Ref ID : 6640
Roberto Valvassori, Giulio Lanzavecchia, Magda de Eguileor, Annalisa Grimaldi, and Laura Colombo; Peripheral vascular apparatus in some aquatic oligochaetes with special references to haplotaxids. Hydrobiologia 334:241-249, 1996
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Notes
The organization of the peripheral vascular apparatus in two haplotaxids has been studied and compared with that of other microdriles. Considerable differences in the circulatory systems of Pelodrilus leruthi and Haplotaxis gordioides, especially in relationships to the body wall muscle fibers, separate and distinguish the two animals. Different organization of the peripheral apparatus that can be observed in these microdriles are: in the first species, capillary vessels have no contact with the body wall; in the second species, capillaries extend between the longitudinal muscle fibers until they reach the body surface, thus approaching the situation in megadriles where circulation can become intraepithelial. Generally, vessels hanging in the coelom are of a large diameter. When a capillary network related to the body wall muscle develops, vessels are small in diameter and their walls have variable numbers of contractile elements, ensuring the forced circulation of the blood.