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 res...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.展开更多
With their suitable habitats significantly affected by climate change and human activities,most of the seven globally recognized sea turtles are facing endangerment.In order to predict their present and future(2090−21...With their suitable habitats significantly affected by climate change and human activities,most of the seven globally recognized sea turtles are facing endangerment.In order to predict their present and future(2090−2100)potentially suitable habitats,we utilized the MaxEnt model,incorporating occurrence data for various sea turtle species and environmental datasets under current conditions,as well as under two climate scenarios from the Shared Socioeconomic Pathways(SSP1-2.6 and SSP5-8.5).Our findings showed that the key environmental variables,such as temperature and distance from shore predominantly influence the prediction on the potentially suitable habitat for sea turtles.The most highly suitable habitats for sea turtles are predominantly found in the tropical coastal waters bordering continents,including South and North America,Asia,and Australia.Under the climate scenarios of SSP1-2.6 and SSP5-8.5 for 2090−2100,the anticipated loss of potential suitable habitats is expected to surpass any potential gains for all sea turtle species.The Kemp’s ridley sea turtle(Lepidochelys kempii)is especially vulnerable,with its potentially suitable habitat area projected to decrease by 0.43%under SSP1-2.6 scenario to 6.15%under SSP5-8.5 scenario.In contrast,the most resilient Dermochelys coriacea is projected with a reduction of 1.02%under SSP1-2.6 and 0.57%under SSP5-8.5 in its potentially suitable habitat.These varying responses to climate change inferred the necessity for species-specific conservation strategies.However,only 9.9%of the integrated potentially suitable habitat is protected within the World Database on Protected Areas(WDPA),which suggested the extending of WDPA for more efficiency on the sea turtle conservation.展开更多
Inspired by the way sea turtles rely on the Earth’s magnetic field for navigation and locomotion,a novel magnetic soft robotic turtle with programmable magnetization has been developed and investigated to achieve bio...Inspired by the way sea turtles rely on the Earth’s magnetic field for navigation and locomotion,a novel magnetic soft robotic turtle with programmable magnetization has been developed and investigated to achieve biomimetic locomotion patterns such as straight-line swimming and turning swimming.The soft robotic turtle(12.50 mm in length and 0.24 g in weight)is integrated with an Ecoflex-based torso and four magnetically programmed acrylic elastomer VHB-based limbs containing samarium-iron–nitrogen particles,and was able to carry a load more than twice its own weight.Similar to the limb locomotion characteristics of sea turtles,the magnetic torque causes the four limbs to mimic sinusoidal bending deformation under the influence of an external magnetic field,so that the turtle swims continuously forward.Significantly,when the bending deformation magnitudes of its left and right limbs differ,the soft robotic turtle switches from straight-line to turning swimming at 6.334 rad/s.Furthermore,the tracking swimming activities of the soft robotic turtle along specific planned paths,such as square-shaped,S-shaped,and double U-shaped maze,is anticipated to be utilized for special detection and targeted drug delivery,among other applications owing to its superior remote directional control ability.展开更多
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 thes...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.展开更多
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 coul...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.展开更多
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(M...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.展开更多
[Objective] This study aimed to isolate and identify the pathogens of soft-shelled turtle fulminant infectious disease,to provide the basis for the prevention and control of aquatic animal diseases.[Method] Commercial...[Objective] This study aimed to isolate and identify the pathogens of soft-shelled turtle fulminant infectious disease,to provide the basis for the prevention and control of aquatic animal diseases.[Method] Commercially available sick soft-shelled turtles were used as experimental materials,to isolate and identify the causative pathogens;pathogenicity test and toxin determination of the isolates were carried out;in addition,hyperimmune serum was prepared and its therapeutic effect was detected.[Result] Nine bacteria were isolated from the livers of sick soft-shelled turtles,including seven Aeromonas sobria strains（JA-1） and two A.caviae strains（JA-2）.The median lethal dose（LD50） of JA-1 and JA-2 was 4.3×10^5/ml and 5.5×10^7/ml,respectively;the broth culture supernatant of the two bacteria contains a type of toxin with hemolytic activity,indicating that the soft-shelled turtle fulminant infectious disease is caused by A.sobria and A.caviae.Vaccine was prepared by using the two bacteria and rabbit immunization with immunopotentiator,showing a titer of 1：512 and a cure rate of 100%.[Conclusion] This study laid foundation for the prevention and control of aquatic animal diseases.展开更多
