First Record of Fibropapillomatosis in a Green Turtle Chelonia mydas from the Baja California Peninsula

Abstract

Fibropapillomatosis (FP) is characterized by multiple fibroepithelial tumors in all parts of the skin and has been reported in sea turtles worldwide. Clinically infected individuals are often emaciated and anemic. In Mexico, however, there are few records of this disease. In this study of green turtles Chelonia mydas in Laguna San Ignacio in Baja California Sur (BCS), we noted one juvenile with multifocal fibropapilloma lesions on the external upper surface of its eyes and hind flippers. Light microscopy revealed hyperkeratosis, epidermal hyperplasia, dermal papillary projections, and fibroblast proliferation. Electron microscopy revealed viral particles. Biopsies of normal skin were done to determine the origin of the turtle through genetic analysis. Its mitochondrial DNA matched that of a haplotype (CMP2) from a Hawaiian green turtle population. Finding FP in a turtle captured in BCS elucidates the need for further monitoring along the west coast of Mexico. Further investigation should include testing tumors to detect and characterize any chelonid herpesviruses and explore any association with FP and other diseases that pose a health risk to other sea turtle species. Received March 26, 2016; accepted August 3, 2016.

Gross examination and Histopathology of Fibropapillomas in Chelonia mydas and Lepidochelys olivacea from Baja California Sur, Mexico

“…External morphology and distribution of the observed neoplasms were consistent with previous descriptions of FP in green turtles [35]. The histopathological analysis revealed that the characteristics and proliferative changes observed in the skin lesions were similar to FP associated with viral particles [27], possibly a herpesvirus [11]; these proliferative changes indicates that are benign neoplasms. However, in this case the lesions could not be monitored to specify its change on size, preventing us to specify the stage of development of the FP [6] or if it was in phase of tumor regression [7]; even so, the neoplasms were registered as 1 (less than 5 cm), according to the classification of green turtles FP's proposed in [6,42] These cases are the fourth and fifth (respectively) recorded and studied by HP in the peninsula, but the first in an EPGT at LOL and the second in an olive ridley turtle at the GU.…”

“…In Mexico, there have been reports of FP with clinical manifestation affecting olive ridley turtles in Colima and Oaxaca [40,41]. In BCS, at the GU two cases of FP with and without clinical manifestation were described in 2014 in an olive ridley turtle and a loggerhead turtle respectively [26]; in 2016, lesions of FP in a green turtle were described macroscopically and microscopically and identifying viral particles by TEM [27].…”

“…Some authors state that this disease develops in areas with calm water, particularly where pollutants are present due to human settlements and agricultural residues [23,24], while others indicate that it can be confined at specific zones, like the east coast of the Big Island of Hawaii [25]. Nevertheless, in Baja California Sur (BCS), after more than 20 years of monitoring the Peninsula, there only are three reported cases of FP in sea turtles, one in a loggerhead turtle, one in an olive ridley turtle [26] and one in a green turtle [27]. Sea turtles health status and presence and dissemination of infectious diseases in BCS have been studied infrequently, so that studies of FP are just a few.…”

Health Assessments in Free-Ranging Sea Turtles: Perspective of Animal Welfare in Wildlife

“…In Mexico, there are several studies related to sea turtles hematology [14,15,16,17]; however, regionally, in BCS, there are still few published works [18,7,13,19]. Thus, there is an urgent need to clearly indicate the health status and rate of diseases in regional sea turtle populations [8]. The present study was aimed at obtaining baseline information on selected health and disease indicators from the EPGT.…”

“…Actually these efforts were notably successful, and these stocks of EPGT appear to be in the process of recovery [6]. However, in 2014 and 2016 there are disease reports and mortality associated with illness [7,8]. Therefore, the idea of carrying out a program of health assessments to complement conservation efforts was proposed in order to minimize the threat of any potentially catastrophic disease outbreaks.…”