The project to provolve manta rays began in 472 A.T. aboard the marine-environment Maalimi Habitat in the Jovian League. Baseline manta rays have the largest brain-to-body ratio of any fish, and had been previously noted as the ideal first candidate for fish provolution. Still, it was the most ambitious provolution project of the time, was heavily funded by a number of interest groups and foundations, and achieved considerable fame across the solar system. The researchers named their planned clade Madi — Maldivian for manta ray.
Starting work with a stock of Manta alfredi, the first stage of the project was a series of cautious intelligence enhancements spread across ten years, eventually bringing the mantas up to presapience — roughly equivalent to a baseline chimpanzee in intelligence.
The final step, development to full sophonce, ran into problems in its final years. Though tests showed the problem-solving abilities of the Madi were as good as those of a baseline human (and sometimes a superbright), they suffered from total aphasia. Lacking a system of abstract symbolic reasoning, they could not be considered true citizens. Attempts to upgrade their linguistic abilities through further gengineering surfaced into other areas — usually kinaesthetic skills — and the Madi remained incommunicative.
For the next fifteen years, the research team tried ever more complex solutions, without success. In the end, funding and public support dwindled, and commentators began to criticise the project on ethical grounds. There was even talk of a lawsuit from the systems various ethics committees. Eventually, in 499 the researchers gave up hope of finding a biological solution. Instead, they tried connecting the Madi to a primitive exoself with inbuilt language facilities. They succeeded — partially — in 503.
It was a suboptimal solution: The Madi found learning a language to a long, difficult process; they were never as proficient with it as other clades; and they were tied to their exoself software. But it worked, and that was enough for the researchers.
With these handicaps, the early Madi never spread far from Maalimi, and when the habitat was destroyed in the early years of the Technocalypse, they were believed extinct.
As it turned out, however, a small group, carrying enough genetic samples to ensure diversity, managed to escape the solar system on one of the first beamrider ships, and set up a habitat around the brown dwarf Yang. (To this day, Madi influence at the birth of the beamrider network is clear: Extensive marine orbitals sit above Ying, Yang and Patala, and Madi crew some 3 million predominantly marine-environment beamrider ships. The oldest of these, the Rannamaari, predates the First Federation and is one of the most famous ships on the network.).
After the emergence of the First Federation, word of the Madi colony at Yang reached the Federal Institute of Provolution in Solsys in 962. A hyperturing working for the FIP created a set of genepatches to fix the language issue, and had them sent to Yang.
The Madi around Yang now faced a choice: Either the could accept the FIP genepatches, or they could continue to upgrade their linguistic exoselves with more advanced cybernetics.
The individuals who opted for exoself upgrades set on a route to becoming full cyborgs. Since then, most have cladised to such an extent that most are no longer recognisable as Madi. But a small subset retain the manta bodyplan in extreme environments. They are sometimes considered a Madi subclade — see below.
The individuals who chose the genepatch are the ancestors of modern Madi. Some emigrated to the Federation, where, working with the FIP, they were responsible for the provolution of their fellow elasmobranchs, Clade Requiem. Otherwise, most Madi expansion through the galaxy was with the Deeper Covenant, through which many have since moved to the Sephirotics.
Madi are slightly larger than baseline reef mantas. The average adult has a wingspan of around five metres, and the largest recorded natural wingspan is seven metres. The central body is noticeably higher compared to the baseline, to accommodate the large brain, but a Madi presents a relatively flat profile.
Madi are countershaded: Largely black on the dorsal (upper) side and largely white on the ventral (lower) side. But within this, there is considerable variation. They are capable of changing the colouration pattern on their dorsal side. On the ventral side, by contrast, every individual has a unique pattern of spots. If a Madi opts for body modification (most often colourful or luminescent tattoos, more rarely scarification), they will usually choose the ventral side.
The cephalic fins, either side of the mouth, are longer and more agile than the baseline.
