The white-blotched river stingray(Potamotrygon leopoldi)is a cartilaginous fish native to the Xingu River,a tributary of the Amazon River system.As a rare freshwater-dwelling cartilaginous fish in the Potamotrygonidae...The white-blotched river stingray(Potamotrygon leopoldi)is a cartilaginous fish native to the Xingu River,a tributary of the Amazon River system.As a rare freshwater-dwelling cartilaginous fish in the Potamotrygonidae family in which no member has the genome sequencing information available,P.leopoldi provides the evolutionary details in fish phylogeny,niche adaptation,and skeleton formation.In this study,we present its draft genome of 4.11 Gb comprising 16,227 contigs and 13,238 scaffolds,with contig N50 of 3937 kb and scaffold N50 of 5675 kb in size.Our analysis shows that P.leopoldi is a slow-evolving fish that diverged from elephant sharks about 96 million years ago.Moreover,two gene families related to the immune system(immunoglobulin heavy constant delta genes and T-cell receptor alpha/delta variable genes)exhibit expansion in P.leopoldi only.We also identified the Hox gene clusters in P.leopoldi and discovered that seven Hox genes shared by five representative fish species are missing in P.leopoldi.The RNA sequencing data from P.leopoldi and other three fish species demonstrate that fishes have a more diversified tissue expression spectrum when compared to mammals.Our functional studies suggest that lack of the gc gene encoding vitamin D-binding protein in cartilaginous fishes(both P.leopoldi and Callorhinchus milii)could partly explain the absence of hard bone in their endoskeleton.Overall,this genome resource provides new insights into the niche adaptation,body plan,and skeleton formation of P.leopoldi,as well as the genome evolution in cartilaginous fishes.展开更多
Freshwater stingrays undulate their flexible disc-like pectoral fins to perform cruising, manoeuvring, and other motions. This undulatory propulsion has a higher propulsive efficiency and more precise manoeuvrability ...Freshwater stingrays undulate their flexible disc-like pectoral fins to perform cruising, manoeuvring, and other motions. This undulatory propulsion has a higher propulsive efficiency and more precise manoeuvrability than most other species at low swimming velocity. In the current study, a new robotic fish inspired by the freshwater stingray was developed and tested. First, the morphology and kinematic patterns of the freshwater stingray were presented. A kinematic model of the pectoral fin was established based on several assumptions. Then a robotic stingray with an undulatory pectoral fin was designed and developed. Experiments were conducted to investigate the effects of various fin actuation parameters on its linear swimming velocity and the forces generated by the robotic stingray. The controllable fin parameters include oscillation frequency, wave number, maximal angular deflection of the fin rays, and the amplitude pattern of the pectoral fin. The experimental results indicate that the developed prototype is able to generate adequate thrust for self-propulsion. Linear swimming velocity and surge force increase rapidly with oscillation frequency, angular deflection, and wave number. A maximum velocity of 4.3 cm.s 1 （nearly 0.18 Body Lengths per second （BL·s-1）） and a maximum surge force of 102 mN are achieved at an oscillation frequency of 0.5 Hz, a wave number of 1, a maximum angular deflection of 30°, and an equal amplitude pattern. The sway force of the robotic fish fluctuates around 0 mN. The heave force varies with wave number and reaches its minimum at a wave number of 1.展开更多
Objective:To investigate functional groups of toxic spines in stingray by Fourier transform infrared spectroscopic analysis.Methods:sephen were centrifuged at 6000 r/min for 10 min.The supernatant was collected and pr...Objective:To investigate functional groups of toxic spines in stingray by Fourier transform infrared spectroscopic analysis.Methods:sephen were centrifuged at 6000 r/min for 10 min.The supernatant was collected and preserved separately in methanol,ethanol,chloroform,acetone(1:2)and then soaked in the mentioned solvents for 48 h.Then extracts were filtered and used for Fourier transform infrared spectroscopic analysis.Results:The venom extract of Himantura gerrardi,Himantura imbricata and Pastinachus and random coiled secondary structure.The presence of O-H stretch,C=O stretch,C-H stretch,N-H deformation,O-H deformation and C-O stretch in the sample aligned with standard bovine serum albumin.The influence of functional groups within the molecule was because of the impact of preferred spatial orientation,chemical and physical interaction on the molecule.In conclusion,compared to bovine serum albumin,Himantura imbricata consists of two C=O stretch,are involved in the hydrogen bonding that takes place between the different elements of secondary structure.Conclusions:The results identified that the presence of free amino acids and protein having β-sheet medicine not available for treatment against injuries causing stingray.Therefore,it's the baseline study,to motivate further process and produce effective antibiotics.The venom of poisonous animals has been extensively studied,since standard.展开更多
