Morfologia cardíaca de Ardea alba.

Abstract

Ardea alba (Linnaeus, 1758), known as the great white heron, is the most common heron on the planet. It has a long neck, black legs and yellow beak, with a body covered in white feathers. It has a circulatory system similar to that of mammals, but a larger heart compared to the coelomic cavity. In several species, the heart has fibrous rings that serve to stabilize the ostia against contractile deformation, called the cardiac skeleton – composed of connective tissue with intercalated parts of cartilage or bone. This study aimed to describe the cardiac anatomy of the species, generating scientific knowledge about the particularities of this Amazonian avifauna. For this purpose, 10 specimens of great white heron were used, coming from the environmental police battalion and the mangal-das-garças park. Before extracting the heart, in situ and ex situ photodocumentation was carried out. The material was then processed for light microscopy, scanning electron microscopy, and immunohistochemistry, in addition to 3D scanning. The species presented a heart tilted slightly to the right and an aortic arch that emerged from the cardiac base and followed the right antimere, with other structures similar to those of mammals. Light microscopy allowed defining the cardiac layers, presence of Purkinje fibers, and intercalated discs. Cartilage at the base of the heart was identified at the valves, valves, and fibrous skeleton. Differential staining marked the cartilage as predominantly elastic. Scanning electron microscopy provided ample visualization of the cartilage pieces that support the aortic base. However, immunohistochemistry was negative for desmin staining. Finally, the colored and 3D organ provided better didactic identification of the structures present at the heart base. Thus, it was possible to determine that the great white heron has a different aorta orientation than that found in mammals, but, like other species, it also has cardiac cartilage in its heart, although the type identified is unusual in the literature. It has large cartilaginous pieces, compared to the size of the organ, and did not present desmin marking in the cardiac tissue, the latter possibly being related to the antibody that was used.