Almost all Madi use handtech. To preserve streamlining, Madi handtech in the modern era is either detachable, entirely separate (controlled by laser implants), or delicately hidden inside the gills or mouth.
Communication, Senses, Locomotion
The most common form of communication is sign language using the cephalic fins. The original Madi sign language has since divided into hundreds of variations, many of which are mutually incomprehensible. Besides signing, Madi communication can be enhanced with the shifting patterns on the upper side, and whole body motion that resembles dancing, with looping and corkscrew motions.
Madi eyesight is better than baseline mantas', and gives a broad field of vision, save for blindspots directly behind and directly ahead. They have an excellent sense of smell, plus the usual elasmobranch complement of electroreception and pressure sense.
They are strong and agile swimmers. While baseline mantas must constantly swim to stay afloat, most Madi have adopted a swim bladder for the sake of convenience, either as a bioborg implant or genemodded in from birth. Even so, they are almost always in motion, and feel uncomfortable staying still for long.
Lifespan and Reproduction
Madi reach sexual maturity at the age of 15, and without augmentation can live up to a century.
In baseline mantas, the standard courting behaviour is a mating train: a female leads a train of males through the reef, dancing back and forth, and sometimes even breaching, to shake loose the least persistent until only one remains. Madi courtships involves similar rituals, but more complex. The train may be intellectual as much as physical, conducted through puzzles on the local net. Any gender may lead, and any may follow.
Gestation takes twelve months on average. Madi are ovoviviparous: The fertilised egg hatches inside the womb, and the female gives birth to a live pup. Unlike baseline mantas, Madi have a strong maternal instinct. The pup will spend the first decade of its life shadowing its mother and learning from her.
Madi are most comfortable in tropical marine environments, with a water temperature of 20-30 degrees Celsius. Most Madi in the current era are augmented to tolerate a broad range of salinities.
They prefer open oceans, and in circumstances where space is necessarily limited — aboard singleships, for example — often resort to virch simulations to make themselves more comfortable.
The efficiency of the gills has been increased to keep up with the higher oxygen requirements of the brain. Even so, Madi need highly oxygenated water, and often take oxygen supplements when venturing away from these regions. They feed often and need high concentrations of plankton.
Being derived from a species which needs to swim constantly to stay afloat, Madi feel a strong urge to stay in motion, even if they have been buoyancy augments.
By human standards, Madi are introverted. They don't speak much, and when they do, the topic is important. By comparison, they consider humans incorrigible gossips. Nor do they get lonely. They need a great deal of time alone in the open water, swimming great distances or feeding. Denied it, they withdraw quickly, become morose, and with time develop psychological disorders.
Such time alone with the plankton lends itself to reflection. Madi, though rarely spiritual, are often meditative. They are often drawn to religions such as Zen Buddhism, Taoism, Undyoism, and some variants of Hinduism; many Madi live in the Sophic league. The meditative pose is always one of motion.
Conversely, swimming contemplation can be turned to other matters. It is a time in which one can ponder anything from aesthetics to some particularly knotty mathematical problem. And sometimes, swimming alone is worth is just for the sake of swimming alone. Madi make excellent singleship pilots and are often found exploring the outer volumes. In such cases, they use sensory stimulators to give themselves the sensation of swimming, and take along a large virch library to satisfy their curiosity.
Madi have a reputation for being pacifistic. While this isn't true — they are quite capable of defending themselves if need be — they are far less aggressive than humans. Neither are they territorial; the open ocean is big enough for everyone, particularly if it's on a megastructure. On the other hand, they are also less compassionate than humans. The feeling is known to them, but they are less moved by suffering.
These traits give rise in popular consciousness to the image of a Madi as a sort of insouciant monk or saint. Many who meet them are surprised by how curious, playful and fickle they are. They will often come up to investigate newcomers to their social sphere, ask about the newcomer's life and special interests, and perhaps invite them to dance and swim.
