JOTOKI

 Art by Souhjiro, copyright © 2009

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Jotoki are non-humanoid sentient communal organisms that developed a space faring civilisation.
The Jotoki resemble large, spindly starfish. They are born as small aquatic swimmers, most of which are eaten by predators; in time, survivors will merge in groups of five to form one collective organism, which grows into an arboreal creature; its tails become arms, and its fins differentiate into fingers. When it grows large enough, the Jotok imprints itself on an adult and enters a stage of rapid learning and brain growth. A Jotok who desires a family can simply go into the wilderness and "harvest" an adolescent. Unimprinted adult Jotoki are considered feral, and regarded as little more than animals. Since the five subunits that make up one Jotok individual are not necessarily genetically related, reproduction does not require sex; a Jotok can simply find a pond and deposit its offspring to begin the cycle again.
The Jotoki were experts at trade. Their interstellar trade empire was quite developed for its time, but when the Jotoki attempted to use the Kzin as mercenaries, the Kzin revolted and conquered the Jotoki. Before their enslavement, Jotoki operated in groups called "clanpods", as part of their former planet-wide tradeweb. Details of this arrangement are not known. Jotok technological specialties included gravity polarizers, linguistics and biotechnology. They had the ability to force-grow clones to adulthood. The Kzinti believe that there is a free Jotoki fleet wandering amongst the stars, which would have provided their most strenuous opposition.
After the Man-Kzin Wars, humans recovered some Jotoki swimmers in an attempt to breed a free Jotok species.
Source: Larry Niven, Known Space Universe, (informations adapted from the Wikipedia entry), "The Asteroid Queen", by Jerry Pournelle and S.M. Stirling, "In The Hall of the Mountain King", by Jerry Pournelle and S.M. Stirling, "The Heroic Myth of Lieutenant Nora Argamentine", by Donald Kingsbury