Wolf-Eel: "The Ugly Old Man of the Sea"

My dive buddy, WDFW Marine Biologist Tony Parra, extends a morsel to a wolf-eel, which speedily shoots out of its den to reach it. The "eye-like spots" extending down its dorsel fin can be clearly seen in this photo. As mentioned in the article, it is from these spots that the wolf-eel's scientific name is derived.

An adult wolf-eel stares out at the camera lens from its tiny den opening at the base of Sunrise Wall in Puget Sound near Tacoma, Washington.

A huge adult male wolf-eel looms out of its den on Sunrise Wall. The wolf-eel is so large and the den opening so small that the opening itself can't even be seen.

A juvenile wolf-eel pokes its head out of its den. In this case the den is an old abandoned pipe laying on the bottom of Puget Sound near Mukilteo, Washington. Juvenile wolf-eels are extremely colorful, often being an almost flourescent orange.

My dive buddy, Tony Parra, approaches a wolf-eel that is slowly extending out of its den, interested in the "tid-bit" Tony is carrying in his hand.

The adult male wolf-eel mentioned in the article. The wound in his forehead, probably from a battle with a rival male, is clearly visible.

An absolutely colossal male wolf-eel and a much smaller female nestled together in their den entrance. The startling physical differences between the two sexes can be clearly seen in this photograph.

Another shot of the "disappointed suitor". Again, the wound on his forehead is clearly visible. Throughout our dive this male was almost frantically swimming about the reef as if searching - for a den....a mate....a chance for revenge....only he knew for certain.

A few years back I attended a local showing of the Hollywood blockbuster, "Lord of the Rings". Frequently, the heroes of the film were attacked by masses of hideous, howling and slathering "Orcs". I was absolutely struck by how much the Orcs resembled one of my favorite underwater creatures here on the west coast, the wolf-eel. After much reflection, I'm convinced that the make-up artists for the film MUST have taken their inspiration from the divinely ugly mugs of big male "Wolfies".

Get any group of divers together in the Pacific Northwest and ask them to reach consensus on what the requirements are for a really GREAT dive, and invariably one of the things they will ultimately agree on is that a wolf-eel will somehow be involved. There's something about the supremely ugly face of an adult wolf-eel staring at you from its den that will turn an ordinary dive into a great one – poor visibility, terrible weather, rotten currents…..all will be forgotten and forgiven once a Wolfie makes a public appearance. Divers travel from all over the world to glimpse these fascinating creatures, and go through all manner of underwater gyrations to get the perfect photo that proves that they, too, were able to "Dance with Wolfies".

Actually a wolf fish, not an eel, the wolf-eel can be found as far south as San Diego in southern California, then northward to the Aleutian Islands in Alaska. Its scientific name, Anarrhichthys ocellatus, comes from both Greek and Latin - Anarrhichthys comes from the Greek word Anarhichas, which is a Greek fish that the wolf-eel resembles. The second half of the name, ocellatus, is Latin for "eye-like spots", which is a pretty apt description of the wolf-eel's skin. The popular name, "wolf-eel", comes from the large frontal canine-like teeth that these fish use in seizing their prey, mainly hard-shelled crustaceans and invertebrates. Capable of growing to approximately 8 feet in length, these massive fish are speculated to live up to 10 years, although documentation of their longevity is currently lacking in available research.

Throughout history, wolf-eels have been held in deep respect by the peoples of the northern Pacific – In many of the native tribes in the area the tasty wolf-eel was reserved as a ritual food to be consumed only by a tribal shaman, never by "ordinary" men and women. In the state of Washington the wolf-eel is now a protected species in both Puget Sound and Hood Canal, not because they are endangered, but simply because their value as a living resource to divers and photographers far exceeds whatever commercial value the species could possibly provide as a source of food. Some dive sites, such as Sunrise Wall near Tacoma, are well known as locations where wolf-eels interact with divers and can be hand fed as part of a unique photo opportunity. In both the American Pacific Northwest and in British Columbia, Canada, the prevailing attitude among divers regarding wolf-eels is that of both affection and protection.

Recent studies conducted by Tony Parra, Wayne Palsson, and Robert Pacunski, Marine Fish Biologists with the Washington Department of Fish and Wildlife, have revealed much new information regarding the life cycle of wolf-eels and also debunked a few myths. In the past it was regarded as a well-known fact that wolf-eels mated for life. This "fact" was the result of previous studies conducted in aquariums and on casual observations in the wild in which individual fish were not clearly identified with certainty. The new research has revealed that wolf-eels indeed do appear to be loyal mates, but apparently only on a fairly seasonal basis rather than for a lifetime. With some mated pairs, even this does not appear to be an ironclad rule, with the occasional female abandoning the loser of a fight between males to share a den with the victor. Adult wolf-eels mate between October and April, although research has revealed that most nests will appear from December to March within the greater Puget Sound area. It is speculated that spawning is timed in such a way that the eggs will hatch at approximately the same time as the major plankton blooms appear in the Spring.

