Hey Man its not possible to identify the nematodes without looking it into Compound microscope. but some attributes suggest that these are mesorhabditis. as the gut appears black in extract
Virtually impossible to identify nematode from your pic. Moreover, many free living nematode species are morphologically conserved. So my suggestion, grow a single nematode on an E. coli plate, hopefully it will reproduce if hermaphrodite, isolate DNA and amplify ITS region, sequence it then BLAST it. You will get to know which nematode you have in hand.
it will be better if you take pictures focussing on the lip region, stoma, pharyngeal region, gonad, etc. identification is not possible in the picture you have given as nothing is clearly visible.
What strain of E.coli did you use? You could look into OP50 that has been made available by researchers and LabTIE https://www.labtie.com/c-elegans-nutrition/31772-op50-c-elegans-nutrition-1-25-gram