HOME | DD

Description

Introduction to the Phytozoan Lineage and their Evolutionary History

The phylum phytozoa comprises the majority of the photosynthetic organisms that originate from the world of the Dune Folk (a.k.a. the Soboleru). Despite any superficial resemblances they might share with conventional plant-forms, this group of organisms actually belong to the same taxonomic kingdom as the ‘animals’ of the Soboleru’s home planet. That being said, phytozoa are only very distantly related to these higher ‘animals’ and display a number of strange adaptations that appear nowhere else.

It is believed that all phytozoa descend from an extinct taxon known as archaephytozoa. This group consisted of sessile benthic filter feeders that would have appeared similar to some of the earliest members of the terrestrial echinoderms. The animal would have held its body aloft with the aid of a series of gas bladders set along its length. It anchored itself to its chosen substratum with the help of externalized suction pads that would later become the ‘leaves’ of their modern descendants. The anterior side of the creature consisted of a ring of chemoreceptive pit organs and subdermal baroreceptors that could help it to perceive its environment. The space above this ring terminated with a rigid, four-part jaw structure which led down into its gastrointestinal recess which could be turned inside out and extruded into the environment for easier feeding. Archaephytozoa and their descendants never evolved a through gut, and as such intake food and excrete waste through the same orifice. Like many sessile creatures, these animals would have displayed radial symmetry, however, they also developed secondary asymmetry early on int the evolutionary process. This occurred most readily with their sex organs and suction pads, which, excepting its head, could seemingly grow just about anywhere on the animal’s body. Their similarity to Earth’s sessile organisms also carried over to their young. The infantile stages of their lifecycle was spent as free-floating worm-like plankton and nekton. They only lost their mobility upon reaching maturity.

The archaephytozoa were later supplanted by other sessile organisms and ultimately went extinct, however, their memory would live on in three daughter clades: the helioskoulikids, anaskaphiskoulikids, and the euphytozoans. These three clades retained many of the traits of their ancestors, save their immobility. Although all of these animals remained capable of ambulation into their adulthood, their ability to move varied dramatically. The anaskaphiskoulikids were the most mobile, and branched out into being scavengers and ambush predators. They used their spade shaped mouth-parts to burrow through the ground in search of detritus or as a way of concealing themselves from potential prey animals. The helioskoulikids chose to abandon their benthic habitat altogether, and adapted to life floating on the water’s surface. These animals could move very little by their efforts alone, but they could still be carried around by the ocean’s currents. They were kept afloat with the help of the gas bladders they inherited from their ancestors and adopted a niche similar to the Portuguese mano-of-war: entangling any creatures that wandered into the tendril-like growths lining their stomachs, and digesting them while they still yet lived. The euphytozoans branched off from the same common ancestor as the helioskoulikids, but rather than rely on predation for nutrition, they became producers. The proto-euphytozoans managed this feat by incorporating photosynthetic planktons into their bodies as part of a budding symbiotic relationship. The plankton desired shelter from the open waters, and the phytozoan wanted a steady source of food. Many animals avoided consuming phytozoans because they exuded noxious tasting chemicals from their bodies, and the plankton only needed sunlight to make ample enough food to sustain the phytozoan. It was a match made in heaven.

This last phytozoan clade rapidly proliferated and adapted to living in a wide variety of different environments, including their world’s beaches and shorelines. While they were likely one of the first ‘animals’ to begin dwelling on dry land, they were not the first photosynthetic organisms to colonize this new frontier. The littoral zones that appeared and disappeared with the ebb and flows of the tides were also inhabited by many different species of algae. Under normal circumstances, these colonial organisms would probably have become the dominant terrestrial producers, however, the circumstances surrounding the development of this ecosystem were far from normal. The early amphibious euphytozoans were not much better at surviving on dry land than these colonies of algae, but they still had two important advantages. On the one hand, larval euphytozoans could move and seek out favorable places to complete their metamorphosis, whereas these algae could only spread by extending out tendrils from the central colony. On the other hand, the euphytozoans already had a vascular system, whereas these algae relied on diffusion alone. This not only allowed euphytozoans to distribute water and nutrients more efficiently, but also helped them to grow larger and diversify more readily. These traits allowed the early land-dwelling euphytozoans to quickly establish themselves in these newly available terrestrial niches and effectively prevented all other photosynthetic taxa from developing beyond the stage of mosses, lichens, and molds.

On their original world, euphytozoans were able to dominate the planet because of their mobility and advanced anatomy (relative to other photosynthetic taxa), however, the traits that allowed them to succeed are also their greatest downfall. Regardless of how you slice out, phytozoans are still ‘animals’ and their cellular make-up reflects this. Phytozoan cells do not possess a cell wall, and this causes them to not be nearly as rigid or sturdy as actual plants. This greatly limits their size, while also making them more vulnerable to changes in osmotic pressure and changes in the ambient temperature. The more derived clades of euphytozoans have developed numerous solutions to allow them to achieve larger body sizes, but none of these are as effective as a cell wall. As mentioned previously, their lack of a cell wall also hampers their ability to handle changes in their environment. The euphytozoans have found effective alternatives for dealing with changes in osmotic pressure, but many of them can’t cope with freezing temperatures. The water in their vital tissues expands outward when it freezes, leading to their cells rupturing and dying. Only a small selection of euphytozoan species (% 30) have evolved ways of dealing with this problem. These animals have convergently evolved a hibernation strategy similar to the wood frog (a.k.a. lithobates sylvaticus). They use the glucose they produce to act as a natural antifreeze, and redistribute the water in their tissues to avoid cellular lysis. Despite all of these efforts, the euphytozoans remain at a bit of a disadvantage. The phytozoans species that were transplanted to the New World have managed to survive into modern times because they have no real competition. The biochemistry of the lifeforms that initially developed on the Soboleru’s home world is markedly different from that of life here on Earth. The microbiota found in the soil where euphytozoans grow are inimical to our plant-life and that of other levo-amino acid-based lifeforms. The ground is essentially poisoned and unable to harbor normal plants, meaning the euphytozoans are effectively isolated from any potential threat by other producers. Were it not for this quirk of biology, they would have likely been out-competed and rendered extinct.

