No. 48–Dangerous Stingers

Resent press accounts of jellyfish swarming in waters off Hilton Head beaches were not anticipated when this series began but it comes as no surprise either. While it’s understandable the thousands reportedly stung no doubt carry a less than fond memory of a day at the beach, they are relatively fortunate to have tangled (literally) with sea nettles rather than box jellies.

While the cladistic arguments continue as to whether the box jelly, aka sea wasp, should be classified among the Syphozoa or ranks a separate but equal class, Cubozoa; there is no disagreement regarding the danger to swimmers the various species pose.

With the one species of sea wasps found in local waters having been discussed previously, attention will turn to its more dangerous and deadly cousins found elsewhere.

A considerable majority of references consulted ascribe to the recognition of Cubozoa as a distinct class in the phylogenetic debate. The twenty species comprising the order Cubomedusae are split between two families, Chirodropidae and Carybdeidae, morphologically differentiated by the number of tentacles. Carybdeidae have one tentacle at each corner of the box while Chirodropidae have up to fifteen.

Both families have members listed among the most dangerous of marine species. Chironex fleckeri grows relatively large at 20cm per side width and its 60 tentacles reach 3 meters when hunting. Possessing what is arguably the most potent venom on earth, the sting of this creature can be deadly if not treated immediately. 100 deaths in the last 100 years have been attributed to C. fleckeri.

The diminutive Carukua barnesi packs a powerful punch for a creature the size of a sugar cube. The sting is relatively mild at first with more severe symptoms to include head, back and abdominal pain along with nausea and general disorientation developing 5 to 45 minutes after. Lucky for us, the range of C. barnesi is limited to the coastal waters of northern Australia and C. fleckeri further from there into the Indian Ocean to southeast Asia.

Two primary factors set box jellies apart from “true” jellyfish. They are capable of strong self propulsion and they have eyes. That’s right, eyes thought to be used in targeting a specific prey animal. This is astounding for creatures known to possess neither central nervous system nor brain.

Each panel of a cubomedusae bell has a cluster of six eyes centered near the base. Four of the eyes are simple light receptors but two have the requisite lens, retina and cornea for true vision and one of those has an iris for adjusting to changing light levels.

Aka bluebottle and bluebubble, (Physalia physalis) the Portuguese man-of-war is a most intriguing collection of creatures made up of an air bladder (pneumataphore), tentacles (dactylozooids), digestive polyps (gastrozooids) and reproductive polyps (gonozooids).

The upper portion of the pneumataphore serves as a sail providing the propulsion needed to trawl for prey. The “sail” is set at an angle, to the left on some and to the right on others in relatively even proportions. This, as it turns out, is an important adaptation helping assure the survival of the species. Should currents carry a man-of-war flotilla near shore, only half are in danger of being wind driven onto the beach.

Denizens tropical and subtropical open waters of the world’s oceans, Physalia are on occasion blown from the Gulf Stream to local waters.

With venom said to be 75% as powerful as that of a cobra, man-of-war stings should not be taken lightly. Unlike for jellyfish, a vinegar rinse is not recommended for the treatment as studies have shown it triggers unfired nematocysts. Carefully remove any tentacle pieces if present and rinse thoroughly with sea or fresh water and apply ice for the pain. Seek immediate medical attention if signs of shock or respiratory distress appear.