The Pacific blackdragon
is a deep sea fish
found to depths of 3,300 ft.
The females are typically two feet long
have fang-like teeth and a long chin whisker
which acts as a lure or simple bait.
They are black both outside and in
to prevent light escaping from
swallowed bio-luminescent prey.
The puny males are but three inches
brown in color
and have no teeth.
With no chin barbel and no stomach either
they are unable to eat
and only live long enough to mate.
regarding this lifecycle
have yet to evolve.