Perhaps the most recognized seahorse of all, the logo of Tatsunoko Productions Co. Ltd.
This anime giant was founded in 1963 by the Yoshida brothers: Tatsuo, Kenji, and Toyoharu.
Because Tatsuo was considered the most talented of the three, they agreed to call the studio "Tatsuo no co", which means "Tatsuo's Company".
Strangely enough, the name sounds like "tatsunoko", which is Japanese for "seahorse"...so that became the studio's name and logo.
Despite a slow start, they soon became famous for such shows as "Speed Racer", "Gatchaman/Battle of the Planets", and "Macross".
Of course, you'll recognize that it's one of their shows by that logo. The animation staff either shows it openly during the credits, or discretely during the scenes.
Hope you like it!

Digital fan art made with DeviantArt's "Muro" feature.