Aquasapiens Profundus
In the dark expanse of the open sea, an almost human form is said to lurk, just beyond the edge of sunlight could expose it.
For centuries, its shifting silhouette has allegedly been glimpsed by sailors, taken as an omen—though whether good or bad is not clear.
Whatever it is, it inhabits a region of this planet that we do not understand—one that, despite our frequent travels across its surface, is as alien to us as any distant planet: the deep ocean.
And yet, sometimes, emissaries from this darkness do breach the separation, and sightings do occur. Such reports have indicated a large creature, disturbingly human-like, but with its features contorted. A mermaid, some have said, but not like any we’d imagined before.
Is there any truth to these sightings? Could a relative of the mermaid exist so far out from land?
I hope you’ll allow me to present to you my answers to these questions, in as much scientific rigor as I am able. But be warned—you may never look at the deep sea the same way again.
Background and Investigation
To be frank, the concept of a humanoid creature that dwelled far into the open ocean had not crossed my mind—especially given our initial findings of the mermaid in Hispaniola, which, even prior to direct observation, led me to believe the legends of the “mermaids” to refer to a primarily tropical creature.
Even our findings of the siren revealed a creature that preferred to stay near the shoreline, where resources are more abundant.
However, during the course of our investigation in Hispaniola, reports of sightings further out to sea became more frequent. At first, I thought all of these to be in reference to the same creature. But in order to be certain, I thought it best to conduct additional searches within a wider range. A certain member of my team strongly disagreed with my decision to even briefly pursue this lead while the primary investigation was still underway, but he did eventually acquiesce.
We chartered a more seaworthy vessel and began an initial observation period that extended eastward to the open North Atlantic. This search yielded nothing, and I thought it likely we wouldn’t return to it at all.
However, after returning to land, in speaking with locals, we discovered that the reports consistently fell into two categories: one of those nearer to shore, or that seemed recount a sense of wonder and curiosity in their sighting. The other was almost always reported as being out of sight of any landmass, and the feelings recounted by those individuals seemed to tend toward bewilderment and even… dread.
I knew we would have to return.
My initial thought was that if an unknown creature of this size did inhabit the deep, dark waters of this open ocean, it was possible that it would utilize biosonar for navigation, at least in some capacity. And so it was that my team and I cobbled together a device that would emit a series of acoustic pulses, intended to draw the attention of any animal with sensitivity to these frequencies.
The details of our methods can be found in the accompanying documentation. Suffice it to say… it worked. And by the end of several tedious days, we had our first glimpse of what we would come to call aquasapiens profundus, or… the “abyssal mermaid.”
Anatomy and Biology
Aquasapiens profundus is a large organism—it appears that an adult averages around 18 feet in length, and with a weight of nearly 2 tons. With the aid of a vessel-mounted crane, we were able to capture and hold a specimen of this size for a period of time, but it is currently unclear whether members of this species reach sizes much larger, or if this is is near the upper size range. As with much of what I will describe here, much more study of these elusive creatures will be necessary in the future.
Now, before I proceed further, it would be prudent to mention the profound similarities between this species and the one that inhabits more tropical regions.
It is my belief that profundus descended from the same, or at least a very similar, terrestrial progenitor species that gave rise to pisciformis.
Like pisciformis, this creature exhibits a distinctly simian body-plan, save for the obvious changes to the lower limbs and spine. Like pisciformis, it breathes atmospheric air, possess articulate forelimbs, and is mammalian.
As such, with the blessed advantage of having discovered these two organisms within such a short time frame, we have tentatively placed both pisciformis and profundus in the aquasapiens genus. Should future genetic data prove this to be incorrect, the documentation will be updated accordingly.
In terms of morphology, the majority of profundus’ body is dark grey to black, save for the face and regions of the head, nape, chest, and forelimbs.
Overall, the dermis of the creature is thick and resistant to damage, though more than one specimen displayed widespread scarring, which could indicate confrontations with prey, members of its own species, or potentially, attempted predation.
The skin of the face and extremities, however, is thinner, pale white, and almost translucent—indeed, dark veins are visible just beneath, giving the creature an admittedly chilling visage.
Interestingly, neither sex of this species appears to exhibit the long hair of the head that is a hallmark morphological element in pisciformis. As a result, sexual dimorphism is difficult to determine. In fact, hair on these creatures is spares at all, though the keratinous “scales” present in pisciformis are present here as well—though generally much thinner, and absent altogether from the face, chest, and distal regions of the forelimbs.
Skeleton
Given my theory of these creatures’ primate ancestry, a vast number of alterations and adaptations to an aquatic environment are not surprising.
As with pisciformis, we see that the bones of the hindlimbs, such as the femur, tibia, and fibula have been greatly reduced, as were many associated muscles, such as the biceps femoris, semimembranosus, and gastrocnemius, to the point that what remains of the hindlimbs are likely entirely vestigial.
I have also observed that the lumbar and caudal regions of the spine exhibit elongated and more robust vertebrae than any land-dwelling primate. Even more astounding, however, is a greatly increased overall number of vertebrae, extending well past the pelvis and forming a tail.
