Vein that drains the vascular plexus of the midgut and hindgut. At early stages the subintestinal vein (SIV) drains into the PCV and the CCV. At later stages the SIV drains into the hepatic sinusoid. The SIV are begin as paired veins. After 4dpf the remains of the left SIV forms separate segments that empty into the right SIV and eventually merge with the right. At 3dpf the rostral end of left SIV begins to form the reticular hepatic sinusoids. The portion of the left SIV caudal to the hepatic sinusoid forms the hepatic portal vein. [ http://zfin.org/ZDB-PUB-010205-5 ORCiD:0000-0002-2244-7917 GOC:cvs ]