The sage Meru had two daughters, named Āyati and Niyati, whom he gave in charity to Dhātā and Vidhātā. Āyati and Niyati gave birth to two sons, Mṛkaṇḍa and Prāṇa.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
आयतिं नियतिं चैव सुते मेरुस्तयोरदात् । ताभ्यां तयोरभवतां मृकण्डः प्राण एव च
āyatiṃ niyatiṃ caiva sute merustayoradāt | tābhyāṃ tayorabhavatāṃ mṛkaṇḍaḥ prāṇa eva ca
SB 4.1.44