Barsnail

In the warm waters of ancient Almaishah, a strange looking retinalphyte sways in the sunlit summer current. This strange plant - a stalk supporting two bars - rests upon a light blue-grey rock, perched up amongst some sargrasso near the shores of Kub-Shay. Nearby, a juvenile magnospina forages for food amongst the sargrasso stalks. The juvenile was recently born, and is no longer than three centimeters. A vulnerable organism, it carefully keeps watch to avoid being ambushed by the many predators in the ecosystem. Slowly, it crawls along the ocean floor, searching for small sargrasso leaves to consume. It is then that it spots the strange retinalphyte, looming over with it’s strange stalks. Along the base rest eight small, budding sargrasso leaves - no longer than a centimeter or so - gently twitching and swaying in the current. Bathed in the summer sun, the purple leaves almost seem to glisten in the light. The temptation of easy food compels the baby magnospina to move towards the stone, which almost seems to unnaturally rise up from the ground. Above, two small, green patches slowly emerge, revealing four line-shaped pupils homing in on the magnospina. As the eyes focus, the strange creature hones in on its next meal. Patiently, it waits for its prey to enter striking distance, carefully watching its every footstep as it slowly inches closer to the predator’s alien jaws. As the magnospina finally reaches its meal, it stops and takes one final look around. A strange sense of danger builds up, as the magnospina momentarily senses danger. It quickly scans the surrounding area for an ambush predator lying in wait, but no movement amongst the sargrasso would indicate anything of the sort - in fact, it would seem that it is alone. Satisfied, the magnospina takes a bite into the sargrasso - or at least it attempts to, for as it’s mandiples open around the leaf, a burst of movement begins all around it. The unfortunate juvenile failed to notice the opening of a round, jawless mouth lined in serrated silicate teeth above it, and in just a few moments the magnospina was pounced upon and forced onto it’s stomach. Defenseless, the magnospina is helpless to prevent itself from being ripped apart by a long, serrated tongue and mouth as it is torn to pieces and devoured by the strange, alien predator. Pictured is famed Xenobiology One's Sean Ring's painting of this scene. [Creature design by Lethal Cuteness]

