Kamisakana

Kamisakana(神魚, God fish), is the zanpakuto of Third Division third seat Katai Gachi, one of the only water-type zanpakuto heard of in the Soul Society. In its sealed form, it is seen as a wakizashi with a design on a circular guard that resembles the jaw of a shark. When in shikai form, the sword broadens considerably, turning a complete shade of blue often said that is akin to sapphire.