The spine itself exhibits numerous further adaptations also seen in pisciformis—intervertebral discs with radially oriented collagen fibers within the annulus fibrosis, which serve to resist hoop stress during swimming, as well as specialized endplates, which creates a smoother transition between the disc and vertebral body, both enhancing load distribution and preventing excessive concentrations of stress.
At the distal end of the spine, or tail, we also see a rigid, horizontally-oriented wedge of flesh, forming a “fluke” of sorts, which provides propulsion through dorsoventral oscillation. Though, in profundus, this fluke is significantly larger and more robust overall than in its tropical cousin.
Additional adaptations appear to include greatly elongated epaxial muscles and hypertophied hypaxial muscles, both of which support this form of locomotion.
Interestingly, the epaxial muscles, in particular, exhibited unusally high proportions of Type II glycolytic muscle fibers.
Overall, the bone structure of profundus is thicker and more robust than in pisciformis, likely in order to cope… with higher pressures.
And indeed, this species does appear to spend a great amount of time at depth, usually in the mesopelagic zone, roughly 300 meters below the surface. But in fact, tagged specimens indicate frequent and extensive vertical travel into the bathypelagic zone, between reaching nearly 3000 meters deep.
This is rare and astonishing behavior for an air breathing mammal, and especially one of this relatively small body size.
The reason for these extended dives, which have been observed lasting as long as three and a half hours, is clear: to search for food.
Stomach contents of certain individuals have revealed an apparent preferred diet of squid, crustaceans, and even benthopelagic fish.
This diet may shed light on a number of extreme adaptations observed in this species—facing competition from other aquasapiens likely forced this lineage to seek out food far from shore, and in deeper regions. Here, they found a niche—because though food sources at these depths are less abundant, they are often less capable of evasion, and there are far fewer competitors.
And over time, this species specialized and adapted to this new environment in many additional ways.
At 1000 meters below the surface, the pressure on any body is 100 times that of the surface—ultimately resulting in mechanical distortion and tissue compression, especially in gas-filled spaces in the body.
This could present a major problem for an air-breathing mammal, but amazingly, profundus is able to counteract these effects and more.
First, before diving, profundus first exhales up to 90% of the air in their lungs, reducing its buoyancy. Meanwhile, blood appears to shunt from the extremities to critical organs, such as the heart and brain, and heart rate slows. The creature exhibits little movement in this phase, simply sinking silently downward.
As depth increases, jointed ribs allow the ribcage to safely collapse, further reducing internal air pockets and preventing damage to the bones. And the lungs themselves also collapse.
This compression of the lungs appears to force air away from the alveoli, reducing gas exchange and helping to prevent the absorption of nitrogen into the bloodstream. This, in turn, likely reduces or eliminates nitrogen narcosis, even in extended dives, and prevents decompression sickness upon ascent.
For humans, other internal spaces prone to compression at these depths are the sinuses and the middle ear cavity—distortion of which is referred to by human divers as “the squeeze.”
However, profundus appears to have lost the frontal cranial sinuses altogether, and as it dives, an extensive venous plexus within the middle ear cavity appears to engorge with blood, filling the air space and effectively equalizing pressure.
But at this point, my valued reader, you may be wondering: if oxygen is not stored in the lungs, how can and air-breathing mammal sustain dive times of nearly four hours?
The answer lies in a truly fascinating network of even more specialized adaptations, beginning with the blood itself.
Samples taken from certain specimens revealed a host of differences to humans—and even pisciformis—in terms of blood composition.
Red blood cell count is greatly elevated, as is myoglobin, lending the blood itself a thick and viscous consistency. Additionally, estimates of total blood volume appear to indicate levels three to four times found in terrestrial mammals, relative to overall mass. This latter point could explain this species’ increased size when compared to its more tropical relative—the greater the size, the more reservoirs for oxygen storage.
But even this, combined with a larger overall mass, would likely not be enough to support dives of the length observed in this species.
In fact, many deep-diving organisms have a calculated aerobic dive limit—essentially, this is the point at which oxygen will run out. But this species regularly surpasses this calculated limit.
I must admit, for a time, we were perplexed as to how this could be possible.
Fortunately, extensive testing has shed some light on the subject. It seems that at some point, which as of now has yet to be determined, profundus is able to extend their dive times by simply “switching" to anaerobic*metabolism.
Indeed, as muscular oxygen reserves become depleted, the muscle tissues undergo a transition from aerobic to anaerobic glycolysis pathways, allowing the muscles to continue functioning long after the calculated dive limit has been exceeded. As an aside, this could certainly be the reason for the high proportions of type II muscle fibers mentioned earlier.
A potential downside to this form of metabolism, however, is the buildup of lactic acid, a natural byproduct of anaerobic metabolism. However, it seems that returning to the surface for a time is enough to clear off any excess without appearing to reduce the creature’s function in any way.
But the depths of the ocean present any endotherm with yet another problem: the cold.
At the depths profundus appears to regularly inhabit, water temperatures can approach near freezing. It seems likely that even if its cousin, pisciformis, could reach these depths, it would develop hypothermia quite rapidly.
