title: The circulatory system in Mysidacea--implications for the phylogenetic position of Lophogastrida and Mysida (Malacostraca, Crustacea).
abstract: The morphology of the circulatory organs in Mysida and Lophogastrida (traditionally combined as Mysidacea) is revisited investigating species so far unstudied. In addition to classical morphological methods, a newly developed combination of corrosion casting with micro computer tomography (MicroCT) and computer aided 3D reconstructions is used. Lophogastrida and Mysida show a highly developed arterial system. The tubular heart extends through the greater part of the thorax and is connected with the ventral vessel via an unpaired descending artery. It is suggested that a distinct ostia pattern supports the monophyly of Mysidacea. The cardiac artery system is more complex in Lophogastrida than in Mysida, consisting of up to 10 pairs of arteries that supply the viscera. In both taxa, an anterior and posterior aorta leads off the heart. In the anterior part of the cephalothorax the anterior aorta forms dilations into which muscles are internalized; these structures are called myoarterial formations. One of these myoarterial formations can also be found in all the other peracarid taxa but not in other Malacostraca.
authors.affiliation: Institut für Spezielle Zoologie und Evolutionsbiologie, Friedrich-Schiller-Universität Jena, Erbertstr. 1, 07743 Jena, Germany. christian.wirkner@web.de
authors.forename: Christian S
authors.initials: CS
authors.lastname: Wirkner
authors.forename: Stefan
authors.initials: S
authors.lastname: Richter
mesh_terms: D000818:Animals; D001775:Blood Circulation / Q000502:physiology*; D002319:Cardiovascular System / Q000033:anatomy & histology* / Q000648:ultrastructure; D016319:Corrosion Casting; D003445:Crustacea / Q000033:anatomy & histology* / Q000145:classification* / Q000502:physiology / Q000648:ultrastructure; D006458:Hemolymph / Q000502:physiology; D010802:Phylogeny; D013909:Thorax / Q000648:ultrastructure