Not much is known about the Aqua Herds other than that they are split into two: the "real" Aqua Herds, which includes the mythical hippocampi (half horse, half sea creature), and the "substitute" Aqua Herds, which consists of water loving horses.
Ocean Herd: This is one of the "real" herds, which means that next to nothing is known about it.
Alphas: accepting two
Deputies: accepting two
Healers: accepting two
Fighters: accepting
Apprentices: accepting
Broodmares: accepting
Studs: accepting
Elders: accepting
Brook Herd: This is a "substitute" herd. More is known about it, including that they have changeable personalities and are friendly and energetic. They are also quite calm and level-headed.
Alphas: accepting two
Deputies: accepting two
Healers: accepting two
Fighters: accepting
Apprentices: accepting
Broodmares: accepting
Studs: accepting
Elders: accepting