfishes and, more recently, lionfishes, and from various types of rays.

NOTE Indo-Pacific lionfishes Pterois spp. entered the Caribbean region sometime in the 1990s, and since then have spread and become more populous, especially in the Bahamas. Their introduction may have been from venting of ballast waters by ships or, more likely, via escape or intentional release from aquarium tanks

  Sea urchins
seahorse dive leader in BIOLOGY OF CARIBBEAN CORAL REEFS website photograph of sea urchin Diadema sp. taken from a video

"Sea urchins are mostly benign…but not this one!  Its spines will go right through rubber and into skin, and boy do they hurt!" - Bonaire 2003

NOTE Diadema antillarum



photograph of black-spined sea urchin Diadema sp.
drawing showing close view of Diadema spineSpines of black sea urchins can penetrate running shoes and swim flippers. In addition to the puncture wound and the spine in the flesh, a venom is contained within the hollow spine, and the skin surrounding the spine secretes a toxic mucus. The end result is a painful, red swelling that may take several days to heal.

NOTE hot-water immersion, which is effective against a number of marine toxins, apparently is not effective against sea-urchin spines

The spine is barbed along
its length, further increasing
the pain when it punctures
the skin of an animal

treatment for sea-urchin spines selection of treatments for sea-urchin spines
  Bristleworms or fireworms have protective bristles that the worms erect when disturbed or irritated. The bristles are needle-sharp and easily penetrate skin. It is not clear whether the bristles contain a toxin, but something like this might well be present because woundings are intensely painful.
photographs of bristleworms Hermodice carunculata
treatment for bristleworm/fireworm spines 1. Other than just "grin and bear it", application of cold packs may help to alleviate the pain. Spines from invertebrates, unlike those from fishes and rays, seem not to become infected.
  Scorpionfishes & lionfishes
  Look, but don’t touch!  Scorpionfishes have 12 dorsal spines, 3 anal spines, and 2 pelvic spines, each carrying a double venom gland.  The glands lie in grooves at the distal end of each spine.  There are no ducts; rather, the venom is released when the skin covering the venom glands is torn away, as it would be following penetration into your, or another organism's, body. The skin and venom glands later grow anew. 
photo composite showing spine configuration of a scorpionfish
seahorse dive leader for BIOLOGY OF CARIBBEAN CORAL REEFS  website photograph of a scorpionfish taken from a video

"See what I see? It's a scorpionfish lying camouflaged, and waiting for prey to happen by. Don't touch! The spines are venomous." - Little Cayman, 2004

NOTE Scorpaena plumieri

treatment for scorpionfish spines

1. Soaking in extremely hot water (but taking care not to scald the patient) can help to denature the protein toxin.
2. Do not apply tourniquets or bandages, nor should any but a qualified doctor slice and suck the wound if such treatment is required.
3. Seek immediate medical attention. 

seahorse dive leader in Biology of Caribbean Coral Reefs website photograph of lionfishes taken from a video

There are 2 species of Indo-Pacific lionfishes Pterois volitans and P. miles presently in the Caribbean area and along the east coast of North America. Their presence was first documented in the mid-1990s, with increased sightings each year after that. Although there is a vigorous programme of eradication underway, including regularly sponsored "hunts" by participating SCUBA shops, the general consensus is that they are here to stay. Both species are voracious predators, grow quickly, and breed prolifically. Without natural predators the liklihood of eliminating them completely is remote. Apparently certain sharks and large grouper species will eat them, but both types of predators have themselves been fished to low levels. Lionfish flesh is reputedly quite tasty (cooking denatures the toxin in the spines), so establishment of a fisheries may be possible. The spine configuration in lionfishes is similar to that in scorpionfishes. - Red Sea, Egypt 2002

  black line
  Stingrays have a barbed stinger on the tail region. The stinger is actually serrated on its edges, but these are covered in skin , making the spine appear smooth. The venom glands in a stingray lie in parallel grooves on the lower surface of the spine, covered in skin. When thrust into flesh by a strike of the muscular tail, the outer sheath of skin is torn away exposing the venom glands, which rupture. The ensuing tissue laceration from the stinger aids in distribution of the venom. The predominant symptom is pain accompanied by reddening of the tissue, muscular paralysis, sweating, arrhythmic heartbeat, and later necrosis of the affected area.
  photo composite of stingray spines
treatment for stingray spines

1. Similar treatment as for scorpionfish spines: soak in extremely hot water (but taking care not to scald the patient). This helps to denature the protein toxin.
2. Seek immediate medical attention. 

hot button for sea-urchin spines hot button for sea-urchin spines