Fig. 1A-1D – Phytozoan Metamorphosis

All euphytozoa begin their lives as small vermiform creatures colloquially known as ‘worms.’ A small minority of euphytozoan species remain motile throughout their entire life cycle, but most worms metamorphose and mature into a plant-like organism that will remain rooted to the place where it began this transition. The image shown above illustrates this metamorphic process in 4 steps:

    a.       Pre-Metamorphosis – The worm has not yet begun its transition into adulthood. The animal is completely blind, but has used its chemoreceptive and baroreceptive organs to navigate its surroundings and find a location suitable to initiate its metamorphosis.

    b.       Seclusion – The animal uses its mouth-parts to bore a hole into the earth until nothing but its tail sticks out. The worm’s appearance has not changed much from its pre-metamorphic phase, but its metabolism will have noticeably slowed down to conserve energy for the next two steps of this process. Its leaves and posterior will also start to redden as the specialized cells there mature and begin to photosynthesize.

    c.        Extrusion – The worm turns its stomach inside out, and creates a surface through which chemical exchange may occur. This step occurs soon after the metabolic changes that happened during the seclusion phase. Overtime, semipermeable tendrils of smooth muscle and epithelial tissue will begin branch out from the stomach’s central mass and permeate the soil surrounding the animal’s body. These tendrils act like roots to greatly increase the amount of surface area over which the organism can intake water and nutrients from the soil and dispose of waste products.

    d.       Metamorphosis – The animal’s physical transformation begins in earnest. The lipid-dense nerve centers governing its ability to move voluntarily and react to certain stimuli are reabsorbed and metabolized by the body in order to fuel its growth, effectively rendering the worm braindead. Its leaves grow larger to increase the surface area over which the animal can photosynthesize. At the same time, heavily modified suction pads erupt from the anterior end of the animal. These dig into the surrounding soil and secure it in place so that it becomes more difficult to pull out of the ground. Finally, the worm’s outer cuticle thickens to better support the body as it continues to grow and help it retain moisture. This process may last little more than a day or as long as a month depending on the species.

While full metamorphosis is the ideal outcome for most euphytozoan worms, most of these larvae never get a chance to undergo this process. Nearly all phytozoan species reproduce with a strong r-selective strategy. They birth teeming hordes of wriggling young, with most ending up eaten by opportunistic animals looking for a few extra calories to round out their diet. Those phytozoans who are lucky enough to reach maturity are still at risk of being predated upon by various herbivorous species (as odd as that might sound), however, they are unlikely to die as a result of these attacks. Most phytozoan species have shown the remarkable ability to regenerate lost limbs and tissue, and some have even been known to fully recover after having lost nearly 75% of their original mass.

Fig. 2A – Phytozoan Reproduction

This image depicts a generic euphytozoan in its active reproductive phase. Nearly all phytozoan species are hermaphroditic, but they do not always display external sexual characteristics. Archaephytozoans possessed the ability to grow, reabsorb and autotomize their gonads at will, and this trait persists among their modern-day descendants. An adult phytozoan will spend most of its time without any defined sex organs up until the situation is suitable for reproduction. Adult euphytozoans are essentially mindless vegetables, but they can still seem quite shrewd when it comes to expending their time and energy.

The specifics of euphytozoan reproduction differs between individual families, but all of them broadly favor a r-selective strategy that prioritizes the quantity of offspring over the quality of rearing provided to them. A brief summary of the reproductive cycle of the three major families in this clade are provided below:

    ·         Malakospermae – The gonads of malakosperms will usually resembles a bulbous, mushroom-like growth perforated by many holes that seep a blue or greenish hued nectar. This nectar is suffused with the organism’s male gametes. Any nectar that gets stuck to a creature’s body as it feeds can ‘hitch a ride’ over to the next euphytozoan, and initiate the fertilization process by travelling through the perforations and fertilizing the ova that lay within the bulb. As the eggs grow and develop, the malakosperm will defend its progeny by secreting an acrid paste from its bulbs to signal to pollinators to steer clear of it. This fluid also helps to keep the soft, permeable membranes of the eggs from drying out and killing the larva within. When the eggs hatch they crawl out from the holes on the bulb in a fashion similar to the young of the South American comm Surinam toad (pipa pipa). Figure 2A depicts a malakosperm at the beginning of its reproductive phase along with a close-up example of its unhatched offspring.

    ·         Epipleounourae – The epipleounourans superficially appear to be closely related to the malakosperms, but their reproductive strategy still differs somewhat from the former. Epipleounourans possess two distinct sets of organs for their male and female gametes. The male organ might initially resemble the bulbs of a malakosperm, but they develop into a fuzz-covered bud that appears reminiscent to tufts of wild cotton. These tufts contain their male gametes and are dispersed via the wind. The female organ somewhat resembles a hair brush, with a wide fibrous pad covered in many spiky growths that can easily trap incoming tufts of 'pollen.' The eggs of the eplipleounourans grow within the walls of the female sexual organ. Their offspring have specialized mouthparts designed to pierce through flesh, and they use these to great effect when they literally dig their way out of walls of their mothers' reproductive system. Nature is so beautiful.

    ·         Gerospermae – The gerosperms are the sister clade of the malakosperms. Gerosperms possess fused male and female gonads like their malakosperm cousins, but they do not produce nectar. Gerosperms form a sharp, silicate pollen that sticks to any creature that draws near to them. Their eggs are also quite different. Malakosperms have evolved to keep their eggs moist by external means (i.e., their fluid filled bulbs), whereas the gerosperms have a hard, leathery egg that retains moisture from the inside. Furthermore, the shells surrounding gerosperm larvae are extremely resilient. They are not only able to keep water inside of the egg, but are also capable of withstanding the corrosive acids and digestive enzymes of the organisms that eat them. This particular property is crucial to their reproductive strategy, as many gerosperms will shed their eggs prior to hatching and rely on animals to consume them and transport them far away. Many species will also grow a 'fruit' around the eggs to further entice organisms into eating them. Gerosperms generally live in more climatically extreme environs, and so they have developed this strategy to help minimize competition with their offspring.

For the sake of completeness, I will also provide a brief summary of the reproductive cycles of non-euphytozoan clades like helioskoulikidae and anaskaphiskoulikidae. Some of the more derived forms of helioskoulikids reproduce via broadcast spawning, but all known species of this order can also propagate themselves by asexual means. Larval helioskoulikids develop from buds that emerge from the bodies of a mature individual and break away upon developing enough to survive on their own. Anaskaphiskoulikids are unable to reproduce asexually, nor do they rely on broadcast spawning. The nature of their reproduction is actually quite conventional for an organism originally hailing from an alien planet. They release pheromones into the water, whereupon they congregate, lay large clutches of eggs and secrete their sperm into the water through their externalized gonads. Most anaskaphiskoulikids expire shortly after reproducing and their corpses will usually be the first thing their offspring will eat after hatching.

