What is the uses of tentacle in hydra

Tentacles of the Hydra are the extension of the body layer that encircles the opening of the mouth, the construction of Hydra is a simple body column and highly extensible tentacles, Hydra uses these tentacles for capturing or hunting the prey.

Hydra tentacles contain barbed, poison containing cnidocytes that they use to stun animals like the water flea, Daphnia, before eating them alive, and to protect themselves from attack by other animals.

i think its white blood cells

i hope this