Basic Information

Anatomy

Dyobares, also called the barsnail, is a strange type of cephaloptin lurking amongst the retinalphytes of Almaishah’s oceans. Externally, while clearly a cephaloptin, it’s relation to other organisms within the clade is difficult to pinpoint. One might expect, for instance, this organism to be closely related to the hornsnails and kelyfoicthyans. However, upon examination of their digestive gland, one would find they are actually closely related to the esoterikians. Like all cephaloptins, the barsnails have a certain set of defining characteristics which clearly show them as part of clade. Along the center of the organism exists a stem which runs from the base of the head tagma to the tailbones, which it joins with to form the anchorpoint for the tail (this is what defines them as closer to esoterikae, as these two groups are the only cephaloptins to have evolved this trait so far). Just beneath the stem rests a stomach, digestive gland, long tubular intestine, a blood-filled cavity which extends into tubular structures lined with muscles that travel throughout the body, and two gonads - one male and one female. The stem serves as the anchor point for four long blocks of muscles which serve as the controlling muscles for the limbs. The limbs themselves are quite bony; each consists of seven bones arranged in a pyramid pointed towards the insides of the body, with tiny muscle blocks between them to provide flexibility and gripping power. Along the stem are two long nerves running the length of the body, which intersect at each limb pair and at the ends of the stem. Connected to these are two pairs of statocysts, which help the organism know how its body is oriented in the water. Beyond this point, however, the barsnails begin to significantly differentiate themselves from other cephaloptins. The tail tagma has changed significantly, and now often takes the form of a large, flat, muscular “foot” like structure resembling what is seen in numerous species of molluscs on Earth. This foot is able to anchor the organism to a perch, so it may rear its body up vertically. The muscle blocks between the bones in the fins have expanded significantly at the expense of the bones, granting the fins far greater flexibility. However, the most changes to their anatomy have occurred within the head and skin. The head tagma is, in and of itself, the species’ most striking feature. The head tagma has elongated significantly, with two pairs of eyestalks emerging - one at the front of the head and one in the middle. These eyestalks often take the form of “bars”, however they are quite flexible and will usually appear to sway in the water. The mouth has elongated significantly, and now runs from the second eye pair all the way to the base of the head. The radula has swelled significantly, and the odontophore now extends to the stem, where it is anchored by a small muscular hydrostat. The esophagus has also expanded, and now possesses additional muscle-blocks dedicated to expanding and contracting the oral cavity. The radula has also seen musculature-related changes, as it now possesses a long muscular hydrostat connecting it to the odontophore - granting it significantly more mobility. Within the cranial tagma, the singular statocyst pair has been replaced by twelve statocysts arranged along the cranial tagma in places of importance; three along the top bar, five along the bottom bar, one pair in between the bars, and one pair at the base of the cranial tagma. These statocysts have an elevated number of cilia hairs lining the interior, increasing their sensitivity by about 200% - this allows them to, with great precision, tell exactly how the different parts of their cranial tagma are oriented compared to both the others and their bodies. Their nervous system has seen some improvements as well. Optical nerves extending from their four eyes to their brain have swelled, and a large cluster of neurons has formed in the cranial tagma dedicated entirely to processing visual information. This primitive brain, while simple in nature, possesses the ability to perform stereopsis when the eyes are oriented correctly - a valuable trait for a predator. Similar structures exist within the eyestalks, however these structures also possess the ability to intimately understand information coming from the many statocysts. This type of nervous system is comparable to that seen in the octopus, and allows the eyestalks to react to stimuli and move themselves in such a way as to replicate retinalphytes with extreme accuracy, precision, and speed - something that would not be possible without autonomy from the primitive brain. The digestive gland has also undergone changes related to a predatory lifestyle, and the barsnail no longer possesses the ability to break down retinalphyte material of any kind. Rather, it’s enzymes have specialized to specifically target xenometazoan proteins, resulting in more efficient digestion at the expense of dietary flexibility. Furthermore, the barsnail’s digestive gland is also capable of producing enzymes essential for the Glyoxylate cycle - an alternative to the Citric Acid cycle focused on converting fatty acids (Acetyl-CoA) into carbohydrates, enabling them to utilize fatty acids in gluconeogenesis - thus significantly aiding their ability to regulate glucose levels in their bloodstream without relying on the breaking down of proteins. This adaptation is also present in basal esoterikians, however to a much lesser extent - thus explaining that both esoterikians who utilize the Glyoxylate cycle and the barsnail both possessed the necessary enzymes ancestrally.

Genetics and Reproduction

Like other cephaloptins, barsnails are diploid hermaphrodites with seasonal mating behaviors. While mostly solitary organisms, barsnails will gather in groups during the summer months to mate. When conditions become optimal for eggs (usually warm waters with days longer than ½ of the average local day-night cycle) the barsnail will begin to excrete pheromones from its posterior anus that are produced by the gonads. These pheremones can be carried through the water and detected from up to several kilometers away, resulting in large congregations of barsnails ranging from twenty to two-hundred individuals. Once the organisms gather, they will begin to use the chromatophores on their head tagma to create vivid color displays to attempt to impress another member of their species. In general, the healthier barsnails will be able to produce more vivid, intricate color patterns - and will thus have a greater chance of impressing a mate. Once a pair of barsnails have chosen each other, they will each lay about ten eggs in a small mucosal sac, before fertilizing the other’s and carrying it off with them. The barsnail will then wonder until it finds a suitable hunting perch. Once it has found one, it will place its egg sac in a place a short distance away and perch itself to hunt. It will watch its egg sac from its perch while hunting, and will protect the egg sac until they hatch.

