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). ...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.展开更多
Strand-ed turtles need fluid parenterally. The jugular access is best for the maintenance and patency of the catheter. The Seldinger technique guided by ultrasound seems to be the safest for catheter insertion. Five j...Strand-ed turtles need fluid parenterally. The jugular access is best for the maintenance and patency of the catheter. The Seldinger technique guided by ultrasound seems to be the safest for catheter insertion. Five juveniles Chelonia mydas with fibropapillomatosis and an adult male leatherback turtle （Dermochelys coriacea） with altered buoyancy were sent to Santos Municipal Aquarium for rehabilitation. Turtles underwent catheterization of the jugular vein using the Seldinger technique with central venous polyurethane catheter monolumen 14 G to Dermochelys and 18 G for Chelonia, guided by ultrasound with 10 MHz transducer catheters were sutured to the skin and animals were subjected to fluid. In all turtles, the catheters were patency and were well established. There were no granulomatous reactions or related infections. The Dermochelys improved clinically after fluid resuscitation, and the catheter was removed one week after. In one Chelonia excision was 21% of its weight in tumors, and the animals received colloid catheter by enabling the mitigation of bleeding due to removal. The use of ultrasonography has enabled monitoring of all access as the patency of the catheter and fluid diffusivity.展开更多
The ability of sea turtle hatchlings to find the seashore soon after hatching is thought to be exclusively dependent upon visual information. Target-oriented movements in most vertebrates, however, relay on combining ...The ability of sea turtle hatchlings to find the seashore soon after hatching is thought to be exclusively dependent upon visual information. Target-oriented movements in most vertebrates, however, relay on combining information gathered through different sensory systems. Hence, in this work, we investigated whether olfactory and/or magnetic information might complement visual cues during hatchling’s seaward crawling. Acute olfactory deprivation and distorted magnetic sensation in visually competent hatchlings resulted in a scattering of seaward crawling routes among cardinal points, some of them being different from those strongly preferred by control hatchlings. In addition, blindfolded hatchlings also displayed a striking misrouting while crawling on the beach surface in spite of having intact olfactory and magnetic senses. Together these results support the notion that visual information is crucial for seaward crawling, but also that olfactory and magnetic information complement visual cues when turtle hatchlings display this behavior. Hence, the present observations suggest that multisensory cues are used by turtle hatchlings while crawling towards the sea. This work also has important implications on the design of species conservation measures and policies. In the near future, efforts must be made to identify and preserve the local natural sources of odors and magnetic cues, in addition to preventing the perturbing effects of artificial lighting on adult and hatchling turtle crawling behavior.展开更多
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 P...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.展开更多
文摘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.
文摘Strand-ed turtles need fluid parenterally. The jugular access is best for the maintenance and patency of the catheter. The Seldinger technique guided by ultrasound seems to be the safest for catheter insertion. Five juveniles Chelonia mydas with fibropapillomatosis and an adult male leatherback turtle （Dermochelys coriacea） with altered buoyancy were sent to Santos Municipal Aquarium for rehabilitation. Turtles underwent catheterization of the jugular vein using the Seldinger technique with central venous polyurethane catheter monolumen 14 G to Dermochelys and 18 G for Chelonia, guided by ultrasound with 10 MHz transducer catheters were sutured to the skin and animals were subjected to fluid. In all turtles, the catheters were patency and were well established. There were no granulomatous reactions or related infections. The Dermochelys improved clinically after fluid resuscitation, and the catheter was removed one week after. In one Chelonia excision was 21% of its weight in tumors, and the animals received colloid catheter by enabling the mitigation of bleeding due to removal. The use of ultrasonography has enabled monitoring of all access as the patency of the catheter and fluid diffusivity.
基金supported by grants from the Consejo Nacional de Ciencia y Tecnologia(CONACyT No.45872M,94312 and 82879 to GGO)from the Coordinacion de la Investigacion Cientifica,Universidad Michoacana de San Nicolas de Hidalgo(No.8.37 to ALFF)Additional funding was provided by the Coordinacion de la Investigacion Cientifica,Universidad Nacional Autonoma de Mexico,and PROMEP,SEP.
文摘The ability of sea turtle hatchlings to find the seashore soon after hatching is thought to be exclusively dependent upon visual information. Target-oriented movements in most vertebrates, however, relay on combining information gathered through different sensory systems. Hence, in this work, we investigated whether olfactory and/or magnetic information might complement visual cues during hatchling’s seaward crawling. Acute olfactory deprivation and distorted magnetic sensation in visually competent hatchlings resulted in a scattering of seaward crawling routes among cardinal points, some of them being different from those strongly preferred by control hatchlings. In addition, blindfolded hatchlings also displayed a striking misrouting while crawling on the beach surface in spite of having intact olfactory and magnetic senses. Together these results support the notion that visual information is crucial for seaward crawling, but also that olfactory and magnetic information complement visual cues when turtle hatchlings display this behavior. Hence, the present observations suggest that multisensory cues are used by turtle hatchlings while crawling towards the sea. This work also has important implications on the design of species conservation measures and policies. In the near future, efforts must be made to identify and preserve the local natural sources of odors and magnetic cues, in addition to preventing the perturbing effects of artificial lighting on adult and hatchling turtle crawling behavior.
基金funded by the L.D.Betz Chair of Environmental Science endowment of Drexel Universitythe Leatherback Trust.
文摘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.