But here, too, profundus has adapted well. Though it is not as thick as in some other deep-diving mammals, such as whales, this species possesses an extensive layer of subcutaneous adipose tissue, much like blubber, that serves to very effectively retain heat.
Furthermore, extensive vascular systems known as retia have been observed in multiple tissues throughout the body. In other mammals, these act as countercurrent heat exchangers, maintaining a temperature gradient and thereby conserving body heat. these structures appear to function the same way in profundus.
Following the capture and subsequent… evaluation of a particular pisciformis specimen, I was loathe to acquire any individual profundus at all, much less to capture for later study. As usual, Marcus vehemently disagreed. But Alison’s presence broke the tension, and we eventually came to an agreement. One specimen had already expired through certain unusual circumstances, but going forward, only non-lethal methods of study would be utilized.
From a personal standpoint, a description of the creature is… difficult. One one hand, the resemblance to pisciformis is undeniable. But where I saw an inquisitiveness in that species, in this, I saw only cold, calculating intelligence that bordered on menace.
I realize that this is not an objective statement, but I don’t think I was alone in feeling this way. Though it is undoubtedly fascinating, and should be protected, profundus inhabits another world… one that we barely understand. The common ground I felt between our species and that of the tropical variety is simply nowhere to be found here.
In any case, observations continued.
We had traveled with a number of tracking devices which, injected into the dermis of these creatures, would provide invaluable data as to not only their dive patterns, as previously mentioned, but also their hunting habits and social behavior.
As discussed, profundus’ primary purpose in undertaking such extreme dives appears to be to procure food.
Locating prey at these depths is difficult, however, as light is scarce and prey items are fewer in general.
To aid in the hunt, profundus’ eyes exhibit a layer of tissue just behind the retina that acts as a retroreflector—a structure known as tapetum lucidum—which, in turn, increases the light available to photoreceptors and greatly enhancing vision in even the lowest lighting conditions.
But more than that, profundus appears to have developed biosonar. At depth, the creature emits a series of high-frequency clicks generated by passing air through bony nares at the rear of the oral cavity. Echoes are then received through fatty tissues in the lower jaw, and which extend near enough to the middle ear to transmit the vibrations.
Profundus even appears to exhibit a rudimentary conglomeration of lipids just behind the cheekbones that may function similarly to the “melon” of certain other aquatic mammals, serving to essentially modulate its acoustic emissions for enhanced directionality.
As mentioned previously, while diving, profundus remains completely silent. Only once it reaches its preferred zone will it begin to make sound, and even then, only sparsely.
Once prey is located, it will swim rapidly, moving its fluke in a powerful, though controlled, motion, often sneaking up on its prey from behind or below.
Though its forelimbs aren’t as articulate as in pisciformis, they are still utilized for grabbing and pulling prey toward the main body and mouth. Interestingly, its teeth are largely unmodified from those seen in its tropical cousin, though they are slightly more pointed and robust.
Interestingly, it appears that these vocalizations, so to speak, are used for more than just echolocation.
Indeed, it appears that individuals communicate with each other, presumably for mating calls and occasional coordinated hunting patterns. Though more research will be necessary to determine for certain, it seems that individuals tend to congregate in “pods” of roughly 4-6, breaking away frequently to hunt.
It could be that profundus may even dive in order to better communicate over long distances, taking advantage of the acoustic properties of the deep sound channel.
In any case, as mentioned before, echolocation and acoustic communication has only been observed to occur below 200 meters. Closer to the surface, they remain almost completely silent. The reason for this isn’t clear, though it may have to do with predator avoidance.
In all the in-depth study of this creature presented so far, it likely goes without saying that profundus exhibits behavior one could easily associate with great intelligence. And indeed, they are—from hunting patterns to our own limited interactions with individuals, this species displays cunning and a kind of tactical intellect.
However, as I mentioned before, this species’ level of intelligence is, if you’ll forgive such a crude categorization, a notable “step down” from that of pisciformis.
We have not had the luxury of extensive testing in this area. Instead, this conclusion is drawn from this species’ behavior toward us: primarily, aggression. This is understandable, given our intrusion into its territory, and our collection methods were undoubtedly perceived as threatening.
Even so, it is my hypothesis that in the process of adapting to its deep and open water environment, this species essentially traded the intelligence of their ancestors for more metabolically economical adaptations. Rather than high-cost tissues like brain matter and viscera, profundus developed increased adipose, bone, and muscle tissues.
It was clearly a worthwhile trade-off, given this species apparent success in their niche—and one that has allowed them to flourish without much competition.
Following the release of our final specimen, as our vessel returned to shore, I was once again struck by my own interactions with these two similar, yet very different species. It is difficult to describe. But in the first, staring into the creature’s dark eyes, it had seemed like a meeting of two minds. Even without language, as we studied that creature, it was clearly studying us.
With profundis, however, staring into its eyes was like peering into a cold abyss. There was life there, to be certain, but so different and alien that even upon the same vessel, we may as well have been miles apart.
And so, my valued reader, I only ask that if you ever find yourself on a similar vessel, floating over the deep ocean, simply be aware. For as you stare into that abyss… something might just be staring back.
Comments