Even Lesser Knightworm
A population of lesser knightworms extended southward, where they found the colony crystal giving way to southern colony crystals. As the southern colony crystal had a yearly life cycle, the lesser knightworm's new offshoot had to adapt their life cycle as well. They became the even lesser knightworm, further reduced in size as their short lives don't give as much time to grow.
Even lesser knightworms are bound to southern colony crystals for much of their lives. As the summer ends, the males bore nests into the mycelium. When a female finds a nest, she lays soft eggs inside, which the male fertilizes, and she leaves. After this expenditure of energy, she will often die soon as the winter sets in, but particularly hardy or rugged individuals occasionally survive into a second year by scavenging. Not so the males; they tend to their nests as winter comes until the crystal dies. At that point, he no longer needs to maintain the nest, for the mycelium is no longer regrowing. He then dies, and when spring comes, becomes the first meal for his newly hatched young. The young scatter to find new growing southern colony crystals and repeat the cycle.
Physically, the even lesser knightworm is little changed. Like other binucleid worms, they consist of a soft inner core with a segmented chitinous shell. They have four segments like their ancestor, but the hind segment is now much reduced; it serves solely to produce eggs or sperm, which are multicellular, providing a cell line for both the core and shell. The female also secretes additional mucus around her eggs after the male has fertilized them.
Though they specialize in southern colony crystals, they aren't averse to eating local photosagnians as well, which are easy meals but not as filling. As for southern colony crystals, they eat both the mycelium and the crystal parts. Their antennae have specialized so that one of them is focused on poking and boring, with a pointy end, while the other has a serrated edge for slicing and sawing through the crystals. This lets them get through the crystals to reach more mycelium, but it also lets them slice the crystals into tiny bits small enough to ingest. Individuals vary as to which one is the left antenna and which the right.