Each zodiacal Sign represents one caste.
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.