Fig. 2B – Malakosperm Reproductive Organs and “Wormspice”

The drawing on the left side of this figure depicts a close-up image of a malakosperm’s reproductive organs. A fairly thorough description of malakosperm reproduction has been provided in figure 2A, and so I will not waste your time by repeating myself. This illustration more or less speaks for itself, however, the one on the right warrants some further exploration. The right half depicts a crystalline mixture known colloquially as ‘wormspice.’

Wormspice, or ‘fuguho’ as it is known among the Northern Mai, is a sweet, granular seasoning that is made by processing malakosperm nectar down into its basest components and blending it with mineral salts harvested from the Northern Mountains. The Northern Mai are quite fond of its taste, as are the Soboleru, but only the latter have the resources at hand necessary for making it. Were a modern chemist given the chance to examine a sample of wormspice, he would learn that it is largely comprised of sodium chloride salt, glucose, and trace quantities of various minerals and denatured proteins that give it its unique flavor. Given that the nectar primarily serves as a matrix for the organism’s gametes, it will also invariably contain damaged strands of DNA corresponding to that of the parent organisms. The glucose found in samples of wormspice is particularly interesting because it is levo-glucose (as opposed to dextro-glucose).

Levo-glucose is an enantiomer, or mirror-image molecule of the naturally occurring monosaccharide, dextro-glucose. The latter can be digested by humans, while the former cannot be metabolized and is thus non-nutritive. Levo-glucose is little better than dietary fiber, but its taste is nearly identical to that of its enantiomer. In this way, levo-glucose may be used by humans as a no-calorie sweetener. Soboleru biochemistry, on the other hand is designed to metabolize left-handed (i.e., levo) carbohydrates. This reality creates an interesting dichotomy. The Northern Mai think of it as an essential spice and a valuable commodity. It is an integral part of Northern Mayic cuisine, and is thus used liberally to season a wide variety of dishes. The Soboleru think it’s fairly mundane, but use it rather sparingly because it is so calorically dense. The Southern and Central Mai have also been known to consume this spice, but very few among them know how it is made. Those few who do know often swear never to eat it again (I have a feeling most people would be a “little disgusted” were they to realize they were eating crystallized worm secreta).

Fig. 3 – Anaskaphiskoulikidae and Neotenic Euphytozoa

The anaskaphiskoulikids are one of the three major classes of the larger phytozoan phylum alongside the photosynthetic euphytozoans and the jellyfish-like helioskoulikids. Unlike their sister orders, members of the order anaskaphiskoulikids do not undergo a metamorphosis, but instead remain in their motile larval phase throughout their entire life cycle. Anaskaphiskoulikids a are predominantly aquatic clade, but a significant minority of the families in this grouping are also amphibious. Fully aquatic anaskaphiskoulikids typically fill niches similar to eels, marine snakes, leeches, and other annelid species found here on Earth. Their amphibious cousins fill some of these same roles in their riverine habitats, but they also display behaviors and hunting strategy similar to the limbless caecilians found in South America and East Asia.

The right half of figure 3 depicts a small, amphibious anaskaphiskoulikid that dwells in and around the alpine rivers of the Northern Mountains. This animal is only about 16 centimeters long, but is still a fairly adept ambush predator for a creature of its weight class. It creates narrow tunnels through the ground with its spade-like mouthparts and hides just below the silt and mud of the riverbed with their primary mandibles splayed out like a beartrap. These vermiform creatures are completely blind, but are able to detect movements with their four feelers. Any prey that wanders too close is snatched up by the vice-like grip of its jaws and dragged down into the depths, never to be seen again. The Soboleru, who are a fair bit bigger than any of their prey like to forage for these worms by waggling their fingers over their tunnels. When the animal takes a bite, they will drag it out and rip off its lower body with their teeth. This may seem rather brutal, but the Soboleru would insist they are best eaten fresh, as their flesh putrefies rapidly upon death.

The organism depicted on the left is actually not an anaskaphiskoulikid, but rather a parasitic euphytozoan that shares the neotenic characteristics of its evolutionary cousin. Motile euphytozoans, otherwise known as neotenic euphytozoans differ from the rest of their kind because they never enter their photosynthetic adult phase. Neotenic euphytozoans are not a unique taxon of organisms, but are instead comprised of several unrelated clades that have convergently evolved the same trait. Most of these creatures belong to one of the branches of the stegnophytozoan suborder since most aquatic niches have already been taken by the elder anaskaphiskoulikids. These organisms have adapted to fill a variety of roles within their respective ecosystems ranging from parasitism (as shown in fig. 3) to soil aeration, and the decomposition of organic matter. Their importance to the continued success of their native ecosystems cannot be understated.

Fig. 4 – Atrikasarkidae

The atrikasarkids are a clade of stegnophytozoan malakosperms that lack any kind of internalized structure. The atrikasarkids depicted in figure 4 are fairly typical of the whole taxon: small, unassuming, and highly numerous. They are the most specious family of euphytozoans, and inhabit a niche identical to that of small grasses and flowering plants here on Earth. They use external rings of levo-chitin to provide their body with some level of rigidity, but they cannot grow much more than about 0.3 meters tall before collapsing under their own weight. That being said, some of these larger atrikasarkids have managed to overcome the limits imposed on their maximum body size by developing a parasitic relationship with more sturdily built clades like the trikasarkids, plegmatrikes and osteosarkids. These organisms use euphytozoans of these clades in much the same way a beanstalk uses its pole or grape vine uses its trellis. They use the suction pads derived from their primeval ancestors to latch onto them and take advantage of their sister clades’ stability. Atrikasarkids can be found in just about any clime with a dextro-amino acid-based ecosystem, though they tend to not thrive as much in particularly dry regions.

Fig. 5 – Epipleounourae

Members of the family epipleounourae are neither malakosperms or gerosperms, but they share several traits with the former. Unlike the atrikasarkids, the epipleounourae have seen fit to rise above their station as boneless invertebrates and reach for the sky, both literally and figuratively. The gas bladders of most stegnophytozoans have become entirely vestigial, but the epipleounourans have retained and modified these organs to lift up the ends of their bodies like a string attached to a balloon. These animals produce hydrogen gas (H2) as a natural byproduct of the photosynthetic process and more actively form it through a parallel biochemical pathway that splits the water in its immediate environment. The terminal gas bladder provides the animal with the most lift, however, it also hosts numerous smaller gas bladders spread along its stem that further increase its and buoyancy and decreases its weight. The Epipleounouran gas bladder is actually comprised of several layers of mesh-like tissue that overlap each other and make it harder for hydrogen gas to escape and diffuse back into the environment. Their body plans are optimized for being large, but incredibly lightweight since gas alone is rather bad at providing lift. A cubic meter of hydrogen only generates enough lift force to carry 1.12 kilograms, and as such minimizing the mass of the main body is of crucial importance.

