Passage: The Ganga is also the mother, the Ganga Mata (Mata="mother") of Hindu worship and culture, accepting all and forgiving all. Unlike other goddesses, she has no destructive or fearsome aspect, destructive though she might be as a river in nature. She is also a mother to other gods. She accepts Shiva's incandescent seed from the fire-god Agni, which is too hot for this world, and cools it in her waters. This union produces Skanda, or Kartikeya, the god of war. In the Mahabharata, she is the wife of Shantanu, and the mother of heroic warrior-patriarch, Bhishma. When Bhishma is mortally wounded in battle, Ganga comes out of the water in human form and weeps uncontrollably over his body. It is also to be noted that Bhishma brought about his own downfall by abducting and disgracing a princess named Amba whose only wish was to be married.The Ganga is the distilled lifeblood of the Hindu tradition, of its divinities, holy books, and enlightenment. As such, her worship does not require the usual rites of invocation (avahana) at the beginning and dismissal (visarjana) at the end, required in the worship of other gods. Her divinity is immediate and everlasting, but only for as long as the river survives.

Question: What does her religion not require?
usual rites of invocation (avahana)