part of part of in taxon Deuterostomia organism substance circulatory system hemolymph GAID:1220 UBERON:0001011 MAT:0000054 FBbt:00005061 MESH:D006458 BTO:0000572 Wikipedia:Hemolymph haemolymph TGMA:0000000 MIAA:0000054 Blood analogue used by all arthropods and most mollusks that have an open circulatory system. In these animals there is no distinction between blood and interstitial fluid. The liquid fills all of the interior (the hemocoel) of the body and surrounds all cells.