Eudore, Clade

Image from Luke Campbell


Clade Eudore is an extreme case of provolution; a species with very little brainpower modified to full sophont status. Like their ancestors, Eudorae are large errant polychaete worms. While they often occur in large numbers, their flexible nature and thigmatropic (tight space loving) habits often conceal their true population in many aquatic habitats.


Eudorae are large worms, commonly 20 centimeters thick and up to 25 meters in length. They are derived from genes taken from a number of polychaete species, but primarily from Eunice aphroditois, a mud-dwelling ambush predator with an adult diameter of 1 to 2 cm and a length of 1 to 3 meters. Like all polychaetes, Eudorae are segmented into a number of nearly independent rings, with each segment containing a pair of parapodia (legs) tipped with numerous setae (poisonous bristles). The first several segments are fused to make a head, with five prominent sensory tentacles, a pair of palps, and four eyes. The head has an eversible proboscis, normally stored inside out. The end of the proboscis contains two opposed pairs of pronged jaws. The slimy skin of an Eudore is an iridescent brown, tan, or green.

Internal Anatomy

The brain of an Eudore is almost entirely gengineered, since the brain of the original species is so minimal. The forward portion, occupying the head, is primarily concerned with sensory functions and locomotion. Each segment has its own brain-node, containing a ganglion for local coordination of locomotion and cap-shaped structure that, when connected via the main nerve trunk to the entire body, gives rise to rational thought.

Circulation occurs through two main blood vessels - a dorsal vessel conveys blood from the tail toward the head, and a ventral vessel returns blood from the head to the tail. Each segment contains two hearts, one on the dorsal vessel and one on the ventral vessel, and branching vessels that deliver blood to that segment.

The respiratory system of a Eudore is similarly de-localized. Each parapodium is highly vascularized, with extensive eversible sheet-like gills that appear as fluttering tissues puffing from the upper surface of the legs.

The gut runs down the center of the body. Nitrogenous waste is filtered from the blood and discharged into the water using kidney-like organs called metanephridia, which are also responsible for maintaining osmotic balance. Greenish chloragogen tissue found in the central cavity acts like a liver.

The internal organs are surrounded by a layer of longitudinal muscle, which allows the Eudore to contract and (by differential contraction across the segment) twist from side to side or up and down. Around the longitudinal muscle lies a layer of circular muscle, which when contracted lengthens the segment and allows for extension. The parapodia are moved by oblique muscles. The outer surface of the Eudore is a collagen cuticle.

The extensive redundancies of Eudorae make them extremely resilient to damage. They have no singular vital organ that is vulnerable to traumatic injury. Lost segments are easily replaced. Even if chopped into bits the lengths of body which have complete segments can regrow heads and tails, and eventually add enough segments to grow back to their full adult size. Even the brain is highly redundant, and moderate damage may leave the individual less capable of collecting separate lines of thought and perhaps rather confused but otherwise more or less functional. Extensive damage to the brain may destroy or fragment the personality of the individual, but will not kill the body and full functionality will be restored once the lost brain segments are replaced.


The eyes of a Eudore are well developed single lens structures. Substantially derived from the primitive light-sensing organs of basal polychaetes, the eyes are largely modeled on the molluscan design. Eudorae have tetrachromatic vision with polarization sensitivity. The forward pair of eyes are larger, providing binocular vision and good resolution and detail vision, while the pair behind them is more laterally oriented for wide angle vision and motion detection. Each segment also has a rudimentary eye that can distinguish light from dark.

Each parapodium is a basic chemosensory organ, combining the functions of taste and smell. The primary chemosensory structure, however, is a cilia filled pit known as the "nuchal organ" on the upper surface of the head. This structure gives Eudorae an acute sense of smell while underwater, less so on land.

Each segment has pressure sensitive organs that enable the Eudore to react to motion in the water. Reflected pressure waves can even give an Eudore a sense of nearby obstacles, and the dimensions and extent of any cavity it may be crawling through. The head tentacles extend this sense to higher frequencies, allowing an Eudore a good sense of hearing.

In a similar fashion the excellent tactile senses along the entire body of an Eudore is taken to an extreme at the tentacles, which can rapidly scan an object to determine its shape and texture. In the darkness of their tunnels and burrows, splayed tentacles are often necessary to let an Eudore know where it is going and what lies ahead.

The proprioceptive abilities of an Eudore are highly developed to allow them to navigate in complete darkness. Eudorae can learn a route or general area well enough to maneuver largely by dead reckoning and muscle memory.


