Correlation of CT and MRI images with anatomic features of the head of the Angelshark (Squatina squatina)

Abstract

The angelsharks are a group of demersal sharks of the genus Squatina characterized by certain morphological features such as a flattened head and body, with pectoral and pelvic fins shaped like wings reminiscent of rays. There are 23 species of angelsharks in the family Squatinidae. Squatina squatina has a worldwide distribution in warm temperate and tropical seas and is found in soft benthic sediments up to at least 150 m deep. It is classified as Critically Endangered on the IUCN Red List of Threatened Species. Three specimens of S. squatina were used to carry out this study. A standardized necropsy was performed in all the cases at the “Instituto Universitario de Sanidad Animal y Seguridad Alimentaria” (IUSA) facilities of the “Universidad de Las Palmas de Gran Canaria”, Arucas (Gran Canaria) and whose causes of death were related to human interaction. Computed tomography (CT) and magnetic resonance imaging (MRI) studies were performed, and two of the specimens underwent transverse and sagittal sectioning to obtain cross-section images. The normal anatomy of the head was divided into two parts: the craniofacies and the neurocranium, in order to facilitate the description of the anatomical structures. The images obtained were compared, in order to provide an atlas of the head. Our results were compared with those of other species of Squatina and similar Elasmobranchii species in order to be used as a reference (or diagnostic tool) in pathologies that may affect these species