Objective:To study the spine structure of stingray Himantura imbricata(H.imbricata)and to evaluate the anticoagulant properties of the spine extract obtained through various solvents extracts followed by antibacterial...Objective:To study the spine structure of stingray Himantura imbricata(H.imbricata)and to evaluate the anticoagulant properties of the spine extract obtained through various solvents extracts followed by antibacterial activity against human pathogens.Methods:Spines of H.imbricata were collected from Nagappattinam coast,Tamil Nadu,India and their spines were observed under the light microscope.The grounded spines were subjected to extraction of metabolites using methanol,ethanol,chloroform and acetone.Antibacterial activity was evaluated by disc diffusion technique against 10 human pathogens.Similarly,anticoagulant activity was also assessed by following United States Pharmacopeia method.Results:Light microscopic observation of spine revealed that the venom apparatus of the stingray H.imbricata consisted of two to three spines,glandular tissue and a sheath.The spine extract showed potent antibacterial activity against all tested pathogen.Maximum activity(14 mm)was found against Staphylococcus aureus.Crude extract showed 91.50 USP units/mg of anticoagulant activity.Conclusions:Microscopic observations gave new insight about the spine structure of the stingray.The spine extracts of H.imbricate showed potent activity against human pathogens revealed by the good zone of inhibition.Chloroform extracts conferred the most prominent antibacterial activity.The anticoagulant activity was also comparable with that of standard heparin.展开更多
The find for the optimal slide of water to bring to the plot during the irrigated onion crop was important in order to limit the recharge of the water table close to the soil surface. The quantities of water supplied ...The find for the optimal slide of water to bring to the plot during the irrigated onion crop was important in order to limit the recharge of the water table close to the soil surface. The quantities of water supplied during onion irrigation were estimated from measurements made with a metal crest to the plot positioned at the tertiary canal. The flow rates at the tertiary canal directly irrigating the plot were recorded during irrigation. From this flow rate, the quantity of water supplied to each plot was determined. From then, the performance of the irrigated system in onion cultivation should pass on the management of this water slide at the level of the hydroagricultural facilities. The integrated soil water mass, salinity and water table dynamics monitoring system was used to assess the water requirements of onion following the irrigation. The daily water requirement of onion in the holland soil of the delta was estimated to average 0.45 g/m<sup>3</sup>. These requirements were varied according to the development stage of the crop. The water level between the ridges was between 6 and 9 mm during irrigation. This was not permanent, it infiltrated between 12 and 18 hours. This type to the stingray irrigation did not favour the arrival of the water table on the surface. The only fluctuations in the water table were observed during the bulb maturation phase. During this phase, the soil water masses were important. The electrical conductivity recorded varied during the campaign. At the beginning of irrigation, it was 3.62 mS/cm on a 30 cm profile, it decreased towards the end of the irrigations to reach 2.06 mS/cm. The quantities of salt recorded on a 30 cm profile varied from one month to the next;they were 0.468 t/ha at the beginning of irrigation (January) and 0.275 t/ha at the end of the campaign (April). From these results we can say that land degradation in the Senegal river delta would be linked to the arrival of salty groundwater on the surface.展开更多