Eudorae communicate complex ideas and thoughts via sound, using language much in the fashion of baseline humans. They produce sound by squirting water through paired internal tubes containing vocal flaps. Among themselves, they use scent extensively for marking and social signaling. Tactile contact reinforces social bonds - they are quick to initiate contact and have little concept of personal space. Members of many other clades tend to be a bit put off when a multi-meter long slimy tentacled worm with venomous bristles writhes all over them as a standard part of its greeting.

Locomotion and Biomechanics

Eudorae are known for very rapid extension and contraction of their bodies. In extremes, the velocity of the distal end of an Eudore may reach 15 m/s. They use this to good effect when waiting in the mouths of a burrow - either for a predatory ambush strike, or to rapidly withdraw if startled.

Eudorae have several "gaits" that they use in different circumstances. They can slither rapidly by undulating their body back and forth. This slithering motion combined with coordinated strokes of their parapodia allows them to swim rapidly. For more leisurely movement or when crawling through tight confines, they produce wave-like ripples along their segments while pushing with their parapodia to crawl forward. Their fastest "gait", however, is a rapid extension of the body to maximum length while anchored from behind, followed by gripping with the forward section and contracting the body.

Since Eudorae lack any rigid body parts with the exception of the jaws, they can squeeze into very small openings. This allows them to pack their bodies into tight spaces and crawl through narrow cracks and tubes.

The longitudinal and circular muscles sheathing the Eudore's body are very powerful, allowing great pulling, pushing, and torsional forces. The lack of rigid structures for support and levers makes pushing with a long span of body difficult, as the span will tend to buckle. However, their ropy bodies allow them to creatively exploit techniques of mechanical advantage. For example, if a weight is too heavy to pull by grabbing with the front portion of the body and anchoring the back, they can loop around the object and pull with both the front and back parts of their bodies to double the force. Likewise, pushing with multiple parts of their bodies can multiply the force by the number of points off which the Eudore pushes. In effect, they can turn themselves into pulleys or hydraulic jacks.

The head tentacles are used for fine manipulation. They are not particularly strong so where extra force is needed an Eudore will extend its proboscis and clamp down with its mandibles. Eudorae have powerful bites, which combined with the serrated blade on the inside of their pincer jaws gives them a useful cutting tool, wrench, pair of pliers, crimpers, and strippers.
Eudore Mouth
Image from Luke Campbell

The setae of an Eudora are typically partially retracted and not dangerous. When an Eudore is alarmed, the setae erect and become primed. When stimulated in this state venom glands will pump toxins down the tube. The setae are sharp and can easily puncture most varieties of bare skin. The toxins cause an immediate agonizing burning sensation to most bionts, eventually wearing off into a permanent numbness that requires medical intervention to treat (results may vary with clade).

Diet and Feeding Habits

Eudorae are omnivores. They are quite indiscriminate about what they eat, and happily consume what many other clades would consider garbage. Much of their food is found by mucking about in the sand and mud. On encountering a food item, they thrust out their jaws to grasp it and then pull it inside their head, where it is fed to the gut. Food that is too large to be eaten intact may have pieces nipped off with their pincers, or firmly gripped and torn off by twisting the body.

Eudorae will hunt. They wait in their burrows with their heads at the entrance, splayed tentacles sampling the water and mandibles partially everted and spread apart like snap-jawed traps. When potential prey wanders by, the Eudore shoots forward as its jaws snap shut on its victim.

Lifespan and Reproduction

Eudorae start life as 1 centimeter long translucent wormlets shortly after hatching. At this age, they are not sapient, and operate mainly on nervous reflexes. They remain close to their brooding parents, feeding on food the parents bring back to the nest. Eudorae grow rapidly at this stage, reaching 1-2 cm in diameter and 1 to 3 meters in length within ten megaseconds (note that linear measurements are necessarily inexact on creatures that can change their length and thickness at will). At this size their brains are starting to develop and they begin to develop a personality. By 100 Ms (3 Terran years), Eudorae are at half adult size and very much full sophonts, although they remain close to their parents for the prolonged childhood needed to learn to be a person and fit into society. They are mature at roughly 500 Ms (16 Terran years). Without medical intervention, they reach senescence at around 10 Gs (300 Terran years).

Eudorae mate for life. An Eudore pair stimulate each other through pheromones to transform the posterior portion of their bodies into an epitoke - a length of segments dedicated to reproduction. Eudorae have distinct sexes. The epitoke of the female will be filled with eggs and that of the male with sperm. When the epitokes are fully developed, they will detach from the rest of the body, seek each other out, spawn, and die. This usually occurs in the nest chamber, allowing the eggs to be collected and brooded, but occasionally epitokes will get lost (or be released when a pair bond is disrupted), and may fertilize each other in the open sea. The size, and thus the fecundity, of the epitokes depends on the population density of Eudorae the parents are exposed to. In crowded environs, the epitokes may be mere centimeters long and result in only one or two viable eggs. Eudore pioneers, on the other hand, may produce broods of hundreds. After spawning, Eudore re-grow their tails.

