Epoch
Epoch, Epocha singular, (Eorcha baschx) live in the Bathypelagic zone of Zone 2, but may go into the Abyssopelagic zone for feeding or mating. These muscals get their name from the period of time they seemed absent.
Males are 3 feet tall by 6 feet long weighing around 90kg, meanwhile, females are 5 feet tall and 10.5 feet long weighing around 170kg. Both males and females are a murky brown color with a black dorsal fin and two pairs of white lateral fins, one located at the base of their neck and the other located at the base of their tail. The tail is fluked for swimming. They have a combined excretory and genitale hole and do internal fertilization. They have flat scales all over the body except on the neck, base of the tail, and front appendages where instead they have specialized feather-like scales.
The feather-like scales are thin and vaned with branching barbs. Epoch have glands beneath the feathers that produce a type of BoNT, or Botulinum toxin that is released into the feathers. This toxin causes paralysis in creatures that ingest the feathers to protect them from predators. The feathered front pair of appendages are small and do not provide much propulsion for swimming and primarily serve as extra surface area for the toxic feathers. The rear pair of fin-like appendages are larger and provide more propulsion for swimming.
They have auditory nerves to hear, a pair of spherical lensed eyes on the side of their head, and olfactory openings near the top of their head that lead to a nasal sac filled with olfactory receptors. They have decent eyesight being able to see about 10 to 15 feet clearly, most cannot see in much color due to a low variety of cone cells.
Epoch have a heart, a closed circulatory system, a stomach, intestines, a pharynx, a liver, a spleen, and a pancreas. They have a swim bladder to allow them to control their buoyancy, though to survive the pressure of the Abyssopelagic zone the swim bladder can collapse.
They have a spongy endoskeleton with a skull that holds their brain and supports their eyes, mouth, and olfactory openings. They have a dorsal support chord that thickens in the tail and a ribcage along their abdomen protecting their vital organs. Their appendages have thinner bones as a result of their slow movement and less need for strong support in the appendages.
Epoch are omnivorous, feeding on muscals and polyphs. They will target prey larger than themselves and will often hunt each other. They hunt by approaching prey from behind and stabbing the prey with their sharp tubular proboscis. They also attempt to hit prey with their tail to stun it making it easier to stab with their proboscis. Smaller prey items can be swallowed whole. They will also feed on sunken corpses.
Epoch live up to about 30 years. They start as 10cm hatchlings and it will take 8 years for the juveniles to reach adulthood. The hatchlings and juveniles are primarily predatory but will shift to a primarily herbivorous diet as adults due to the extending of the gut. Epoch are solitary unless hunting or gathering for breeding season. Epoch will often fight each other when encountered.
Epoch breed every 4 years. Each breeding season starts with 20 to 50 males gathering and making a large pit about 100 to 120 feet long in diameter and 100 feet deep, then they will call to attract females and even more males causing larger breeding frenzies. During the frenzy females will begin acting very cannibalistic, eating males and sometimes other females. Afterwards they will continue to eat males but will avoid other females. The females will remain at the pit until they are ready to lay eggs. They will produce an adhesive substance to cover their 200-300 eggs with substrate leaving after laying their eggs. After 4 months the eggs will start hatching en masse, hatchlings will not eat for the first 3 days after hatching still having some egg yolk to rely on. After they metabolize the remaining yolk they will begin to cannibalize other hatchlings for the next two weeks after which they will leave the pit.