Ashtavasus are ganadevas, who were born to Dharma and Vasu, the daughter of Daksha. Some scriptures also have a version that they were the children of Kashyapa.

Their names are Dhara, Dhruva, Soma, Ahas, Anila, Anala, Pratyusha, Prabhasa, as per Mahabharata Adiparva Chapter 65 verses 17,18. But as per Vishnupurana, Ansh 1 Chapter 15, their names are Apa, Dhruva, Soma, Dharma, Anila, Anala, Pratyusha, Prabhasa, and as per Bhagavata, they are Drona, Prana, Dhruva, Arka, Agni, Dosha, Vasu, Vibhavasu. According to Harivansha, they are Akha, Dhara, Dhruva, Soma, Anila, Anala, Pratyusha, Prabhasa. It is assumed that they are the same set known by several names.

Once, when they were traveling with their wives, they happened to reach Vasishta’s hermitage. One of the wives liked Vasishta’s cow Nandini, and to please her, her husband carried it away along with its calf. Later, ater failing to find the calf nearby, Vasishta used his divine vision to locate it. Having found out what had happened, he cursed that the vasus would be born as humans. The vasus apologised to Vasishta, who said that the seven vasus who weren’t guilty would spend a negligible time in human form, but Apa, who took the cow would definitely remain human for a very long time. As per Devibhagavata Dwitiyaskanda, it was Apa who was later born as Bhishma.

When the vasus were contemplating the curse, Ganga approached them. They requested her to take a human form, marry a king, become their mother when they took the human form, and throw them into the river as soon as they were born. Ganga agreed.

There was a Chandravanshi king named Pratipa. Once, while praying to Surya by the river, he saw a beautiful woman emerging from the river. She came and sat on his right thigh. He was distressed and asked her why she had done this, and whether she thought he lusted after women. He also said that the right thigh as meant for daughters or daughters-in-law. He told her that when he had a son, she could perhaps marry him. The woman, who was Ganga, disappeared on hearing this.

Later, Pratipa had a son named Shantanu, whom Ganga married. Before agreeing to marry him, Ganga had laid one condition – that he would not question any act of hers, and would not offer an opinion, and that if he did so, she would disappear. After their marriage, one by one, the vasus were born to them, and as per their agreement, she drowned seven of them, who went back to heaven. The king stopped her when she tried to drown the eighth, and a furious Ganga disappeared. This child was Bhishma, as per Devibhagavata Dwitiyaskanda.

When Bhishma fought Parashurama on account of Amba, the vasus, helped him by giving him the Praswapastra, as per Mahabharata Udyogaparva Chapter 183 verses 11-13.

The first vasu was Apa and his sons were Vaithanda, Shrama, Shanta, Dhwani. The second was Dhruva, whose son was Kala. The third was Soma, whose son was Varchas. Fourth was Dharma, whose wife was Manohari. Their children were Dravina, HutahavyavahanaShishira, Prana, Varuna. The fifth vasu was Anila who was married to Shiva. Their children were named Manojava and Avijnatagati. Sixth was Agni whose sons were Kumara, Shakha, Vishakha and Naigameya. Pratysha was the seventh vasu and his son was Devala. Varastri, who was Brihaspati’s sister and was famous for her travels and yogic prowess became the wife of Prabhasa, the eighth vasu. Their son was the famous prajapati Vishwakarma, who was a skilled artisan and possessed the knowledge of many arts and crafts. He went on to become the devas’ sculptor, goldsmith and architect, and even built their flying machines. He had four sons – Ajaikapat, Ahirbundhya, Twashta, Rudra. Twashta’s sons were Vishwarupa, Hara, Bahurupa, Tyambaka, Aparajita, Vrishakavi, Shambhu, kapardi, Raivata, Mrigavyadha, Garva, Kapali. They are called Ekadasha rudras, as per Vishnupurana Ansh 1 Chapter 15.