AIM:Dasyatis jenkinsii is used traditionally to treat inflammatory complaints and arthritis by the fisherman community and local population.The present study was designed to scientifically investigate the traditional ...AIM:Dasyatis jenkinsii is used traditionally to treat inflammatory complaints and arthritis by the fisherman community and local population.The present study was designed to scientifically investigate the traditional practice through the analgesic,anti-inflammatory,and organ toxicity studies and characterization of bioactive compounds of crude extracts of D.jenkinsii.METHOD: Solvent extract of homogenized fresh fish was prepared using petroleum ether and diethyl ether.The chemical and spectral analyses of extracts were carried out using FT-IR and GC-MS.Analgesic and anti-inflammatory activities were assessed by hot plate,tail clip,and carrageenan induced rat paw edema methods.The organ toxicity of each extract was assessed on brain,liver,and kidney of mice.RESULTS:The IR spectrum indicated the presence of aromatic and aliphatic compounds.GC-MS analysis revealed the presence of 1-(4-carboxy)phenylnona-2,5-diene and 3-hydroxymono-glyceryl hydrogen phthalate in the petroleum ether extract and carboxyl serine,dihydrotryptophan,and indolyl carboxylic acid in the diethyl ether extract.Both extracts showed significant analgesic and anti-inflammatory effects in all the methods tested.The vital organs of the test animals were not affected by the crude extracts significantly.CONCLUSIONS:The presence of biologically active compounds in the crude extracts with analgesic and anti-inflammatory properties justifies the traditional knowledge and paves the way for isolation of these compounds for further experimentation.展开更多
Coastal and demersal chondrichthyans(sharks,rays,and skates)are expected to exhibit high levels of genetic differentiation in areas of complex geomorphology.Population genetic studies investigating the extent to which...Coastal and demersal chondrichthyans(sharks,rays,and skates)are expected to exhibit high levels of genetic differentiation in areas of complex geomorphology.Population genetic studies investigating the extent to which demographic history shapes the genetic structure of thesefishes are rare.Here,we combined mitochondrial DNA(Cytb and ND2)and 8 nuclear microsatellite loci from 244 individuals to examine the population genetic structure and demographic history of the 3 Indo-West Pacific species of sharpnose rays(Telatrygon zugei,Telatrygon biasa,and Trygon crozieri).High levels of genetic variation both within and between species were identified.Phylogenetic analysis partitioned haplotypes into 2 lineages supporting divergence of T.zugei from T.crozieri and T.biasa during the Pleistocene.Furthermore,microsatellite-based clustering analyses identified 4 genetic groups(i.e.T.zugei from Japan,T.zugei from coastal China,T.biasa from Gulf of Thailand,and T.crozieri from the Andaman Sea).Measurements of genetic differentiation also support these 4 groups.Additionally,Pleistocene demographic expansions were examined in all genetic groups.The climate oscillations and current hydrologic cycles in the Indo-West Pacific appear to coincide with the hypothesis regarding speciation and the observed demographic history trends of the sharpnose rays.Considering the species group has,until recently,been thought to be one species,these results are critical for defining management units and guiding conservation efforts to preserve stingray biodiversity.展开更多
Stingrays can undulate their wide pectoral fins to thrust themselves and swim freely underwater.Many researchers have used bionics to directly imitate their undulating mechanism and manufacture undulatory underwater r...Stingrays can undulate their wide pectoral fins to thrust themselves and swim freely underwater.Many researchers have used bionics to directly imitate their undulating mechanism and manufacture undulatory underwater robots.Based on the limitations of the existing undulatory underwater robots,this paper proposes a novel undulatory propulsion strategy,which aims to use the stingray undulating mechanism more thoroughly.First,the mathematical models of both traditional and novel structures are established to accurately describe their undulating mechanism.Then,based on the dynamic mesh technology,the flow field vortex structure they generated is analyzed through fluid-structure interaction simulation,and the thrust force and lateral force generated by them are calculated,which verified that this novel propulsion strategy is indeed more effective.Finally,a prototype robot based on the improved propulsion strategy is manufactured.Compared with the existing stingray robots,the prototype has obvious advantages,thus verifying the accuracy of the simulation results.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.31801049)the Major Science and Technology Innovation Program of Shanghai Municipal Education Commission,China(Grant No.2019-01-07-00-01-E00059)the Shanghai Nanmulin Biotechnology Company Limited.
