Introduction One of the most unusual types of sea serpent sightings is that of large creatures with multiple rows of fins on each side. Due to their noted abundance of limbs, author Loren Coleman reffered to such cryptids as "Great Sea Centipedes". These animals do not bring to mind any of the more familiar of the ocean's denizens, such as whales or sharks. What aquatic giant could have such a large number of fins? Whales only have 2 fins in addition to their tail fluke, and sharks have but 2 pectoral fins and 2 pelvic fins. In this essay, I intend to expound upon a potential identity of this swimming enigma: a giant polychaete worm.
Before beginning, it is important to know what characteristics these creatures have. Therefore, I will start by showing a list of reports and sightings relevant to this cryptid:
*Cape Falcon, Algeria: May 21, 1899Sailors aboard the ship HMS Narcissus stated that they had an encounter with an extraordinary animal near Cape Falcon, Algeria. Described as an amazing 150 feet long, the monster was seen swimming in pace with the ship. Its most notable trait was the presence of a very large number of fins on each of its sides, which turned over and over to propel the creature forward. Unfortunately, no one was able to see this animal's head, as the splashing of water produced by its fins obscured it. The sailors observed it for half an hour, and were certain that what they saw was not something mundane, such as a line of porpoises.
*Hongay, Along Bay, Vietnam: 1883
One day, on a beach in Vietnam, witness Tran Von Con reportedly saw the stranded remains of a giant, centipede-like creature. The segmented body had a length of 60 feet and a width of 3 feet, with a pair of 2-foot-long filament-like appendages on each of its segments. The carcass was dark brown on its dorsum and light yellow on its ventral side. The body lacked a head. In this region, the Great Sea Centipede is referred to, quite appropriately, as "Con Rit", which is Vietnamese for "centipede".
*South Africa: July 8, 1856
Whilst travelling near the coast of South Africa, the captain of the ship Princess sighted a "fish" with a row of 6 fins on each of its sides. It was stated to have a head similar to that of a walrus, which spouted something from its mouth. After firing at the creature, the crew of the Princess believed that they had struck it near its head.
Polychaetes Explained It is quite possible that these sightings were caused by a very large, and yet unconfirmed, species or number of species of aquatic worm called the polychaetes, also called the "bristleworms". The polychaetes are a diverse class of typically marine invertebrates that have a pair of fleshy limbs called parapodia on each section of their multisegmented body. These limbs are used not only as paddles to propel the worm through the water as it swims, but also as the respiring organs for the intake of oxygen. The known polychaetes come in a variety of sizes, ranging from a few millimeters to over 9 feet in length.
Perhaps the most important similarity between the Great Sea Centipede and the polychaetes is their large number of laterally-positioned fins. This is what prompted me to consider that the Great Sea Centipede might be a form of polychaete in the first place. For example, the Vietnamese carcass was characterized by a large number of repeating segments, each of which possessed a pair of appendages. This is exactly what we would expect if this carcass came from a giant polychaete. The long, tube-like body is also compatible with a polychaete identity.
The Issue Of Size As mentioned before, the known polychaetes are capable of growing to nearly 10 feet in length, although this falls quite short of the 60 feet observed for the Vietnamese carcass and the grand 150 feet observed by witnesses aboard theNarcissus. A polychaete capable of growing to 150 feet would easily be the largest invertebrate known to man, far outstripping the current record holder; the colossal squid (at 46 feet long). Of course, even if we attribute this incredible length estimation to exagerration, the Vietnamese carcass is still large enough to take the record. Could a polychaete grow to such a size?
Although I cannot prove that polychaetes can grow to 60 feet in length, I can provide reasons to believe that it is not impossible. For example, one objection may be that all known polychaetes are under 10 feet in length, and therefore the likelihood of a giant polychaete is low. Afterall, they would have to be related to their smaller cousins, right? However, the polychaetes comprise a biological group called a "class". Sizes of organisms within a class can vary greatly. The mammals provide a great case-in-point. The smallest mammal is the 4-centimeter long Bumblebee Bat, whereas the Blue Whale may exceed 100 feet in length. Both of these extremes in size exist within a single class. Therefore, similar extremes might also exist within the polychaetes.
Another objection may be that, since polychaetes are invertebrates, they cannot grow to very large sizes. What reason do we have to believe this, though? The small size of land-based insects may have given rise to this notion, since creatures with bones tend to be far larger than their exoskeletal competitors. One of the basic reasons for such size limitations is gravity. In the case of insects, the exoskeleton is heavy and a very large insect would have trouble supporting such weight. In the case of soft-bodied invertebrates like worms, I believe that gravity imposes limits on them because they have no internal supporting structures akin to bones. Hence, a very large worm wouldn't have much of a way to support its bulk. Worms also tend to be burrowers, and burrowing favors small size over large size.
The limitations of gravity can be surpassed by an organism living in water. The great elephants still have to deal with gravity, whereas their much larger, distant relative, the Blue Whale does not. With water to support its mass, the Blue Whale has exceeded all confirmed animals in size. Therefore, the reason we always see tiny land invertebrates (gravity) would not be a hindrance to the development of a giant polychaete.
Comparing Proportions Although not entirely necessary, a comparison between the proportions of known polychaetes and the Great Sea Centipede may be helpful. The measurements of the Vietnamese carcass are the most helpful in this situation. The length of the body was 60 feet, whilst its width was 3 feet. That leads to a length-to-breadth ratio of 1/20. That's a fairly worm-like shape. Do any known polychaetes compare with these proportions? A species of polychaete called the lugworm found on the coasts of Europe may grow up to 9 inches long, with a width of 0.375 inches. The resulting ratio is 1/24, a difference in proportion of less than 17% from that of the Vietnamese carcass. Since the carcass was stated as being headless, its true length would actually be somewhat greater than 60 feet, making its actual proportions even more similar to that of the lugworm.