Approximately 24 hours prior to mating, the female's abdomen becomes noticeably distended. The male will butt his head against the back of her abdominal region, an action which appears to stimulate physiological activity in which a series of waves move through the body of the female from her head to her tail, being particularly pronounced in her abdominal area. The male will then wrap himself around the female in such a way that their heads will be side by side and their genital areas adjacent to each other. It is in this position that the female releases the eggs, usually between 5,000 and 10,000 in number, and the male fertilizes them as they appear. Following fertilization, the female will coil about the eggs, molding them into a ball-like cluster. The eggs are apparently adhesive to each other, but not to the rocky walls of the den. Both parents will then coil themselves about the egg mass, sometimes together and at other times individually, tending the eggs and taking care to ensure that they are rotated so that a good flow of water regularly passes through them. The primary role of the male during this time appears to be guarding the nest from any intruders that might appear. Males do make occasional forays out of the den itself, but at this point it is yet to be ascertained if they bring food back to the female.

Following an incubation of approximately 13 weeks (+ or -, the variation probably due to water temperature and/or other environmental conditions) the eggs will begin to hatch. In the Puget Sound area this will normally occur from February through the end of April. Larval wolf-eels are approximately 1 inch in length and are born hungry. From the moment of birth they are voracious predators and will strike at their planktonic prey much like a coiled snake will strike at a mouse. Constantly in search of prey, the larval wolf-eels will then lead a pelagic existence, free-swimming with the plankton, for between as little as one month to as long as two years, the length of time presumably based on the availability of food and preferred habitat. They then will settle to the bottom, searching out nooks and crannies in which to dwell when not hunting.

The change from a pelagic to a bottom dwelling existence spawns physical changes in the juvenile wolf-eel. Juveniles will begin to change from a brownish, bright orange or orange-striped color pattern to the distinctive spotted pattern of an adult ("eye-like spots"). Males and most females will turn to a light blue/gray color, although often females will retain their brownish color into maturity. The males will also begin to develop a puffy face, enlarged jaws, huge bulbous lips and a powerful sagital crest at the top of their heads to support the increased muscle mass required as support for the jaws. With the exception of the frontal canine teeth, the teeth in the rear of the mouth become flattened molars designed to crush the hard-shelled crustaceans and mollusks that now will make up the majority of their diet. Favorite prey items will differ based on their immediate environment, with the most abundant food source often being the most preferred. For example, wolf-eels in Puget Sound appear to favor Sea Urchins, those in the waters of the northern Olympic Peninsula apparently prefer the Hairy Triton (a snail), while those off Monterey, California apparently prefer Sand Dollars and Graceful Crab.

Life just isn't fair…..especially not on a rocky reef when the ownership of a nice den site is in question. The giant Pacific octopus, Enteroctopus dofleini, is the wolf-eel's primary competitor and will often force a wolf-eel, or even a mated pair, out of a den and take it for its own. Basically, wolf-eels and octopuses occupy the same habitat, hunt the same prey, and value the same type of den sites. The competition can be fierce! Once an octopus of even moderate size has made up its mind that it wants to occupy a particular den there is not much that a wolf-eel can do to prevent the take-over because, as many a diver can attest, when an octopus has established itself in a den getting it to come out when it has no interest in doing so is a virtual impossibility.

Other species, however, seem to be able to share a den with wolf-eels as benevolent "roommates", or even as partners. Ling cod, for example, have been observed sharing the same crevice with wolf-eels, the egg masses of both within close proximity. It is unclear whether the relationship is competitive or cooperative, but both the ling cod and the wolf-eels have been seen apparently acting jointly to ward off unwanted intruders. Copper rockfish, brown rockfish, sailfin sculpin, and several species of shrimp have also been observed sharing wolf-eel dens, apparently with no threat being perceived by either party.

The dive……

The inboard engine howled, drowning out the wind with its roar, as we shot over the calm green waters of Puget Sound toward our destination, Sunrise Wall, just North of the Tacoma Narrows and the sunken remains of "Galloping Gertie". Noted for its color and beauty, divers also flock to the wall because of the high population of both wolf-eels and giant Pacific octopuses that can be found there. Despite having been to Sunrise many times this dive promised to be a special one for me. I would be diving with Marine Biologist Tony Parra, who, along with other Washington Department of Fish and Wildlife Biologists, has been conducting an extensive biological study of wolf-eels over the past few years. Few people know as much about wolf-eels as Tony and I was anxious to tap into his knowledge as well as to meet some of his "Wolfie" buddies from the study both close up and personal. It was late October and we excitedly expected that the wolf-eels would be beginning to pair off to breed, giving us the opportunity of photographing that aspect of their behavior.

