All of us know that there are Seven Rishis mentioned in our Puranas, viz. Gautama, Bhardwaja, Vishwamitra, Jamadagni, Vasistha, Kashyapa and Atri. Brahmin communities are said to be descendants of these 8 Rishis. Gotra hereditary was streamlined for the purposes of identifying one's ancestors and pay respects during various occasions such as rituals, etc their fathers, fore-fathers and so on, up to their respective Rishis. Subsequently it was extended to other areas such as Marriage and temple worship during Archana etc. Generally Marriage is not performed within the same Gotra. The details very
exhaustive. One may have to go through with patience. The site is mentioned the next thread hereunder:
Some say during Abivandanam : Aangirasa, Bharhaspathya, Bharatwaja, Thrayarsheya, pravaranvitha, etc.
Vashishta - 13 sub lineage Rishis. As per this, Kaundinya - Vaashista, Maithravaruna, Kaundinya, Thrayarsheya. For Maithravaruna. it starts like Vaashista and Maithravaruna and Kaundinya.
Vashishta ( 13 sub lineage Rishis)
01 Kaundinya
Vaasishta, MaithravaruNa, Kaundinya -
Thrayarsheya
02 Parasara
Vaasishta, saakthya, Paarasarya -
Thrayarsheya
03 Vaasishta
Vaasishta, MaithravaruNa, Kaundinya -
Thrayarsheya
04 Vasishta Vaasishta - Ekarsheya
05 Haritha Vaasishta - Ekarsheya
06 Aachvalaayana
Vaasishta, Aindrapramatha,
Aabarathvasasya - Thrayarsheya
07 Upamanyu
Vaasishta, Aindrapramatha,
Aabarathvasasya - Thrayarsheya
08 KaaNva
Vaasishta, Aindrapramatha,
Aabarathvasasya - Thrayarsheya
09 JaadhookarNya
Vaasishta, Aindrapramatha,
Aabarathvasasya - Thrayarsheya
10 Bhodayana
Vaasishta, Aathreya, JaadhookarNya -
Thrayarsheya
11 MithraavaruNa
Vaasishta, MaithravaruNa, Kaundinya -
Thrayarsheya
12 Mauthgala
Vaasishta, MaithravaruNa, Kaundinya -
Thrayarsheya
13 Vaasida
Vaasishta, Aindrapramatha,
Aaabarathvasasya - Thrayarsheya