These videos are of organisms found in sludge water taken from the Baylands near Stanford. The water was teeming with life, including this roundworm. At first, we identified it as a polychaete, a type of annelid worm. However, upon further inspection, we have concluded that it is most likely a nematode.
Annelids tend to have larger bodies than nematodes but without a comparison, we have to use other discrepancies to determine the type of worm. Nematodes like the one in the video have tapered ends are not segmented, unlike the untapered, segmented annelid.
It was really cool to see the life in the water, especially getting to see what I would guess was the same nematode twice!