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 embryo...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.展开更多
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,...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.展开更多
In 1998,a study on forty-five four-eyed turtles(Sacalia quadriocellata) was initiated to gather preliminary biological data of this species and to investigate the feasibility of its captive reproduction.In the followi...In 1998,a study on forty-five four-eyed turtles(Sacalia quadriocellata) was initiated to gather preliminary biological data of this species and to investigate the feasibility of its captive reproduction.In the following six years,no courtship behavior was found occurring in males and no oviposition in females.From 2004 to 2007,two successful techniques were applied to initiate reproductive behavior:1) injecting exogenous reproductive hormones; and 2) reducing the stress of living in captivity.As a result of the hormone treatments,courtship behavior and copulation were observed during September and October,2005.However,no courtship displays were seen from the CK males,which were not treated with hormones.Ovulation occurred between December and March,and the correlation was not significant between behavior of ovulation and food intake.Females laid only one clutch of eggs each year,with 2.47 eggs(n=34,range=1–4) at average,and 84 eggs were totally obtained,of which 13 were damaged,52 were infertile and 19 fertile.Of the fertile eggs,nine were hatched with mean incubation period of 105.9 days(n=9,range=89–122 days) at temperature ranging from 24 to 27℃.展开更多
The gastrointestinal tracts of four Chelonia mydas hatchlings were examined at the anatomical, histological and ultrastructural level. Our results show that the gastrointestinal tract（GI） is composed by esophagus, s...The gastrointestinal tracts of four Chelonia mydas hatchlings were examined at the anatomical, histological and ultrastructural level. Our results show that the gastrointestinal tract（GI） is composed by esophagus, stomach, small intestine（SI） and large intestine（LI）, and histologically of mucosa, submucosa, muscularis externa（ME） and serosa. The esophagus is marked by conical papillae lined by keratinized stratified squamous epithelium, whereas the remaining GI by simple columnar epithelium; esophageal diverticulum is absent. The stomach covered with mucous granule cells, contains cardia, fundic regions and pylorus, which are separately characterized by cardiac glands, fundic glands and pyloric glands, and have the thickest submucosa and ME of the GI. The ME of the esophagus mainly consist of one layer of circular smooth muscle whereas the rest of GI of two layers, inner circular muscle and outer longitudinal muscle. The SI is slightly longer than the LI and the GI is approximately 5.11 times of the carapace length. The SI is lined with longitudinal zigzag folds and characterized by absorptive cells with longer and denser microvilli, whereas the LI by transversal folds, goblet cells and lymphoid nodules. Only intestinal glands appear in duodenum. Endocrine cells are observed in all sections of the GI and accounted for the largest proportion in duodenum. The results demonstrate a perfect combination of the structure and function of the GI and reveal that the digestion and absorption primarily occurs in the foregut. C. mydas hatchling may prefer carnivorous diet.展开更多
A 120-day feeding experiment was conducted to investigate the effects of partial replacement of brown fish meal (BFM) by fermented soybean meal (FSBM) in diets of Chinese soft-shelled turtle (Pelodiscus sinensis). The...A 120-day feeding experiment was conducted to investigate the effects of partial replacement of brown fish meal (BFM) by fermented soybean meal (FSBM) in diets of Chinese soft-shelled turtle (Pelodiscus sinensis). The turtles (initial mean body weight, (115.52 ± 1.05) g) were fed with three experimental diets, in which 0%, 4.72% and 9.44% BFM protein was replaced by 0%, 3% and 6% FSBM, respectively. Results showed that the feeding rate (FR), specific growth rate (SGR) and feed efficiency ratio (FER) of turtles fed with the diet containing 3% FSBM were not significantly different from the control group (0% FSBM) (P > 0.05). However, FR, SGR and FER of turtles fed with the diet containing 6% FSBM were significantly lower than those of the control group (P < 0.05). No significant differences were observed in the activities of serum glutamic-oxalacetic transaminase and glutamicpyruvic transaminase among dietary treatments (P > 0.05). However, the uric acid concentration in turtles fed with the diet containing 3% or 6% FSBM was significantly lower than that in the control group (P < 0.05). There were no significant differences in the activities of lysozyme, alkaline phosphatase and total superoxide dismutase among dietary treatments (P > 0.05). The results suggested that FSBM could replace 4.72% BFM protein in turtle diets without exerting adverse effects on turtle growth, feed utilization and measured immune parameters.展开更多
文摘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.
基金The National Key Research and Development Program of China under contract No.2023YFC2811400.
