Some Clade Requiem individuals and associated handtech drones search the seabed of Avensis for ancient xenosophont remains
Introduction and History
The requiem are a clade of shark provolves created in the early First Federation period. A team of Madi and human researchers worked with a stock of lemon sharks (Negaprion brevirostris) saved by the Burning Library Project. Of the species available, lemon sharks were chosen as the most promising candidate, exhibiting comparatively strong social bonds and social learning.
Success was announced in 1130. The earliest Requiem shared the marine habitats with their Madi creators, but in the Current Era the clades are rarely associated.
Requiem retain the appearance of lemon sharks: stocky but streamlined bodies with a broad, rounded snout. The second dorsal fin is almost as large as the first. The eyes have nictitating membranes. They are naturally countershaded — sandy-grey on the dorsal side and white on the ventral — but many cultures opt from a variety of artificial colours. The dorsal fin is tipped with white, and the other fins with black.
They are larger than baseline lemon sharks: A fully grown requiem averages 3 metres in length, but can grow as large as 4.5 metres.
Requiem may decorate their bodies through artificial colours or scarification. In such matters, each individual follows their own aesthetic preferences, and there is little in the way of a common standard.
Though the Requiem brain is considerably larger than that of a baseline lemon shark, this is not evident from the outside. Rather, the brain has been made longer, taking up the addition space of a larger body and displacing some of the organs.
In order not to impede streamlining, Requiem handtech is either separate from the body or hidden inside the mouth or gills.
Communication, Senses and Locomotion
Requiem, like baseline lemon sharks, have a pressure-detection and electroreception senses. Their sensorium is far more powerful than a baseline human's, and indeed can outmatch some superiors'.
Sharks have no organs dedicated to making sound, and requiem prefer to remain silent if they can. Instead, they tend to communicate either with body language (moving the mouth, fins, tail and handtech) or by twitching to create pressure waves that can be picked up by their interlocutor's lateral line. Some clades have been augmented with electrogenic organs, and communicate using electroreception.
Requiem are powerful and agile swimmers, and can reach speeds of up to 30km/h, though they usually prefer a more leisurely 5-10km/h.
Lifespan and Reproduction
Requiem have considerably extended lifespans compared to baseline lemon sharks. They reach sexual maturity after around eight years, but continue growing for another twenty years. The natural lifespan is around 60 years, though most Requiem take advantage of longevity technology.
Mating generally follows a short period of courtship, after which the mating partners will rarely see one another. Females can retain spermatozoa for several years, and are able to ovulate voluntarily.
Requiem are viviparous. The female gives birth to between two and six pups ten months after conception in shallow nursery waters. In baseline lemon sharks, pups form friendships among themselves. This trait is carried over, and puphood friends form some of the strongest bods in requiem society. The pups are entirely independent after birth, and most Requiem have adopted a system where the pups are educated in the nursery by automated bots.
Requiem are most comfortable in tropical marine environments, with a water temperature of 20-30 degrees Celsius, and can tolerate a broad range of salinities.
The efficiency of their gills has been increased to keep up with the higher oxygen requirements of the brain. Even so, Requiem need highly oxygenated water, and often take oxygen supplements when venturing away from these regions.
Psychology and Society
Requiem are highly practical beings. Facts and realities take precedence over abstractions and ideals. They are highly detail orientated - when something is under scrutiny, even the most trivial detail is unlikely to go overlooked. Conversely, they are less likely to notice the big picture. This is not to say they have trouble with abstract thought, but they are unlikely to take an interest unless a practical application is immediately obvious. Similarly, Requiem are in touch with their senses to a degree few other modosophonts can match. There is very little can come into a requiem's sensorium and go unnoticed.
Requiem tactical and strategic abilities are extremely high. Great reserves of patience and the ability to plan ahead and prepare for contingencies makes a requiem a formidable opponent. Despite such thorough planning, a Requiem may also avoid a consistent strategy and make completely spontaneous actions during conflict to throw their opponent off-guard.
Requiem leisure actives often reflect this strength. Chess-variants are always popular, as are strategy sims, escape puzzles, competitive sports and competitive hunting (usually of bots, though some Requiem in the outer volumes have been known to hunt sophonts). Such competitions may be turned into tournaments attracting thousands, or even, over the local net, millions of spectators.
Lemon sharks are social, and this trait is carried over to the requiem. They are comfortable working together in large groups, and team games are common in their recreation. At the same time, they are not as social as humans, and from this perspective they seem to exhibit a strong individualistic streak, even among puphood friends. Amongst themselves, they rarely form tightly-knit organisations, and where they are subjected to external governments rarely participate in politics so long as they are left in relative peace. They make good singleship pilots, and sometimes chose the Indexdep lifestyle.
Social behaviour is characterised more by dominance assertion more than warmth or affection. This can manifest in the form of challenges and duels, or wit and mockery — many who with requiem have noted their sharp tongues.
Relations With Other Clades
It is a common misconception that requiem have a long running feud with enhanced dolphins. In fact, the clades are not particularly antagonistic towards each other, and are quite capable of living and working together when they share a habitat.
The relationship with acties is rather more tenuous. Beneath the veneer of provolution and civilisation, the two clades are still aware of the predator-prey relation. The two are capable of living in the same habitat, but often choose separate niches. On the more positive end of the scale, some Utopia Sphere worlds are known to host requiem and acties living in doe-eyed harmony; on the other, requiem in the outer volumes may actively hunt acties for both food and sport.
Aruan make better associates. They share a predator's outlook and competitive streak with requiem. Shared tournaments and competitions (usually with appropriate rules to ensure balance) are common, and many requiem can't help but respect the strategic prowess of such small, prey-like creatures.
Requiem get along surprisingly well with Mawas. They don't trouble one another with the gossip and neediness that characterise other primates, and both can respect the other's practical intelligence. They can often be found working together in the Outer Volumes. Strong Mawas-Requiem friendships are common, though they can appear remarkably distant from a human perspective. On the other, when such friendships go sour both, they can turn into extraordinarily bitter and protracted feuds. The longest such incident on record lasted a little over a century and ended with the temporary death of several hundred sophonts in the explosion of a conversion-drive vessel in the outer reaches of the Disarchy. When the local Power revived the Requiem and Mawas at fault, e stripped their emotional connections to one another and inserted in them a desire to seek the Inner Sphere (by very different routes).
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.