Sponges, although so often unattractive and unassuming to look at, have a rich and glorious history. In ancient times, it was discovered that the flexible remains of certain sponges were both tough and absorbent. These sponges proved to be quite practical in cleaning and scrubbing of people, of objects, and for use in certain types of art.
While some of these wonder-sponges potentially could have been washed ashore after storm activity, demand for the product prompted active collecting under the sea. Early predecessors of today’s divers in the Mediterranean, especially around certain islands of Greece, learned to descend from boats, holding onto rocks for a rapid decent, then grab whatever squishy sponge they could lay their hand on. Later, more sophisticated methods were employed, including hard-hat diving equipment, so as to harvest sponges in deeper waters. A booming profitable industry arose in the collection of these sponges (members of the genera Spongia and Hippospongia, family Spongiidae), and so these as a group logically came to be called “commercial sponges.”
And although the Mediterranean was the sponge capital of the world for many centuries, later it was discovered that similar sponge species were to be had in the Caribbean and Gulf of Mexico. While these contributed to satisfy the ever-growing consumers’ demand for sponges, eventually synthetic sponges were developed. Nowadays, these fake-sponge sponges are the type of sponge most people associate with the word.
In the big grouping of sponges (or the Phylum Porifera), though, there are approximately five thousand species, with only a small minority being commercial sponges.
Similarly, along the California coast, there are several dozen species, the majority being from families other than that of the commercial sponges. In general, though, California sponges are not all that appealing to the touch. There are, however, a couple of West Coast sponges that can be extremely impressive to the touch – so much so, that as a rule, should only be seen and NOT felt!
These are the two members of the genus Stelletta, the “stinging sponges” or “prickly sponges.” As the former of their common name implies, they are quite capable of inflicting pain to anyone foolish enough to touch them.
Stinging sponges have spicules (or tiny skeletal support structures) which are long, sharp, and fragile (in contrast to the soft, flexible make-up of scrub-a-dub commercial sponges.) Most of Stellettas’ spicules are beautifully star-shaped when viewed under magnification (and these star-like structures are what led to their celestial generic name.) But unfortunately, while not quite ‘shooting stars’, these needle-like spicules can easily penetrate human flesh and thereafter break off, causing discomfort to the unwary.
The Thick White Prickly Sponge (Stelletta clarella) tends to be found on the undersides of subsea caves and ledges. It can grow to about a foot-and-a-half across and three-inches thick, with sort of a non-descript bristly surface, often interspersed with miscellaneous debris and matter. This species ranges from British Columbia to Southern California.
The Dirty White Prickly Sponge (S. estrella) is smaller and more southerly in its range, being found from Southern California down to Baja and the Gulf of California. It differs anatomically from its larger ‘cousin’ by possessing more “megascleres” (or large skeletal spicules), giving it a lumpier, bumpy appearance.
While it would seem that since these sponges are nothing much to look at and often painful if touched, good creatures to avoid, this is not the case. Certain species of nudibranchs have no objection to munching on these sponges. But of much more significance than seemingly daredevil sea slugs is recent investigation by medical researchers into the therapeutic properties of stinging sponges.
Much of the work so far has concentrated on Western Pacific and Asian species, such as S. tenuis and S. clavosa. Compounds such as stellettins (a term name clearly based on that of the sponges) have already been discovered and are being scrutinized for their potentials in fighting all sorts of ailments, including certain cancers.
Time will probably tell what eventually becomes of such research. But the potential does seem to exist that these blobby sponges, that are named after stars, and which can inflict pain and cause people to see ‘stars’ when touched, could actually ‘touch’ the lives of many persons inflicted with some very painful illnesses, making them ‘stars’ in a whole new way.