Relationship between anatomy and histopathology of fibropapillomatosis in Chelonia mydas(Testudines, Cheloniidae) (Linnaeus 1758)

• Grant number: 14/24683-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2015
• End date: December 31, 2015
• Field of knowledge: Biological Sciences - Ecology - Applied Ecology
• Principal Investigator: Eliana Reiko Matushima
• Grantee: Luísa Carvalho
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Sea turtles are a primitive and particular component of biological diversity and an essential part of marine ecosystems. There are five species of sea turtles that feed and nest in Brazil such as green turtle (Chelonia mydas), which according to the International Union for Conservation of Nature (IUCN, 2014) is considered endangered. According to the Marine Turtle Specialist Group, currently, the main threats to marine turtles are incidental capture by fisheries, human consumption of meat, coastal development, pollution, and exposure to pathogens that include the fibropapillomatosis. This disease affects sea turtles worldwide, predominantly green turtles. However, little is known about its etiology, but it is believed that there is a relationship between the presence of Chelonid Fibropapilloma-associated Herpesvirus, environmental factors, especially those related to anthropogenic pressure, and genetic factors. The fibropapillomatosis is characterized by the presence of benign skin tumors ranging from 0.1 to 30 cm in diameter and involves different anatomical regions, including carapace, plastron, neck, eye, and base tail. These tumors are characterized by the proliferation of epidermal cells (papillomas), fibroblast (fibroids), or both (fibropapillomas). This tumor may present different aspects (warty, smooth, sessile, pedunculated) and colors (pink, black, or both). Although the tumors are benign, the fibropapillomatosis is debilitating and can be fatal because it can hinder the turtle's ability to swim, locomotion, or prevent breathing and seizure of food, representing a major threat to sea turtles, especially Chelonia mydas. In order to better understand the anatomic distribution and histopathologic characteristics of fibropapillomatosis 50 green turtles from Ubatuba / SP, Almofala / CE, and Vitória / ES affected by this disease will be studied. Biometric data (curvilinear carapace width - LCC; curvilinear carapace length-CCC and body weight -MC) will be obtained. We will verify the size (classified into categories A, B, C, and D), number and location of tumors, in addition to collecting tumor fragments of different sizes and locations. This formation will be analyzed by histopathology tests to evaluate a possible kinetic evolution of tumors and differences at the cellular level of the formations of different sizes and locations. Thus, it is expected to generate important data that may contribute to a better understanding of fibropapillomatosis and maybe generate information to supplement the Action Plan for the Conservation of Sea Turtles, in particular, Chelonia mydas. (AU)