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.

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.

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.

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.

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.