One of the bilateral pairs of vessels clearly seen on the ventral surface of the head, running between the heart and the tip of the jaw, and draining the filter apparatus. This vein is more developed by NF stage 45, when it crosses the head dorsolaterally to drain into the Duct of Cuvier and pronephric sinus. [ http://www.ncbi.nlm.nih.gov/pubmed/12606281 ]

Synonyms: external jugular

This is just here as a test because I lose it