Twilight Colony Crystal
For millions of years, the lack of sunlight impeded the expansion of colony crystals into the deep ocean. Now, a new species has managed to take hold in the dim depths. This species is the unimaginatively named twilight colony crystal.
With light being scarce in the twilight zone, the twilight colony crystal has adapted by relying more on decaying matter for food. Their crystals have become significantly smaller, and are mainly used for reproduction. Their mycelial network has changed as well. In order to conserve nutrients in the sparsely-populated twilight zone, the mycelial network has become smaller. It will also prioritize growing over biomass over growing over soil.
Twilight colony crystals have a short lifespan. They will consume anything it can grow on and digest within a 50-centimeter radius, reproduce, and then die. The spores will then drift through the water column until they land on some form of biomass.