Ferrofilament
The ferrofilament split from its ancestor when some Barlowe ferrumcarcers settled closer to the surface of the substrate. Here, they were more easily found and consumed by predators. The resulting predation resulted in the formation of filament-like colonies, which ultimately gave rise to the ferrofilament.
Ferrofilaments are most common in temperate waters, where there is enough resources for the ferrofilament to form colonies. In polar regions, the colony will break apart and reproduce sexually before the onset of winter, releasing hardy auxospores that will become new ferrofilaments when the spring comes. This occurs less often in temperate waters due to the milder climate. Ferrofilaments often congregate around large amounts of detritus, forming thin, thread-like colonies.