They didn't. :)
In myth it is not told.
His Trident.
maserati
Neptune can usually be seen holding a trident.
Poseidon's trident is one of his most iconic symbols.
Cadbury Adams introduced Trident gum under Cadbury Adams in the UK in 2007. Originally Trident was produced in 1960 by the American Chicle company.
According to the company, it was discontinued in 2013
His trident is his symbol. It also represents his power. The trident is what fisherman used to use to catch fish. So a trident was the perfect symbol for him because he is in control of the waters.
It varies with artistic depiction, it was not important in Greek myth to know such details as they were left to artists or imagination.
trident
The company with a black trident logo is Maserati, the Italian luxury vehicle manufacturer. The emblem symbolizes Neptune's trident, reflecting the brand's connection to the sea and its origins in Bologna, Italy. Maserati is known for its high-performance sports cars and elegant design.
You can visit the Trident website to see what research they already offer. Or look up Trident gum in academic food journals. You might be able to find out the history of the company, the history of gum, the positive and negative impacts of chewing Trident gum, whether the whitening product from Trident really works, etc.