The stratification of blubber fatty acids(FAs)is a widely used strategy in marine mammals and can be influenced by many factors,including their diet,environmental temperature,and physiological status.There are 3 disti...The stratification of blubber fatty acids(FAs)is a widely used strategy in marine mammals and can be influenced by many factors,including their diet,environmental temperature,and physiological status.There are 3 distinct finless porpoise species/subspecies in Chinese coastal and inland waters in a wide range from 20°N to 40°N.The biochemical stratification of the blubbers of finless porpoises in different regions may provide valuable information for understanding their environmental adaptations.The FA compositions of 4 geographic populations of finless porpoise(FP)collected from the Bohai Gulf,East China Sea,South China Sea,and Yangtze River were therefore analyzed and compared.The blubber FA compositions of finless porpoises were dominated by∑MUFAs,followed by∑SFAs and∑PUFAs,and were generally consistent with those of other cetaceans.The blubber of finless porpoises was significantly stratified with increasing levels of∑MUFAs and decreasing levels of∑SFAs and∑PUFAs from the inner to the outer layers.The 3 marine populations shared more similarities in their FA compositions and stratifications compared to the freshwater porpoises,particularly regarding the PUFAs in the inner layers,which might have been mainly influenced by the diet compositions of marine and freshwater porpoises.Contrary to what was expected,in the 3 marine populations,the SFA and MUFA levels showed opposite correlations(negative and positive,respectively)with habitat temperatures,possibly indicating an adaptation mechanism in finless porpoises characterized by a trade-off between the insulation and fluidity properties of the blubber through the adjustment of the compositions and gradients of MUFAs and SFAs across the blubber depth in response to environmental temperature/latitude changes.展开更多
Blubber thickness(BT)has a seasonal pattern in most small cetaceans in temperate and polar regions,which may be a crucial adaptive mechanism in response to environmental temperature changes.However,BT and environmenta...Blubber thickness(BT)has a seasonal pattern in most small cetaceans in temperate and polar regions,which may be a crucial adaptive mechanism in response to environmental temperature changes.However,BT and environmental temperature correlations have never been tested experimentally in any cetacean species owing to logistical difficulties in the aquatic environment.The Yangtze finless porpoise(Neophocaena asiaeorientalis asiaeorientalis,YFP)is one of the smallest cetacean species worldwide,which exclusively inhabits the middle and lower regions of the Yangtze River in China.Here,we investigated BT variation patterns in YFPs and their relationship to environmental temperature changes using ultrasound imaging technology by longitudinally monitoring four YFPs in human care.We found that blubber was not evenly distributed in the skin of YFPs.BT increased along the craniocaudal axis from the head to the umbilical girth,and decreased towards the fluke,with relatively thicker blubber in the dorsal region than in the ventral and lateral regions.Significant negative correlations between BT and seasonal water temperature changes were observed in YFPs.However,different body regions display different sensitivities to seasonal temperature changes.The BT in the anal girth region exhibited noticeable seasonal changes.In contrast,the umbilical lateral and ventral regions showed relatively blunt seasonal changes,indicating different adaptive functions of the blubber in different regions.BT in the dorsal region decreased linearly with increasing water temperature.In the lateral and ventral regions,BT significantly changed with water temperature at a threshold of 18C.The YFPs had relatively thinner BT than similar-sized harbor porpoises that inhabit relatively high latitudes with much lower water temperatures.This further demonstrates the adaptive function of BT in response to environmental temperatures in small cetaceans.This study elucidates the seasonal pattern of BT variation in small cetaceans and provides insight into adaptation mechanisms of small cetaceans to temperature changes.展开更多
Liver, muscle and blubber tissues of seven Common dolphins (Delphinus delphis) stranded along the Algerian west coast have been analysed for six traces elements Cu, Fe, Cd, Pb, Zn and Ni. This work confirms more accur...Liver, muscle and blubber tissues of seven Common dolphins (Delphinus delphis) stranded along the Algerian west coast have been analysed for six traces elements Cu, Fe, Cd, Pb, Zn and Ni. This work confirms more accurately the relations shown previously between age, sex and trace element concentrations in this species. Liver was shown to be the most important accumulating organ for Cu, Fe and Zn, and the results also indicated the importance of toxic metal transfer from mother to offspring. Significant differences between the liver, muscle and blubber were detected;except for the Ni concentrations were similar in these tissues.展开更多
基金This study was financially supported by the Ocean Park Conservation Foundation Hong Kong(MM01.2021).
