Published July, 2004
By Greg Coppa
For Points East
For nearly 20 summers, my family has anchored in a shallow area of Block Island's Great Salt Pond, a few hundred yards northeast of Payne's Dock. Around sunset we always heard a string of clickety sounds coming from the water beneath and around us, quickly followed by another string of sounds. Throughout the night the same signals would reverberate through the hull of the boat, though with decreasing frequency.
Visiting yachtsmen and locals were of no help when it came to identifying what we assumed must be a fish of some type. Actually, nobody else even seemed to hear the almost mechanical sound or associate it with a living organism. When I did my best representation of the fish "call," I was greeted with skepticism and derision. Some people even asked what I drank before hearing the sounds or gave me that look reserved for a good but pathetically impaired friend. But I was undaunted. I knew what I heard and I had witnesses.
We wondered what manner of fish could make such a loud, strange and at times, for small children, fearsome sound. Was it large? Were the fish solitary or did they travel in schools? Could the noise be attributed to a porpoise or a distant whale whose acoustical signals somehow made it through the narrow channel and to our boat?
Over the years we spent much time snorkeling around the harbor, hoping to catch a glimpse of our "friends," but we never did. The children began to simply refer to them as the "chatterfish," but being a science teacher I felt compelled to give a more formal name — chatterfishus blockislandus. That moniker would suffice until a positive identification of the marine organism was made. Frankly, though, after a couple of decades of asking questions around the Block about the chatterfish and making a fool of myself, I was beginning to resign myself to the fact that I would probably never discover its identity.
Then, at a neighborhood Christmas party, I spoke with Joe DeAlteris, who works for the University of Rhode Island's renowned Graduate School of Oceanography (GSO). One discussion led to another, and pretty soon I was asking Joe about our Block Island mystery fish. He didn't know what it was, but at least he didn't give me the funny looks that my imitation and description elicited from others.
Instead, Joe referred me to the GSO's web site, where I could find a recently posted collection of fish sounds. It seems that a Dr. Marie P. Fish (I am not making this up) and William H. Mowbray auditioned some 153 species of fish from the western North Atlantic. Their magnetic tapes had been lost in a storage vault for many years, but when they were found and their value realized, the GSO put them into a digital format for all the world to hear.
I went to the GSO web page and before long I was listening to a cacophony of fish calls that I never thought I would hear. There are a surprising number of submarine characters that exhibit soniferous (sound producing) behavior.
I also found that fish, in general, have some very interesting names, but that few of them give a good hint as to what they sound like. I was serenaded by the mutton hamlet, scrawled filefish, gray triggerfish, and swordspine snook. I then compared the attributes of the barred, Caesar, French, and Spanish grunts. The mutton snapper and blackbar soldierfish were almost interesting to listen to, along with the Atlantic croaker. But after I heard the longhorn sculpin I just gave up. I was never going to get paid enough for this story to justify the time spent on this research.
Take it from me, readers-if you ever have one of those nights when you can't sleep visit one of these web sites: www.fishecology.org/soniferous/; www.fishecology.org/soniferous/soniferous.htm; www.gso.uri.edu/fishsounds/. You'll either get very sleepy or you won't care about sleeping till the next afternoon.
Though I had struck out in my quest to identify the fish, I had a feeling I was close. In an act of desperation, I simply threw out my question with a pitiful email description of the chatterfish sound to the assistant and associate deans of the GSO. The next day I was surprised to hear from Ken Hinga, assistant dean, and Mark Wimbush, associate dean. Even with my poor description, they had a couple of possibilities for me to check, such as the snapper shrimp or oyster toadfish. But it was their bioacoustic colleague to whom they forwarded my email, Dr. Rodney Rountree of the UMass Dartmouth School for Marine Science and Technology who right away said he would bet me $2 that what I had been hearing in Block Island's New Harbor area was the sound of the "enigmatic cusk eel." He sent me to www.fishecology.org/soniferous/cuskeel12aug89_1922h.wav, and after downloading the clip and playing it I whooped with joy. Rountree was right! Chatterfishus blockislandus is actually ophidion marginatum, unfamiliar to most of us as the striped cusk eel.
After happily playing the clip 70 or 80 times to my wife and kids and anyone else unfortunate enough to stray into the house, I got down to doing some serious research.
Ophidion marginatum is only about 8 inches long, a huge relief to my daughter, whose first question to me after hearing the audio clip was, "Is it a man-eater?" Come to think of it, that is always the first question Alexis asks about any fish we come across during our sailing adventures.
According to Rountree, we don't know much about the cusk eel. In fact I would have to say after reading his publications and perusing his web site that he is probably the world expert on this fish. Andy, our family fisherman, asked if we could eat cusk eel for our traditional Christmas Eve dinner. According to the expert, we could eat it and it probably would taste pretty good, too, as it is related to the codfishes.
However, it is not likely that this species will be consumed in any quantity, because of its small size and because it burrows into the bottom mud and only begins to come out of its hole at sunset, which is why we never saw one in 20 years of searching. Another reason why we won't be eating cusk eel at our house is because my wife, Abby, forcefully proclaimed while maintaining eye contact with Andy that this family is not eating anything that has been entertaining and amusing us for so long.
Until Rountree and others began researching the cusk eel, it was thought that ophidion marginatum ranged only from northeastern Florida to Long Island. But then they found the species in New Bedford and around Cape Cod by listening for it with inexpensive hydrophones rather than trying to dig up or seine for the eel.
My family can place cusk eels in Block Island waters for the better part of the last two decades, and perhaps people who read this and listen to the audio clip can provide even more information about how long this little eely looking fish or fishy looking eel has been in Rhode Island.
As with so many species, the males in this one make the most noise, using sonic muscles in the vicinity of the swim bladder and cranium. It has a pronounced hump on its forehead due to these muscles, which females lack.
The call of the cusk eel is associated with the mating process, and begins around sunset while the eels are in their burrows, which they emerge from over a period lasting many minutes, and in some cases close to an hour. The male initiates the courtship ritual, but once the female is aroused, well, watch out! Suffice it to say that female ophidids are little tramps. We need say no more about the perverse sexual behavior to which consenting adult cusk eels are inclined and I urge you not to view the archived video entitled "cusk1spawn.rm" under any circumstances.
So the next time you find yourself in Great Salt Pond, draw the attention of others to the (now) easily identified clackety call, and with a knowledgeable look tell them about one of Rhode Island's little-known marine residents, the striped cusk eel.
