Each zodiacal Sign represents one caste.

Pisces Aries Taurus Gemini
Aquarius     Cancer
Capricorn     Leo
Sagittarius Scorpio Libra Virgo

Brahmin Kshatriya Vaishya Shudra
Shudra     Brahmin
Vaishya     Kshatriya
Kshatriya Brahmin Shudra Vaishya

To find out why see notes on Zodiac. The caste sequence repeats 3 times. The lion is Kshatriya and the pisces fishes is Brahmin. This is how the animals have been selected by Indian sages thousands of years ago.

For predictions the castes indicate properties. If Cancer is my house of occupation [10th], then my job involves teaching, training or other skilled jobs.