Morphology and Morphometry of the Magellanic Penguin (Spheniscus magellanicus) Trachea

Abstract

Objective: This work aimed to describe the trachea of the Magellanic Penguin (Spheniscus magellanicus) through descriptive and morphometric approaches. Methods: ten adult male Spheniscus magellanicus were used, which were collected, fixed, and kept immersed in an aqueous solution of 10% formaldehyde. Results: the trachea of the penguin began caudally from the cricoid cartilage of the larynx, represented by 121.3±5.65 cartilaginous rings joined together, which extended to the syrinx (19.75±0.70 cm). Considering its five segments (I-V), the number of tracheal rings decreased in a cranio-caudal direction. The medial tracheal septum, which started caudally from the cricoid cartilage of the larynx, was approximately 2±0.08 cm and was formed by approximately 6.75±0.25 rings. The dimensions of the lumen of the trachea decreased cranio-caudally, with a statistical difference between segment I and the others (II to V). The syrinx of the tracheobronchial type presented 7.52±0.65 rings. Conclusions: these data will contribute to the understanding of the anatomy of this species, as well as to the diagnosis and treatment of possible tracheal pathologies found in it.