A Review of the “Open” and “Closed” Circulatory Systems: New Terminology for Complex Invertebrate Circulatory Systems in Light of Current Findings
Figure 5
The cardiovascular system of decapod crustaceans is highly
developed with a globular heart capable of delivering hemolymph at relatively
high pressures and flows into capillary-like vessels supplying metabolically
active tissues. This distribution system is dramatically illustrated (a) in
a corrosion cast of the blue crab’s circulatory system. The complexity of the decapod crustacean
vasculature is seen in a corrosion cast of the antennal gland ((b) from McGaw
and Reiber [26]) and a highly magnified image of the capillary like vessels
serving this structure (d) (CCA—coelomosac
artery) [27]. A transmission electron micrograph of
a cross-section through the gills also clearly shows well-defined hemolymph
channels that maximize branchial exchange ((c) from McGaw and Reiber [26]) (CH—chitinous exchange surface of lamellae; HC—hemolymph
channels; PC—pillar cells).