文摘The white-blotched river stingray(Potamotrygon leopoldi)is a cartilaginous fish native to the Xingu River,a tributary of the Amazon River system.As a rare freshwater-dwelling cartilaginous fish in the Potamotrygonidae family in which no member has the genome sequencing information available,P.leopoldi provides the evolutionary details in fish phylogeny,niche adaptation,and skeleton formation.In this study,we present its draft genome of 4.11 Gb comprising 16,227 contigs and 13,238 scaffolds,with contig N50 of 3937 kb and scaffold N50 of 5675 kb in size.Our analysis shows that P.leopoldi is a slow-evolving fish that diverged from elephant sharks about 96 million years ago.Moreover,two gene families related to the immune system(immunoglobulin heavy constant delta genes and T-cell receptor alpha/delta variable genes)exhibit expansion in P.leopoldi only.We also identified the Hox gene clusters in P.leopoldi and discovered that seven Hox genes shared by five representative fish species are missing in P.leopoldi.The RNA sequencing data from P.leopoldi and other three fish species demonstrate that fishes have a more diversified tissue expression spectrum when compared to mammals.Our functional studies suggest that lack of the gc gene encoding vitamin D-binding protein in cartilaginous fishes(both P.leopoldi and Callorhinchus milii)could partly explain the absence of hard bone in their endoskeleton.Overall,this genome resource provides new insights into the niche adaptation,body plan,and skeleton formation of P.leopoldi,as well as the genome evolution in cartilaginous fishes.
文摘Freshwater stingrays undulate their flexible disc-like pectoral fins to perform cruising, manoeuvring, and other motions. This undulatory propulsion has a higher propulsive efficiency and more precise manoeuvrability than most other species at low swimming velocity. In the current study, a new robotic fish inspired by the freshwater stingray was developed and tested. First, the morphology and kinematic patterns of the freshwater stingray were presented. A kinematic model of the pectoral fin was established based on several assumptions. Then a robotic stingray with an undulatory pectoral fin was designed and developed. Experiments were conducted to investigate the effects of various fin actuation parameters on its linear swimming velocity and the forces generated by the robotic stingray. The controllable fin parameters include oscillation frequency, wave number, maximal angular deflection of the fin rays, and the amplitude pattern of the pectoral fin. The experimental results indicate that the developed prototype is able to generate adequate thrust for self-propulsion. Linear swimming velocity and surge force increase rapidly with oscillation frequency, angular deflection, and wave number. A maximum velocity of 4.3 cm.s 1 （nearly 0.18 Body Lengths per second （BL·s-1）） and a maximum surge force of 102 mN are achieved at an oscillation frequency of 0.5 Hz, a wave number of 1, a maximum angular deflection of 30°, and an equal amplitude pattern. The sway force of the robotic fish fluctuates around 0 mN. The heave force varies with wave number and reaches its minimum at a wave number of 1.
基金Supported by Center for Marine Living Resource and Ecology(CMLRE-Office Memorandum No:G4/3366/2013),Ministry of Earth Sciences.
