Search results for "turtle"

Who's better at spotting? A comparison between aerial photography and observer-based methods to monitor floating marine litter and marine mega-fauna.

2020

Pollution by marine litter is raising major concerns due to its potential impact on marine biodiversity and, above all, on endangered mega-fauna species, such as cetaceans and sea turtles. The density and distribution of marine litter and mega-fauna have been traditionally monitored through observer-based methods, yet the advent of new technologies has introduced aerial photography as an alternative monitoring method. However, to integrate results produced by different monitoring techniques and consider the photographic method a viable alternative, this ‘new’ methodology must be validated. This study aims to compare observations obtained from the concurrent application of observer-based and…

Two decades of monitoring in marine debris ingestion in loggerhead sea turtle, Caretta caretta, from the western Mediterranean

2018

Abstract Anthropogenic marine debris is one of the major worldwide threats to marine ecosystems. The EU Marine Strategy Framework Directive (MSFD) has established a protocol for data collection on marine debris from the gut contents of the loggerhead sea turtle (Caretta caretta), and for determining assessment values of plastics for Good Environmental Status (GES). GES values are calculated as percent turtles having more than average plastic weight per turtle. In the present study, we quantify marine debris ingestion in 155 loggerhead sea turtles collected in the period 1995–2016 in waters of western Mediterranean (North-east Spain). The study aims (1) to update and standardize debris inges…

Last Interglacial Iberian Neandertals as fisher-hunter-gatherers.

2020

Fruits of the sea The origins of marine resource consumption by humans have been much debated. Zilhão et al. present evidence that, in Atlantic Iberia's coastal settings, Middle Paleolithic Neanderthals exploited marine resources at a scale on par with the modern human–associated Middle Stone Age of southern Africa (see the Perspective by Will). Excavations at the Figueira Brava site on Portugal's Atlantic coast reveal shell middens rich in the remains of mollusks, crabs, and fish, as well as terrestrial food items. Familiarity with the sea and its resources may thus have been widespread for residents there in the Middle Paleolithic. The Figueira Brava Neanderthals also exploited stone pine…

Ichnological evidence of semi-aquatic locomotion in early turtles from eastern Iberia during the Carnian Humid Episode (Late Triassic)

2018

Abstract Some of the earliest European records of fossil turtle footprints (Late Triassic, Middle Carnian, ~ 227–237 Ma) are interpreted from 46 footprints from three outcrops, Domeno, Quesa and Cortes de Pallas, located in the Iberian Range (eastern Spain). The samples were obtained from Upper Triassic rocks in Keuper Facies. They are characterized in the studied area by two well-defined evaporitic sequences, separated by a detrital stratigraphic interval, constituting the Manuel Sandstones Formation in which the studied fossil footprints were recorded. These fluvial deposits are correlatable with the Carnian Humid Episode. The footprints are tridactyl and tetradactyl, mainly digitigrade, …

Hypothermic Stunning in Juvenile Green Turtles (Chelonia mydas) in Uruguayan Coastal Waters: Learning for Future Events

2017

Abstract Chelonia mydas in temperate areas exhibits behavioral changes for adapting to sea temperature fluctuations; however, prolonged exposure to cold temperatures can lead to hypothermia and thus hypothermic stunning events. Here we report an unusual stranding event of 90 green turtles recorded in a 12-d period in July 2012 in southeastern Uruguay, analyzing the event in an oceanographic and meteorological context. Monitoring such events provides a unique opportunity to understand the impact of hypothermic stunning on juvenile green turtle stocks that spend the entire year in this temperate region of the southwestern Atlantic Ocean.

Nonmodal scutes patterns in the Loggerhead Sea Turtle (Caretta caretta): a possible epigenetic effect?

2016

Eleven specimens of the threatened Loggerhead Sea Turtle (Caretta caretta (L., 1758)) were caught accidentally by fishermen in different parts of Sicily (Mediterranean Sea). Five of them showed an atypical number of carapacial and plastron scutes, making the immediate identification of the specimens as C. caretta difficult. Both genetic and epigenetic analysis were carried out on these specimens. Sequencing of a 649 bp sequence of the mitochondrial cytochrome c oxidase I (COI) gene allowed us to classify all the individuals as C. caretta. Epigenetic analysis, performed by evaluating the total level of DNA cytosine methylation, showed a reduced and significant (F = 72.65, p < 0.01) globa…

The good, the bad and the ugly: Emys trinacris, Placobdella costata and Haemogregarina stepanowi in Sicily (Testudines, Annelida and Apicomplexa)

2016

Endemic Sicilian pond turtles Emys trinacris Fritz, Fattizzo, Guicking, Tripepi, Pennisi, Lenk, Joger et Wink were examined for the presence of haemogregarine parasites. The presence of haemogregarines, occurring mainly in the microgametocyte stage (13.2 ± 0.12 μm in length and 6.4 ± 0.52 μm in width), was observed in approximately 9% of the sampled E. trinacris. Based on the observed morphology and on the sequencing of nuclear 18S rDNA, we identified the parasite as Haemogregarina stepanowi Danilewsky, 1885. Morphometric study of uninfected and infected red blood cells has shown that H. stepanowi induces different changes in erythrocyte shape depending on the infective stage. The different…

Impact of gas emboli and hyperbaric treatment on respiratory function of loggerhead sea turtles (Caretta caretta)

2018

We investigated lung function in bycaught sea turtles with and without gas emboli. Hyperbaric O2 treatment significantly improves lung function. Pulmonary function testing may be a useful diagnostic tool to assess fisheries induced trauma.

Some like it cold: the glossiphoniid parasites of the Sicilian endemic pond turtle Emys trinacris (Testudines, Emydidae), an example of ‘parasite ine…

2016

The freshwater turtles of the genus Emys and some leech species of the family Glossiphoniidae are the only Palaearctic representatives of primarily Nearctic taxa, which jointly colonized Eurasia and the Maghreb during the Miocene. The strict trophic relationships occurring between the glossiphoniid parasite leech Placobdella costata and its host, the emydid Emys orbicularis, make them a prime example of host–parasite cophylogenetic evolution. In the light of the discovery of the Sicilian cryptic endemic species Emys trinacris, which is the sister species to the widespread Palaearctic E. orbicularis, the possible cophylogenetic divergence of the turtle hosts and their leech parasites was inv…

2020

Turtles, a speciose group consisting of more than 300 species, demonstrate karyotypes with diploid chromosome numbers ranging from 2n = 26 to 2n = 68. However, cytogenetic analyses have been conducted only to 1/3rd of the turtle species, often limited to conventional staining methods. In order to expand our knowledge of the karyotype evolution in turtles, we examined the topology of the (TTAGGG)n telomeric repeats and the rDNA loci by fluorescence in situ hybridization (FISH) on the karyotypes of two emydids: the Sicilian pond turtle, Emys trinacris, and the yellow-bellied slider, Trachemys scripta scripta (family Emydidae). Furthermore, AT-rich and GC-rich chromosome regions were detected …