Number Of Limbs The number of fins observed on the Great Sea Centipede may be highly variable. The Vietnamese carcass would have had 40 or so appendages (although they are described as being filamentous instead of fin-like, they may indeed have been fins in the living animal. Decay could well have reduced the fins to thin filaments). The creature observed near South Africa had 12 fins. These differences support my idea that the Great Sea Serpent would be comprised of multiple species. Hence, I think that scientist Bernard Heuvelmans' designation of Cetioscolopendra aeliana to describe all such creatures is far too narrow of a grouping.
The number of fins in known polychaetes is also highly variable. They may have over 100 parapodia, or as few as 30. I am not an expert in polychaetes, and am therefore unfamiliar with the exact range of limb numbers. Hence, some polychaetes may have far fewer than 30 limbs. Either way, the number of limbs in an organism can easily be changed via mutation, making 12-40 fins easily acheivable for a large polychaete.
Other Issues One particular attribute of concern is the description of the creature's head as described by the captain aboard the Princess. He stated that it's head appeared to be walrus-like. How can a worm have a mammal-like head? That's a tricky question to answer. It would probably be easier to address if a more detailed description was given of it. However, with only the word "walrus" to go on, an analysis can still be made.
The first thing to delve into is the question of "what does a person think of when they imagine a walrus' head?". Various attributes come to mind, such as the small eyes, the naked skin, the whiskers, and, most importantly, the tusks. Small eyes have certainly been observed in polychaetes, and may be observed in giant specimens as well. Since polychaetes lack true hair (sometimes hair-like growths appear on some species), a polychaete's head may well appear like the naked skin of a sea mammal. The whiskers can also be explained in terms of polychaete anatomy. Polychaetes are known to possess a myriad of tentacles or antennae on their head. Perhaps such a mass of thin filaments adorning a giant polychaete's face may give the impression of mammalian whiskers.
Even the appearance of tusks can be addressed. Some polychaetes are predacious, and possess large, fang-like mandibles for catching their prey. If a giant polychaete possessed a pair of large, ivory-colored mandibles, one may be easily mistake them for tusks. This would be especially true if such polychaetes had adapted their mandibles to point downward from their face instead of protruding forward. Thus, an unknown, giant polychaete could have evolved a walrus-like head simply by modifying parts of its anatomy that its ancestors already possessed.
Why Are There No Specimens? If such enormous animals exist, then why don't we have any proof? Where are the carcasses? There are multiple possible explanations. One is that the Great Sea Centipedes were endangered before the first sightings even occured. As time went on, perhaps their numbers decreased more and more until most if not all of the species became extinct. Therefore, we don't have proof because they are either exceedingly rare or no longer alive. Finding remnants of these deceased beasts would be no easy task. Searching the ocean floor for their bodies would be almost fruitless, as they have no bones that might be preserved (if they are indeed invertebrates). Scavengers would be more than happy to get rid of the bodies before we even see them.
Another theory, which I feel more satisfied with, is that the Great Sea Centipedes are deep sea animals which very rarely venture to the ocean's surface. In fact, some polychaetes are already known to live deep in the ocean. Unlike whales, polychaetes have no need to surface for air, as they can extract oxygen from the surrounding water. Without any need to come to the surface, sightings would be rare. Perhaps these Great Sea Centipedes only come to the surface in unusual circumstances; if they were sick or disoriented, for example. That may explain why there have even been any sightings at all. Afterall, the giant squid has reportedly been seen at the surface of the ocean from time-to-time, despite being a deep sea mollusk.
The oceans are enormous and the bottom of the ocean has not been thoroughly explored. It was once said that mankind knows more about the surface of the Moon than the sea floor. In fact, scientists regularly discover new species of sea life at such depths, even today. In light of this, the possibility of a giant polychaete hiding in the deep sea should not be discounted.
Other Proposed Identities Perhaps the most famous proposal for the Great Sea Centipede's identity is the one put forth by Bernard Heuvelmans; that of an armored archeocete. The archeocetes were an ancient group of whales who are now supposedly extinct. A dubious association between hard plate-like structures and archeocete fossils found together led some people to believe that there may have been archeocetes with armor. This is apparently what led Heuvelmans to believe that an ancient, armored whale was responsible for sightings of the Great Sea Centipede. However, it is now known that the plate-like structures were from other animals. Hence, there is no evidence that whales ever had armor plating.
Another potential identity is that put forward by cryptozoologist Dr. Karl P.N. Shuker. He has suggested that the animal may be a giant, marine chilopod. The chilopods are most familiar to us as the centipedes. Many features of the chilopods are compatible with that of the Great Sea Centipede, such as the long, segmented body, the presence of 1 pair of limbs per segment, and the armored skin. However, chilopods are typically terrestrial animals, and to my knowledge, no marine forms have been found. The chilopods would need to do much evolving to become something akin to the Great Sea Centipede. However, polychaetes are already marine and are known to grow to much larger sizes than chilopods. Hence, I still prefer the polychaete identity over the chilopod identity. It is probably easier for a polychaete simply evolve hard skin and a large size than for a chilopod to evolve fins, gills, and a large size.
An Important Note Although I wrote this essay exploring the possible identity of the Great Sea Centipede, that does not necessarily mean that I believe in their existance. Actually, I'm slightly agnostic about it, even though I do lean more towards a belief in their existance than a belief in their nonexistance. The purpose of this essay was to explore what group of animals I feel is most likely to constitute the Great Sea Centipedes' identity, if they exist.