文摘Objective:To investigate functional groups of toxic spines in stingray by Fourier transform infrared spectroscopic analysis.Methods:sephen were centrifuged at 6000 r/min for 10 min.The supernatant was collected and preserved separately in methanol,ethanol,chloroform,acetone(1:2)and then soaked in the mentioned solvents for 48 h.Then extracts were filtered and used for Fourier transform infrared spectroscopic analysis.Results:The venom extract of Himantura gerrardi,Himantura imbricata and Pastinachus and random coiled secondary structure.The presence of O-H stretch,C=O stretch,C-H stretch,N-H deformation,O-H deformation and C-O stretch in the sample aligned with standard bovine serum albumin.The influence of functional groups within the molecule was because of the impact of preferred spatial orientation,chemical and physical interaction on the molecule.In conclusion,compared to bovine serum albumin,Himantura imbricata consists of two C=O stretch,are involved in the hydrogen bonding that takes place between the different elements of secondary structure.Conclusions:The results identified that the presence of free amino acids and protein having β-sheet medicine not available for treatment against injuries causing stingray.Therefore,it's the baseline study,to motivate further process and produce effective antibiotics.The venom of poisonous animals has been extensively studied,since standard.
基金Supported by Center with Potential for Excellence in Particular Area(CPEPA),Ministry of Environmental Forest(MOEF)(Grant No.G4(1)/1011/2012).
文摘Objective:To study the spine structure of stingray Himantura imbricata(H.imbricata)and to evaluate the anticoagulant properties of the spine extract obtained through various solvents extracts followed by antibacterial activity against human pathogens.Methods:Spines of H.imbricata were collected from Nagappattinam coast,Tamil Nadu,India and their spines were observed under the light microscope.The grounded spines were subjected to extraction of metabolites using methanol,ethanol,chloroform and acetone.Antibacterial activity was evaluated by disc diffusion technique against 10 human pathogens.Similarly,anticoagulant activity was also assessed by following United States Pharmacopeia method.Results:Light microscopic observation of spine revealed that the venom apparatus of the stingray H.imbricata consisted of two to three spines,glandular tissue and a sheath.The spine extract showed potent antibacterial activity against all tested pathogen.Maximum activity(14 mm)was found against Staphylococcus aureus.Crude extract showed 91.50 USP units/mg of anticoagulant activity.Conclusions:Microscopic observations gave new insight about the spine structure of the stingray.The spine extracts of H.imbricate showed potent activity against human pathogens revealed by the good zone of inhibition.Chloroform extracts conferred the most prominent antibacterial activity.The anticoagulant activity was also comparable with that of standard heparin.
文摘The find for the optimal slide of water to bring to the plot during the irrigated onion crop was important in order to limit the recharge of the water table close to the soil surface. The quantities of water supplied during onion irrigation were estimated from measurements made with a metal crest to the plot positioned at the tertiary canal. The flow rates at the tertiary canal directly irrigating the plot were recorded during irrigation. From this flow rate, the quantity of water supplied to each plot was determined. From then, the performance of the irrigated system in onion cultivation should pass on the management of this water slide at the level of the hydroagricultural facilities. The integrated soil water mass, salinity and water table dynamics monitoring system was used to assess the water requirements of onion following the irrigation. The daily water requirement of onion in the holland soil of the delta was estimated to average 0.45 g/m<sup>3</sup>. These requirements were varied according to the development stage of the crop. The water level between the ridges was between 6 and 9 mm during irrigation. This was not permanent, it infiltrated between 12 and 18 hours. This type to the stingray irrigation did not favour the arrival of the water table on the surface. The only fluctuations in the water table were observed during the bulb maturation phase. During this phase, the soil water masses were important. The electrical conductivity recorded varied during the campaign. At the beginning of irrigation, it was 3.62 mS/cm on a 30 cm profile, it decreased towards the end of the irrigations to reach 2.06 mS/cm. The quantities of salt recorded on a 30 cm profile varied from one month to the next;they were 0.468 t/ha at the beginning of irrigation (January) and 0.275 t/ha at the end of the campaign (April). From these results we can say that land degradation in the Senegal river delta would be linked to the arrival of salty groundwater on the surface.
