Undersea

Ongoing Serial: a series of episodes, published over a span of weeks/months/years where the story plot is connected from chapter to chapter and must be read in chronological order for it to be understood properly.
Chapter Serial: a series of episodes, published over a span of weeks/months/years where the story plot is self-contained to a single chapter. There may be an overarching plot, but the stories can generally be read in any order and be understood
Book: an all-in-one self contained story published as a one-off.
Supplement: an an all-in-one self contained story published as a stand-alone supplement to a regular weekly/monthly periodical.
Short Story: an all-in-one, self contained story that was published in a regular weekly/monthly periodical
Anthology: a collection of all-in-one, self contained stories that were published in a regular weekly/monthly periodical but are generally grouped together.

Poseidon

A tyrant who rules the undersea world with an iron fist, and leader of the Poseidon family. He fears the survival of the Tritons, so he intends to exterminate Triton and end his family line forever. To that end, he sends his 33 children - each more hideous than the last - to hunt them down.