First report of fibropapillomatosis (FP) and Chelonid alphaherpesvirus 5 (ChHV5) in a green sea turtle (Chelonia mydas) from the historically fibropapillomatosis-free Fernando de Noronha Archipelago, Northeastern Brazil / Primeiro caso de fibropapilomatose (FP) e de Chelonid alphaherpesvirus 5 (ChHV5) em tartaruga-verde (Chelonia mydas) no Arquipélago de Fernando de Noronha, Nordeste do Brasil

Fibropapillomatosis (FP) is an infectious disease caused by Chelonid alphaherpesvirus 5 (ChHV5). Nevertheless, its clinical manifestations are considered multifactorial. Due to its relevance, FP is currently monitored in sea turtle populations in the United States, Australia, Caribbean, and Brazil. Between 2000 and 2020, the TAMAR Project/ TAMAR Project Foundation analyzed the prevalence of FP in nine states and oceanic islands along the Brazilian coast, including Fernando de Noronha Archipelago (FNA), a historically FP-free area. A total of 4,435 green sea turtles (Chelonia mydas) were monitored from 2010 to 2016. Additionally, in 2012 and 2014, 43 FP-free skin samples were analyzed for ChHV5 using a qualitative PCR for the UL30 polymerase (pol) sequence. In 2015, a bilateral ocular nodule characterized as an FP tumor was reported in one of the monitored individuals undergoing rehabilitation. Tissue samples were collected following surgical removal of the tumor. Characterization of a 454 bp UL30 polymerase gene revealed a ChHV5 sequence previously reported in other areas of the Atlantic Brazilian coast. In the years following this finding from January 2017 to March 2020, a total of 360 C. mydas were monitored in the same area and no FP tumors were detected. This is the first report of FP and the first detection of ChHV5 in FNA, a finding of great concern considering this site's historical absence of FP occurrence. This study highlights the importance of monitoring this disease in historically FP-free areas of the Brazilian Atlantic coast.(AU)

A fibropapilomatose (FP) é uma doença infecciosa causada pelo Chelonid alphaherpesvirus 5 (ChHV5). No entanto, as manifestações clínicas da doença são consideradas multifatoriais. Esta doença é monitorada atualmente em populações de tartarugas marinhas nos EUA, Austrália, Caribe e Brasil. Desde 2000, o Projeto TAMAR/Fundação Projeto TAMAR analisa a presença de FP em nove estados da costa brasileira e ilhas oceânicas, incluindo o arquipélago de Fernando de Noronha, uma área historicamente livre de FP. Um total de 4.435 indivíduos de Chelonia mydas foram monitorados de 2010 a 2016 e 43 amostras de pele foram analisadas para detectar ChHV5 em 2012 e 2014 com o objetivo de avaliar a presença do vírus em tecidos sem FP, usando uma PCR qualitativa para detecção de sequências do gene da UL30 polimerase. Em 2015, uma tartaruga verde (C. mydas) foi relatada com um nódulo ocular bilateral caracterizado como FP. Amostras de tecido foram coletadas durante sua reabilitação e procedimento cirúrgico para remover o tumor. A caracterização parcial de uma sequência de 454 bp do gene UL30 polimerase detectou ChHV5 anteriormente relatado em outras áreas da costa atlântica brasileira. Após estes achados, de janeiro de 2017 a março de 2020, um total de 360 indivíduos de C. mydas foram monitorados e nenhum caso de FP foi registrado. Este é o primeiro relato de FP e a primeira caracterização de ChHV5 no arquipélago de Fernando de Noronha, uma questão preocupante e que ressalta a importância do monitoramento desta doença em áreas historicamente livres de FP na costa atlântica brasileira.(AU)

Ghrelin and leptin modulate the feeding behaviour of the hawksbill turtle Eretmochelys imbricata during nesting season.

Female sea turtles have rarely been observed foraging during the nesting season. This suggests that prior to their migration to nesting beaches the females must store sufficient energy and nutrients at their foraging grounds and must be physiologically capable of undergoing months without feeding. Leptin (an appetite-suppressing protein) and ghrelin (a hunger-stimulating peptide) affect body weight by influencing energy intake in all vertebrates. We investigated the levels of these hormones and other physiological and nutritional parameters in nesting hawksbill sea turtles in Rio Grande do Norte State, Brazil, by collecting consecutive blood samples from 41 turtles during the 2010-2011 and 2011-2012 reproductive seasons. We found that levels of serum leptin decreased over the nesting season, which potentially relaxed suppression of food intake and stimulated females to begin foraging either during or after the post-nesting migration. Concurrently, we recorded an increasing trend in ghrelin, which may have stimulated food intake towards the end of the nesting season. Both findings are consistent with the prediction that post-nesting females will begin to forage, either during or immediately after their post-nesting migration. We observed no seasonal trend for other physiological parameters (values of packed cell volume and serum levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, γ-glutamyl transferase, low-density lipoprotein, and high-density lipoprotein). The observed downward trends in general serum biochemistry levels were probably due to the physiological challenge of vitellogenesis and nesting in addition to limited energy resources and probable fasting.

The interplay of homing and dispersal in green turtles: a focus on the southwestern atlantic.

Current understanding of spatial ecology is insufficient in many threatened marine species, failing to provide a solid basis for conservation and management. To address this issue for globally endangered green turtles, we investigated their population distribution by sequencing a mitochondrial control region segment from the Rocas Atoll courtship area (n = 30 males) and four feeding grounds (FGs) in Brazil (n = 397), and compared our findings to published data (n (nesting) = 1205; n (feeding) = 1587). At Rocas Atoll, the first Atlantic courtship area sequenced to date, we found males were differentiated from local juveniles but not from nesting females. In combination with tag data, this indicates possible male philopatry. The most common haplotypes detected at the study sites were CMA-08 and CMA-05, and significant temporal variation was not revealed. Although feeding grounds were differentiated overall, intra-regional structure was less pronounced. Ascension was the primary natal source of the study FGs, with Surinam and Trindade as secondary sources. The study clarified the primary connectivity between Trindade and Brazil. Possible linkages to African populations were considered, but there was insufficient resolution to conclusively determine this connection. The distribution of FG haplotype lineages was nonrandom and indicative of regional clustering. The study investigated impacts of population size, geographic distance, ocean currents, and juvenile natal homing on connectivity, addressed calls for increased genetic sampling in the southwestern Atlantic, and provided data important for conservation of globally endangered green turtles.