Growth Rate & Stages

The barsnail naiads hatch after about 7-14 local days, and emerge from their eggs as miniature adults; the largest of them is only 5 millimeters long. These organisms are not large enough to freely swim or crawl, and spend this portion of their lives at the mercy of the current. As they cannot hunt at this time, they have a small yoke from their egg connected to their stomach; other than this and the underdevelopment of the gonads, there are no differences between them and an adult organism. The naiad will continue to be at the mercy of the current for the first week of their life, by the end of which they will reach a size of 2 centimeters; by this point, if they have not figured out the basics of hunting or foraging for food, they will die as their yokes run out. Once they reach this size, they will first feed on mycoids among the substrate before reaching a size large enough to go after larger prey - fortress misas are the most common prey for a juvenile barsnail, and remain so for the entirety of this phase of life. Once the barsnail reaches a size of about 12-15 centimeters, it enters the adolescent phase of its life. During this phase, it will begin to hunt larger prey, such as megaspina hatchlings, and is functionally identical to an adult - with one key difference. A barsnail of this age is not sexually mature; in fact, it is during this phase that it’s gonads only begin to develop, and will not fully develop until the completion of this phase. Once this development completes, the barsnail is fully developed and enters the adult stage of its life - it will attempt to mate and survive for the remainder of its life. Overall, this entire process takes approximately 90 local days to complete, and most naiads will not survive to reach adolescence. As a general rule for this species, the highest chance of death is the juvenile stage - passing through this phase into adolescence, on average, assures survival into adulthood. Overall, about 70% of naiads born will not make it past this phase, leaving roughly 28% on average to survive into adulthood and mate (an average of 2% die during the adolescent phase - significantly lower than either of the other two phases.

Ecology and Habitats

The barsnail inhabits shallow environments along the coastlines of Kub Shay, southern Yama, and southern Artica. These organisms blend in with retinalphytes by making use of their chromatophores and flexible head-tagma to lure in and ambush small herbivorous animals.

Biological Cycle

The barsnail, uniquely amongst basal cephaloptins, is exclusively a carnivorous organism. This has naturally necessitated numerous adaptations to the consumption of other organisms - most notably adaptations to the radula and digestive gland - however this has come at the cost of a significant increase in rigidity regarding nutritional demands. The barsnail specifically gains the vast majority of its nutrients from fats, and as such prefer organisms that possess high concentrations of fat within their bodies. However, carbohydrates can be extracted through the breaking down of proteins into amino acids, which subsequently can be inserted into the Citric Acid cycle to allow gluconeogenesis without the input of fatty acids. While this is feasible, it is far more preferable for the barsnail to consume fatty organisms, as these proteins can be more efficiently used to repair and generate new tissues as opposed to synthesizing glucose to maintain proper glucose levels in their haemocyanin. Their preferred food includes magnospina and megacarid hatchlings, unlucky juvenile bopeds, rose limpets, and small armor globes. Of these, rose limpets and juvenile bopeds are the most reliable, with megacarid and magnospina hatchlings being less reliable prey. Small armor globes can prove particularly challenging due to their armor, however this can be overcome by gnawing at the gaps between armored plates, where soft flesh is exposed and able to be lacerated by the radula.

Additional Information

Perception and Sensory Capabilities

The barnsails are, like most other cephaloptins, visually-based organisms. In the case of the barsnail, several key advancements have been made to help give the species a competitive edge in their ecosystems. Their eyestalks possess their own complex neuron clusters, enabling them to effectively “think” and act autonomously from the brain. This allows the processing of immediate data quickly and efficiently, without taxing the central brain. The central brain itself has mostly swelled as a response to the needs of comparing visual information from four separate locations, as well as to process and keep track of the orientation of it’s numerous body parts - handling this information accurately is crucial to blend in and disguise itself as a retinalphyte. The central brain therefore is responsible for performing stereopsis when able, controlling the movements of the body and tail tagma, and ensuring the smooth coordination of the eyestalks - ensuring that the organism blends into its habitat and is able to attract prey.

EXTINCT

Genetic Ancestor(s)

• Xenoeuly kirbyi

Scientific Name

Dyobares dyoptica

Origin/Ancestry

Xenosegmenta

Lifespan

3 local years

Average Height

8 cm

Average Weight

20 cm

Geographic Distribution

• Almaishah