Sentence:  Like Pisces and Capricorn, Aquarius is located in that part of the sky known as "Astral Sea," a region inhabited by water <WSD>asterisms</WSD> such as Eridanus, Cetus (the Whale), and the Dolphin. 
Meaning of the word marked with <WSD> tags:  An unofficial constellation (small group of stars that forms a visible pattern).