Spectral Cave Dragon

Beneath the boggy landscape of south-central Serinarcta 280 million years PE, there lies a hidden habitat below the ground. A large network of subsurface caves, first formed as coal seams burned and left large hollow pockets in surrounding rock at the end of the ice age, and expanded by the piecemeal excavation of soil particles over millions of years by cementrees, lie hidden below the landscape. Most are now flooded - though many contain large pockets of trapped air. And where there is water, there can be life. Some animals only venture down into the darkness in brief forays. For others, this is the only home they know.

The Serinarctan caves frequently open up into shallow surface ponds through sinkholes where the ground has given way and collapsed without sufficient support. Freshwater fish and invertebrates easily wash down into the ground, and many specialized troglodytes now exist here. The longer species spend in the darkness of the system, the more their bodies change; many long-time resident fish, shrimp, and insects are pale and unpigmented, and blind. Though no plants can grow in this pitch-black, claustrophobic environment these caves are fed by nutrient-laden water regularly washed down from the soglands above and so are unusually productive, supporting not only small fish and bugs, but larger predators in a several-tiered food chain. 

The cave dragons are the largest full-time cave specialists in the Serinarctan caves. Growing to seven feet long, but thin and serpentine, these eelsnakes are descendants of the migratory sea dragon which swam down into the caves 7 million years ago, seeking prey. Two subpopulations now exist; to the west can be found one fully pigmented and with large eyes, which leaves the caves occasionally at night and migrates through surface waters or even crawls overland to new territory. This is the more primitive form. Less widespread, a slightly smaller, nearly-albino variant with almost no skin pigment occurs in just two south-eastern cave systems. These dragons have eyes only one-third the size of their cousins and almost never leave their subterranean habitat. Their barbels are long and highly sensitive to motion in the water, as is their lateral line; hunting in a world without sunlight, they prey on anything they can catch, but especially slow-moving bottom-dwelling fishes and crayfish. Their metabolisms are slow, allowing them to rest and fast for months, sometimes years between large meals when necessary, yet they are highly responsive to the scents and movements of potential prey and can rise to activity quickly when necessary.

Deep sinkholes, hidden in the muddy bottoms of surface ponds otherwise just a few feet deep, are hazardous to large land animals that step into them. Large thorngrazers are denser than water and cannot really swim; if they fall into such natural traps they are likely to sink below ground to their deaths. These large carcasses, as they wash down into the caves, are windfalls to its native life much like the fall of a whale in Earth's deep sea. All cave creatures converge from hundreds of feet in every direction and soon the corpse writhes with strange worms, crustaceans, and fishes. At the front of the line come the cave dragons, highly mobile and with the strongest jaws of anything below ground to open the body cavity and so allow other smaller animals to feed. They bore into the flesh like huge pink earthworms, seeking out the organs first. They can eat more than twice their fasting body weight in a few hours - enough to last them the next 18 months, if nothing else falls down again before that time. Females bear young infrequently and only after huge meals like this; a couple dozen young, each about six inches long, are produced after a year-long gestation as rarely as once a decade. They are small and vulnerable, especially to other, cannibalistic adults which they instinctively avoid, hiding below rocks and crannies too narrow for them to access. Yet if they can grow to their adult size - a process taking up to 25 years in low-food caves or just 5 years in highly productive ones - thanks to their slow metabolic rates, they have life expectancies of some 250 years.