The first record of dermochelyid turtles in the Eocene of Tierra del Fuego:new insights on the evolution of the Weddellian faunas

The Antarctic Paleogene marine fossil record has been the key to reconstructing the evolution of the Weddellian Sea and final dismemberment of Southern Gondwana.In this context,Eocene marine vertebrates from Seymour(Marambio)Island have provided valuable information.We present the first Eocene record of marine reptiles from the southern Atlantic Coast of South America.This corresponds to several postcranial turtle remains represented by a proximal end of the right humerus,three caudal and one thoracic vertebrae,a fragment of the left pubis,and ten ossicles of the dorsal carapace,coming from the Leticia Formation(late-mid Eocene)at Cabo Tiburones,Tierra del Fuego,Argentina.These materials show severalfeatures such as the size and general morphology of the humerus and vertebrae,and the presence of relatively small,irregular,smooth,and unkeeled ossicles,which allow us to assign them to Dermochelyidae indet.Dermochelyids are a cosmopolitan group ofcryptodiran turtles,registered from the late Cretaceous up to the recent,with some physiological-biological peculiarities(e.g.,endothermy and an exclusive jellyfish-based diet)and characterized by the presence of an osseous carapace formed by ossicles.The new finding from the Leticia Formation is an addition to the scarce and extremely fragmentary record of Eocene dermochelyids from the southern seas like those from the La Meseta and Submeseta formations(Antarctica)and the Waihao and Burnside formations(New Zealand).This new information allows us to discuss the presence of these turtles in such high latitudes in the past and its implication in the evolution of the Weddellian fauna.

Tracking the Confiscated Green Sea Turtles in the South China Sea:Where Did They Come From?Where Will They Go?

The population of the green sea turtle(Chelonia mydas)is under decline,threatened by bycatch and illegal acquisition despite worldwide protection efforts.However,the confiscation of illegally acquired sea turtles could aid in tracking their origin and movement patterns,crucial for effective conservation strategies.Combining satellite tracking and genetic analysis offers an opportunity to investigate the relationship between the origins and migration directions of green sea turtles in the western Pacific.Here,we applied two methods to investigate the spatial ecology of 18 green turtles caught as bycatch in the South China Sea.Our results revealed the genetic origins and diverse movements of the turtles.Bayesian Mixed Stock Analysis(MSA)suggested that these turtles originated from the rookery of the Xisha Islands(49.6%),central Ryukyu(24.6%),NE Borneo(8%),and the Sulu Sea(5.2%),with other rookeries in meagre proportions(<2%each).Satellite tracking showed the ranges of their travel were smaller than the whole contributed rookery range,but diverse.The haplotype diversity of these turtles is high,and CmP19 stands out as both the most frequent and the most diverse haplotype in terms of swimming destinations.These results indicate that the South China Sea is likely an important transportation hub and mating spot for green turtles.Our findings provided evidence for the rehabilitation of these green turtles in the wild and illustrated the complexity of movement during the green turtle’s life history,and the“mixed backgrounds”of the green turtles also highlight the need for joint conservation efforts of neighbouring countries in the South China Sea.

White-spot disease of Chinese soft-shelled turtles (Trionyx sinens) caused by Paecilomyces lilacinus

Chinese soft-shelled turtles （Trionyx sinens） in culture farms using an artificial warming system in Zhejiang, China, often show typical signs of white-spot disease such as white spots on their bodies, skin lesions, anorexia and eventually death. The sick turtles were mostly 5-80 g in weight. A suspected fungal pathogen was isolated from the sick turtles and verified as Paecilomyces lilacinus by sequence analysis of the internal transcribed spacer （ITS） of its ribosomal DNA （rDNA）. Detailed morphological examinations were also conducted to confirm the white-spot disease.

