Troglobite

As the biggest fish found on the Dan-nui underwater cave complex, the Skullfish is a true apex predator. A strong jaw, a keen sense of smell and a specialized sensory organ capable of detecting movement, chemical components and subtle electrical stimuli gives the Skullfish a huge advantage while hunting on the completely devoid of light waters it inhabits. Without any sign of vestigial eyes left anywhere, many argue it may never had them in the first place. Evolving early on to depend on other senses and specializing in living in darkness. Its presence is fundamental to the equilibrium of its ecosystem, for not only does it contribute with population control of other species, its constantly shedding skin also makes up for a big part of the zooplankton found on these lakes, which together with the scarce chemosynthesis based phytoplankton keep this whole delicate ecosystem alive.