Fukaboshi

Fukaboshi is a shark merman and also the first son of the royal Neptune family on Fishman Island.

Appearance
He is a muscular merman with a round torso and a polka dot tail with a dark garment around his waist and a sash. He has long wavy hair, and always seems serious. He carries a trident with him.

Personality
He appears to be protective of his country, as he himself went to look for the crew who had entered the island illegally instead of just sending his guards. He has a very serious demeanor, but is also polite, as he apologized for bothering the mermaids when he was about to leave the cove. He also seems knowledgeable of at least Luffy's abilities, as he was not surprised when he used Haki on a sea monster.

Abilities and Powers
As the first son, he is by tradition the next one in line to take the thrown should the current king die or otherwise abdicate his duties. As a prince, he has some authority in the country. He carries a trident, and is presumably efficient at using it. Hammond refered to Fukaboshi and his brothers as the three strongest in the Neptune Army, implying he has great physical strength.

History
He first appears in Mermaid Cove with his brothers Ryuuboshi and Manboshi, looking for Luffy and his crew because of their illegal entry. The mermaids deny seeing any intruders. As Fukaboshi and his brothers are leaving, Sanji suffers a massive nosebleed resulting in critical blood lost. Luffy, Usopp, and Chopper then reveal themselves to Fukaboshi, begging anyone for a blood donation to save Sanji's life. Hammond and his group appear and attempt to capture the four Strawhats. Fukaboshi witnesses Luffy's strength as the Strawhat captain punches the New Fishman Pirates and stops their sea monster with Haki. He remains in Mermaid Cove after Keimi stole the gondola he was riding on to help Sanji, Luffy, Usopp, and Chopper escape. After the Strawhats left, Fukaboshi questions the mermaids on why they were hiding the Strawhats and reveals that he was about to give them a message from Jinbe.

Trivia

 * Though his species is not directly related to the sawtooth shark (the sawtooth is not actually a type of shark but is still rated to sharks and rays) fishman that Arlong is, he is nonetheless related by species to Arlong.