Xenonoid in its cave
Homeworld of the Xenonoids
arantius-alpha 8-prime
The eighth planet orbiting the orange star Arantius-alpha is a small frozen
world. Its surface is layered in ices of water and methane. However, it is far
from barren. The ice is stained with great swathes of green photosynthetic
broken by sutures between ice plates, which are punctuated by geysers that
spew forth xenon and nitrogen gases and cryovolcanoes that erupt plumes of
aqueous and hydrocarbon mixtures that freeze into particles of ice.

Some twenty kilometres beneath this ice sheet is a rocky surface, but one
which is perforated with openings to subterranean caves that form an
extensive network within the planet's porous inner crust. Deep within these
caves flow rivers of water with an overhanging subterranean atmosphere
primarily of xenon and nitrogen, with some oxygen, argon and other noble
gases. Here there is another peculiar kind of life. In some caves the water,
actually a solution of xenic acid, is coated with floating spherules that
coalesce and slime together, shape-shifting as they pulsate. These slimy
spherules exist in a multitude of hues and vary in size, but average some 15
cm in diameter and reproduce by binary fission. These are the Xenonoids.
Each of these spherules is a giant cell. These cells respire using xenic acid, a powerful oxidising agent, in place of elemental oxygen. The xenic
acid is produced in turn by other organisms that live far beneath in the deepest caves. These primary producers use the heat generated by the
planet's intensely radioactive core to synthesise organic materials from raw elements that gush from subterranean volcanic vents. Oxygen is a
toxic byproduct of the metabolism of these organisms, and so they enzymatically convert the oxygen into xenon trioxide, which dissolves in the
surrounding water to form xenic acid which is safely excreted and carried away by the rising thermal streams where it reaches the Xenonoids far

Xenonoids are curious creatures. For much of their lives they form the ponds, or brood pools, of floating spherules, already described, but
periodically a number of these cells fuse into a syncitium which is able to float above the waters by regulating the content of gas vacuoles.
These amorphous shape-shifting protoplasmic masses can move by forming transient limbs that pull them through the caves as they graze the
bioluminescent biofilms that coat these caves in great swathes and which they cultivate in special caverns. They periodically shed propagules  
in the form of spheres that either float upwards or sink back into the waters beneath. In addition to these asexual means of reproduction, two
spherules of compatible types can fuse and produce genetically novel offspring by binary fission and coalescence.
The coalesced locomotive forms represent the mature stage in the
life-cycle. The vary in size, but most consist of about 400 cells and one
cubic metre in initial volume, but swelling to 3 or 4 times this volume
after synthesis of gas vacuoles and later growth. Each possesses 1 to
3 special cells that function as eyes. These beings have considerable
powers of regeneration with all parts being replaceable from a single
fragment. Fragments can also fuse together again.

Of particular note is the nervous system of Xenonoids. Each giant cell
has its own control system consisting of a network of microscopic
protein filaments that transmit laser-like pulses of coherent
electromagnetic energy. When two or more cells fuse, to form a
continuous syncitium, their control systems connect together and about
of a mature individual. Memories may be distributed among the cells
and if a n individual regenerates from a single cell, then it will retain
some of its original memories. Some memories can be inherited also
through the propagules. As a result. Xenonoids possess a complex
racial memory. Individuals are extremely long-lived and are capable of
replacing worn out cells from the brood pools. Some individuals chose
to end their individual existence by splitting up into their individual cells
and returning to the brood pools. New individuals emerging from the
pools may then incorporate some of their predecessor's memories.
sexual reproduction is now extremely rare as the whole planet has
become populated by a few dominant individual clones. Genetic integrity
is now maintained by artificial means. The Xenonoids have evolved into a
highly technological race. Communication is primarily by means of
complex bioluminescent displays, although sounds can be formed by the
release of gas from specialised gas vacuoles.

Though not overtly hostile, Xenonoids have little apparent empathy for
other races. The xenon gas released by the normal metabolism of these
organisms can have an anaesthetising effect on humans.