The azygos veins of the Weddell seal, Leptonychotes weddelli (Lesson)

• Published in: Canadian Journal of Zoology
• Main Authors: Watson, A. G., Dowd, David A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1972
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Weddell; Leptonychotes weddelli; Weddell Seal
• Online Access: http://dx.doi.org/10.1139/z72-208; http://www.nrcresearchpress.com/doi/pdf/10.1139/z72-208

The azygos venous system of one Weddell seal (Leptonychotes weddelli) has been described. Both left and right azygos trunks were present with segmental anastomoses between them. The right azygos trunk was the larger and opened into the anterior vena cava; the left azygos trunk terminated in the left costocervical vein. At each segmental level the azygos trunks communicated with collecting sinuses into which drained blood from intercostal spaces and the extradural intravertebral vein. These collecting sinuses were themselves connected to each other by longitudinal anastomoses. The relationship of this system to blood flow during diving is briefly discussed.