The epipleounourans are not a particularly specious group. They were once the dominant photosynthesizing organisms, but nearly all of them were wiped out when a mass extinction event befell their world. Ironically, the epipleounourans were actually to blame for the very cataclysm that wiped them out. These organisms constantly emit hydrogen gas, and this contributed to major changes to the planet’s atmospheric composition. The tremendous quantities of hydrogen accumulating in the atmosphere reacted with the planet’s ozone layer, causing it to thin with frightening rapidity. This loss of ozone not only led to more ultraviolet radiation passing through the atmosphere, but also caused a trend of global cooling that would later evolve into a devastating ice age that wrought havoc on the biosphere. Most of the epipleounourans were unable to cope with these new environmental conditions and went extinct. Fortunately, their absence allowed the ozone layer to gradually recover, but life would never be quite the same. For example, a large number of animals originating from the Soboleru’s home world are able to see in the ultraviolet spectrum, but are also far better at resisting damage from ultraviolet radiation. In addition, some of the euphytozoans who survived evolved the ability to freeze their tissues without rupturing the constituent cells and killing the organism.

Fig. 6 – Trikasarkidae

Trikasarkids are a family of malakosperms that can be distinguished from the similarly named atrikasarkids by the quasi-skeletal structures they use to allow them to have much larger body sizes. Their ‘skeletons’ are comprised of contiguous strands or bundles of levo-chitin similar to those seen in the fossil remains of the colossal and primitive fungus known as prototaxites. The species depicted in figure 6 is among the largest of its family. It belongs to an informal grouping of loosely related euphytozoans referred to as ‘loopers’ or ‘archworms’, so named because they form arch-like shapes as their bodies bend and contort under their immense weight. Each loop is secured in the place with highly modified, spikey suction pads that help it remain more stable. The Soboleru believe that it is bad luck to pass under the arched tails of these creatures. A trikasarkid can grow approximately 5 to 6 meters tall before its internal support structures become too weak to prevent its body from sagging. Trikasarkids are extremely common, second only in diversity to the smaller and more fecund atrikasarkids. They can be found in a variety of different climates, but much like their soft-bodied cousins, the atrikasarkids, they prefer humid places where it is easier for them to keep their eggs from desiccating.

Fig. 7 – Osteosarkidae

The osteosarkids are among the most derived and specialized groups of the order euphytozoa. One might reasonably argue that they are just an aberrant subfamily of plegmatrikes, however, I believe that their adaptations are numerous and unique enough to warrant them having their own classification. These organisms are adapted to dwelling in considerably drier and hotter climates than their malakosperm relatives. Osteosarkids are named after their spongy, calcium carbonate and levo-chitin mesh skeletons that they use to sustain their impressive size and height. The tallest known species of osteosarkid can grow up to 18 meters tall. This might sound pretty large, but it seems downright tiny when one remembers there are plants here on Earth that can exceed over 100 meters in height. The osteosarkid depicted in the illustration for figure 7 is only about 12 meters tall, but it is still quite gigantic compared to most humans. Many osteosarkids possess small holes along the length of their body to dissipate the heat generated from their gigantothermy. Relatives of the Soboleru dwelling in the northern deserts and savannahs of the Midlands carve the bones of these organisms into peculiar little trinkets and even simple tools, but they aren’t quite sturdy enough to serve as an effective alternative to actual wood. Both the Soboleru and their cousins consider wood of terrestrial trees a trade commodity and a luxury good, not only because of their utility, but also because the bacteria and saprovores of their native ecosystem can’t make wood rot.

Fig. 8 – Helioskoulikidae

The helioskoulikids are the least specious of the three major phytozoan classes, and also one of the strangest. They are more closely related to the euphytozoans than they are the neotenic anaskaphiskoulikids, however, they do not possess the photosynthetic capabilities of the former. Helioskoulikids have adapted the air bladders of their archaephytozoan ancestors to serve as a floatation device that allows the animal to glide over the surface of the water. The adults can slowly swim about using their stubby little tails, but they more often rely on the winds to carry them from place to place. The tail is more often employed like a rudder that helps them to direct the course of their motions. The individual depicted in figure 8 possesses a thin membrane of skin growing along its length that it uses as a sail to catch the wind. This ‘sail’ is actually a highly derived version of their suction pads. The stomach of the animal has seen similarly dramatic modifications. Upon completing its metamorphosis, the helioskoulikid’s stomach will have grown so massive that it can no longer suck it back into their body. The stomach simply hangs out of its mouth while its many tendrils drift with the motions of the sea. These animals do not hunt so much as wait for other organisms to foolishly wander into their venomous, mucus-covered tendrils. Any creature dumb enough to get caught will end up paralyzed, drawn up by the tendrils to the main stomach and slowly digested by secreted acidic compounds. All in all, the helioskoulikids are fascinating, but somewhat nasty little creatures.

Fig. 9 – Plegmatrikae

Plegmatrikes are the gerosperms evolutionary response to the wildly successful trikasarkids. They are superficially similar to the former, however their levo-chitin quasi-skeletons are organized into a net-like mesh of fibers instead of long bundles. The plegmatrike's support system is not as effective as those of the trikasarkids, and as such they cannot grow as large as them. Figure 9 depicts a fairly generic representative of the group with a long, greenish ootheca waiting to be eaten by a hungry desert dweller. The northerly cousins of the Soboleru living in the great deserts and savannahs of that clime have a special fondness for one of the species of this clade that they call 'rain-seekers.' The rain-seeker is a unique among the relatives within its family as it only undergoes a 'partial metamorphosis.' Larval rain-seekers progress into a photosynthetic adult phase like most other euphytozoans, however, they still retain the ability to retract their extruded stomachs and move around, albeit somewhat slowly. These organisms can detect changes in the local air pressure that allows them to accurately predict when and where it is going to rain, and instinctively move towards it. In this way, these nomadic Dune Folk can follow these creatures around to find reliable sources of water in an otherwise inhospitable environment.

