Mermaids:

Somewhere, in the warm, tropical waters of the Inner Sea, lies the underwater Kingdom of the Mer. While many, adventurers, explorers, scholars and slavers, have searched for the mythical place, thus far, it remains lost to the surface world. None the less, the beautiful mermaids can often be seen, in clear water swimming through the deep and occasionally venturing to the surface, to investigate passing ships. This often proves to be a bad idea for them as some of those ships prove to be specialized slaving ships, with nets ready to be cast in an instant and holds with water tanks to store their catch of mermaids until the ship reaches port and they can begin the long, difficult process of transporting the sea maidens over land to the slave fair. 

There, the mermaids will fetch a fabulous price, given their rarity and the difficulties in their procurement. Many wealthy nobles seek exotic slaves to show off their wealth and taste and there is nothing more exotic then a mermaid or two. Many have also found mermaids to be very fine singers, with hauntingly beautiful voices. The Sultan of Omri has in his palace a salt-water pool, complete with islands in the center where he can row out and listen to his choir of mermaids sing.

For those looking to purchase a mermaid of their own, I recommend Old Salt’s establishment. They are a consortium of several mermaid-fishing companies and always have a good catch each summer. They will even offer some sorcerous help in transporting your purchase to whatever body of water you plan to keep her in.