What is the next sign of Pisces?

Aries. The date of birth of Pisces is 19 from February to March 20th, while the date of birth of Aries is from March 2nd to April 9th, after the date of birth of Pisces. So the constellation behind Pisces is Aries, which is located in the first house of the zodiac, to the east of Pisces and to the west of Taurus.