Description

Introduction to the Phytozoan Lineage and their Evolutionary History

The phylum phytozoa comprises the majority of the photosynthetic organisms that originate from the world of the Dune Folk (a.k.a. the Soboleru). Despite any superficial resemblances they might share with conventional plant-forms, this group of organisms actually belong to the same taxonomic kingdom as the ‘animals’ of the Soboleru’s home planet. That being said, phytozoa are only very distantly related to these higher ‘animals’ and display a number of strange adaptations that appear nowhere else.

It is believed that all phytozoa descend from an extinct taxon known as archaephytozoa. This group consisted of sessile benthic filter feeders that would have appeared similar to some of the earliest members of the terrestrial echinoderms. The animal would have held its body aloft with the aid of a series of gas bladders set along its length. It anchored itself to its chosen substratum with the help of externalized suction pads that would later become the ‘leaves’ of their modern descendants. The anterior side of the creature consisted of a ring of chemoreceptive pit organs and subdermal baroreceptors that could help it to perceive its environment. The space above this ring terminated with a rigid, four-part jaw structure which led down into its gastrointestinal recess which could be turned inside out and extruded into the environment for easier feeding. Archaephytozoa and their descendants never evolved a through gut, and as such intake food and excrete waste through the same orifice. Like many sessile creatures, these animals would have displayed radial symmetry, however, they also developed secondary asymmetry early on int the evolutionary process. This occurred most readily with their sex organs and suction pads, which, excepting its head, could seemingly grow just about anywhere on the animal’s body. Their similarity to Earth’s sessile organisms also carried over to their young. The infantile stages of their lifecycle was spent as free-floating worm-like plankton and nekton. They only lost their mobility upon reaching maturity.

The archaephytozoa were later supplanted by other sessile organisms and ultimately went extinct, however, their memory would live on in three daughter clades: the helioskoulikids, anaskaphiskoulikids, and the euphytozoans. These three clades retained many of the traits of their ancestors, save their immobility. Although all of these animals remained capable of ambulation into their adulthood, their ability to move varied dramatically. The anaskaphiskoulikids were the most mobile, and branched out into being scavengers and ambush predators. They used their spade shaped mouth-parts to burrow through the ground in search of detritus or as a way of concealing themselves from potential prey animals. The helioskoulikids chose to abandon their benthic habitat altogether, and adapted to life floating on the water’s surface. These animals could move very little by their efforts alone, but they could still be carried around by the ocean’s currents. They were kept afloat with the help of the gas bladders they inherited from their ancestors and adopted a niche similar to the Portuguese mano-of-war: entangling any creatures that wandered into the tendril-like growths lining their stomachs, and digesting them while they still yet lived. The euphytozoans branched off from the same common ancestor as the helioskoulikids, but rather than rely on predation for nutrition, they became producers. The proto-euphytozoans managed this feat by incorporating photosynthetic planktons into their bodies as part of a budding symbiotic relationship. The plankton desired shelter from the open waters, and the phytozoan wanted a steady source of food. Many animals avoided consuming phytozoans because they exuded noxious tasting chemicals from their bodies, and the plankton only needed sunlight to make ample enough food to sustain the phytozoan. It was a match made in heaven.

This last phytozoan clade rapidly proliferated and adapted to living in a wide variety of different environments, including their world’s beaches and shorelines. While they were likely one of the first ‘animals’ to begin dwelling on dry land, they were not the first photosynthetic organisms to colonize this new frontier. The littoral zones that appeared and disappeared with the ebb and flows of the tides were also inhabited by many different species of algae. Under normal circumstances, these colonial organisms would probably have become the dominant terrestrial producers, however, the circumstances surrounding the development of this ecosystem were far from normal. The early amphibious euphytozoans were not much better at surviving on dry land than these colonies of algae, but they still had two important advantages. On the one hand, larval euphytozoans could move and seek out favorable places to complete their metamorphosis, whereas these algae could only spread by extending out tendrils from the central colony. On the other hand, the euphytozoans already had a vascular system, whereas these algae relied on diffusion alone. This not only allowed euphytozoans to distribute water and nutrients more efficiently, but also helped them to grow larger and diversify more readily. These traits allowed the early land-dwelling euphytozoans to quickly establish themselves in these newly available terrestrial niches and effectively prevented all other photosynthetic taxa from developing beyond the stage of mosses, lichens, and molds.

On their original world, euphytozoans were able to dominate the planet because of their mobility and advanced anatomy (relative to other photosynthetic taxa), however, the traits that allowed them to succeed are also their greatest downfall. Regardless of how you slice out, phytozoans are still ‘animals’ and their cellular make-up reflects this. Phytozoan cells do not possess a cell wall, and this causes them to not be nearly as rigid or sturdy as actual plants. This greatly limits their size, while also making them more vulnerable to changes in osmotic pressure and changes in the ambient temperature. The more derived clades of euphytozoans have developed numerous solutions to allow them to achieve larger body sizes, but none of these are as effective as a cell wall. As mentioned previously, their lack of a cell wall also hampers their ability to handle changes in their environment. The euphytozoans have found effective alternatives for dealing with changes in osmotic pressure, but many of them can’t cope with freezing temperatures. The water in their vital tissues expands outward when it freezes, leading to their cells rupturing and dying. Only a small selection of euphytozoan species (% 30) have evolved ways of dealing with this problem. These animals have convergently evolved a hibernation strategy similar to the wood frog (a.k.a. lithobates sylvaticus). They use the glucose they produce to act as a natural antifreeze, and redistribute the water in their tissues to avoid cellular lysis. Despite all of these efforts, the euphytozoans remain at a bit of a disadvantage. The phytozoans species that were transplanted to the New World have managed to survive into modern times because they have no real competition. The biochemistry of the lifeforms that initially developed on the Soboleru’s home world is markedly different from that of life here on Earth. The microbiota found in the soil where euphytozoans grow are inimical to our plant-life and that of other levo-amino acid-based lifeforms. The ground is essentially poisoned and unable to harbor normal plants, meaning the euphytozoans are effectively isolated from any potential threat by other producers. Were it not for this quirk of biology, they would have likely been out-competed and rendered extinct.