The offspring of lost epitokes grow up essentially as wild animals and most are quickly eaten. The lack of parenting of any survivors tends to stunt their psychological development such that they have a difficult time integrating into society.

There is another option for Eudore reproduction. If severed, the front half of the body will grow a new tail and the rear half a new head. This results in a clone of the original individual. However, this severs the brain and results in a fragmentation of personality.


Eudorae live in water. While they can survive some time out of water, particularly if kept moist, they will not thrive and will eventually need to return to an aquatic environment. They can adapt to fresh, brackish, and sea water, but need about 100 kiloseconds (28 hours) to adapt their osmotic regulation. Rapidly dumping an Eudore from salt to fresh water, or vice versa, will lead to osmotic shock and death within kiloseconds.

Without shelter, Eudorae become stressed and neurotic. Certainly, they can spend tens of kiloseconds exposed and in the open without adverse psychological effects, but they are most comfortable when squeezed into tight cracks, tubes, burrows, or crevices.

Eudorae have an optimum temperature range of 25 to 35 degrees C. They can survive temperatures down to -5 degrees C, but they become sluggish and confused below 20 degrees C and nearly paralyzed and unconscious below 10 degrees C.


The segmented brain of an Eudore allows it to multi-task easily. Approximately 1 meter of relaxed body length has the general intelligence of a human baseline. Multi-meter bodies do not necessarily think more deeply or profoundly, but can in essence run several coordinated thoughts in parallel. Different segments tend to specialize their thinking functions - some will be more creative, others handle logic, still others are specialized for social interaction. Conversing with an Eudore can be confusing, as they jump back and forth between several lines of thought (not to mention that they may be holding different conversations with each of their two separate voice-tubes). Eudorae excel in synthesizing diverse elements into a coherent whole. For this reason, they are often found in management. They also make inspired scientists who often put together diverse lines of study into novel conclusions.

Eudorae are predators, and retain a predator's drive. They are drawn to rapid motion, and are fascinated by the smell of blood, splashing and flapping motions, and signs of weakness. Those clades that care for their young tend to find the predatory attention Eudorae display towards children to be particularly disturbing. However, as civilized beings, most Eudorae are quite capable of suppressing these urges. Those with damaged psyches, however, can become particularly depraved criminals.


Due to their reproductive habits, Eudorae quickly form dense societies. They do well living, literally, underneath the habitations of other clades, swarming through their hidden places and eating their garbage (and the occasional feral pet or non-sophont commensal). Perhaps because they can easily sympathize with and synthesize multiple points of view, Eudorae societies tend to be fairly tolerant and accepting. This helps to reduce conflict between individuals at high population densities. They rarely tolerate autocracies, and naturally tend toward communal decision making and planning.

Eudore art is often best appreciated from multiple perspectives simultaneously. Their stories and literature are often convoluted, with multiple interweaving plot lines. Their representative art includes touch-sculptures and texture art. Eudore visual art is best perceived by those able to resolve the polarization of light.

Eudore architecture typically involves networks of branching tunnels the width of a relaxed Eudore adult. Rooms are flat voids, chambers whose ceiling is the height of a relaxed Eudore's thickness. Storage chambers may be much thicker, depending on the nature of the items being kept. Where Eudorae dwellings intersect with the structures of other clades, such as sewer tunnels or flooded underground neighborhoods, a visitor may find numerous 20 cm holes in the walls, ceilings, and floors with glistening betentacled worm heads partially protruding, and the occasional partially exposed length of an Eudore as it crawls about.

Relations with other Clades

In multi-clade societies, Eudorae occupy a number of niches. In labor, they can find work as mechanics in hard to access areas - an Eudore can easily slither down skinny pipes, crawl between walls to lay wire, or get into the most inaccessible places to repair machinery. They also commonly come to dominate the waste management and recycling portion of the economy, since Eudorae will happily take the waste of others for their own food and wealth and do not consider these occupations as a stigma. In lower-tech societies, Eudorae are typical laborers in aquaculture and hydroponic installations, as they can slither among tight plantings while underwater, and are fairly cheap to feed and house. In dangerous or lawless areas, Eudorae make effective guards and enforcers. As previously mentioned, they are talented managers and excel at creative endeavors where seeing things from a fresh perspective or integrating diverse fields of thought is a benefit.

