The acuatic spitits: The Oceanids, The Nereid, The Tritons, The Naiads. Also the 12 Olympians (being one of them and 5 of them where his siblings)
the function of Poseidons temple was for Poseidons honor.
Rhea.
cronus
Cronus and Rhea
Triton
Neptune
Rhea.
a trident
He doesn't had friends
In myths, he does not have one.
you don't
Give it back to Poseidon.