Fig. 1A-1D – Phytozoan Metamorphosis

All euphytozoa begin their lives as small vermiform creatures colloquially known as ‘worms.’ A small minority of euphytozoan species remain motile throughout their entire life cycle, but most worms metamorphose and mature into a plant-like organism that will remain rooted to the place where it began this transition. The image shown above illustrates this metamorphic process in 4 steps:

    a.       Pre-Metamorphosis – The worm has not yet begun its transition into adulthood. The animal is completely blind, but has used its chemoreceptive and baroreceptive organs to navigate its surroundings and find a location suitable to initiate its metamorphosis.

    b.       Seclusion – The animal uses its mouth-parts to bore a hole into the earth until nothing but its tail sticks out. The worm’s appearance has not changed much from its pre-metamorphic phase, but its metabolism will have noticeably slowed down to conserve energy for the next two steps of this process. Its leaves and posterior will also start to redden as the specialized cells there mature and begin to photosynthesize.

    c.        Extrusion – The worm turns its stomach inside out, and creates a surface through which chemical exchange may occur. This step occurs soon after the metabolic changes that happened during the seclusion phase. Overtime, semipermeable tendrils of smooth muscle and epithelial tissue will begin branch out from the stomach’s central mass and permeate the soil surrounding the animal’s body. These tendrils act like roots to greatly increase the amount of surface area over which the organism can intake water and nutrients from the soil and dispose of waste products.

    d.       Metamorphosis – The animal’s physical transformation begins in earnest. The lipid-dense nerve centers governing its ability to move voluntarily and react to certain stimuli are reabsorbed and metabolized by the body in order to fuel its growth, effectively rendering the worm braindead. Its leaves grow larger to increase the surface area over which the animal can photosynthesize. At the same time, heavily modified suction pads erupt from the anterior end of the animal. These dig into the surrounding soil and secure it in place so that it becomes more difficult to pull out of the ground. Finally, the worm’s outer cuticle thickens to better support the body as it continues to grow and help it retain moisture. This process may last little more than a day or as long as a month depending on the species.

While full metamorphosis is the ideal outcome for most euphytozoan worms, most of these larvae never get a chance to undergo this process. Nearly all phytozoan species reproduce with a strong r-selective strategy. They birth teeming hordes of wriggling young, with most ending up eaten by opportunistic animals looking for a few extra calories to round out their diet. Those phytozoans who are lucky enough to reach maturity are still at risk of being predated upon by various herbivorous species (as odd as that might sound), however, they are unlikely to die as a result of these attacks. Most phytozoan species have shown the remarkable ability to regenerate lost limbs and tissue, and some have even been known to fully recover after having lost nearly 75% of their original mass.

Fig. 2A – Phytozoan Reproduction

This image depicts a generic euphytozoan in its active reproductive phase. Nearly all phytozoan species are hermaphroditic, but they do not always display external sexual characteristics. Archaephytozoans possessed the ability to grow, reabsorb and autotomize their gonads at will, and this trait persists among their modern-day descendants. An adult phytozoan will spend most of its time without any defined sex organs up until the situation is suitable for reproduction. Adult euphytozoans are essentially mindless vegetables, but they can still seem quite shrewd when it comes to expending their time and energy.

The specifics of euphytozoan reproduction differs between individual families, but all of them broadly favor a r-selective strategy that prioritizes the quantity of offspring over the quality of rearing provided to them. A brief summary of the reproductive cycle of the three major families in this clade are provided below:

    ·         Malakospermae – The gonads of malakosperms will usually resembles a bulbous, mushroom-like growth perforated by many holes that seep a blue or greenish hued nectar. This nectar is suffused with the organism’s male gametes. Any nectar that gets stuck to a creature’s body as it feeds can ‘hitch a ride’ over to the next euphytozoan, and initiate the fertilization process by travelling through the perforations and fertilizing the ova that lay within the bulb. As the eggs grow and develop, the malakosperm will defend its progeny by secreting an acrid paste from its bulbs to signal to pollinators to steer clear of it. This fluid also helps to keep the soft, permeable membranes of the eggs from drying out and killing the larva within. When the eggs hatch they crawl out from the holes on the bulb in a fashion similar to the young of the South American comm Surinam toad (pipa pipa). Figure 2A depicts a malakosperm at the beginning of its reproductive phase along with a close-up example of its unhatched offspring.

    ·         Epipleounourae – The epipleounourans superficially appear to be closely related to the malakosperms, but their reproductive strategy still differs somewhat from the former. Epipleounourans possess two distinct sets of organs for their male and female gametes. The male organ might initially resemble the bulbs of a malakosperm, but they develop into a fuzz-covered bud that appears reminiscent to tufts of wild cotton. These tufts contain their male gametes and are dispersed via the wind. The female organ somewhat resembles a hair brush, with a wide fibrous pad covered in many spiky growths that can easily trap incoming tufts of 'pollen.' The eggs of the eplipleounourans grow within the walls of the female sexual organ. Their offspring have specialized mouthparts designed to pierce through flesh, and they use these to great effect when they literally dig their way out of walls of their mothers' reproductive system. Nature is so beautiful.

    ·         Gerospermae – The gerosperms are the sister clade of the malakosperms. Gerosperms possess fused male and female gonads like their malakosperm cousins, but they do not produce nectar. Gerosperms form a sharp, silicate pollen that sticks to any creature that draws near to them. Their eggs are also quite different. Malakosperms have evolved to keep their eggs moist by external means (i.e., their fluid filled bulbs), whereas the gerosperms have a hard, leathery egg that retains moisture from the inside. Furthermore, the shells surrounding gerosperm larvae are extremely resilient. They are not only able to keep water inside of the egg, but are also capable of withstanding the corrosive acids and digestive enzymes of the organisms that eat them. This particular property is crucial to their reproductive strategy, as many gerosperms will shed their eggs prior to hatching and rely on animals to consume them and transport them far away. Many species will also grow a 'fruit' around the eggs to further entice organisms into eating them. Gerosperms generally live in more climatically extreme environs, and so they have developed this strategy to help minimize competition with their offspring.

For the sake of completeness, I will also provide a brief summary of the reproductive cycles of non-euphytozoan clades like helioskoulikidae and anaskaphiskoulikidae. Some of the more derived forms of helioskoulikids reproduce via broadcast spawning, but all known species of this order can also propagate themselves by asexual means. Larval helioskoulikids develop from buds that emerge from the bodies of a mature individual and break away upon developing enough to survive on their own. Anaskaphiskoulikids are unable to reproduce asexually, nor do they rely on broadcast spawning. The nature of their reproduction is actually quite conventional for an organism originally hailing from an alien planet. They release pheromones into the water, whereupon they congregate, lay large clutches of eggs and secrete their sperm into the water through their externalized gonads. Most anaskaphiskoulikids expire shortly after reproducing and their corpses will usually be the first thing their offspring will eat after hatching.