Satellite Tracking of Post-nesting Migration of Green Turtles

During the period August 17-28, 2001, in collaboration with the Provincial Bureau of Oceanography & Fisheries of Guangdong and the South China Institute for Endangered Species, the South China Sea Institute of Oceanology, a CAS affiliate in the city of Guangzhou, conducted a sea turtle satellite tracking project at Haigui Bay (Fig. 1) in the vicinity of Gangkou Town, Huidong County, Guangdong Province.

An Experimental Biotelemetric Study Based on Satellite Tracking During Post-nesting Migrations of Green Turtles

A biotelemetry experiment is conducted to study the migrant behavior of green turtles (Chelonia mydas) in South China Sea and acquire the physical environment data. The method in use is to track the post nesting migrant routes of green turtles through the satellite linked transmitters attached on the back of turtles and the global satellite signal transmitting system of Argos. We obtained the positions of the post nesting migrant routes of three green turtles and environment data, which are important in conservation of green turtles and the research of physical oceanography. Based on the test, the concept, principle and method of biotelemetry are also introduced in this paper with a discussion of the further development of this technique and its applying prospection in future.

The National Action Plan： An Approach to Prioritise Acts Related to the Conservation of Marine Turtles at Jordan＇s Gulf of Aqaba

The Jordan＇s NAP （national action plan） provides a set of priority actions for the conservation of marine turtles and their habitats in the Gulf of Aqaba, Red Sea. The main threats to the maintenance of stable turtle populations in Jordan range from opportunistic capture to global threats such fishing mortality and from pollution incidents. Jordan＇s NAP addresses the primary causes of turtle mortality with a series of proposed actions. It includes reducing threats from commercial fisheries, development operations, promoting turtle rescue and rehabilitation along with public awareness activities. It considered also a set of recommendations to reflect the importance of protecting marine turtles in Jordan＇s Gulf of Aqaba. It includes community participation in conservation, capacity of national agencies to carry out management activities and to enforce legislations. To each priority actions identified in NAP, expected results and performance indicators were defined. Hence, the designation of a level of urgency to each specific priority action allowed a phased approach for implementation, subject to budget and available national capacity. Currently, NAP is performing effectively through an integrated network of national working groups including government and non-governmental organisations and other stakeholders.

Body Size as an Indicator of Health for Green Turtles at the TCMP （Tobago Cays Marine Park）, Eastern Caribbean

Gazetted in 1997, The TCMP （Tobago Cays Marine Park） is the only marine protected area within the territorial boundaries of St. Vincent and the Grenadines. Sea turtles are an important species in TCMP, and because their globally endangered status have become the focus of an in-water monitoring program, primarily for green turtles （Chelonia mydas）. Preliminary assessment indicated that the TCMP contains an important foraging aggregation of sub-adult green turtles. Since then two additional years of data has been collected; this data was analyzed to assess the health of the turtle population. The data also indicated that the weight was predictable according to carapace width and length and that the population is dominated by larger sub-adults.

The First Vertebrate Assemblage Dominated by Fishes and Turtles of the Jehol Biota in Jilin Province, NE China

Objective The Early Cretaceous sediments are well-exposed in southern Jilin Province,and yield abundant invertebrate and plant fossils,including the typical EosestheriaEphemeropsis trisetalis-Lycoptera（E-E-L）assemblage of the Jehol Biota（Shao Tiequan et al.,2017）.However,vertebrate fossils,especially tetrapods,are extremely rare and there is no formal documents on these fossils.Recently,a new fossil site dominated by fishes and turtles has been discovered in the middle part of the

Nest Site Selection of Loggerhead and Leatherback Sea Turtles at the Eastern Coast of Inhaca Island, Mozambique

