Review Article

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).
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