Fig. 2B – Malakosperm Reproductive Organs and “Wormspice”

The drawing on the left side of this figure depicts a close-up image of a malakosperm’s reproductive organs. A fairly thorough description of malakosperm reproduction has been provided in figure 2A, and so I will not waste your time by repeating myself. This illustration more or less speaks for itself, however, the one on the right warrants some further exploration. The right half depicts a crystalline mixture known colloquially as ‘wormspice.’

Wormspice, or ‘fuguho’ as it is known among the Northern Mai, is a sweet, granular seasoning that is made by processing malakosperm nectar down into its basest components and blending it with mineral salts harvested from the Northern Mountains. The Northern Mai are quite fond of its taste, as are the Soboleru, but only the latter have the resources at hand necessary for making it. Were a modern chemist given the chance to examine a sample of wormspice, he would learn that it is largely comprised of sodium chloride salt, glucose, and trace quantities of various minerals and denatured proteins that give it its unique flavor. Given that the nectar primarily serves as a matrix for the organism’s gametes, it will also invariably contain damaged strands of DNA corresponding to that of the parent organisms. The glucose found in samples of wormspice is particularly interesting because it is levo-glucose (as opposed to dextro-glucose).

Levo-glucose is an enantiomer, or mirror-image molecule of the naturally occurring monosaccharide, dextro-glucose. The latter can be digested by humans, while the former cannot be metabolized and is thus non-nutritive. Levo-glucose is little better than dietary fiber, but its taste is nearly identical to that of its enantiomer. In this way, levo-glucose may be used by humans as a no-calorie sweetener. Soboleru biochemistry, on the other hand is designed to metabolize left-handed (i.e., levo) carbohydrates. This reality creates an interesting dichotomy. The Northern Mai think of it as an essential spice and a valuable commodity. It is an integral part of Northern Mayic cuisine, and is thus used liberally to season a wide variety of dishes. The Soboleru think it’s fairly mundane, but use it rather sparingly because it is so calorically dense. The Southern and Central Mai have also been known to consume this spice, but very few among them know how it is made. Those few who do know often swear never to eat it again (I have a feeling most people would be a “little disgusted” were they to realize they were eating crystallized worm secreta).

Fig. 3 – Anaskaphiskoulikidae and Neotenic Euphytozoa

The anaskaphiskoulikids are one of the three major classes of the larger phytozoan phylum alongside the photosynthetic euphytozoans and the jellyfish-like helioskoulikids. Unlike their sister orders, members of the order anaskaphiskoulikids do not undergo a metamorphosis, but instead remain in their motile larval phase throughout their entire life cycle. Anaskaphiskoulikids a are predominantly aquatic clade, but a significant minority of the families in this grouping are also amphibious. Fully aquatic anaskaphiskoulikids typically fill niches similar to eels, marine snakes, leeches, and other annelid species found here on Earth. Their amphibious cousins fill some of these same roles in their riverine habitats, but they also display behaviors and hunting strategy similar to the limbless caecilians found in South America and East Asia.

The right half of figure 3 depicts a small, amphibious anaskaphiskoulikid that dwells in and around the alpine rivers of the Northern Mountains. This animal is only about 16 centimeters long, but is still a fairly adept ambush predator for a creature of its weight class. It creates narrow tunnels through the ground with its spade-like mouthparts and hides just below the silt and mud of the riverbed with their primary mandibles splayed out like a beartrap. These vermiform creatures are completely blind, but are able to detect movements with their four feelers. Any prey that wanders too close is snatched up by the vice-like grip of its jaws and dragged down into the depths, never to be seen again. The Soboleru, who are a fair bit bigger than any of their prey like to forage for these worms by waggling their fingers over their tunnels. When the animal takes a bite, they will drag it out and rip off its lower body with their teeth. This may seem rather brutal, but the Soboleru would insist they are best eaten fresh, as their flesh putrefies rapidly upon death.

The organism depicted on the left is actually not an anaskaphiskoulikid, but rather a parasitic euphytozoan that shares the neotenic characteristics of its evolutionary cousin. Motile euphytozoans, otherwise known as neotenic euphytozoans differ from the rest of their kind because they never enter their photosynthetic adult phase. Neotenic euphytozoans are not a unique taxon of organisms, but are instead comprised of several unrelated clades that have convergently evolved the same trait. Most of these creatures belong to one of the branches of the stegnophytozoan suborder since most aquatic niches have already been taken by the elder anaskaphiskoulikids. These organisms have adapted to fill a variety of roles within their respective ecosystems ranging from parasitism (as shown in fig. 3) to soil aeration, and the decomposition of organic matter. Their importance to the continued success of their native ecosystems cannot be understated.

Fig. 4 – Atrikasarkidae

The atrikasarkids are a clade of stegnophytozoan malakosperms that lack any kind of internalized structure. The atrikasarkids depicted in figure 4 are fairly typical of the whole taxon: small, unassuming, and highly numerous. They are the most specious family of euphytozoans, and inhabit a niche identical to that of small grasses and flowering plants here on Earth. They use external rings of levo-chitin to provide their body with some level of rigidity, but they cannot grow much more than about 0.3 meters tall before collapsing under their own weight. That being said, some of these larger atrikasarkids have managed to overcome the limits imposed on their maximum body size by developing a parasitic relationship with more sturdily built clades like the trikasarkids, plegmatrikes and osteosarkids. These organisms use euphytozoans of these clades in much the same way a beanstalk uses its pole or grape vine uses its trellis. They use the suction pads derived from their primeval ancestors to latch onto them and take advantage of their sister clades’ stability. Atrikasarkids can be found in just about any clime with a dextro-amino acid-based ecosystem, though they tend to not thrive as much in particularly dry regions.

Fig. 5 – Epipleounourae

Members of the family epipleounourae are neither malakosperms or gerosperms, but they share several traits with the former. Unlike the atrikasarkids, the epipleounourae have seen fit to rise above their station as boneless invertebrates and reach for the sky, both literally and figuratively. The gas bladders of most stegnophytozoans have become entirely vestigial, but the epipleounourans have retained and modified these organs to lift up the ends of their bodies like a string attached to a balloon. These animals produce hydrogen gas (H2) as a natural byproduct of the photosynthetic process and more actively form it through a parallel biochemical pathway that splits the water in its immediate environment. The terminal gas bladder provides the animal with the most lift, however, it also hosts numerous smaller gas bladders spread along its stem that further increase its and buoyancy and decreases its weight. The Epipleounouran gas bladder is actually comprised of several layers of mesh-like tissue that overlap each other and make it harder for hydrogen gas to escape and diffuse back into the environment. Their body plans are optimized for being large, but incredibly lightweight since gas alone is rather bad at providing lift. A cubic meter of hydrogen only generates enough lift force to carry 1.12 kilograms, and as such minimizing the mass of the main body is of crucial importance.

