As part of its ongoing efforts to promote every single Pokémon out there, The Pokémon Company has shared special content dedicated to Seadra:
Did you know? It’s the males that raise the offspring. While Seadra are raising young, the spines on their backs secrete thicker and stronger poison. Seadra’s mouth is slender, but its suction power is strong. In an instant, Seadra can suck in food that’s larger than the opening of its mouth.
Source: The Pokémon Company