No. 47–Jellyfish, Part II

Jellyfish inhabit all the world’s oceans with most species found in coastal waters. A few, however, are known to inhabit depths of greater than 1,000 feet. They range in size from an inch to seven feet or so across the bell. The oral arms of some are compact and close to the bell and sans tentacles while others trail stinging tentacles of more than 100 feet in length. Both stinging and more benign species of jellyfish may be found in local waters through much of the year.

The cannonball, aka cabbage head jellyfish (Stomolophus meleagris) is commonly found here through the summer and fall. They typically arrive in greater numbers than any other species and fortunately are among the least threatening of the bunch with few stinging cells in their short tightly bunched oral arms at the base of the bell. They are easily identified in that they are more dense and heavier than most jellies and have an opaque white bell with a brown band at the base. They reach approximately 8 inches in diameter.

Also of little danger, and often mistaken for the cannonball, is the mushroom jelly (Rhopilema verrilli). They may be distinguished from the cannonball in that they are less dense an flatten out when beached, more translucent, lack the brown ring, and may reach 20 inches.

A little more care must be taken with our local species of lion’s mane jelly (Cyanea capillata). Fortunately they tend to arrive after the waters have cooled and fewer of us are taking a dip. The more saucer than cup shaped bell of the commonly called “winter jelly” measures 6 to 8 inches across. The sting is said to be relatively mild producing a burning sensation. A close relative living in arctic waters, Cyanea capillata is the largest known jellyfish with a bell reaching a diameter of 2 meters trailing hundreds of stinging tentacles up to 120 feet below. Kind of makes one tingle all over doesn’t it?

A step up on the discomfort ladder brings us to the sea nettle (Chrysaora quinquecirrha). It is a summer visitor and rated moderate to severe on the pain scale. The bell is 6 to 8 inches in diameter with 16 radiating reddish-brown stripes. They trail 24 to 40 stinging tentacles.

Another step up the latter we find (Chiropsalmus quadrumanus), better known as the sea wasp. It is one of the box jellies, so called for the cube-shape of the bell, it packs the most powerful punch of any jellyfish species frequenting local waters. The “box” (bell) of the sea wasp can measure 4 to 6 inches in height and 5 to 6 inches across with tentacles streaming from the four corners. Severe dermal injuries requiring hospitalization have been recorded.

Stinging jellyfish are armed with a specialized network of tiny venomous structures called cnidoblasts in numbers into the thousands in some species. They are located primarily on the oral arms and tentacles. Within the cnidoblasts lies the nematocyst (stinging cell) containing a tightly coiled thread-like venomous harpoon. The nematocyst trigger is exposed at the base of the cnidoblasts and will fire on contact with any unrecognized foreign object.

Two things became clear in reviewing several sources for treatment of stings. One, forget the bar room talk and don’t pee or pour beer on the affected area as ureic acid and alcohol will set off unfired nematocysts and may aggravate skin inflammation; and two, stick a pair of tweezers and bottle of vinegar in your beach bag. The first order of business in treating a wound if tentacles are present is to remove them without coming in contact with them. Rinse area with sea water followed by the vinegar. Vinegar neutralizes the remaining nematocysts. Options for treatment beyond this point are various, too numerous to include here and available on the internet.

Again we have run out of space and the Portuguese man-o-war still floats out there. While not a true jellyfish, this fascinating creature (actually creatures) along with more on box jellies will fill this page next month.