Nest site selection represents an important reproductive strategy for sea turtles as it can strongly affect the development and survival of the offsprings and the reproductive fitness of the adults. In this study we analyzed the nest site selection of loggerhead and leatherback turtles and the factors correlated with that selection at Inhaca Island. The spatial position of the nests was recorded during sea turtles nests monitoring and six nesting seasons were used. Satellite images of Inhaca were used to characterize some of the beach features that might be correlated with nest site selection. Nest distribution analysis revealed that loggerhead turtles tend to spread their nests along the entire beach, but a higher aggregation of nests was evident at the northern most section of the eastern coast. Leatherback turtles tend to nest in a restricted area, with approximately 40% nests at the central sections of the coast. Beach height was the physical variable significantly correlated to loggerhead＇s nest density （r = 0.309, N = 125, P 〈 0.01） while fin grain particles （specifically 0.125 mm grain size particles） （r = 0.399, N = 125, P 〈 0.01） and organic content （r = 0.218, N = 125, P 〈 0.05） were the variables significantly correlated to leatherback＇s nest density. No other factors investigated affected nest site selection of either species.

Turtle before Turtles

People are familiar with modern turtles, but the evolution of turtles remains one of the biggest mysteries in paleontology. The turtle has a unique body form of tetrapods (four-leg vertebrates,or vertebrates except fishes, such as lizards/crocodiles,birds, and mammals).

Effects of Pesticide Exposure on Embryonic Development and Hatchling Traits of Turtles

Deltamethrin is a widespread environmental hormone with endocrine-disrupting properties, but its effect on embryonic development of reptiles is largely unexplored. We investigated the effects of deltamethrin on embryonic development and offspring traits in two turtle species, one with parchment-shelled eggs and the other with rigidshelled eggs. Deltamethrin exposure during egg incubation did not affect hatching success and hatchling body size in either species. However, embryonic exposure to deltamethrin resulted in reduced hatchling locomotor performance in the red-eared slider turtle（Trachemys scripta） with parchment-shelled eggs, but not in the Chinese three-keeled pond turtle（Chinemys reevesii） with rigid-shelled eggs. These results suggest that parchment-shelled eggs are likely more vulnerable to deltamethrin than rigid-shelled eggs.

Ultrastructural Study of Limb Bud Development in Green Turtles Chelonia mydas

Morphological changes during the embryonic development of limbs of the green turtle,Chelonia mydas,were studied during the entire period of incubation,using transmission and scanning electron microscopy(TEM and SEM). Limb buds were first observed at Stage 2. At that stage,the tip was covered with an apical ectodermal ridge(AER) which began to regress at Stage 6. Associated with AER was the presence of the mesenchymal cells which,consequently,differentiated into muscles,cartilage and bones. The gross features of the skeletal development appeared as a condensation of the cartilaginous structures in the proximal distal region of the limbs. The primordial digits were gradually enclosed by hard keratinized webbed skin. The increase in rate of ossification and skin pigmentation was correlated with the growth of the limbs. The development of the limbs was closely related to the transitional appearance of mucus secretion from the epidermis.

Measurement of Liver Size and Intrahepatic Blood Flow of Red-eared Turtles by Color Doppler Ultrasound

In the study, a total of 20 red-eared turtles （ half male and half female） were selected to conduct the measurement of liver size and intrahepatic blood flow of red-eared turtles by color Doppler ultrasound. The results showed that the fight hepatic lobe could be scanned through the right carotid anterior acoustic win- dow, and the left hepatic lobe could be scanned through the left carotid anterior acoustic window, but the vision would be obstructed by the air in trachea. The liver could also be scanned through the left femoral anterior acoustic window and the fight femoral anterior acoustic window when filling of bladder was good. The correla- tion regression analysis suggested that estimated values of liver showed no linear relationship with weight, the longest back curve and the widest back curve. Through the study, the normal indicators for ultrasound examination of red-eared turtle liver were established, in order to provide a reference for examination of turtle liver.

