One verse

Srimad Bhagavatam 9.16.37

9.16.37

एवं कौशिकगोत्रं तु विश्वामित्रै: पृथग्विधम् । प्रवरान्तरमापन्नं तद्धि चैवं प्रकल्पितम् ॥ ३७ ॥

evam kausika-gotram tu visvamitraih prthag-vidham pravarantaram apannam tad dhi caivam prakalpitam

evam
in this way (some sons having been cursed and some blessed)
kausika-gotram
the dynasty of Kausika
tu
indeed
visvamitraih
by the sons of Visvamitra
prthak-vidham
in different varieties
pravara-antaram
differences between one another
apannam
obtained
tat
that
hi
indeed
ca
also
evam
thus
prakalpitam
ascertained.

Visvamitra cursed some of his sons and blessed the others, and he also adopted a son. Thus there were varieties in the Kausika dynasty, but among all the sons, Devarata was considered the eldest.