Análise multivariada da forma de mandíbulas e dentes como ferramenta para identificação de espécies de tubarões na costa pernambucana

Abstract

Sharks have low resilience and require a very high energy demand due to their swimming activities, so they are always looking for food and although humans are not included in their diet, incidents end up happening. Due to these occurrences in Pernambucano’s coast, there was a need to identify the species, given a large number of reported cases without species identification in this region. Thus, this study aimed to identify, among the related species, differences and similarities of their dental arches, using both 2D and 3D templates and images. To do so, dental arches of several shark species were obtained from the acquisition of the head of specimens landed by the artisanal fleet of Pernambuco and, soon after, were taken to the laboratory to make clay templates. Subsequently, these molds and images (2D-3D) were used to study separately the contour of the curvature of the upper and lower mandibles, as well as the interdental distance marked on the templates and obtained directly from the dental arches. From the photos made with a camera, it was possible, not only identifying which species resemble and which differ but also observe where there is a greater variation between species. In summary, we see that Carcharhinus limbatus are similar in shape, width, and distance from end to end. The Galeocerdo curvier mandible curvature contour differs from all others. A pattern of proximity between the flat-headed shark (Carcharhinus leucas) and the tiger shark (Galeocerdo cuvier) has been revealed. Understanding the pattern of the arcade and bite form of shark species is an initial and vital step in the study of human incidents since through these results it will be possible to identify the main species involved in the incidents and then to start thinking about sustainable management proposals for the communities involved.