Sea Turtles in Vietnam： On the Edge of Extinction

Five species of foraging and breeding sea turtles have been identified in Vietnam, they are Green turtle （Chelonia mydas）, Loggerhead turtle （Caretta caretta）, Olive ridley turtle （Lepidochelys olivacea）, Hawksbill turtle （Eretmochelys imbricata） and Leatherback turtle （Dermochelys coriacea）. Among them, with the exception of Loggerhead turtle （Caretta caretta）, four species have been being lay eggs on the beaches along the country. However, these populations have been strongly suffered by human activities for decades. The number of foraging and breeding Hawksbill and Leatherback sea turtles has dramatically decreased, and Olive Ridley turtle has almost disappeared on their traditional nesting beaches. Beside the reason of harvesting eggs and nesting turtles by catch or by purpose, the developments in coastal areas where sea turtles laying eggs such as in shrimp aquaculture, tourist resort and residential area developments etc., also contributed to this decline of sea turtles. Despite the fact that the recent raising awareness programs on protection and conservation of the sea turtle were very well done with the participation of many organizations and provinces, this important animals still face the risk of extinction in Vietnam.

Seasonal Variation of Hearing Sensitivity in the Red-eared Slider(Trachemys scripta elegans)

Seasonal variation of hearing sensitivity has been observed in many vertebrate groups with obvious vocal behaviors.Circulating hormones,conspecific calling signals,and temperature are potential factors that drive these plasticity patterns.Turtles have a hearing range that appears to be limited to under 1.5 kHz and are often thought to be non-vocal;thus,they are commonly neglected in vocal communication research.In this study,we aimed to determine whether the auditory phenotype exhibits seasonal variation in sensitivity and to analyze the potential factors driving such variation patterns in turtles.We measured hearing sensitivity and sex hormone levels in female(estradiol)and male(testosterone and dihydrotestosterone)Red-eared sliders(Trachemys scripta elegans)during spring and winter.The results showed that auditory brainstem response(ABR)thresholds were significantly lower in spring than in winter at a frequency range of 0.5-0.9 kHz.The hearing-sensitivity bandwidth was wider,and the ABR latency was significantly shorter in spring than in winter.No significant differences were found in estradiol,testosterone,and dihydrotestosterone levels in T.scripta elegans between spring and winter.This study is the first to reveal the seasonal variation of peripheral hearing sensitivity in turtles,a special animal group with limited hearing range and less vocalization.Temperature variations may be used to explain these seasonal effects,but further research is required to confirm our findings.

基于循序渐进方式的Python-turtle库教学设计

本文针对turtle绘图一堂课的实践教学,以任务为驱动,全面覆盖turtle知识点,以循序渐进方式将内容综合融入其中,结合线上线下混合式课堂,引导学生找到解决问题的方法,极大地提高了学生的编程兴趣,培养了学生的创新思维。

Conservation of freshwater turtles in Amazonia:retrospective and future prospects

This paper aims to discuss the current status of conservation of freshwater turtles of the Amazon and the absence of the genus Podocnemis the Official List of Species of Brazilian Fauna Threatened with Extinction.Amazonian turtles are used as food by indigenous people and fisherman communities.However,fishing of adult females,uncontrolled egg collecting,habitat degradation and trafficking in wildlife have caused the decline of these populations.Nevertheless,Podocnemis expansa and Podocnemis unifilis were not included in the Brazil’s official list of animals threatened.Therefore,the turtles remain at great risk,due to the intense pressure that they are suffering.It is recommended that the criteria and the conservation status are reviewed including those animals in the category of vulnerable and to ensure a thorough review and modification in the current Brazilian law to be covered studies and management of turtles for subsistence,respecting and adding value to way of life of Amazonian peoples.

