A clade of human-arachnid rianths.

Image from Julia Harrison

Most rianths are the result of combining human traits with those of other mammals (since the genetic modifications involved are relatively minor and often merely cosmetic). The Imtonasi are a human clade with features which recall those of certain arachnids, especially spiders.


The Interplanetary Period saw the first widespread occurrence of sapients custom-designed for life in space. Many megacorporations created designs for zero-G colonists and construction workers. Most were tweaks modified to live long-term in microgravity and/or with increased radiation resistance, and some combined human and ape genes to replace walking feet with functional hands. The majority originated in Old Earth nations on the continents of Europe and North America, but the forerunners of the Imtonasi were the products of the Kenya-based Umoja Corporation. Umoja proposed a radical redesign of the human skeleton, musculature and nervous system, to produce an eight-limbed form inspired by spiders; this new form was also tolerant of zero-gee, since Umoja anticipated that these spider-like people would be well-adapted for space construction work.

The plan was to create laborers with multiple limbs and the dexterity of an arachnid, enhanced climbing ability and the microgravity adaptations that had by that time become industry standard. Experts agreed that the concept was revolutionary, but many doubted that Umoja could succeed in implementing it. Computer-simulated gene sequencing revealed flaws that would have resulted in fatal genetic instabilities in live subjects. After three decades of failure the Umoja board of directors was ready to give up on the design when a new project head took over.

Samuel Butler was North American rather than African — historians disagree on which nation he was from — but he was of African descent. He was also one of the early superbrights, and his field of expertise was biology with a specialty in genetics. Butler personally "debugged" the experimental genome section by section. His advanced intellect allowed him to identify changes which were themselves unstable or that caused instability in other genes. The finished genome passed simulation just 14 months later and progressed to in vitro trials. The first births followed within 11 months. Butler named the new species Mtoto Anansi (mmm-TOE-toe ah-NAHN-see) after a beloved trickster hero from African folklore. The current name is the result of many centuries of linguistic drift.

Umoja wasted no time in putting their new products to work. Mtoto Anansi built a number of orbital habitats throughout the solar system, including Umoja's new corporate headquarters in Earth orbit. The ancestors of the Imtonasi remained indentured while they performed this labor, but public pressure — aided by the concurrent efforts of provolves, splices and vecs to gain full sapients' rights — eventually led to emancipation. Many Mtoto Anansi continued doing the work for which they were designed, but others set about building communities of their own. By the end of the Interplanetary Period most of the species lived in orbital habs. Nearly all of those habs, singly or in groups, declared themselves sovereign nations.

When the Technocalypse struck the Mtoto Anansi habs were as vulnerable as any other settlements. A few of the orbital nations were able to build drives and escape to interstellar space, though many of these improvised ships were lost. Many more habs were destroyed before they could mount effective defenses. A very few communities were able to hold out long enough for GAIA to intervene on their behalf — usually by moving to the outskirts of the Solar system and becoming Hiders. By the end of the Technocalypse period the Imtonasi had spread out among the stars with the rest of Terragens society. The scattered populations in Solsys joined into a single nation that was at one point the largest predominantly Imtonasi polity in known space. The other Imtonasi made their homes wherever they could. They have since established thriving communities that now outnumber their kin in Solsys.

Image from Steve Bowers

Modern Imtonasi are found throughout the Civilized Galaxy. They prefer to establish communities of their own, but they are sometimes found in cosmopolitan areas. The largest concentration is in the Zoeific Biopolity, but there are large Imtonasi communities in the Solar Dominion and the Utopia Sphere. The Imtonasi nation in Solsys is among the main points of contact between the clade's system of origin and the rest of the Civilized Galaxy.

Appearance and Capabilities

Imtonasi have a body plan that is humanoid except that they have three pairs of arms. Each brachial pair includes associated chest and shoulder muscles. Females have three pairs of breasts, each of which is smaller than the norm among most other hu. For Imtonasi the milk production capacity of six breasts is equal to what plebhu get from two. All Imtonasi have slim builds with little body fat. Height ranges from 2-2.6 meters with body mass of about 65-90 kilograms — females on average are slightly taller but more lightly built. The skin is medium to dark brown, sometimes with darker brown or black markings. For most variants the only visible hair is the eyebrows and eyelashes, but a few subclades can grow scalp and/or facial hair. The tactile hairs dotted across the skin are so fine as to be nearly invisible even close up. The eyes are noticeably larger than the human norm with deep brown (almost black) irises that are large enough that very little white is visible.

The hands of the Imtonasi have long, graceful fingers that grant them great (though not superhuman) manual dexterity. Their body plan makes many forms of gymnastics difficult, but Imtonasi are excellent climbers who handle microgravity very well. They have adaptations that prevent loss of bone density due to long-term exposure to a microgravity environment, and their resistance to ionizing radiation is superior to that of baselines. Changes to the circulatory system greatly reduce the disruption of blood flow that occurs in microgravity or when the body is inverted. The spine is surprisingly flexible, and the supporting muscles and connective tissues function better than the equivalent structures in baselines — otherwise Imtonasi would be hard-pressed to stand up straight in 1 G. A few Imtonasi excel at speed swimming after learning special strokes that require multiple arms. The average strength of Imtonasi is about 10% less than that of baselines — the reduction in muscle mass being one of the trade-offs that allowed the lengthening of the spine and the addition of bone matter for the extra arms.