Society and Culture
Madi social behaviour is based around cleaning stations. Their ancestors would spend time at cleaning station being having parasites removed by a variety of commensal species. Modern Madi (barring some prim cultures) are entirely free of parasites, but keep the cleaning stations nonetheless. Individual Madi, though they may travel great distances, generally remain faithful to the same set of cleaning stations.
At the most basic level, they find the sensation of being cleaned pleasurable in itself. The cleaners may be the original species — butterfly fish and wrasse — or specialised neogens or bots designed for this purpose. In some Madi cultures, the creation and programming of cleaners with entirely new behaviours is an art in its own right.
For the otherwise solitary Madi, cleaning stations provide an important hub for social interaction. Here one may see great mating trains — not just as a prelude to mating, but as a game in itself — and larger dances.
Dances and sports (for the Madi, there is no difference between the two) conducted at the cleaning stations are an important part of all cultures. The details vary greatly. They may emerge spontaneously among a few friends after a cleaning session, or be preplanned as a performance. The largest can involve thousands of Madi in complex, synchronised patterns the form immense but transitory works of art. Two traits are universal: First, imitation and synchronisation is always a major element. Second, even the most heavily choreographed dances retain a strong element of improvisation.
Almost all Madi fiction is theatre: it is meant to be performed and seen rather than read. Dance sequences are often sprinkled liberally throughout. Tragedy doesn't excite them because they don't resonate with the emotions presented. Comedy and melancholy are more popular. Some of the more popular human works among Madi include the Noh plays of Japan, the plays of Anton Chekhov, and dance-adapted translations of the works of Gilbert and Sullivan (all of which were saved in translation by the original Madi colony at Yang).
The other great Madi artform is landscape architecture. Some specialise in designing the environments of their cleaning stations. These architectures vary greatly depending on the culture and artist. Some don't resemble natural cleaning stations at all: Everything from minimalist rock gardens to ultrabaroque arrangements can be found across Terragen space. Some of the greatest Madi architects work in the MPA, creating landscapes covering hundreds or even thousands of square kilometres on megastructures such as Cableville, Kepleria and Kiyoshi.
Relations With Other Clades
Being non-territorial, Madi are happy to share their living space with other marine sophonts. In general, they have better relation with acties than either do with dolphins, cephalopods or merpeople, if only because neither group is a natural predator of the other. They may share their cleaning stations (and hence social environment) with iniliak and streyas, and may co-operate with these clades when designing their landscapes.
Madi are often found in association with amphisapiens. Both clades share a meditative view of swimming in the open water and a cultural keystone of aquatic habitat design.
Eagle Madi have lungs instead of gills and a dry, moisture-retaining skin. They live in open-air freefall habitats, such as freespheres, Ederbubbles, and smoke rings.
Transapient Mantas, like transapient whales, are first- and second-singularity beings that have retained or adopted the manta body plan. They are much larger than normal Mantas — sometimes reaching a wingspan of hundreds of metres. Most transapient mantas can be found in the Biopolity, where they oversee the local ecologies. Their dorsal surfaces are covered with bionano chromatophores that can even work as a phased array lasers. Individual plankton processors trapped in their gill arches connect directly to these mantas' nervous systems, integrating them full with the local computational ecology.
The Cyborg Rays, derived from those Madi who chose an exoself upgrade rather than a genepatch, are rather less communicative than other Madi. Plasma Rays, who live in the atmosphere of jovians and brown dwarves, helping with the operation of sunlines, and sometimes can found in stellar atmospheres. Vacuum Rays, living in open space, may serve as bioships or asteroid miners.
Fish - Text by M. Alan Kazlev  Polyphyletic taxon; aquatic non-tetrapod Terragen vertebrates, usually though not necessarily with paired fins and with scales. An important component of most Terragen aquatic ecosystems. There have been several successful fish provolves, especially since the Empires Age. However most fishes are subsapient sentient animals.  More generally, alifes, bioships, and xenobiota of fish-like morphotype.