Movements and diving behavior of internesting green turtles along Pacific Costa Rica

Using satellite transmitters,we determined the internesting movements,spatial ecology and diving behavior of East Pacific green turtles(Chelonia mydas)nesting on Nombre de Jesús and Zapotillal beaches along the Pacific coast of northwestern Costa Rica.Kernel density analysis indicated that turtles spent most of their time in a particularly small area in the vicinity of the nesting beaches(50%utilization distribution was an area of 3 km^(2)).Minimum daily distance traveled during a 12 day internesting period was 4.6±3.5 km.Dives were short and primarily occupied the upper 10 m of the water column.Turtles spent most of their time resting at the surface and conducting U-dives(ranging from 60 to 81%of the total tracking time involved in those activities).Turtles showed a strong diel pattern,U-dives mainly took place during the day and turtles spent a large amount of time resting at the surface at night.The lack of long-distance movements demonstrated that this area was heavily utilized by turtles during the nesting season and,therefore,was a crucial location for conservation of this highly endangered green turtle population.The unique behavior of these turtles in resting at the surface at night might make them particularly vulnerable to fishing activities near the nesting beaches.

Parasitic nematodes from turtles:New species and new record from Indonesia

Objective:To describe the morphological characteristics of some species of parasitic nematodes found in freshwater turtles from Sumatera(Amyda cartilaginea)and Kalimantan(Notochelys platynota).Methods:Specimens for light microscopy examination were fixed with warm 70%alcohol,cleared and mounted in lactophenol for stout specimens and glycerine for delicate specimens,prior to wet mounting.Drawings were made with the aid of a drawing tube attached to an Olympus compound microscope.Specimens for scanning electron microscope examination were fixed in cacodylate buffer and glutaraldehyde,dehydrated in alcohol concentration series,dried in vacuum dried and coated with gold in Eiko-IB2 Ion Coater.Measurements were given in micrometers as the mean followed by the range in parentheses,unless otherwise stated.Results:Four species of parasitic nematodes were found,namely,Monhysterides jambiensis sp.n.(M.jambiensis),Spiroxys sumatraensis sp.n.(S.sumatraensis),Cissophyllus laverani and Cissophyllus roseus.M.jambiensis differed from Monhysterides lissemydis in ratio of right-to-left spicule(1:3 in M.jambiensis vs.1:3.8-5.6 in M.lissemydis)and had no gubernaculum.M.jambiensis also differed from Monhysterides testudinicola in longer spicule(11.2%-12.7%in M.jambiensis vs.5.6%-6%of body length),ratio right-to-left spicule(1:3 in M.jambiensis vs.1:2)and the numbers of caudal papillae and differed from Monhysterides testudinicola because of the lateral alae began from the half posterior of body,but that in M.jambiensis began from anterior part of body,behind the anterior end.S.sumatraensis differed from Spiroxys annulatus in having tooth at median lobe and having no well mark cuticular collar behind the based of lips and constriction at the base of pseudolabium was not pronounced.S.sumatraensis differed from Spiroxys transversalata in having no tooth at median lobes of each pseudolabium and differed from Spiroxys chelodinae in the unpaired position of median caudal papillae since it was more anterior than that of Spiroxys jambiensis.Additionally there was no adanal papillae in the male of Spiroxys chelodynae.S.sumatraensis also differed from Spiroxys ankarafantsika in having double papillae on each pseudolabium,more anterior of deirid and longer spicule(9.5%-12.4%vs.6%of body length in Spiroxys ankarafantsika).Two species of Cissophyllus morphologically were agreed with its previous species.Conclusions:Monhysterides spp.are found in Oriental region turtle,suborder Cryptodira,and there is no report from others zoogeographical regions.S.sumatraensis belonging to Group 2 includes three other species.This group was found in Oriental,Australian and Ethiopian,Spiroxys presumably widespread amongst the species of turtle when Gondwanaland existed.Cissophyllus laverani is a new record in Indonesia.

基于Python语言的Turtle库绘图实例

Python语言语法简洁、清晰、易读。学生在学习Python语言时,学习难度起点低,容易入门。国内许多高校都开设了Python程序设计课程。Python语言的Turtle库设计巧妙,作图模型简单强大。初学者能很快编写出趣味生动的作图程序,极大地提高了学习者的兴趣和积极性。