The quat smoolk has developed a mutualistic symbiosis with the terraton. Terratons eat quat smoolks and disperse the smoolk's spores in their metallic pellets. Though the spores are naturally resilient, for added protection they are stored within capsules of pectin, which is tougher than the surrounding smoolkflesh. Quat smoolks' development of internal spore capsules prevents them from spreading their spores to the wind. Though this makes them dependent on terratons for propagation, at the time the quat smoolk evolved it is quite sensible. The other option, airborne spores, is less viable in a weak atmosphere.
Quat smoolks' spikes help terratons locate them. As terratons are eyeless, they do not exactly see the spikes. Rather, their thermal vision detects the slight temperature difference in the shade created by the spikes.
Though quat smoolks have an orange color and fulfill a fruit-like function, they are not named after Earth kumquats for these reasons. They are called quat smoolks after the 'Margarita' variety of kumquats, which are unique in having edible rinds. Thus, they can be eaten whole, just as terratons eat quat smoolks whole. Despite their similarities, quat smoolks taste nothing like kumquats. For lack of a better comparison, they taste like raw button mushrooms, blueberries, and green apples. The green apple part can be explained by its residual slight toxicity, which tastes sour. (to the human tongue, anyway)
Quat smoolks specialize in iron oxide found in sand or sandstone.