The baseline human reaction to Eudorae is typically one of disgust, and this trait is usually carried over into their descendants (nearbaselines, rianths, tweaks, and superiors) who have not been specifically modified for increased tolerance or decreased sanitation. Common descriptions are "far too many tentacles" or "glistening ropes of writhing intestines". However, a significant minority also find Eudorae fascinating and will admire them from a distance - although few care for physical contact. Humans typically tolerate Eudorae as long as they mostly remain hidden, and strong human-Eudore relations are often built over networks and in virtualities. For their part, Eudorae realize that they make humans feel uneasy and tend to limit physical contact. These are, of course, generalizations: humans and Eudorae occasionally form friendships.

Unfortunately, the disgust reaction of humans and their descendants can turn ugly when demagogues and rabble-rousers need a scapegoat or a focus around which to rally their base. The resulting pogroms can backfire, however, if the humans underestimate the true numbers of the Eudorae living among them, or if the repression succeeds in driving the Eudorae out only to find that they have no recourse for waste management, for example.

On a few occasions, nearbaseline or tweak clades have developed closer relations with their Eudore neighbors. In these cases, each has come to view the other essentially as pets, leading to a strong mutualistic relationship.

Many aquatic clades, of both humans and provolves, are too pelagic (open ocean dwelling) to have much interaction with the normally hidden and bottom dwelling Eudorae. Those who live closer to the surface, however, will often come into contact with their verminous neighbors. Those who also prefer the shelter of burrows must deal with Eudorae if they live in the area. This brings the worms
in contact with provolved octopus, Actie, and crustacean clades, among others. In most cases, differences in psychology and ecology allow each to specialize, reducing conflict as each takes up an appropriate niche.

The most numerous of the provoloves with which Eudorae share a habitat are the various octopus-based clades. Communication with the octopuses can be difficult, since the baseline state of cephalopods is deafness, and cephalopod communication is typically based on flickering visual patterns and postural displays. With some difficulty, Eudorae can learn to understand the language of cephalopods, but talking back is difficult without artificial aides.

Eudorae often develop a close mutualistic relationship with brain kelp. The kelp provide shelter and concealment, while the Eudorae prey on animals that would normally parasitize the kelp.

"Wild" Eudorae, either from the spawn of escaped epitokes or from lost regenerated individuals who suffered injuries extreme enough to effectively destroy their mind, give their more civilized brethren a bad name. These monsters often predate other sophonts, and must be tracked down and either captured or thoroughly killed. Where wild Eudorae are common, the entire clade often gets a bad name and innocent civilized Eudorae are persecuted.


The original Eudore species, described here, has served as the base stock for a number of modifications and daughter clades. Some of the more notable are described below:

Clade Penelope has modified gills, which are drawn into the ring segments to form lungs. The Penelope are primarily terrestrial, and must hold their breath when diving. Penelope live in damp soils, commonly in and among the roots of trees or even inside the tree trunks. Clade Penelope forms the base for most air-breathing Eudorae sub-clades.

Clade Pitys originated in the Orwoods of the Jaysen system where they embraced the hedonic culture. These "Euphorae" have equipped themselves to give and receive pleasure when in contact with other bionts. Pitys skin produces a perfumed aphrodisiac and their setae inject stimulants or relaxants instead of toxins. To receive pleasure their tentacles have chemosensory organs which reinterpret sweat and other bodily secretions as Hedonipharmicologicals. Pitys use bionano to tailor their biochemistry to each individual client.

Clade Calypso are Eudorae modified for survival in sub-surface oceans of tidally heated ice moons. They typically have increased resistance to low temperatures and can remain aware and mobile (if slower) at temperatures well below the freezing point of water.

Clade Thetis has been modified for pelagic existence. These Eudorae have psychological modifications to enable long term residence in open environments, as well as enlarged parapodia for extra swimming propulsion, enlarged gills for greater oxygen uptake needed for prolonged aerobic swimming, and counter-current heat exchange "rete mirabile" blood vessel networks for increased activity and an extended range of active temperatures. This is at the expense of flexibility and contortion abilities. Thetis rely on sight, sonar, and vibration pressure senses; their proprioceptive and tactile senses are reduced.

Clade Asteria is a micro-gravity adapted sub-clade of Clade Penelope. They have the same psychological modifications as Clade Thetis to enable long term residence in open environments and even larger, fan-like, parapodia to push against the air when needed. Asterias' setae are not poisonous, instead they are modified into microscopic branched structures tipped with gecko-like spatulae. These coat the outer surface of the parapodium fans, allowing them to adhere to any surfaces they encounter.

Sub-clades of Eudorae are typically named after nymphs in Greek mythology. This is a tradition going back to the base gene-stock — the worms of the genus Nereis and Eunice.
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Development Notes
Text by Luke Campbell

Initially published on 01 February 2010.