文摘With their suitable habitats significantly affected by climate change and human activities,most of the seven globally recognized sea turtles are facing endangerment.In order to predict their present and future(2090−2100)potentially suitable habitats,we utilized the MaxEnt model,incorporating occurrence data for various sea turtle species and environmental datasets under current conditions,as well as under two climate scenarios from the Shared Socioeconomic Pathways(SSP1-2.6 and SSP5-8.5).Our findings showed that the key environmental variables,such as temperature and distance from shore predominantly influence the prediction on the potentially suitable habitat for sea turtles.The most highly suitable habitats for sea turtles are predominantly found in the tropical coastal waters bordering continents,including South and North America,Asia,and Australia.Under the climate scenarios of SSP1-2.6 and SSP5-8.5 for 2090−2100,the anticipated loss of potential suitable habitats is expected to surpass any potential gains for all sea turtle species.The Kemp’s ridley sea turtle(Lepidochelys kempii)is especially vulnerable,with its potentially suitable habitat area projected to decrease by 0.43%under SSP1-2.6 scenario to 6.15%under SSP5-8.5 scenario.In contrast,the most resilient Dermochelys coriacea is projected with a reduction of 1.02%under SSP1-2.6 and 0.57%under SSP5-8.5 in its potentially suitable habitat.These varying responses to climate change inferred the necessity for species-specific conservation strategies.However,only 9.9%of the integrated potentially suitable habitat is protected within the World Database on Protected Areas(WDPA),which suggested the extending of WDPA for more efficiency on the sea turtle conservation.
基金supported by National Natural Science Foundation of China(Grant nos.52275290,51905222)Natural Science Foundation of Jiangsu Province(Grant no.BK20211068)+2 种基金Research Project of State Key Laboratory of Mechanical System and Vibration(Grant no.MSV202419)Major Program of National Natural Science Foundation of China(NSFC)for Basic Theory and Key Technology of Tri-Co Robots(Grant no.92248301)Opening project of the Key Laboratory of Bionic Engineering(Ministry of Education),Jilin University(Grant no.KF2023006).
文摘Inspired by the way sea turtles rely on the Earth’s magnetic field for navigation and locomotion,a novel magnetic soft robotic turtle with programmable magnetization has been developed and investigated to achieve biomimetic locomotion patterns such as straight-line swimming and turning swimming.The soft robotic turtle(12.50 mm in length and 0.24 g in weight)is integrated with an Ecoflex-based torso and four magnetically programmed acrylic elastomer VHB-based limbs containing samarium-iron–nitrogen particles,and was able to carry a load more than twice its own weight.Similar to the limb locomotion characteristics of sea turtles,the magnetic torque causes the four limbs to mimic sinusoidal bending deformation under the influence of an external magnetic field,so that the turtle swims continuously forward.Significantly,when the bending deformation magnitudes of its left and right limbs differ,the soft robotic turtle switches from straight-line to turning swimming at 6.334 rad/s.Furthermore,the tracking swimming activities of the soft robotic turtle along specific planned paths,such as square-shaped,S-shaped,and double U-shaped maze,is anticipated to be utilized for special detection and targeted drug delivery,among other applications owing to its superior remote directional control ability.
基金funded by the Natural Science Foundation of Hainan Province(320QN256 to TW)the High-level Talent Project of the Hainan Natural Science Foundation(322RC661 to TW)+1 种基金the National Natural Science Foundation of China(31860608 to JW)the Specific Research Fund of the Innovation Platform for Academicians of Hainan Province.
文摘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.
基金supported by the Society of Entrepreneurs and Ecology,the Aquatic Wildlife Conservation Branch of the China Wildlife Conservation Association,and Ocean Park Hong Kong.
文摘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.
基金funded by the Agencia Nacional de Promoción Científica y Tecnológica-Proyectos de Investigación Científica y Tecnológica-PICT 2017-0607(to M.Reguero)and PICT 2019-00327(to M.Buono).
文摘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.
基金Supported by Project of Science and Technology Bureau of Hebei Province(09220402D)~~
文摘[Objective] This study aimed to isolate and identify the pathogens of soft-shelled turtle fulminant infectious disease,to provide the basis for the prevention and control of aquatic animal diseases.[Method] Commercially available sick soft-shelled turtles were used as experimental materials,to isolate and identify the causative pathogens;pathogenicity test and toxin determination of the isolates were carried out;in addition,hyperimmune serum was prepared and its therapeutic effect was detected.[Result] Nine bacteria were isolated from the livers of sick soft-shelled turtles,including seven Aeromonas sobria strains（JA-1） and two A.caviae strains（JA-2）.The median lethal dose（LD50） of JA-1 and JA-2 was 4.3×10^5/ml and 5.5×10^7/ml,respectively;the broth culture supernatant of the two bacteria contains a type of toxin with hemolytic activity,indicating that the soft-shelled turtle fulminant infectious disease is caused by A.sobria and A.caviae.Vaccine was prepared by using the two bacteria and rabbit immunization with immunopotentiator,showing a titer of 1：512 and a cure rate of 100%.[Conclusion] This study laid foundation for the prevention and control of aquatic animal diseases.