文摘The stratification of blubber fatty acids(FAs)is a widely used strategy in marine mammals and can be influenced by many factors,including their diet,environmental temperature,and physiological status.There are 3 distinct finless porpoise species/subspecies in Chinese coastal and inland waters in a wide range from 20°N to 40°N.The biochemical stratification of the blubbers of finless porpoises in different regions may provide valuable information for understanding their environmental adaptations.The FA compositions of 4 geographic populations of finless porpoise(FP)collected from the Bohai Gulf,East China Sea,South China Sea,and Yangtze River were therefore analyzed and compared.The blubber FA compositions of finless porpoises were dominated by∑MUFAs,followed by∑SFAs and∑PUFAs,and were generally consistent with those of other cetaceans.The blubber of finless porpoises was significantly stratified with increasing levels of∑MUFAs and decreasing levels of∑SFAs and∑PUFAs from the inner to the outer layers.The 3 marine populations shared more similarities in their FA compositions and stratifications compared to the freshwater porpoises,particularly regarding the PUFAs in the inner layers,which might have been mainly influenced by the diet compositions of marine and freshwater porpoises.Contrary to what was expected,in the 3 marine populations,the SFA and MUFA levels showed opposite correlations(negative and positive,respectively)with habitat temperatures,possibly indicating an adaptation mechanism in finless porpoises characterized by a trade-off between the insulation and fluidity properties of the blubber through the adjustment of the compositions and gradients of MUFAs and SFAs across the blubber depth in response to environmental temperature/latitude changes.
基金financially supported by the National Key R&D Program of China,Grant No.2021YFD1200304.
文摘Blubber thickness(BT)has a seasonal pattern in most small cetaceans in temperate and polar regions,which may be a crucial adaptive mechanism in response to environmental temperature changes.However,BT and environmental temperature correlations have never been tested experimentally in any cetacean species owing to logistical difficulties in the aquatic environment.The Yangtze finless porpoise(Neophocaena asiaeorientalis asiaeorientalis,YFP)is one of the smallest cetacean species worldwide,which exclusively inhabits the middle and lower regions of the Yangtze River in China.Here,we investigated BT variation patterns in YFPs and their relationship to environmental temperature changes using ultrasound imaging technology by longitudinally monitoring four YFPs in human care.We found that blubber was not evenly distributed in the skin of YFPs.BT increased along the craniocaudal axis from the head to the umbilical girth,and decreased towards the fluke,with relatively thicker blubber in the dorsal region than in the ventral and lateral regions.Significant negative correlations between BT and seasonal water temperature changes were observed in YFPs.However,different body regions display different sensitivities to seasonal temperature changes.The BT in the anal girth region exhibited noticeable seasonal changes.In contrast,the umbilical lateral and ventral regions showed relatively blunt seasonal changes,indicating different adaptive functions of the blubber in different regions.BT in the dorsal region decreased linearly with increasing water temperature.In the lateral and ventral regions,BT significantly changed with water temperature at a threshold of 18C.The YFPs had relatively thinner BT than similar-sized harbor porpoises that inhabit relatively high latitudes with much lower water temperatures.This further demonstrates the adaptive function of BT in response to environmental temperatures in small cetaceans.This study elucidates the seasonal pattern of BT variation in small cetaceans and provides insight into adaptation mechanisms of small cetaceans to temperature changes.
文摘Liver, muscle and blubber tissues of seven Common dolphins (Delphinus delphis) stranded along the Algerian west coast have been analysed for six traces elements Cu, Fe, Cd, Pb, Zn and Ni. This work confirms more accurately the relations shown previously between age, sex and trace element concentrations in this species. Liver was shown to be the most important accumulating organ for Cu, Fe and Zn, and the results also indicated the importance of toxic metal transfer from mother to offspring. Significant differences between the liver, muscle and blubber were detected;except for the Ni concentrations were similar in these tissues.
