eel

After adding all the live rock and 3 days later my Nitrates start spiking up waiting for it all to cool down no fish in it just live rock and sand

Really bad picture of unidentified eel, first sighting in over 5 months! What is it and is it eating my fish?

I bought two of these eels a couple of days back, and I was wondering what species they are, as the shop assistant told me they will eat the red mosquito larve, although when i have given food, they have not been eating. Would anyone be able to identify this species and give me any advice?