The epipleounourans are not a particularly specious group. They were once the dominant photosynthesizing organisms, but nearly all of them were wiped out when a mass extinction event befell their world. Ironically, the epipleounourans were actually to blame for the very cataclysm that wiped them out. These organisms constantly emit hydrogen gas, and this contributed to major changes to the planet’s atmospheric composition. The tremendous quantities of hydrogen accumulating in the atmosphere reacted with the planet’s ozone layer, causing it to thin with frightening rapidity. This loss of ozone not only led to more ultraviolet radiation passing through the atmosphere, but also caused a trend of global cooling that would later evolve into a devastating ice age that wrought havoc on the biosphere. Most of the epipleounourans were unable to cope with these new environmental conditions and went extinct. Fortunately, their absence allowed the ozone layer to gradually recover, but life would never be quite the same. For example, a large number of animals originating from the Soboleru’s home world are able to see in the ultraviolet spectrum, but are also far better at resisting damage from ultraviolet radiation. In addition, some of the euphytozoans who survived evolved the ability to freeze their tissues without rupturing the constituent cells and killing the organism.

Fig. 6 – Trikasarkidae

Trikasarkids are a family of malakosperms that can be distinguished from the similarly named atrikasarkids by the quasi-skeletal structures they use to allow them to have much larger body sizes. Their ‘skeletons’ are comprised of contiguous strands or bundles of levo-chitin similar to those seen in the fossil remains of the colossal and primitive fungus known as prototaxites. The species depicted in figure 6 is among the largest of its family. It belongs to an informal grouping of loosely related euphytozoans referred to as ‘loopers’ or ‘archworms’, so named because they form arch-like shapes as their bodies bend and contort under their immense weight. Each loop is secured in the place with highly modified, spikey suction pads that help it remain more stable. The Soboleru believe that it is bad luck to pass under the arched tails of these creatures. A trikasarkid can grow approximately 5 to 6 meters tall before its internal support structures become too weak to prevent its body from sagging. Trikasarkids are extremely common, second only in diversity to the smaller and more fecund atrikasarkids. They can be found in a variety of different climates, but much like their soft-bodied cousins, the atrikasarkids, they prefer humid places where it is easier for them to keep their eggs from desiccating.

Fig. 7 – Osteosarkidae

The osteosarkids are among the most derived and specialized groups of the order euphytozoa. One might reasonably argue that they are just an aberrant subfamily of plegmatrikes, however, I believe that their adaptations are numerous and unique enough to warrant them having their own classification. These organisms are adapted to dwelling in considerably drier and hotter climates than their malakosperm relatives. Osteosarkids are named after their spongy, calcium carbonate and levo-chitin mesh skeletons that they use to sustain their impressive size and height. The tallest known species of osteosarkid can grow up to 18 meters tall. This might sound pretty large, but it seems downright tiny when one remembers there are plants here on Earth that can exceed over 100 meters in height. The osteosarkid depicted in the illustration for figure 7 is only about 12 meters tall, but it is still quite gigantic compared to most humans. Many osteosarkids possess small holes along the length of their body to dissipate the heat generated from their gigantothermy. Relatives of the Soboleru dwelling in the northern deserts and savannahs of the Midlands carve the bones of these organisms into peculiar little trinkets and even simple tools, but they aren’t quite sturdy enough to serve as an effective alternative to actual wood. Both the Soboleru and their cousins consider wood of terrestrial trees a trade commodity and a luxury good, not only because of their utility, but also because the bacteria and saprovores of their native ecosystem can’t make wood rot.

Fig. 8 – Helioskoulikidae

The helioskoulikids are the least specious of the three major phytozoan classes, and also one of the strangest. They are more closely related to the euphytozoans than they are the neotenic anaskaphiskoulikids, however, they do not possess the photosynthetic capabilities of the former. Helioskoulikids have adapted the air bladders of their archaephytozoan ancestors to serve as a floatation device that allows the animal to glide over the surface of the water. The adults can slowly swim about using their stubby little tails, but they more often rely on the winds to carry them from place to place. The tail is more often employed like a rudder that helps them to direct the course of their motions. The individual depicted in figure 8 possesses a thin membrane of skin growing along its length that it uses as a sail to catch the wind. This ‘sail’ is actually a highly derived version of their suction pads. The stomach of the animal has seen similarly dramatic modifications. Upon completing its metamorphosis, the helioskoulikid’s stomach will have grown so massive that it can no longer suck it back into their body. The stomach simply hangs out of its mouth while its many tendrils drift with the motions of the sea. These animals do not hunt so much as wait for other organisms to foolishly wander into their venomous, mucus-covered tendrils. Any creature dumb enough to get caught will end up paralyzed, drawn up by the tendrils to the main stomach and slowly digested by secreted acidic compounds. All in all, the helioskoulikids are fascinating, but somewhat nasty little creatures.

Fig. 9 – Plegmatrikae

Plegmatrikes are the gerosperms evolutionary response to the wildly successful trikasarkids. They are superficially similar to the former, however their levo-chitin quasi-skeletons are organized into a net-like mesh of fibers instead of long bundles. The plegmatrike's support system is not as effective as those of the trikasarkids, and as such they cannot grow as large as them. Figure 9 depicts a fairly generic representative of the group with a long, greenish ootheca waiting to be eaten by a hungry desert dweller. The northerly cousins of the Soboleru living in the great deserts and savannahs of that clime have a special fondness for one of the species of this clade that they call 'rain-seekers.' The rain-seeker is a unique among the relatives within its family as it only undergoes a 'partial metamorphosis.' Larval rain-seekers progress into a photosynthetic adult phase like most other euphytozoans, however, they still retain the ability to retract their extruded stomachs and move around, albeit somewhat slowly. These organisms can detect changes in the local air pressure that allows them to accurately predict when and where it is going to rain, and instinctively move towards it. In this way, these nomadic Dune Folk can follow these creatures around to find reliable sources of water in an otherwise inhospitable environment.