"From the union of rumbling Poseidon and Amphitrite
came the great Triton, whose might is far-flung,
an awesome god dwelling in a golden house that lies
at the sea's bottom, near his cherished mother and lordly father."
Triton is often described as having the form of a merman. Although there were several variations of the merman shape in art and myth, the water god is most commonly depicted with a human torso that tapered into fish's tail (indeed, this distinctive form influenced art to the extent that the name Triton is synonymous with the word merman in some cases). See the Mythography gallery (link below) for images of Triton.
Two of the symbols associated with Triton are the conch shell and the trident. It is interesting to note that Triton takes after his father Poseidon in his choice of the trident as an attribute.
Triton in Art History
Gallery | For pictures and information about Triton in art, visit the Mythography gallery!
Who's Who in Classical Mythology