There are 13: Capricornus, Aquarius, Pisces, Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpius, Sagittarius, and (the not so well known) Ophiuchus.
The "classical" zodiac consists of 12 constellations, most of them represent some animal (hence the name). According to the current definitions of constellations, however, the Sun goes through 13...
There are 12 zodiac constellations, althought some belive there are 13, but most people think there is only 12. If the project is not to Important put 12, same with important ones, but I WoulD...