Bhagwad Gita chapter 10
आयुधानामहं वज्रं धेनूनामस्मि कामधुक् |
प्रजनश्चास्मि कन्दर्प: सर्पाणामस्मि वासुकि:।।28।।I am the Vajra (thunderbolt) amongst weapons and Kamadhenu amongst the cows. I am Kaamdev, the god of love, amongst all causes for procreation; amongst serpents I am Vasuki.
अनन्तश्चास्मि नागानां वरुणो यादसामहम् | पितृणामर्यमा चास्मि यम: संयमतामहम् || 29||
Amongst the snakes I am Anant(sheshanag); amongst aquatics I am Varun. Amongst the departed ancestors I am Aryama; amongst dispensers of law I am Yamraj, the lord of death.
In one verse, Lord is saying that I am vasuki among snakes and in very next verse he is saying that I am shesha. Is it a contradiction or my misunderstanding?
EDIT: "nagas and sarpas are different" does not seem to be a satisfactory answer because Ananta and Vasuki are brothers (born from same parents). Is it being suggested that out of 2 brothers, one became naga and another became sarpa and both brothers belong to different classes of beings? There is no clarity on this. Moreover, if someone reads the answer given in the link, it classifies Vasuki as a naaga and not a sarpa. Therefore, I am voting to reopen the question.