Descrição morfológica do anel esclerótico de coruja murucututu (Pulsatrix perspicillata)

Abstract

Birds have sclerotic rings inside their eyes, consisting of small juxtaposed and superimposed bone plates, which have different shapes and numbers depending on the animal species. This study aimed to describe the morphology of the sclerotic ring of the eyes of the spectacled owl (Pulsatrix perspicillata), through radiographic, ultrasonographic and macroscopic analyses. Twelve eyes of murucututu owls of different ages and sexes, which died, were used, with 6 eyes preserved in 10% formaldehyde and 6 frozen with the whole animals, originating from the collection of the Zoology Museum of the Federal Rural University of Amazonia. As a methodology to describe the morphology of the rings, we used radiographic and ultrasonographic examinations in addition to anatomical techniques. The eyeballs of 3 birds were macerated, resulting in 15 scleral ossicles interconnected by an aponeurosis, generating a ring with a tubular shape. During a radiographic evaluation, a ring-shaped radiopaque structure was visualized inside the eyes, as well as the delimitations of each ossicle that makes up the ring was formed by overlapping areas between them, observed as lines during the examination. Simultaneously, ocular ultrasonography was performed, where the sclerotic ring showed a round, hyperechogenic and thin appearance, it was not possible to observe the boundaries between the ossicles that make up the ring, nor to detect its morphology in its entirety. Thus, the sclerotic rings of P. perspicillata are bilaterally similar in terms of shape and number of ossicles that make up the rings, with a pattern similar to that found in other species of owls.