文摘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.
基金the Science and Technology Department of Zhejiang Province, China (No. 2004C26026)the Science and Technology Department of Hangzhou City, China (No. 20051322 B33)
文摘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.
基金supported by the National Natural Science Foundation of China(30910103916)the Key Project of Science and Technology Program of Hainan,China(06122)
文摘In 1998,a study on forty-five four-eyed turtles(Sacalia quadriocellata) was initiated to gather preliminary biological data of this species and to investigate the feasibility of its captive reproduction.In the following six years,no courtship behavior was found occurring in males and no oviposition in females.From 2004 to 2007,two successful techniques were applied to initiate reproductive behavior:1) injecting exogenous reproductive hormones; and 2) reducing the stress of living in captivity.As a result of the hormone treatments,courtship behavior and copulation were observed during September and October,2005.However,no courtship displays were seen from the CK males,which were not treated with hormones.Ovulation occurred between December and March,and the correlation was not significant between behavior of ovulation and food intake.Females laid only one clutch of eggs each year,with 2.47 eggs(n=34,range=1–4) at average,and 84 eggs were totally obtained,of which 13 were damaged,52 were infertile and 19 fertile.Of the fertile eggs,nine were hatched with mean incubation period of 105.9 days(n=9,range=89–122 days) at temperature ranging from 24 to 27℃.
文摘The gastrointestinal tracts of four Chelonia mydas hatchlings were examined at the anatomical, histological and ultrastructural level. Our results show that the gastrointestinal tract（GI） is composed by esophagus, stomach, small intestine（SI） and large intestine（LI）, and histologically of mucosa, submucosa, muscularis externa（ME） and serosa. The esophagus is marked by conical papillae lined by keratinized stratified squamous epithelium, whereas the remaining GI by simple columnar epithelium; esophageal diverticulum is absent. The stomach covered with mucous granule cells, contains cardia, fundic regions and pylorus, which are separately characterized by cardiac glands, fundic glands and pyloric glands, and have the thickest submucosa and ME of the GI. The ME of the esophagus mainly consist of one layer of circular smooth muscle whereas the rest of GI of two layers, inner circular muscle and outer longitudinal muscle. The SI is slightly longer than the LI and the GI is approximately 5.11 times of the carapace length. The SI is lined with longitudinal zigzag folds and characterized by absorptive cells with longer and denser microvilli, whereas the LI by transversal folds, goblet cells and lymphoid nodules. Only intestinal glands appear in duodenum. Endocrine cells are observed in all sections of the GI and accounted for the largest proportion in duodenum. The results demonstrate a perfect combination of the structure and function of the GI and reveal that the digestion and absorption primarily occurs in the foregut. C. mydas hatchling may prefer carnivorous diet.
基金financially supported by the Project of Hangzhou Producing, Study and Researching Cooperation of China (Grant No. 20092632E27)
文摘A 120-day feeding experiment was conducted to investigate the effects of partial replacement of brown fish meal (BFM) by fermented soybean meal (FSBM) in diets of Chinese soft-shelled turtle (Pelodiscus sinensis). The turtles (initial mean body weight, (115.52 ± 1.05) g) were fed with three experimental diets, in which 0%, 4.72% and 9.44% BFM protein was replaced by 0%, 3% and 6% FSBM, respectively. Results showed that the feeding rate (FR), specific growth rate (SGR) and feed efficiency ratio (FER) of turtles fed with the diet containing 3% FSBM were not significantly different from the control group (0% FSBM) (P > 0.05). However, FR, SGR and FER of turtles fed with the diet containing 6% FSBM were significantly lower than those of the control group (P < 0.05). No significant differences were observed in the activities of serum glutamic-oxalacetic transaminase and glutamicpyruvic transaminase among dietary treatments (P > 0.05). However, the uric acid concentration in turtles fed with the diet containing 3% or 6% FSBM was significantly lower than that in the control group (P < 0.05). There were no significant differences in the activities of lysozyme, alkaline phosphatase and total superoxide dismutase among dietary treatments (P > 0.05). The results suggested that FSBM could replace 4.72% BFM protein in turtle diets without exerting adverse effects on turtle growth, feed utilization and measured immune parameters.
