Which sea goddess or sea god had a fishtail?

Question

I want to know which sea goddess or sea god had a fishtail.

Answer 1

GLAUKOS (or Glaucus) was a mortal fisherman who was transformed (via apotheosis) into a sea-god after eating a magical herb. Others, however described him as a marine born son of Nereus. He was described as a blue-skinned merman, with copper-green hair and a serpentine fish-tail in place of legs.
http://www.theoi.com/Pontios/Glaukos.html

Nereus was depicted in ancient Greek vase painting as an old man with a wooden staff accompanied by a host of his Nereid daughters. Sometimes he had a coiling fish tail in place of legs (like the image right). But unlike other similar gods, such as Triton and Akheloios, Nereus was almost always depicted clothed in a chiton.
http://www.theoi.com/Pontios/Nereus.html

Others and others.
As you see, it depends on the one who describes/paints them.

Answer 2

She's not a sea goddess, but Melusine is a river goddess / wellspring goddess who is often depicted in mermaid form.

In the language of heraldry, a melusine is specifically a two-tailed mermaid (think two legs but both of them fish tails.

Several legends / myths / fairy tales report Melusine as the founding mother of a noble or royal house in western middle Europe. One such specifies that the line of the Counts of Lusignan in Luxembourg derived from the marriage of their founder to Melusine.

Now, Poseidon, Greek god of the sea was father to the Nereids, the nymphs of the sea, often depicted as classic mermaids (upper body woman, lower body fish).

Answer 3

Zeus's brother POSEIDON, a river and sea god, was another important male Olympian (all the other male Olympians were sons of Zeus). Poseidon's weapon was the trident, and he was associated with horses as well. Like his brother, he courted the sea-nymph Thetis, a daughter of Nereus, a prophetic old man (or god) of the sea, often conflated with the shape-changing Proteus, another companion of Poseidon. Poseidon finally married another Nereid (there were 50), Amphitrite. Their children included the merman Triton. By mother Earth Poseidon was the parent of the monstrous Charybdis (or Kharybdis, a sea-monster who sucked in waters and spewed them out again--a kind of whirlpool. Poseidon's father in law Nereus was the son of mother Earth and an earlier sea god, PONTUS. Pontus and Ge's son Thaumas, was important mainly as the father of the winged women-monsters the Harpies and of Iris, the goddess of the rainbow and a messenger of the gods, particularly of Hera. Another brother of Nereus was the sea god god Phorcys (Phorkys), who was (with Hecate) the parent of Charypdis's companion in the straits of Messina, Scylla (or Skylla). Scylla did not start has an octopus-like monster with rapid dog heads on her tentacles, but Poseidon had been interested in her and a jealous Amphitrite turned her into a monster. Phorcys is also sometimes given as the father of the Sirens

Answer 4

Neptune

Answer 5

You need to read more.

"Atargatis, also known as Tirgata, Aphrodite, Derceto, Salacia, Pelagia, or Delphine..."

Answer 6

I think Poesidon..?..Or Neptune..?

Answer 7

all of them!!!its hard to swim all the time when you have legs!!!:Dlol

Answer 8

Ol' mr. barracuda man.