文摘AIM:Dasyatis jenkinsii is used traditionally to treat inflammatory complaints and arthritis by the fisherman community and local population.The present study was designed to scientifically investigate the traditional practice through the analgesic,anti-inflammatory,and organ toxicity studies and characterization of bioactive compounds of crude extracts of D.jenkinsii.METHOD: Solvent extract of homogenized fresh fish was prepared using petroleum ether and diethyl ether.The chemical and spectral analyses of extracts were carried out using FT-IR and GC-MS.Analgesic and anti-inflammatory activities were assessed by hot plate,tail clip,and carrageenan induced rat paw edema methods.The organ toxicity of each extract was assessed on brain,liver,and kidney of mice.RESULTS:The IR spectrum indicated the presence of aromatic and aliphatic compounds.GC-MS analysis revealed the presence of 1-(4-carboxy)phenylnona-2,5-diene and 3-hydroxymono-glyceryl hydrogen phthalate in the petroleum ether extract and carboxyl serine,dihydrotryptophan,and indolyl carboxylic acid in the diethyl ether extract.Both extracts showed significant analgesic and anti-inflammatory effects in all the methods tested.The vital organs of the test animals were not affected by the crude extracts significantly.CONCLUSIONS:The presence of biologically active compounds in the crude extracts with analgesic and anti-inflammatory properties justifies the traditional knowledge and paves the way for isolation of these compounds for further experimentation.
基金financially supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDA19050202)the Natural Science Found of China(No.31272287 and No.41666008)+1 种基金the Grants-inaid for Conservation of Fishery Resources of the Ministry of Agriculture in China(No.171721301354052003)the JSPS Invitation Fellowship Program for sampling and Research in Japan.
文摘Coastal and demersal chondrichthyans(sharks,rays,and skates)are expected to exhibit high levels of genetic differentiation in areas of complex geomorphology.Population genetic studies investigating the extent to which demographic history shapes the genetic structure of thesefishes are rare.Here,we combined mitochondrial DNA(Cytb and ND2)and 8 nuclear microsatellite loci from 244 individuals to examine the population genetic structure and demographic history of the 3 Indo-West Pacific species of sharpnose rays(Telatrygon zugei,Telatrygon biasa,and Trygon crozieri).High levels of genetic variation both within and between species were identified.Phylogenetic analysis partitioned haplotypes into 2 lineages supporting divergence of T.zugei from T.crozieri and T.biasa during the Pleistocene.Furthermore,microsatellite-based clustering analyses identified 4 genetic groups(i.e.T.zugei from Japan,T.zugei from coastal China,T.biasa from Gulf of Thailand,and T.crozieri from the Andaman Sea).Measurements of genetic differentiation also support these 4 groups.Additionally,Pleistocene demographic expansions were examined in all genetic groups.The climate oscillations and current hydrologic cycles in the Indo-West Pacific appear to coincide with the hypothesis regarding speciation and the observed demographic history trends of the sharpnose rays.Considering the species group has,until recently,been thought to be one species,these results are critical for defining management units and guiding conservation efforts to preserve stingray biodiversity.
基金This work is supported by the National Science Foundation of China(No.91748123)the Natural Science Foundation of Shaanxi Province(Grant No.2019JM-145).
文摘Stingrays can undulate their wide pectoral fins to thrust themselves and swim freely underwater.Many researchers have used bionics to directly imitate their undulating mechanism and manufacture undulatory underwater robots.Based on the limitations of the existing undulatory underwater robots,this paper proposes a novel undulatory propulsion strategy,which aims to use the stingray undulating mechanism more thoroughly.First,the mathematical models of both traditional and novel structures are established to accurately describe their undulating mechanism.Then,based on the dynamic mesh technology,the flow field vortex structure they generated is analyzed through fluid-structure interaction simulation,and the thrust force and lateral force generated by them are calculated,which verified that this novel propulsion strategy is indeed more effective.Finally,a prototype robot based on the improved propulsion strategy is manufactured.Compared with the existing stingray robots,the prototype has obvious advantages,thus verifying the accuracy of the simulation results.