Anchoring near the center of the wall, we descended the anchor line into the rich emerald green depths and soon found ourselves gliding down the slope of the wall, which was covered with bright pink swaths of coralline algae interspersed with clumps of bright and shining white and orange plumose anemones. Fall was at hand and the bull kelp that graces the wall in the Spring and Summer had decayed away to virtually nothing – small brown stalks being all that was left of the once mighty carpet I had seen earlier in the year. Orange, red and purple seastars dotted the seascape as they slowly inched along the rocks in their search for prey, while multi-colored red Irish lords and buffalo sculpins peered at us as we descended from their ledges on the wall. Often not visible until they moved, tiny hermit and decorator crabs scuttled here and there as we approached. The shiny and colorful remains of shellfish lay in heaps before numerous holes on the rocky reef – a sure sign of at least past occupancy by either wolf-eels or giant Pacific octopuses. Within seconds of arriving at the bottom, Tony flashed his light in my direction and pointed out our first "clients" – a pair of mated wolf-eels sharing a den and nestled in side-by-side. The male was quite literally a monster, with a gnarled and puffy head the size of a slightly deflated basketball. As his mouth opened and closed we could clearly see his huge set of teeth, blunt and square as molars, worn away as a result of many years of feasting on the hard armor of urchins and other shellfish. Next to his huge bulk his mate looked almost toy-like, despite the fact that she, too, was clearly an adult. His body pale with age, her darker gray body stood out distinctly as she lay beside him in the large entryway to their den. We would later estimate the huge old male's size as between 7 feet and 8 feet in length.

Tony attempted to lure the pair out into the open with a proffered treat of raw chicken, but neither of them appeared to be the slightest bit interested. Prior to entering the water, Tony had explained to me that once a male has enticed a female into sharing a den with him, he becomes extremely reluctant to leave it and will not allow her to do so either, undoubtedly over concern that a "bachelor" male will quickly attempt to take his place. Nearby we noticed that there was another male, unusually out in the open and with a huge raw wound in his forehead - probably from a clash with another male. He circled around the den site, his eyes appearing to gleam bright with an intensity that seemed to border on desperation. He reminded me of a teenager who had just had his girlfriend lured away by the high school football star and whose anger was fed by a constant flow of pumping adrenalin. Obviously, he was a recent loser in the "game of love" and quite possibly he was the primary reason that our mated pair refused to leave their den even for a moment.

Moving southward down the wall we encountered two other mated pairs, who also, like the first, refused to leave their dens. Along with the wolf-eels we were encountering we also discovered no less than 6 giant Pacific octopuses during the dive. Like the pairs of mated wolf-eels they also refused to come out to play. Still, they were only too happy to accept bits of our chicken, which they eagerly hauled into their dens with a single extended arm.

Toward the end of our dive we found what we were seeking, a single male in his den by himself and because of his bachelorhood still interested in such mundane things as food! Tony extended his hand, holding out a bit of chicken as an invitation. No sooner had he done so than the wolf-eel shot out of the den much like a torpedo launched from a tube! Swirling about Tony's arms, the wolf-eel chomped down on the treat while Tony rubbed under his chin and petted his head like I would one of my dogs at home. A beautiful purplish-gray, the dark eye-like spots on the flanks of the wolf-eel stood out brightly in my viewfinder as I happily clicked away. Piece after piece of food was consumed as copper rockfish, striped seaperch and various species of sculpins darted in to snatch up the tiny bits that were scattered about in the current as the big Wolfie fed, the sound of his huge jaws clearly audible through the water. All too soon the bottom of the feedbag was reached and suddenly Tony and I became MUCH less interesting. With a swirl of his long sinewy tail the male turned and plunged back into his hole, where he busily began enlarging it in anticipation of attracting a feminine housemate - sand, small rocks and shells swirling out of the hole as he twisted and turned in his endeavors.

As we swam back toward the anchor line we again came across our friend with the open gash in his forehead, still wandering about the wall in search of a female not yet spoken for, the look on his fleshy face still every bit as intense as before. His glare seemed to say, "What the HELL are YOU lookin' at?!!!" as we passed by and he continued on with his mission. As we slowly made our way up the anchor line toward the waiting surface I found myself wondering if he would eventually achieve success. Perhaps another dive in the near future will provide the answer – after all, a wolf-eel with a bite taken out of his forehead shouldn't be THAT hard to recognize!

As we reached the surface and began to clamber into the boat we noticed that another, larger, boat had arrived carrying several divers. Tony and I grinned at each other, knowing the wonders that the newcomers would be treated to when they arrived on the bottom. Later, as our small boat sped along eastward toward the huge silhouetted outline of Mount Rainier, the boat launch and home, Tony and I talked about the conclusions that we might draw from the types of behavior we had observed and photographed that day. It had been a marvelous and entertaining experience, one that we had been graciously allowed to share with the "Ugly Old Man of the Sea" – the wolf-eel.

The author would like to extend his thanks to Marine Biologist, Tony Parra, for his extensive help in the preparation of this article as well as his friendship. Thanks also to all the other staff members of the Washington Department of Fish and Wildlife who have taken time to answer my questions and assist me whenever they could.

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Deep Intelligence - the Giant Pacific Octopus

John Rawlings

Thu Jun 26

31