The Imtonasi nervous system has a number of arachnid qualities. They can easily coordinate the movements of all six arms, even while walking or climbing. They cannot multitask any more easily than baselines can, but they can bring combinations of arms to bear on a single task with spectacular results. Handedness is left-right as in baselines and applies to all three pairs of arms; a right-handed Imtonasi can use all three right hands equally well. Imtonasi skin is rich in sensory nerves. This gives them the same sensitivity to pressure differentials that grants spiders their "distant touch" capability — an Imtonasi can form a crude quasi-visual picture of eir immediate vicinity (a radius of up to four meters) just by sensing air currents. Imtonasi sensory acuity is roughly equal to that of baselines except for the sense of touch, which is notably superior. Even the slowest Imtonasi have reflexes that are above average by baseline standards, and the fastest individuals have reflexes that border on superhuman.

Imtonasi reproductive biology is nearly identical to that of baselines except that twin births are the norm and triplets are about 20 times more common than they are among baselines. Multiple births — quadruplets or more — are largely unknown among Imtonasi. Single births are as rare among Imtonasi as quadruplets are among baselines. Despite the propensity for twin births Imtonasi are slightly less fertile than baselines; females ovulate only four times per year.

The most noteworthy feature of Imtonasi biology is their spinnerets. An Imtonasi has two pairs of glands on eir lower abdomen. When not in use these glands appear as four small bumps just below the abdominal muscles. Each gland can evert a fingerlike duct for the purpose of spinning silk. This silk is just like spider silk — including optional stickiness and a tensile strength higher than that of steel — but Imtonasi can secrete it in quantities hundreds of times greater than even the largest unmodified spiders could ever hope to. All adult Imtonasi can spin silk into ropes, and master weavers can create silken objects of art. Spinning ability was actually a by-product of corrections made to other genes, but the designers saw no reason to eliminate it.

The Imtonasi suffered from the limited lifespan issues that often appeared among the earliest splices, rianths and provolves; their unaugmented lifespan is intermediate between that of humans and unmodified animals. An Imtonasi can expect to live about 200 years without medical intervention, but in the Current Era individuals can choose to live well over a thousand years, thanks to everyday medical technology. An Imtonasi's center of gravity is slightly higher than that of a baseline of the same height due to the redistribution of muscle and bone mass. This causes a small reduction in balance, especially for running and jumping. Imtonasi are creatures of low gravity — they are uncomfortable in gravity greater than 0.6 standard G and cannot function without augmentations in gravity of 1.2 G or above.


Imtonasi culture stresses the enjoyment of life and happiness earned through hard work. Even in polities where the local transapients provide for subsistence-level needs most Imtonasi prefer to work. Members of this clade tend to appreciate humor and celebration — while they are found throughout the Civilized Galaxy they generally avoid the more stoic societies. The ancestors of the clade preferred a primitive existence of subsistence farming using nothing beyond Bronze Age technology, and many Imtonasi maintain such lifestyles in the present day. Others have embraced the environment for which the clade was created and taken to life in space. Space-dwelling Imtonasi generally prefer orwoods to inorganic structures, and even many primitive groups live in orwoods.

There are a few cultural traits unique to this clade. Most Imtonasi communities use Kiswali — a descendant of the trade languages of ancient Africa — as their primary language, and Imtonasi musicians have invented several instruments that require more than two hands to play. The Imtonasi's most important idiosyncrasy is a penchant for wearing clothing spun from their own bodies. Clothing styles vary widely between groups, but all Imtonasi retain this trait to some degree. In some groups an individual isn't considered an adult until e can make eir own clothes, while others only wear "self-silk" on special occasions like weddings or births. Early Imtonasi developed a technique for using dietary supplements to dye the silk as it was secreted, but only the prim groups still practice this. More advanced communities sometimes use transcutaneous dye patches to the same effect. Master weavers have even developed techniques for blending self-silk with plant fibers or inorganic polymer strands. Garments made of Imtonasi silk are in great demand — not just because of their beauty, but because some grades of silk are very effective as ballistic armor. Textiles, from raw fabrics to tapestries to high test climbing lines, are often the primary exports of Imtonasi communities. Ship-based communities often make their livings as zero-G laborers.

The Imtonasi have developed a unique martial art called ingekono. This fighting style takes full advantage of the clade's morphology; no one with less than six hands can make full use of it, and no one with less than three hands can use it at all. The inclusion of kicks, cartwheels, leg locks and tripping techniques means that practitioners also need functional legs. Masters of the style can simultaneously defend with one pair of limbs, feint with another pair and attack with the third — sometimes while climbing. Ingekono also includes techniques for using the klabu (a 0.7-meter stick with one hooked end; often used in pairs) and fighting in microgravity. This effective yet graceful fighting art uses flowing movements that were apparently derived from ancient traditional dances. Many Imtonasi who have no interest in unarmed combat practice ingekono as an art form or as dynamic meditation.

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Development Notes
Text by Michael Walton
Initially published on 10 February 2007.