To send YOs, first you have to go to My Account, and click in your Fishland profile.

Inside your profile you must select a friend. While clicking on your friend you redirect to his profile page, here you must click on the link to Send YOs. While clicking will appear a list of available YOs , you must choose one and send it. The YOs will be available in your friends profile page.

Note: To send YOs, you and your friend must be on the friends list of eachother.